1. Why is the cardiovascular system is a closed delivery system? because doesn’t open to anything and begins/ends at heart.
2. What are the the blood vessels referred to as? vascular system.
3. Why is the vasculature dynamic? They change to the changing needs of body by getting larger or smaller (vasodilation/constriction), and proliferate (increase in numbers) 4. What are the functions of the cardiovascular system dependent on? Cardiovascular system is dependent on what happens at capillary level because capillaries are site of exchange- moves products in and out through diffusion.
5. Why is diffusion so valuable? It’s a passive process that costs us NO energy 6. Why do arteries branch? Arteries branch because they are leaving heart in large arteries and then delivering oxygen to tissues throughout the body.
7. Why are veins are joining? because they are returning blood to the heart 8. What is a companion vessel? It’s both an artery and vein that travel together to supply the same body region with blood supplies. We also discuss several other topics like What are the bases for the legitimation of structure inequality?
9. What are capillaries designed for? Erythrocytes to move through them in single file (rouleau formation)
10. What does an anastomosis represent? Where two or more arteries/ veins converge and provide blood to same region.
11. Why is an end artery is detrimental? Why is is so bad to have it blocked? End artery (small anastomoses) provides a limited alternate pathway, if any. So if the blood flow is blocked, the tissue is left without oxygen. (ex. coronary artery)
12. What is a “functional end artery”? An end artery that loses function because of lack of alternative pathway
13. Which vasculature forms more anastomoses? veins (remember that veins converge/join) 14. What are the three layers (tunics) of blood vessel walls? Tunica intima , Tunica media, Tunica externa
15. What is the functional importance of the structure of Tunica intima? It’s the innermost layer- smooth layer/slick surface. This type of structural surface (slick) provides little turbulence to allow blood to flow through easily and avoid forming plaques.
16. What is the functional importance of the structure of Tunica media? It’s made of smooth muscle that controls the blood vessels diameter: regulates the constriction and dilation of vessel, thus controlling how much blood flows through at a time. Don't forget about the age old question of What is hematopoiesis?
17. What is the functional importance of the structure of Tunica externa? It’s used to protect, reinforce and stabilize the blood vessel by anchoring.
18. No matter the size of an artery, what can you find? Vaso vasorum.
19. What is the Vaso vasorum? A vaso network that assists with providing nourishment (blood supply) to the blood vessel wall.
20. Aside from the layers of tunica, what other layers are in blood vessels (in arteries)? internal and external elastic lamina
21. How do the two elastic lamina layers differ? thickness, diameter, and location. 22. What are located in veins only? Valves
23. what is the function of valves? Vales help with blood flow of large veins
24. what makes up valves? folds of tunica intima
25. Do capillaries have the tunicas? No, they are designed for exchange so they don’t have all those layers and have thin walls.
26. Why does an artery have much thicker layer of tunica media? To make sure blood gets to where it needs to be. We also discuss several other topics like What is used to test a theory?
27. Why system is more complex: veins or arteries? Arteries are more complex, with more tunica media, to ensure that the organs are supplied with oxygen. Remember that for veins, the blood is basically “drained” to heart so it’s an easier process/less work.
As diameter decreases, there is a decrease in elastic fibers and an increase of smooth muscle. There are 3 types:
● Elastic arteries-
○ “conducting arteries”
○ main job: take blood away from the heart
○ example: aortic
○ has low resistance pathways
○ has elastin fibers that are found throughout tunicas (no internal/external lamina) ○ they have a pressure smoothing effect -
● Muscular arteries
○ job: distribute blood to specific organs
○ their tunica media is thick to have greater control over vasoconstriction and vasodilation
○ they deliver and control blood flow to specific organs
○ less resilient (has elastic lamina) Don't forget about the age old question of Cladogenesis (aka branching evolution)
○ found in “two” sizes
○ adapted for control over vasoconstriction and vasodilation
○ functions to regulate minute to minute changes of the environment
1. what type of cells make up capillaries? endothelium (simple squamous) 2. what type of unique cells are found? pericytes
3. what are pericytes? smooth muscle like cells used to stabilize cell wall 4. are pericytes continuous? not continuous
5. how thick are capillary walls? very thin to allow for diffusion (quick exchange) 6. what is important about the branching of capillaries? The branching allows the blood to slow down so that exchange can occur.
7. Capillaries are functional units of cardiovascular system.
8. Capillary beds function with capillaries to facilitate diffusion.
9. You do not have enough blood in body to fill all the capillary beds in your body.
10. What controls if blood is in the capillary beds? We have precapillary sphincters that contract and relax to allow blood in and out of beds. They go through cycles of contraction and relaxation to fill beds or shunt blood through (from artery to vein side).
11. What is Vasomotion? Vasomotion is the 5-10 cycles per minute of contraction and relaxation. Rate/cycles depend on how heavily the tissue needs oxygenated blood. 12. What are the types of capillaries? continuous, fenestrated, sinusoids 13. What unites all capillary types? They are all designed for exchange but the difference is that some are more continuous than others. We also discuss several other topics like Race and the status attainment process.
Continuous capillaries are the most common type that are joined by tight junctions but with some gaps between them. If you want to learn more check out 4 steps to life on early earth
● What are these gaps called? intercellular cleft
● What are the functions of intercellular cleft? limited exchange of fluids and solutes ● pinocytotic vesicles- used to ferry fluids across capillary wall
● examples: GI tract
● different from continuous because they contain pores or fenestrations ● function: allows for exchange and usually found where active absorption or filtration occurs
● in kidneys
● VERY leaky!
● designed for passage of large molecules
● set up so that flow is very slow
● huge intercellular clefts
● huge lumens
1. What is the pattern of diameter and thickness with veins? They increase in diameter and wall thickness as they get closer to the heart.
2. What are venules? When capillaries merge (small), very porous, allows fluid and white blood cells to move from bloodstream to tissues
3. What is unique about venules (how do they work with lymphatic system)? Venules are the type of veins that are used to move lymphocytes to sites of infections 4. What makes up veins? Veins have the 3 tunics (thin tunica media & thick tunica externa), large lumen, walls are thinner. Veins accommodate large blood volume by serving as blood reservoir.
5. How much of the blood supply to veins account for? Veins contains 65% of body’s blood supply
On the venous side of heart, is the pressure high or low? the pressure is low on venous side (right side of heart)
1. what are the adaptations of veins to help with blood movement? Larger diameters, venous valves, skeletal muscle pumps, and a respiratory pump.
2. Why is a larger in diameter important? It creates lower resistance = blood flows easier 3. Why are venous valves important? Valves prevents backflow in low pressure system (no mixing of blood)
4. What are valves constructed of? folds of tunica interna
1. where are valves located? placed strategically in veins of limbs
2. what are the functions of valves? to compartmentalize blood between two valves. This makes it easier to move blood- because blood is moved through one valve at a time. This is improves venous return.
3. Can you describe the functions of the skeletal muscle pump? When the skeletal muscles are stretched, it helps to move blood through venus portion of your skeletal circuit. 4. Can you describe how the respiratory pump works? When you inhale in, you increase blood flow into thoracic cavity. When you exhale (out), you increase blood flow into lungs.
1. What is the flow of blood from heart to body to back to heart? Blood is sent through arteries → arterioles → capillaries → venules → veins → heart
2. What does T.I.M.E. represent in relation to the makeup of veins? Tunica intima Media Externa (inside to out).
1. What type of pressure represents contraction? systole = systolic pressure (highest pressure)
2. What type of pressure represents relaxation? diastole = diastolic pressure (lowest pressure)
3. Where does the biggest “smoothing” of pressure takes place? in aorta 4. What is Hydrostatic pressure (mmHg)? the amount of push/pressure that blood puts on vessel walls
5. Why are the adaptations in veins important to get blood back to heart? Important adaptations that to move blood even though the pressure is so low in veins. 6. What is the pressure gradient? (between 100 and 0) it’s the difference of blood pressure within that vasculature circuit. blood pressure is the driving force that keeps blood moving.
How to influence blood pressure: increase blood volume, increase cardiac output (amount of blood pumped out of heart), vasoconstriction
1. Why can you live without your reproductive system? You don’t need it to survive as an individual, just as a species you need it so that you have continuation of your species.
2. Why is the reproductive system quiescent? It’s inactive/quiet until puberty. Puberty is the time of reproductive maturity so that you can now successfully reproduce.
3. What organs does the reproductive system include? gonads, ducts, accessory glands, and external genitalia
4. Do you start out with a gender? No, for the first 7-8 weeks you are sexually indifferent.
5. What causes male? The activation of SRY gene initiates the sexually indifferent gonad to become a testes (male) if activated. The SRY gene is the sex determining region of Y chromosome.
6. What happens if the SRY gene is not activated? You’re female! 7. When you are sexually indifferent, what are the two duct systems? Mesonephric duct (Wolffian duct) and Paramesonephric duct (Mullerian duct) 8. In males, what duct system is used? Wolffian duct (Mesonephric duct)- forms duct for epididymal duct
9. In females, what duct system is used? Paramesonephric duct (Mullerian duct) forms the oviduct and uterus, and a small portion of vagina
10. How long is the window for the SRY gene to become activated? 2 week window. 11. What happens if the androgen is blocked and you have male chromosomes (XY)- and you have estrogens presence? Then you have a genotypic male( XY) but a female phenotype (XX)
12. Why is the male reproductive system a continuous system? Because it deals with anatomical construction of the perms journey: start in testes move to epididymis to ductus deferens then to ampulla to ejaculatory duct and then it joins the urinary system and use the urethra. Anatomically speaking there is no breaks, it goes from one anatomical region to another.
13. What is the process of testicular development? At the 7th month of development, the gubernaculum contracts to pull testis through inguinal canal to form scrotum. Thus, the testes comes down but part of the parietal peritoneum comes down also to form the tunica vaginalis. This parietal layer that is also pulled down is a serous membrane that allows testicular movement within the scrotum sac.
14. What is the spermatic cord made from? The ductus deferens, testicular blood vessels, nerves and lymphatic vessels
15. What is the one structure not present in spermatic cord? lymphatics 16. What is the gubernaculum? This is a bundle of CT fibers that extend from testis to floor of scrotal swelt (scrotum). As this structure grows, it does not actually change length, it only changes position.
17. What structures make up the testes? The testes has a parietal and visceral layer, which are serous membranes to allow movement. The testes are wrapped in tunica albuginea - this CT invaginates into vastus proper to form septa, which then finds globulus to form seminiferous tubulus.
18.What is spermatogenesis? It’s the structurally maturation of sperm cells that occurs in the lumen of seminiferous tubules
19. What is the mediastinum testis? It forms the network called rete testis and is a site of entry into testes proper for vasculature.
20. What are the two compartments of the seminiferous tubule? The seminiferous tubule is made up of sertoli cells (sustentacular cells) that forms tight junctions that form: Basal and adluminal compartment.
21. What is significant about the basal compartment?It’s the site where spermatogonia occurs- and it’s located close to the basal lamina 22. What is significant about the adluminal compartment? adluminal compartment needs to be separated from immune system to form blood-testis barrier. 23. What is significant about the blood-testis barrier- formed by these two compartments? This barrier does not allow large molecules pass through. This is important to keep spermatogonia, spermatocytes, spermatids, and mature spermatozoa from blood so that the immune system does not become introduced and try to kill the sperm bodies. This is what causes many men to become infertile.
24. Where are the testis located? outside of body
25. What is the cremaster muscle?it’s skeletal muscle that is derived from internal oblique muscle and it covers the spermatic cord and testis.
26. What is the function of the cremaster muscle? Functions to retract testis (brings testes closer to body to keep it warm or relax to allow more circulation testes) 27. What is the dartos muscle? smooth muscle within scrotal wall
28.what is the function of the dartos muscle? temperature regulation of testis by causing wrinkling of the scrotum → more SA to retain more heat when it’s cold. when it relaxes, the surface area decreases so heat radiates
29. What two muscles are important in spermatogenesis? cremaster and dartos muscle - because spermatogenesis depends on temperature
30.What is the structure referred to as raphe? It’s the line that results from the union between two contiguous, bilaterally symmetrical structures. But it has nothing to do with reproduction.
31. What is a plexus? interweaving network of something
32.What’s the significance of pampiniform plexus? It provides a countercurrent mechanism as a heat exchange. As warm arterial blood flows into the testes it is wrapped by a section of the testicular vein- where it becomes the pampiniform plexus within the spermatic cord. So blood is cooled as it enters testis, but warmed as it leaves the testis. This mechanism is a way to make sure the testis remains correct temperature so that spermatogenesis can be successful.
33. What is spermatogenesis? A progress of forming a structurally mature sperm cell through meiosis. It continues constantly from time of puberty. It starts with a spermatogonia and ends with a sperm.
34. Are spermatogenesis ells seen as self? Yes- but cells modified after this process are seen as non-self.
35.What is spermiogenesis? IT’s a part within spermatogenesis that focuses on the reconstruction of the round spermatocyte into a structurally mature sperm with an acrosome cap (head), nucleus, mitochondria, and a tail (flagellum).
36. What is spermiation? Another process that sperm undergoes when sperm loses attachment to sustentacular cells.
37. What are the 3 regions of the epididymis? caput (head) - where sperm comes in, corpus (body), and the cauda (tail/end)
38. What is the function of epididymis? It monitors/adjusts fluid composition to support developing cells, is a recycling center for damaged sperm (anything “bad” is reabsorbed and taken away), stores, protects, and facilitates functional maturation of sperm. And most importantly, sperm earns “diploma” saying they have learned how to swim in epididymis and now have capacity to fertilize
39. Where does sperm go from testes? sperm moves along epididymis via peristaltic contractions of wall smooth muscle. so sperm is constantly move to caput/head, corpus and cauda of epididymis.But it’s stored in tail/cauda region until ejaculation.
40. After the sperm leaves the cauda region of the epididymis, where is it sent to? Through ductus deferens, and ampulla (storage cavity within body cavity) of
ductus deferens, then to ejaculatory duct the seminal vesicles then it’s joined with the urethra to exit the penis.
41. What tissues make up the ductus deferens? thick layer of smooth muscle and lined with pseudostratified ciliated columnar epithelium.
42. So all together, what is the Sperm’s journey? testes → epididymis (caput to corpus to caudal)→ ductus deferens → ampulla → seminal vesicle → ejaculatory duct → prostatic urethra → urethra
43. what are the accessory glands? seminal vesicles, prostate gland, and bulbourethral gland
44. What is the function of the accessory glands? provides fluid medium that is part of the semen that sperm is suspended it. The fluid provide nutrients and functional maturation
45. What is the function of the seminal vesicles? It makes 60% of the fluid composition of the semen. The secretions high in fructose - sperm’s favorite energy source.The fluid is slightly alkaline - because female reproductive tract which is slightly acidic so having buffers is important. it helps to keep gametes in the female reproductive tract. causes contraction of vagina muscles to keep sperm in there. the human semen actually gels to help it stay and protect it from environment - helps it into cervix.
46. What is the function of the prostate gland? It’s slightly acidic and contains seminalplasmin to help get rid of bacteria. The prostate gland is wrapped in smooth muscle, encircles the urethra, and produces prostatic fluid.
47.What is the function of the bulbourethral gland? (Cowper’s gland). This is a tubuloalveolar mucous gland that primarily secretes thick mucus that is alkaline. 48.What is semen? in human it’s milky white, someway sticky (because presence of fructose). mixture of sperm and accessory gland secretions.
49. What is the function of semen? provides a transport medium, nutrients, chemicals to protect and activate sperm. It also facilitates sperm’s movement 50. What are the two functions of the penis? conduct urine to exterior and also used to deposit male gamete in female Reproductive tract
51. What is the erectile tissue of the penis made of? it’s a dense network of elastic fibers. largest erectile tissue in body, not the only location of erectile tissue. There are vascular channels moving through it. it’s a spongy network of connective tissue and smooth muscle riddles with vascular spaces. so vascular channels that are separated by networks of connective tissue and smooth muscular fibers
52. What are the 3 cylinders/columns of erectile tissue? There are 2 corpus cavernosum columns and one corpus spongiosum. The corpus cavernosum contain a central artery, and the corpus spongiosum has the spongy urethra.
53. What allows the movement of erectile tissue with skin? deep fascia that allows tissue to become flaccid and erect
54. why is it better to use this type of erectile tissue- why have cylinders of erectile tissue-why erectile tissue instead of just a hollow tube? it offers structural support! erectile tissue gives better rigidity and more structural strength with this anatomical design
55. What are the two blood supplies of the penis? one is blood supply that provides regular nutrients and one is helicine arteries (these are actually involved with the functionality of the erectile tissue).
56. How does erectile tissue function? vasodilator impulses from parasympathetic NS
This causes relaxation of penile vessels → allows the blood flow into erectile tissue. As the tissue fills with blood, this creates a high pressure system that traps the blood within penis to sustain erection. The drainage elements are found more peripherally (on the sides), so as the erectile tissue flows in, it blocks the drainage vessels flow. so by trapping the blood flow, erection is sustained. At the same time are are going to suppress sympathetic NS
57. How is ejaculation completed? It’s coordinated by sympathetic nervous system. The contractions of vas deferens and have “sweeping” peristaltic contractions in penile urethra (also in urethra as well) to move sperm through series of ducts
58. What action is completed by the parasympathetic system? Erection (point) 59. What action is completed by the sympathetic system? ejaculation (shoot) 60. What stimulates the anterior pituitary to send LH and FSH to gonads? hypothalamus produces GnRH
61. What does LH do? stimulates the leydig (interstitial) cells release testosterone 62.
63. What hormones does spermatogenesis require? both FSH and testosterone 64. What does prolactin do for a male? This increases sensitivity of interstitial cells to LH. prolactin is supportive of LH influencing interstitial cells and making sure they are producing testosterone.
65.What is the importance of Inhibin? It serves as a “sperm barometer” because when sperm numbers increase, then the testes releases more inhibins 66. What is the function of inhibin? shuts down the release of the gonadotropins (shuts down GrnH) because it tries to help regulate the number of sperm being made and keep it within a normal range. Thus, when sperm numbers decreased, inhibin secretion declines so the release of gonadotropins increases to lead to sperm production.
67. Why is the female reproductive system discontinuous? there is a break in the system at the ovaries. the ovaries expel oocytes (side note: this is how you get ectopic pregnancies). the ovaries are where oogenesis occurs and expelled- to be picked up from oviduct - which is picked up by the fimbriae (finger like structures of oviduct) then it goes into the uterus and then goes into the vagina. oocytes don’t have to go into the oviduct- they can go away into the nearby tissues. same thing for sperm that enters female tract- can go away. doesn’t have to go into oviduct. can be found in fluid/tissue surrounding.
68. What are the structures that anchor the ovaries and uterus? fimbriae/oviducts, broad ligaments, suspensory ligament, ovarian ligament.
69. What is the structure fimbria? hangs over uteries (fimbriae holds ovaries) 70.What is the broad ligament? It’s the “cape”, which is made of peritoneum that folds over the structures of the female reproductive system
71. What are the two ligaments that keep ovaries stationary? Suspensory and ovarian ligaments.
72. What is the structure of suspensory ligaments? They attach ovary to the body wall. This is where vasculature comes into this suspensory ligament 73. What is the structure of ovarian ligaments? They are posteriorly located, attaches to uterus to ovary to keep ovary in place . important to keep it in reach of fimbriae 74. What is anteverted? where uterus is inclined forward. Note: most young women our age should have this
75. What is retroverted? uterus is turned backwards toward rectum (as you age it tilts this way)
76. What are the two domains of an ovary? medulla and cortex
77. What is the structural characteristics of the medulla? It's the inner layer that vasculature and lymphatics comes in through the suspensory ligament 78.What’s the structural characteristics of the cortex? It’s the outer layer where follicles develop.
79. What are primordial follicles? these are recruited oocytes during each cycle (usually 10-15). they then flow through grow to be a mature follicle. 80. What are mature follicles? (vesicular follicles)- They are a fluid filled antrum with oocytes with zona pellucida and corona radiata
81. After the follicle is mature, what happens? the follicle is ovulated and then the follicle then converted into corpus luteum
82. What are oogonia? These are diploid cells that divided by mitosis. (equivalency in males is spermatogonia)
83. What is the difference between male and female reproductive cells? in adult male, you have presence of spermatogonia. stem cell is retained.in females, right before birth- the oogonium starts in meiosis and becomes arrested. this means that women are born with their full compliment of oogonium. Women are born
with all the oocytes they will ever have. This is different from male that continually produce spermatogonia
84. Why is radiation bad for both males and females? bad for males because spermatogonia are ready to divide. bad for females because they have their whole set that they are born with.
85. What is the process of the reproductive cycle of females? each month, up to 20 primordial follicles mature into primary follicles. from there, only one of the primordial follicles develop into secondary follicles. the primary follicles that do not mature into secondary follicles undergo atresia. the one primary follicle that matures into secondary follicle completes the first meiotic division. This creates a polar body and a secondary oocyte. This secondary oocyte is a haploid cell (23 chromosomes) and pauses in the second meiotic metaphase. Only if it is fertilizes does this secondary oocyte complete the second meiotic division to become an ovum. if not fertilized, it is degraded.
86. once primordial follicles are recruited and undergo development, what happens next? they undergo mitosis and stop right before meiosis 2.
87. What is menarche? first reproductive cycle
88. what is menopause? one full year without reproductive cycle (and not pregnant) then you are officially in menopause
89. How many sex cells are created for each reproductive system? For males, spermatogenesis ends up with 4 structurally mature sperm cells (4 gametes) and for females we end up with 1 ovum. the extra genetic material is released as first and second polar bodies.
90. why one ovum and 4 sperm? This difference is because the uterus is set up for one, maybe 2 young. all the elements are in place for the first cell division. ovum has all the nutrients are there. until the nucleus for the first zygote can take over and use it’s own genetic material -which takes time. so that’s why the ovum is such a large cell - it houses and provides energy for the first division for the zygote.
91. How many oocytes are ovulated each cycle of female reproductive 1-2 oocytes per cycle
92.What does meiosis result in? diploid cell → haploid cell 93.What does mitosis result in? diploid cell → diploid cell 94. What are the two phases of the ovarian cycle? follicular and luteal phases 95. What is the follicular phase? represented by recruiting one of these primordial
follicles and progress under series of events to turn into mature (or graafian) follicle which is a cell that’s ready to ovulate. during these time,this mature follicle produces estrogen. then we have ovulation
96. What is ovulation? ovulation is like an eruption because the walls of follicle thin and the pressure inside builds. so the oocyte “pops out”
97. What causes ovulation? rise in gonadotropins (FSH and LH, LH is larger force). important because it’s then going to affects the cells left over in the follicle. this represents luteal phase. these cells go through luteinization. under impression of LH. take the follicle that was making estrogen, now undergo morphological changes to become the corpus luteum and make progesterone. this change in hormone product being produced = steroidogenesis to produce progesterone. luteal cells produces the progesterone. remains active and has a timer: has a signal for pregnancy - to maintain corpus luteum is maintained if pregnant. if the signal is not maintained, the cycle restarts again. follicle cells produces estrogen 98. What is the luteal phase? remains fairly constant
99. What are the oviducts? hollow muscular tubes that are held up by broad ligaments and open into the peritoneal cavity.
100. What are the segments of the oviducts? Infundibulum, ampulla, isthmus 101. What is unique about the infundibulum of the oviduct? The ends have fimbriae that are close to the ovary (but not attached to) to pick up the egg. 102. What occurs in the ampulla region of the oviduct? fertilization occurs here. 103. What occurs in the isthmus of the oviduct? This structure connects to the uterus and is the site of fertilization. This region serves as “sperm reservoir” . 104. What happens to the sperm as it enters the vagina? As sperm comes into vagina, sperm “takes a break”/comes immobile on isthmus of oviduct so that they reach the infundibulum at different times. This method decreases risks of missing ovulated egg because the egg is continually met by sperm.
105. What is the functionality of the oviduct? It’s designed to receive the oocyte, be the site of fertilization, and preimplantation of development (until the zygote heads to uterus).
106. What is an ectopic pregnancy? It’s when the fertilized egg doesn’t go into the uterus, so it’s growing in the fallopian tube.
107. What’s significant about the uterus? It’s the hollow, muscular muscular organ that houses the embryo.
108. What helps the uterus have limited movement? muscles and ligaments 109. What are the 3 anatomical subdivisions? Fundus, corpus, cervix 110. What is the fundus? dome shaped superior portion
111. what is the corpus? the body (middle region)
112. What is the certix? the bottom basement of uterus- inferior narrow portion opens into vagina
113. What shape does the human female uterus resemble? a triangle because it has a simplex, inverted design where the larger portion is superior with a narrow base.
114. What is the function of the uterus? serves as a site of implantation and embryonic/fetal development, and also parturition
115. What are the 3 layers of the uterine wall? endometrial, myometrium, and perimetrium
116. What is the endometrial layer made of? It’s a mucosal lining made of simple columnar epithelium on top of a thick, robust basal lamina. it’s made up of two elements: stratum functionalis and stratum basalis.
117. Where is the stratum functionalis located? Next to the lumen 118. What is the functionality of the stratum functionalis? It responds to the hormonal environment- so it undergoes the cyclic changes in response to the hormonal changes from estrogen to progesterone. this layer is fed by a spiral artery( coiled arteries). This layer is lost during menses.contains most of uterine glands. This is a thick layer.
119. Where is the stratum basalis located? It sits next to myometrium. 120. What is the stratum basalis? It’s a thin layer fed by straight artery. also has uterine glands. This is the foundation for new functional layer after menses. 121. What is the structure of the myometrium? It has no distinct layers. It’s made of interwoven smooth muscle bounded together.
122. What is the structure of the perimetrium? It contains a serosa layer (visceral peritoneum)
123. What are the 3 phases of the uterine cycle? Menses, proliferation, and secretory.
124. What happens in menses? It’s the degeneration of endometrial functional zone. The endometrial layer breaks down in patches because of the constriction of spiral arteries. However, the entire endometrial functional zone is lost → menstruation. (menses is actually a lack of hormones).
125. What happens in the proliferative phase? The endometrial basilar zone grows to restores integrity of endometrium by forming the functional layer. growth and vascularization is restored in functional layer. supported by estrogen.
126. What does estrogen and progesterone do? estrogen builds. progesterone maintains.
127. What happens in the secretory phase? There is an enlargement of uterine glands along with increased secretory rate and elongation of coiled arteries. tissues maintained by progestins.
128. What happens when hormones releases decline? The spiral arteries respond by constriction - which leads to menses and so the whole uterine cycle begins again.
129. Do the straight arteries respond to hormone levels? No, the straight arteries are insensitive to hormone levels. so the stratum basalis is never really affected by hormonal changes because it consists of straight arteries.
130. What is amenorrhea? It’s the loss of reproductive cycle. There is a correlation between amount of body fat and reproductive cycle. Because the female reproductive cycle is very costly- it requires a certain amount of body fat to have a cycle. So without meeting the fat requirement, there is no cycle. 131. What is dysmenorrhea? It’s painful menstruation
132. What is the vagina? It’s a thin-walled elastic fibromuscular tube that extends from certix → vestibule 133. What’s the functionality of the vagina? It serves as birth canal, serves as passage for elimination of menstrual fluids, and a site of semen deposition. So basically a conduit or deposition place
134. What’s the structurality of the vagina? It has vaginal rugae. This is important because the folds in the inner layer provides flexibility to stretch. the primary tissue type of this mucosal membrane is connective tissue and epithelium. (remember epithelium doesn’t allow stretching. and connective tissue is somewhat stretchy. So rugae of mucosal folds allows structure to stretch without tearing.
135. Who has mammary glands? Both men and woman.
136. What are mammary glands? a specialized organ of integument - modified sweat gland.
137. What do mammary glands do in women? produce milk (lactation for newborn offspring)
138. What hormones regulate lactation? prolactin stimulates milk production and oxytocin activates smooth muscles that helps with milk injection/”milk let down”.
139. Do guys produce prolactin? Yes, prolactin is supportive of gonadal activity. Males also produce oxytocin
140. What does oxytocin do? oxytocin stimulates smooth muscle contraction in male reproductive system. oxytocin also referred to as ȩcuddleȪ hormone because it does enhance pair bonding and maternal behaviors. elevated levels of oxytocin found in mated pairs. also may be connected to limbic system. evidence: when couples cuddle their oxytocin levels rise → brings down cardiac output and heart beat, which brings down blood pressure. makes you more relaxed, lessens stress and anxiety.
141. What are accessory parts to mammary glands? ductal system and milk producing alveoli. Females have both but males only have ductal system. 142. What is gynecomastia? “man boobs” - excessive development of male mammary glands due to ductal proliferation due to increased estrogen levels.
Seen mostly at time of puberty in males because sex hormones are being produced.. But over time the tissue is reabsorbed and the mammary structures will not longer exist.
143. How do males males produce estrogen just like they produce testosterone? because the zona reticularis produces gonadocorticoids (estrogens and androgens)
Chapter 22- Heart
1. How does blood help to maintain homeostasis? It circulates continuously throughout the body.
2. How is blood able to circulate continuously? via the pumping action of the heart and adjustment of pressures because circulation is a closed system. 3. What is the flow of blood? body to inferior vena cava to RA to RV to pulmonary trunk to lungs to pulmonary veins to LA to LV to aortic to body
4. What are the functions of the heart? Serving as a pump to propel blood through vessels.
5. What are the main vessels of the heart called? Great Vessels 6. Why is the heart the “Center” of cardiovascular system? because blood is brought to the heart and sent away from the heart
7. What are the conduit systems of blood vessels? Arteries, veins, capillaries 8. What is the function of arteries? always carry blood AWAY from heart 9. Do arteries always carry oxygenated blood since they carry blood away from the
heart? No, it’s not always oxygenated. The exception is pulmonary artery 10. What is the function of veins? always carry blood TO the heart (not always deoxygenated; exception is pulmonary vein).
11. What is the function of capillaries? Capillaries are the functional unit that is the site of exchange
12. What are the anatomical characteristics that assist with function? Unidirectional flow, side-by-side pump, and blood pressure
13. What is the mechanism for blood flow through vessels? A pressure gradient is
used to move blood through blood vessels
14. Why is the heart a “side-by-side” pump? It serves 2 separate blood circuits (pulmonary and systemic circuit?
15. Because the circuits of the heart have equal volumes of blood, do they also have the same amount of work? No, the right side requires less work because pulmonary circuit is short, and low pressure system.
16. Why does the systemic Circuit (left side) require more work? It is longer (sends blood to limbs) and is more resistant to blood flow
17. What is the weight of the heart? modest weight (~300 grams or 1 pound) 18. What is the size of the heart? about the size of your fist
19. What is unique about the weight and size of heart? masks incredible strength and endurance to pump all blood needed each day
20. Where is heart located? located in thoracic cavity between lungs within mediastinum between 2 and 5th rib. superior to diaphragm. extends obliquely to mediastinum. posterior to sternum. anterior to vertebral column. obliquely placed 21. Where is the apex of the heart? tip of heart at bottom
22. Where is the base of the heart? the top region
23. Is the heart completely vertical or tripped? tipped:apex is tipped anteriorly (forward), base is tipped posteriorly (backward). thus, obliquely oriented. 24. On which side of the body is the heart located? and heart is more to the left of body
25. What is the double-walled sac that the heart is enclosed by called? pericardium 26. What is the pericardium constructed of? fibrous pericardium, serous pericardium 27. What is the fibrous pericardium made from? loose fitting, tough dense connective tissue layer
28. How does the fibrous pericardium protect your heart? The fibrous pericardium wraps around heart, anchors heart to surrounding structures to prevent it from overfilling so you don’t “blow out” the wall of your heart.
29. What two layers does the serous pericardium have? parietal and visceral layer 30. Where is the parietal layer? It lies next to the fibrous pericardium- it’s the outer layer that lies next to the fibrous pericardium.
31.Where is the visceral layer located? It’s the innermost layer of serous pericardium. The visceral layer consists of the epicardium, myocardium and endocardium .
32.What is the “epicardium”? The outermost part of the visceral layer that is an integral part of heart wall.
33.What is the myocardium? It’s packaged in spiral/circular bundles- uses connective tissue to crisscross fibers to link areas of heart together. The crisscrossing is important because it allows the heart to twist as it contracts to squeeze the blood out of the ventricles. It compresses the heart to pump large amounts of blood out of ventricles.
34. What is the endocardium? The innermost layer, deepest layer of the visceral layer. It’s made up of layers of endothelium supported by connective tissue. Remember that endothelium is simple squamous epithelium.
35. What is special about the endocardium regarding valves and vessels? Endocardium endothelium is continuous with the endothelium of the vessels that are leaving the heart and also covers the valves of the veins.
36. What is the pericardial cavity? A slit like structure between layers of serous pericardium containing film of serous fluid. This is important because it permits free movement within sac. Every time the heart contracts and beats- it moves. so the serous fluid is important to provide friction free environment.
37. What structure does Cardiac muscle tissue have? Cardiac has intercalated disks provide “interlocking” of the cardiac muscles together.
38. What two elements make up intercalated discs? desmosomes & gap junctions 39. What do desmosomes do? keep the cells attached to keep them from pulling apart during contraction with all the pressure
40. What do gap junctions do? set up a situation where they are electrically coupled. so once we have a depolarizing wave on one cell, it spread to all cells.
41. What forms a functional syncytium? Intercalated discs form syncytium because these discs allows a bunch of individual cells to work as a single unit. result in highly coordinated contractions.
42.Where is the nuclei found in intercalated discs? in center. (in skeletal muscle it’s peripherally located)
43. What type of tissue is located between the intercalated discs? loose connective tissue - the matrix fills intercellular spaces along vasculature to connect to fibrous skeleton of heart. It acts as a tendon to provide an insertion for cardiac muscle tissue. Know that microscopically: cardiac muscle cells have sarcomeres, z lines, A bands, I bands, etc. but has numerous mitochondria to give cardiac muscles high resistance to fatigue, which is important because we don’t want heart to stop beating.
44. Compared to the skeletal system, is the calcium delivery system more or less developed? It’s less developed (less robust than skeletal muscle) and the T tubules are wider and fewer. enter once per sarcomeres. no triads.
45. At physiological level, is skeletal and cardiac muscle the same? They are similar, but if you look at cellular level, it’s designed is slightly different.
46. What is located in the fibrous skeleton between the heart valves (in a cross section)? A dense connective tissue network is found between atria and ventricles. The functions of this dense CT is that it physically and electrically separate atria and ventricles, anchor heart valves with supportive rings (important because valves are just flaps of connective tissues), and provides a rigid framework for attachment of cardiac muscles - reinforces myocardium internally and anchors cardiac muscles.
47. Where are the atria located? superior located. Also know they are smaller, and thin-walled.
48. Where are the ventricles located? inferior located. Also know they are larger, thick-walled.
49. Where do all of the vessels from the ventricles exit from? The base (basal surface)
50. What structures are on the anterior side? trunk or aora. or interventricular sulcus.
51. What structures are on the posterior side? inferior or superior vena cava & coronary sulcus (coronary sinus sits on coronary sulcus)
52. What are the suli of heart? anterior and posterior ventricular sulcus, and coronary sulcus
53. What is the function of coronary sulcus? This specific sulcus holds coronary circulation that provides heart with private circulation
54.What’s significant concerning the opening of coronary sinus? It’s where blood returns to heart in right atria
55. What can all valves be called? all valves are atrioventricular valves 56. What is hooked to papillary muscles? tendinae
57. Do the papillary muscles contract? No- the heart wall contracts and creates tension on the papillary tendinae to cause movement.
58.What makes sure the right ventricle doesn’t blow out in right ventricle? septomarginal trabecular
59.What is the significance/function of the trabeculae carnae? It’s the ridges and valleys (remnant left over from when we had 2 chambers) that makes sure blood doesn’t stay sedentary in the heart to prevent a clot - keeps blood flowing. heart doesn’t eject ALL blood, some are residual.
60. What is function of semilunar valves? These valves are folds of connective tissue on the wall that open and close depending on blood flow
61. What is function of ligamentum arteriosum? This structure arises after birth - remnant of ductus arteriosus (fetal structure that shunts blood) so this detours from pulmonary trunk to the atria. this is bypassing pulmonary circuit- important because fetus isn’t breathing. but once you are born, you can breathe so this is closed off and becomes a fibrous structure.
62. What is function of crista terminalis? The crista terminalis separates the pectinate muscle from heart
63. What is the function of the fossa ovalis? The fossa ovalis shunts between left and right because we don’t always use full circuit. it’s a hollow depression where foramen ovale existed in fetal heart.
64.What’s the difference between left vs right ventricle? In left, the heart wall is thicker because it pumps to the entire body. Whereas the right ventricle sends
blood to pulmonary circuit so it’s weaker because it’s a shorter distance with less pressure and less resistance.
65. What's the difference between atria vs ventricles? ventricles are larger. the difference in function between atria and ventricles is reflected in size. atria contract enough to fill up. atria are primer pumps. ventricles are power pumps that generate pressure to move blood
66. why is the heart constructed how it is- why is left larger than right ventricle- why atria and ventricle size difference? because of the functional demands placed on it. The left side= systemic. The right side- pulmonary circulatory. 67. How is a one-way flow accomplished? heart valves
68. What makes valves open and close? They open/close in response to different in blood pressure
69. What is systole? ventricles contracting
70. What is diastole? ventricles relaxing
71. What happens when ventricles contract? The semilunar are open because Ventricular pressure is greater than the systemic circuit. This is because heart can only pump blood out when pressure inside ventricle is greater than pressure in circuit.
72. What happens as pressure falls in ventricles (relaxing)? This would make the atria pressure greater so the atrioventricular valves open and fill ventricles. 73. What happens when systemic circuit pressure is greater than ventricular pressure? blood flows back in through the atria and fills ventricles. 74. so why no valves on vena cavas or pulmonary veins- couldn’t blood backflow into those? pressure is really low, the walls are thin, so when the heart contracts - the heart compresses them shut so there is no backflow
75. What happens to the atrioventricular valves when ventricles contract? Because of the little blood in atria, there is no pressure so it creates compression to prevent no backflow
76. What is a cardiac cycle? it represents the period from the time of one contraction (one heartbeat) to the next contraction/heartbeat
77. class video: http://www.youtube.com/watch?v=rguztY8aqpk&feature=related
78.How is the heart coordinated to be an efficient pump? it’s coordinated by conduction system - which is made up of specialized cardiac (myocardial) cells that are noncontractile. They serve as a mechanism to distribute impulses that are generated at sinoatrial node. so the heart contracts in orderly, sequential manner.
79. Why is the conduction system so important? conduction system ensures signal moves fast enough through heart
80. What does it mean that the heart has autorhythmicity? heart initiates its own contraction through self depolarization. Thus, the heart does not need NS. 81. Where does a contraction originate? from the SA node -- internodal pathway brings the signal to the right side and the atria contracts.
82. What keeps order in the contractions of the heart? atrioventricular node - causes a delay so the atria contracts and then ventricular contraction.
83. What is the function of the AV bundle (bundle of His)? The AV bundle conducts the muscle impulse into the interventricular septum
84. What happens to the AV bundles once inside the the interventricular septum? the L and R bundles split from the AV bundle
85. What type of fibers receive and distribute the muscle impulse in each ventricle myocardium? purkinje fibers
86. How is the heart innervated? By the autonomic nervous system via the coronary plexus.
87. What are the main layers of coronary plexus? sympathetic through cardiac nerve and parasympathetic through the vagus nerve.
88. What structure is used to set the pace of the conduction system of the cardiac muscle’s contractions? pacemaker!
89. so why need innervation of the heart? the brain stem can modify heart rate and force of contraction. BUT they do NOT initiate contraction- that is by the pacemaker (sinoatrial node)
90. What is the function of the parasympathetic innervation of the heart? It decreases heart rate
91. what is the function of the sympathetic innervation? increases heart rate and can increase force of contraction
92.What is the “3rd circuit”? coronary circuit - the coronary arteries arise at the base itself and goes out to supply oxygenated blood to the heart
93. What specific type of arteries are the coronary arteries referred to? functional end arteries.
94. What is the function of the functional end arteries? They have anastomoses - which allows us to have alternative blood vessels to have alternative pathways of blood supply.
95. What is the coronary sinus? coronary sinus is a large vessel that enters to the right atrium
96. What is an interesting fact on the heart? heart represents 1/200th of the body weight but it requires of 1/20th of the body’s blood supply
Cardiovascular system= blood (transport medium), heart (pump) + blood vessels 1. blood is unique because it’s the only fluid tissue found in body.
2. What tissue system does blood belong to? Blood belongs to connective tissue
3. What are the components of whole blood? plasma (nonliving fluid matrix) + cellular components (formed elements)
4. What are some physical characteristics of blood?
a. sticky because of glucose components
b. metallic odor
c. denser/more viscous than water
d. slightly alkaline (pH 7.35 - 7.45)
e. temperature slightly higher than body temperature (38 degrees C) because blood is used to move heat within system.
5. if you centrifuge blood, how will divide out into different layers of components? a. plasma: 55%
b. erythrocyte: 44%
c. butty coat: <1%
6. When you centrifuge blood, what are the colored layers? white, yellow, red 7. What does the white layer consist of? puffy coat
8. what does the red layer consist of? erythrocytes
9. what does the yellow layer consist of? plasma
10. What is plasma? water + proteins + solutes (electrolytes, nutrients) 11. What are erythrocytes? red blood cells
12. what is a buffy coat? white layer & platelets and white blood cells 13.hematocrit looks at percentage of erythrocytes (number of RBC) a. males usually 45%, females around 40% mainly because menstruation. so during menstruation years women tend to be anemic. during the years younger than 35.
Functions of blood:
1. Performs numerous functions that are important in the maintenance of homeostasis
2. Involved in substance distribution & regulation of blood levels of particular substances as well as protection
3. How are these functions accomplished?
a. distribution: transportation to and from tissues.
i. transporting oxygen, nutrients, enzymes & hormones to tissues ii. transporting carbon dioxide & waste products away from tissues (to kidneys/liver)
b. maintaining body temperature
i. “moves” heat from deep tissues to body’s surface as you generate heat. this helps to eliminate excess heat.
ii. the surface of skin can come to outside temperature, like if it’s cold outside, while maintaining a warm body core temperature
c. maintaining levels of cellular components: fluid, electrolyte & pH balance d. protecting body from disease-carrying microorganisms, foreign substances & tumors
i. cellular component of blood, antibodies
e. preventing blood loss
i. platelets & clotting factors
1. fluid component that suspends elements of blood
2. plasma = serum + proteins + chemical substances
3. straw-colored, yellow color.
4. sticky fluid
5. composed of mostly water
6. Comparing serum vs plasma:
a. to get serum- you let old blood clot and then spin it now and take the supernate off. so serum is plasma without the clotting factors.
b. plasma- it’s serum (water portion) + array of proteins
i. what do you find in plasma?
1. water + proteins + electrolytes
2. the most abundant plasma solute = plasma proteins
7. plasma is not just a fluid, it’s a complex mixture that contains many different solutes.
8. homeostatic mechanisms serve to keep the composition of plasma relatively constant, even though there are over 100 different dissolve solutes that can be found in plasma
9. however if you look at blood in lungs or liver, the makeup of plasma is different because the blood is constantly being added to as the body filters blood. 10. overall plasma is constant, but at tissue level there are changes of solutes leaving/entering, new/old substances
Formed elements are the cellular components of blood
● 3 players: erythrocytes, leukocytes and platelets
○ erythrocytes - anucleated
■ go for about 20 days
○ leukocytes- complete cell
■ may last 6 hours
○ platelets- cellular fragments
● in general, formed elements are short lived and amitotic so they must be continually renewed. they are formed in red bone marrow.
● used for internal micrometers because they are always 7.5 micrometers in diameter
● look like biconcave discs: similar shaped to dumbbells
● why a concave disc shape of erythrocyte?
○ it allows us to have a large SA , which allows the movement of molecules like gases by utilizes diffusion, which does not cost anything.
○ also permit the stacking of erythrocytes next to each other = rouleau formation is when they are stacked so that they can move through a small vessels (capillary)
● during development and as they go through erythropoiesis, they lose nuclei and most organelles and just retains cytoskeletal elements with an interesting shape ● plasma membrane sac with hemoglobin (a protein)
○ other elements:
■ antioxidant enzymes (functional protein)
■ spectrin (structurally important enzyme) - attaches to plasma
membrane and allows them to twist/change shape and allow them to spring back to original shape - allows them to fit through blood
vessels. helps them flow through capillaries. provides RBC
● erythrocytes contributes to viscosity/fluidity of blood
● function of red blood cells: transport gases - oxygen and carbon dioxide ● Note: what happens when they are damaged? they are removed from circulation. ○ they have little ability to heal itself because it doesn’t produce proteins for cellular repair
1. red blood cells formed in red bone marrow
2. life cycle is 120 days
3. after 120 days they are phagocytized (eaten) by liver or spleen 4. in the liver, the heme components of blood are recycled:
a. globin portion is broken down and the amino acids are utilized. iron keep, but heme is eliminated through bile.
b. iron is transferred and store by the protein ferritin in the livery
i. iron in free state is toxic. it needs to be bound to transport protein - taken to liver if not already there- and bound to ferritin (protein in
liver than stores iron for us)
ii. iron is absorbed easier from food, rather than supplement.
c. heme (without iron) is converted into biliverdin and then to bilirubin, which is secreted in bite from the liver
5. the erythrocyte membrane proteins and globulin proteins are broken down into amino acids, and some of these components are used to make new erythrocytes 6. What organ keeps the red blood cell numbers relatively constant? a. the kidney (produces erythropoietin) is in charge of looking at the balance of oxygen in the erythrocytes by looking at the oxygen content. it doesn’t
count erythrocytes, it just looks at oxygen content. if correct oxygen content , then correct red blood cell number.
1. What is hemoglobin made up of? 2 alpha and 2 beta amino acid chains 2. what is in the center of hemoglobin? a heme group
3. what is located within a heme group? iron atom
4. what does bright red color pigmentation of blood indicate? That it contains oxyhemoglobin- a lot of oxygen → bright red color 5. what does a darker red pigmentation of blood indicate? That it is deoxyhemoglobin - little oxygen → darker red color 6. What is carbaminohemoglobin? A hemoglobin structure where carbon dioxide binds to molecule but does not compete for heme with oxygen, the carbon dioxide binds to the amino acid portion of globin protein
7. Why is it important that hemoglobin is packaged within erythrocytes? The packing protects the molecule from breaking into fragments, and an erythrocyte is a transport vesicle that carries 200 hemoglobin molecules. The packing contributes to blood viscosity and osmotic pressure.
1. What are the two types of leukocytes? granulocytes and agranulocytes 2. What do all leukocytes have in common? They are mobile, flexible, found in blood vessels and body tissues, helps in body defense, and presents a small percentage of total blood volume (less than 1%).
3. What is a granulocyte? A leukocyte with granules present.
4. What are the 3 types of granulocytes? neutrophils, eosinophils, and basophils 5. What is an agranulocyte? A leukocyte without granules.
6. What are the 2 types of agranulocytes? monocytes and lymphocytes. 7. What are the two reasons a leukocyte leaves the bloodstream? Diapedesis and amoeboid motion
8. What is diapedesis? passage of blood cells through intact vessel walls into tissue 9. what is amoeboid motion? the flowing movement of the cytoplasm of the cell/phagocyte
10. What triggers leukocytes to leave blood circulation? The infection site releases signaling molecules to attract leukocytes to the specific site.
11. What are the signaling molecules? Positive chemotaxis.
12. What do the positive chemotaxis do to get the leukocyte attention? Lay down a chemical trail to lead leukocytes to infection
13. What other molecule type does the infection site use to attract leukocytes? Adhesion molecules are used at entrance of infection site to inform leukocytes of where to dive out of the blood vessel.
1. What is the common shape of nuclei among all 3 granulocytes? They have a lobed nuclei within their spherical cell shape.
2. What is the functional purpose of granulocytes? Phagocytize
3. How do neutrophils operate? Like Kamikaze pilots (if needed, they are willing to go in and bust open to release oxidizing substances to kill self, but also kill the nearby intruder as well).
4. What do neutrophils contain? Fine granules that are filled with lysosomal enzymes or antibiotic-like proteins (defensins)
5. What type of burst do neutrophils undergo? Respiratory bursts- involves the formation of oxidizing substances
6. How do the eosinophils operate? Like P52 bombers- they drop granules then take care of large parasitic worms that are too large to be phagocytized. 7. Aside from helping destroy parasitic worms, what else are eosinophils associated with? Allergic reactions- they phagocytize immune complexes associated with allergies and release chemicals that inactivate inflammatory chemicals. 8. What type of granules do basophils have? Histamine and Heparin
9. What is histamine linked to? Edema/swelling through vasodilation (advantageous when treating an infection site). Histamines are positive hemostatic agents that can recruit neutrophils.
10. What is heparin linked to? Anticoagulation - prevents blood clots from forming so that the injury site continues to have blood flow
1. Comparing granulocytes to agranulocytes, which is larger? agranulocytes 2. What are the two types of agranulocytes? Lymphocytes and monocytes 3. Where are lymphocytes mainly located? Lymphoid tissue (few in circulation) 4. How much of the cell does the nucleus occupy? Majority - cytoplasm is in outer edge. Nucleus is very large.
5. What are the 3 “flavors” of lymphocytes? T cells, B cells, and Natural killer cells. 6. What is the function of T cells? T cells aim to destroy virus-infected cells & tumor cells (basically any antigens found within a cell)
7. What is the function of B cells? B cells give rise to plasma cells that produce & release antibodies when it notices any antigens found outside the cell. these are part of specific immune system.
8. What is the function of Natural killer cells? Natural killer cells attack abnormal and infected tissue cells because they are nonspecific. Thus, they target anything that shouldn’t be there. Basically, if they see foreign then they kill.
9. What is distinctive about a monocyte (size wise)? It’s the largest WBC 10. What do monocytes differentiate into? macrophages
11. What are the functions the macrophage monocyte? Activate lymphocytes to mount immune responses and assist lymphocytes (mostly T and B cells) 12. What is the structural characteristic of the monocyte nucleus? the nucleus is kidney-bean shaped.
1. How do platelets arise? When megakaryocytes in the bone marrow break off from large cells, it creates cell fragments that are known as platelets. 2. What is unique about the nucleus of a platelet? They are multinucleated because they undergo many mitotic divisions but never undergo cytokinesis. 3. What is the structural characteristics of platelets? Platelets are simply plasma membranes “packets” of cytoplasm that have granules (that have many chemicals).
4. What is the function of platelets? Helps with blood coagulation (blood clots), hemostasis, and blood thrombus formation.
5. What is a thrombus? A thrombus is a clot that forms in an unbroken blood vessel.
1. what is hemopoiesis? the production of formed blood cell formation 2. what does hematopoiesis occur? red bone marrow
3. From what type of cell do all formed elements arise from? A single population of stem cells (hemocytoblasts)
4. Myoblasts differentiate into what two types of lines? Lymphoid stem cell line and myeloid stem cell line.
5. What is the lymphoid stem cell line? The lymphoid stem cell line makes only lymphocytes - so B cells, T cells and natural killer cells.
6. What is the myeloid stem cell line? The myeloid stem cell line makes erythrocytes, thrombocytes (platelets), eosinophil, basophil, neutrophil,& monocyte
7. How are the two stem cell lines regulated? Two domains: erythropoiesis and thrombopoiesis
8. What is erythropoiesis regulated by? erythropoietin
9. What is thrombopoiesis regulated by? thrombopoietin
Chapter 20 Notes:
The Endocrine System:
● a system of ductless glands that work together along with the Nervous System to coordinate and integrate the activities of the body’s cells. Thus, regulating body functions.
Endocrine System Nervous System
Communication Method: Hormones Neurotransmitters targets: Cells with receptors specific response time & effect slow. metabolic activities rapid. contraction/secretion range of effect widespread; general localized; specific response duration long-lasting short term recovery time slow rapid; immediate
Endocrine = ductless glands
● the cells release the product into
interstitial fluid (blood or lymph)
● chemical messengers= hormones
Endocrine system organs:
● Organs are small and not as valued as other organs
○ example: pituitary- size of pinky but it has a large impact on body ○ Other endocrine organs:
■ Pituitary (anterior and posterior)
■ pineal gland
■ parathyroid gland
■ adrenal gland
Endocrine system- does not display anatomical continuity- organs are scattered throughout the body
Target organs -
● comprised of target cells
● has receptors that hormone binds to and affects
○ can cause wide variety of responses:
■ mobilization, maintaining water levels, growth and development, regulation of cellular metabolism and energy balance
Endocrinology- study of ductless glands, the hormonal products, and how they affect target organs
Hormones are classified based on their chemical structure:
Hormone Type Chemical Structure
peptide hormones: chains of amino acids
hormones that have amino acid derivatives
steroid hormones derived from lipids fatty acid-derived hormones eicosanoids
eicosanoids - are signaling molecules made by oxidation of 20-carbon fatty acids.
Hormone Regulation through Feedback Loops
1. Negative Feedback loop:
a. most common
b. there is an OPPOSITE directional change.
c. the system causes a decrease/end to original stimulus
d. example: Human body temperature
i. The hypothalamus of a human responds to temperature
fluctuations and responds accordingly.
ii. If the temperature drops, the body shivers to bring up the temperature
iii. If it is too warm, the body will sweat to cool down due to evaporation.
1. Stimulus = eating food causes a rise in blood glucose levels 2. The insulin-secreting cells of pancreas detect high blood glucose levels. 3. Pancreas secretes hormone: insulin
4. insulin causes liver cells to take up glucose and store it as glycogen 5. as body cells and liver take up blood glucose, glucose levels decrease and the insulin being released stops
6. body is now returned to homeostatic blood glucose level
2. Positive Feedback loop:
a. same directional change
b. the system causes an increase or exaggerated response over the original signal.
c. output is increased
d. usually the control is episodic or infrequent - meaning they do not require continuous adjustments
e. An example of a positive feedback mechanism is blood clotting. i. Once a vessel is damaged, platelets start to cling to the injured site and release chemicals that attract more platelets.
ii. The platelets continue to pile up and release chemicals until a clot is formed.
Summary: Positive feedback mechanisms enhance the original stimulus and negative feedback mechanisms inhibit it.
Hypothalamic Control of Endocrine System:
● “master control” of endocrine system because it oversees most activities, but NOT ALL endocrine glands/structure are controlled by hypothalamus. ● However, the activity that is controlled is done via the pituitary gland ● Hypothalamus is responsible for:
1. producing regulatory hormones stimulate or inhibit anterior pituitary hormone secretion.
2. produces hormones that are stored and released from posterior pituitary a. hormones = antidiuretic + oxytocin
3. stimulates hormone secretion of adrenal medulla via sympathetic innervation
a. hypothalamus is overseer of autonomic nervous system
Pituitary Gland (Hypophysis)
● located below the hypothalamus
● structurally and functionally divided:
○ anterior pituitary “adenohypophysis”
○ posterior pituitary “neurohypophysis”
● this gland is derived from embryonic structures
Hormones secreted from the anterior pituitary
Hormone: tropic? Secreted by: Acts on:
hormone (TSH) ✓
thyrotropic cells thyroid gland to release thyroid
prolactin (PRL) mammotropic cells mammary glands to stimulate milk
adrenocorticotropic hormone (ACTH)
✓ corticotropic cells adrenal cortex to cause release of
growth hormone (GH) ✓ somatotropic cells all body tissues to grow (esp. bone,
follicle-stimulating hormone (FSH) &
luteinizing hormone (LH)
✓ gonadotropic cells gonads (testes/ovaries) to
melanocyte-stimulating hormone (MSH)
pars intermedia cells (in anterior pituitary)
melanocytes in epidermis to
stimulate melanin synthesis
Tropic hormones are hormones that have other endocrine glands as their target. Most tropic hormones are produced and secreted by the anterior pituitary.
Control of Anterior Pituitary Secretions:
→ Hypothalamo-Hypophyseal Portal System
● is a system of blood vessels in the brain that connects the hypothalamus with the anterior pituitary.
● function = transport and exchange of hormones to allow a fast communication between both glands.
● The fenestrated structure of capillaries in the hypophyseal portal system facilitates a rapid exchange between the hypothalamus and the pituitary, with only a small amount of hormones needed to stimulate an accurate effect in the respective target organs in the body.
● Fenestrated capillaries have pores in the endothelial cells that are spanned by a diaphragm of radially oriented fibrils and allow small molecules and limited amounts of protein to diffuse.
● aka Neurohypophysis
● does NOT produce any hormones!
● made up of Pituicytes (main cell type of posterior pituitary gland) ● has hypothalamo hypophyseal tract
○ a tract of nerves connecting the hypothalamus and the posterior pituitary
Adenohypophysis= anterior pituitary gland
neurohypophysis= posterior pituitary gland
● located: in neck
○ inferior to larynx
○ anterior to trachea
● surrounded by capsule made from connective tissue ● has two lobes (left and right)
● isthmus connects the left and right lobe
● composed of follicle cells (simple cuboidal epithelium) ○ follicle cells surrounded by central lumen
○ filled with viscous fluid that is rich in protein = colloid ○ follicle cells produce thyroid hormones
○ colloid stores the thyroid hormones
■ note: this is the only hormone that is made “in advance” and store extracellularly
● parafollicular cells: produce calcitonin
○ located in clusters between follicle cells or individually
● Negative Feedback inhibition of releasing thyroid hormone:
1. stimulus (low body temperature)
2. hypothalamus then secretes thyrotropin-releasing hormone (TRH) → anterior pituitary
3. the thyrotropic cells in anterior pituitary then release thyroid-stimulating hormone (TSH)
4. TSH stimulates follicular cells of thyroid gland to release thyroid hormone (TH)
5. TH stimulates target cells to increase metabolic
activities → to increase basal body temperature
6. hypothalamus detects increased temperature → inhibits secretion of TRH
a. so TH blocks the interactions of TRH from hypothalamus to anterior pituitary so that formation of TSH is prevented.
● located: on the posterior surface of thyroid - wraps around the backside ● function: produces parathyroid hormone (PTH)
● Operates by:
1. parathyroid gland detects low blood calcium levels → secrets PTH in bloodstream
2. target organs respond to PTH → causes increase of blood
a. this is done by osteoclasts releasing calcium because they resorb bone connective tissue
b. also: intestine increases absorption of calcium (with help from calcitriol)
3. rising calcium levels in blood prevents release of PTH into bloodstream ● calcitriol promotes calcium absorption
Parathyroid ^ Thyroid^
● pyramid shaped
● superior to each kidney
● retroperitoneal- behind the peritoneal
● no ligaments to attach them - so they are held in place by fat and strategically placed fascia to minimize movement
● it is very well vascularized - (common features with endocrine organs)
● two regions: cortex and medulla
(structurally different - like how the anterior
and posterior pituitary are different)
○ cortex- outer region
■ has 3 layers
● zone glomerulosa
balls of cell
● zone fasciculata - stacks of cells
● zone reticularis- cluster of cells
■ and produces corticosteroids
● which are important for life - regulate nutrients, water,
● we need to know: do you know where GH is from? and what it’s basic function is?
○ medulla- inner region
■ looks more like nervous tissue
■ chromaffin cells- modified postganglionic cells of somatic NS (so modified neurons)
■ releases biogenic amines into blood circulation and has fairly good halflife
■ produce epinephrine and norepinephrine
● they have longevity, and different functionality.
● epinephrine & norepinephrine- are hormones that are
secreted by populations of chromaffin cells (when stimulated
by the sympathetic division of the autonomic nervous
○ because hormones are released more slowly than
nerve impulses and their effects are longer lasting,
the secretion of these hormones help prolong the
effects of the sympathetic stimulation. so the
sympathetic responses continue to linger because
these hormones are still present in the bloodstream to
still affect their target cells.
○ they are structurally and functionally different because of where these parts arose from during embryonic development
Histology slide : book explains this Table 20.6
● usually you see cortex- medulla- cortex in slides
● Zone Glomerulosa- balls of cells
○ produces: mineralocorticoids
■ the main mineralocorticoid is aldosterone- regulates sodium
● so it also regulates water
● Zone Fasciculata
○ produces glucocorticoids
■ main glucocorticoid is cortisol - regulates glucose in blood
■ and plays a role in lipid and protein metabolism
● Zone Reticularis: clusters of cells
○ produces gonadocorticoids
■ minor role in adults
■ the time they really have a big influence is in puberty - important they make a transition at the time of puberty
■ can be androgens and estrogens
^^ these are all types of corticosteroids= hormones important for survival of the organism
● important because they regulate important things: water, sodium , nutrients, reproduction
● heterocrine organ - but majority of function is exocrine , like 1% of mass is endocrine function
● endocrine function in pancreatic islet:
○ main endocrine cells found here:
■ alpha cells- glucagon
● works to regulate blood glucose levels (increases levels of
■ beta cells- insulin
● works antagonistically with glucagon to regulate blood
glucose levels (decreases blood glucose levels)
■ delta cells - somatostatin
● somatostatin from islets helps to regulate the alpha and beta
cells - so it indirectly regulates the blood glucose levels
■ F cells - pancreatic peptide
● this is an interesting hormone that acts locally - it helps to
digest the digestive processes occurring in the GI tract
○ with all these hormones we are growing, regulating, and digesting ■ basically directing nutrient processes
● located in part of the diencephalon - near the epithalamus
● composed of: pinealocytes
● also called “brain sand” - small grains of calcareous material . a sign of aging. ○ older people have more sand
○ you can use pineal gland to map where you are in the brain because the sand is easily seen
● produces melatonin -hormone that is cue for night
○ cyclic release
■ increases at night, decreases during the day
○ cue for night
■ produces melatonin when no or little light. when light is present - it’s shut down
● makes hormones but they don’t travel outside the thymus
● what: fatty structure
● located: superior to heart, posterior to sternum, within the mediastinum ● it’s a bilobed structure
● large in infants, but regresses with age (puberty is marker here) ○ this transition is noted by functional tissue of thymus replaced with fat and fibrous CT so it become inactive in function
● function: regulate and modulate body immunity
○ lymphatic system
● has thymopoietin and thymosin stimulate and promote differentiation, growth, and maturation of lymphocytes (T cells)
○ lymphocytes arrive in bone marrow, and then go to thymus to get “educated” into T cells
○ so this is why diseases like AIDS are bad- it causes you to lose T cells. ■ so once you lose T cells, you can’t get them back.
● produce steroidal sex hormones
● controlled by gonadotropins (FSH & LH)
■ hormones produced by ovaries: estrogens and progestins
● select cells of ovarian follicle produce these in the ovaries
■ produces: androgens-
● produced by Leydig cells (interstitial cells) of testes
○ testosterone is most prominent of androgens
■ produces inhibin produced by Sertoli cell (sustentacular cells)
● inhibit GnRH release by hypothalamus
- gonadotropin releasing hormones (GnRH)
Non-Endocrine Organs - have endocrine functions
○ produces atrial natriuretic factor (ANF) “atriopeptin”
○ produced by atrial muscle cells & released in response to elevation in blood pressure
● Gastrointestinal tract
○ Variety of hormones released from enteroendocrine cells, which are found throughout GI tract
■ primary function to regulate digestive processes
○ produces two hormones:
■ Erythropoietin - signal bone marrow to increase red blood cell
■ Renin- initiate the Renin-Angiotensin system & stimulates thirst and elevation of bp
● renin is an enzyme!
● renin does not actually do this, it just starts the cascading of
■ this is the precursor molecule that allows skin to produce vitamin D from sunlight by changing the structure
■ released into circulation and activated in kidney (calcitriol)
● adipose tissue
○ leptin- peptide hormone
■ appetite control / the feeling of “fullness”
■ so pumping people with these hormones alone doesn’t make them feel full - more complicated than that
○ resistin- peptide hormone
■ linked to high levels of ȩbadȪ cholesterol → which increases risk of heart disease
Endocrinopathies- any disease resulting from a disorder of an endocrine gland or glands
● caused by:
○ too much hormone (hypersecretion)
○ too little hormone (hyposecretion)
○ receptor isn’t working (receptor dysfunction so they won’t respond)