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UF / Animal Sciences / ANS 3319C / What is the start of puberty dependent on?

What is the start of puberty dependent on?

What is the start of puberty dependent on?

Description

Repro Test 2 Review


What is the start of puberty dependent on?



1. What is the start of puberty dependent on? It requests what to mature and to  support what?

2. Puberty is required for what production? Does it differ between male and  female? What things influence it?

3. What sign in females means puberty has begun? (definition) 4. What sign in females/definition means they are sexually mature?

5. What two things impact development of the hypothalamic GnRH neurons in  the female?

6. What is the first definition of puberty in males?

7. What is the second definition of puberty in males?

8. What is the third definition of puberty in males?  

9. What is the surge center responsible for? Tonic?  

10. What is the structure that connects the hypothalamus with the AP?  11. What prevents reproductive sexual maturation in the body?  


What two things impact development of the hypothalamic gnrh neurons in the female?



Don't forget about the age old question of What causes microcytic anemia?
We also discuss several other topics like What is totalitarianism?

12. What causes females to have an active surge center and not males? All  hypothalamus’s start off as a? We also discuss several other topics like What happened to the anasazi?

13. What does LH need from the surge center? After puberty, how does this differ in males and females?  

14. What type of feedback is occurring when estrogen feedback is low? High?  What does high estrogen cause?  

15. What is the limiting factor of the maturation of the hypothalamus?  

16. What does GnRH do with age in the male and female? Therefore, puberty is a  ___ process.

17. In the female, what happens during maturation of the hypothalamus?  18. What is the fundamental requirement for puberty?

20. Explain maturation of the hypothalamus in males.

21. Explain maturation of the hypothalamus in females.  


What has the least amount of estrogen receptors tonic center or surge center?



22. Label sequence chart of maturation of hypothalamus in females  

23. Before puberty there is low ____ and ____ secretion. __ pulse frequency is also  low. Low ____ from the ovaries and no ____ on _____ GnRH center. With age, _____  rises, ____/___ rises, ______ ________ rises, ___ feedback estrogen rises and _____  rises. An ____ surge causes ovulation.

24. What has the least amount of estrogen receptors tonic center or surge  center?

25. What is the function of glands? Name three and what they secrete. 26. Is the ovary a gland? Don't forget about the age old question of What is ir theory?

27. Name the three major things that effect hypothalamus maturation.

28. When it comes to genetics, what two things effect the onset of hypothalamus  maturation? What type is typically more delayed and give an example.

29. When it comes to nutrition, what about it is what triggers/controls when  puberty will/ can occur?  

30. If you have extra nutritional characteristics like fat what does it do to puberty  onset? Restricted amounts?  

31. Explain the metabolic signals that occur in puberty. Review flow chart page 8  of slides.  

32. What two things affect the hypothalamus control of GnRH secretion? Moment  to moment regulation of GnRH only occurs when what is available? If you want to learn more check out What types of religious specialists have anthropologists classified?

33. What is leptin? What are they from?

34. When it comes to metabolic signals in puberty, what two things are involved  in it and what are they directed by?

35. Leptin concentration is directly related to what?  

36. What are the two leptin receptors?  

37. What is leptin possible associated with? It has an association with what two  other things as well?

38. Why do we interfere to modify age at onset of puberty?

39. What can we do to modify age at onset of puberty?

40. What are two environmental cues that will cause hypothalamus maturation?

41. What two sensory neurons notify the hypothalamus of these environmental  factors?

42. Optic and olfactory cues translate stimuli to hypothalamus and tell it to do  what? What types of feedback can it cause and what will each feedback cause?

43. Explain the difference between spring born ewes and fall born ewes when it  comes to onset of puberty.  

44. Season of birth is present in ____ but not ____. What effect does it have on a  Bitch? Queen?

45. What is the social cue of puberty in animals?

46. What are pheromones?

47. Explain how the vomeronasal organ works.  Don't forget about the age old question of What is the slope factor?

48. In swines, what is the social cue that stimulates the onset of puberty?

49. When swines are in large groups what effect does this have on puberty?  Small groups? Male exposure?  

50. Heifers with high growth rate compared to moderate have a more  accelerated or delayed onset of puberty? What about moderate with a bull? High  with a bull?

51. What is spermatogenesis?  

52. What is spermiogenesis?

53. What is spermiation?

54. What three endocrine requirements must be met before spermatozoa can be  produced?

55. Explain endocrine regulation for spermatogenesis starting with GnRH. 56. Explain why LH pulses are important and what occurs because of it. 57. What is secreted at the peak of LH secretions?

58. What four things do successful testis require?

59. For four things are required for production of normal number of fertile  spermatozoa?

60. Label endocrine system of the male

61. Review diagram on page 205 of book

62. Label cell in testes

63. Sertoli cells are ___ dependent. It transfers testosterone to _____ (role unclear) Negative feedback on ______. Inhibin blocks ___.

64. Name the four general functions/goals of spermatogenesis.  65. Where does spermatogenesis occur?

66. What are the three phases of spermatogenesis?

67. Explain the proliferation phase (basal compartment).

68. Explain the mitosis.

69. Explain the meiosis phase.  

70. Explain the differentiation phase.

71. What is the purpose of intercellular bridges?

72. What is the tight junction?

73. What is interstitial space?  

74. Review flow diagram in notebook.

75. Explain the Golgi phase of differentiation  

76. What is an acrosome?  

77. Explain the Cap phase of differentiation.

78. What is acrosome reaction?

79. Explain the acrosomal phase of differentiation.  

80. Explain maturation phase of differentiation.  

81. Review structure of sperm tail pics in slides

82. What are the three reproductive behavior stages?

83. In males, what are the three precopulatory behaviors and explain each 84. In males, what is the copulatory act and how is it learned

85. In males, during copulatory behavior, what is emission? Intromission?  Ejaculation?

86. In males, what are three parts of the post copulatory stage

87. Review male and female reproductive behavior charts. Just know basics of  what each animal does and differences  

88. In females, what are the three reproductive behaviors and explain each  

89. Explain what impact the central nervous system has on sexual behavior.  What reflex system does this relate too?  

90. Explain pheromones in females  

91. Explain how female pheromones initiate male behavior  92. Explain pheromones in males  

93. What is vocalization? Give female and male examples.

94. Visual signals in females? Males? Give example for male 95. Males role in tactile stimulation. One example

96. Name the penile erection requirements  

97. Review penile erection figure on page 238 of book

98. What is penile erection?

99. What is erotogenic stimuli?

100. What controls penile vascular muscle tone? (goes with erotogenic stimuli) 101. Review basic steps in erectile process diagram on page 239 of book 102. Explain vascular and biochemical control of erection  

103. What is a flaccid penis?

104. What is NANC? What must be present for an erection?

105. What is occurring vascularly and biochemically in an erect penis?  106. What is the role of Viagra?  

107. Copulatory behavior for males involves what three things and explain each. 108. Explain the process of emission starting from sensory stimulation  109. Explain the process of ejaculation  

110. Give the sequence of fluid fractions in these 5 species: Ram & bull, Stallion,  Boar and Dog  

111. Explain the first stage coitus in dog copulation  

112. Explain “the turn” in dog copulation  

113. Explain the second stage coitus in dog copulation  

115. What is the refractory period? What factors determine its length? 116. What is satiation?  

117. What is exhaustion?  

118. What are two ways that reproductive behavior can be enhanced? 119. What is the Coolidge effect?

120. What is sexual stimulation and what is its purpose?  

121. What is sexual preparation, what is its purpose, and what are three  approaches?

122. What is false mounting? Restraint? What does doing both result in?

123. For sit of semen deposition in natural mating, what animals are in the cranial  vagina? Cervix? Cervical lumen of uterus?

124. For site of semen deposition in AI, where is it deposited in the mare, cow, and sheep? Sow? Dogs and cats?  

125. What are two ways that sperm are lost from the female tract? 126. Explain phagocytes by neutrophils in the female vagina and uterus  127. What is the function of the cervix during fertilization?

128. In the cow, what are the two types of mucus secreted in the cervix and their  roles

129. Cervix may be a filter that eliminates what?

130. What is the result of rapid transport?

131. What is the transport stage?

132. What must be present for tone to occur?  

133. Explain capacitation  

134. Explain how sperm bind to the zona pellucida  

135. Label sperm head  

136. Explain the acrosomal reaction  

137. During the acrosomal reaction, what enzymes allow sperm to digest zona?  Explain what how they do it. What happens in acrosomal reaction after that?

138. Explain fertilization of the oocyte

139. What is the cortical reaction and what does it prevent.  

140. What is polyspermy?  

141. What is decondensation of the sperm nucleus?  

142. What is superfecundation?

Repro Test 2 Review Answers

1. Hypothalamus production of GnRH. Requests hypothalamus to mature to  support oogenesis and spermatogenesis.  

2. Gamete (testes, ovaries) production. Yes, response to E2. Genetics,  environment, nutrition, season, social cues

3. First ovulation occurs (with or without estrus) and is at threshold body size 4. Able to support a pregnancy  

5. Development of a threshold body size and exposure to certain environmental  cues

6. Behavioral traits first expressed (mounting and erection, precedes sexual  maturity)

7. First ejaculation. Coordination of nerves, muscles, seminal fluids.  Substantially precedes ability to produce enough sperm for fertilization  

8. Ejaculate contains threshold spermatozoa for fertilization  9. GnRH spikes, Basal GnRH secretions

10. PPP- primary portal plexus  

11. Hypothalamus  

12. Protein (alpha-fetoprotein) in female that is bound to estradiol, prevents  estradiol from being able to enter the brain. In males they do not have that protein  and it enters the brain creating testosterone which turns into estrogen/estradiol in  the brain and causes the surge not to develop. “Female”

13. Secretion from the surge center to peak and induce ovulation. After puberty  in males it stays a basal GnRH secretion with small LH spikes due to an  undeveloped surge center than in the female causes GnRH secretion and large LH  spikes which is what induces ovulation.  

14. Negative. Positive. Makes hypothalamus secrete GnRH.  

15. Ability of the hypothalamus to secrete enough GnRH (limiter of prepubertal  animals) to induce LH spike.  

16. Increase gradually. Gradual

17. Prepubertal pituitary and ovaries respond to exogenous GnRH, the mechanics (neurons) which switch from negative to positive feedback, are already in place  when this occurs  

18. Secretion of GnRH at appropriate frequencies and quantities to stimulate  gonadotrophins release by pituitary  

20. GnRH secreting neurons loose sensitivity to blocking estrogen so both  estrogen and testosterone levels rise to inhibit GnRH secretion and enhance puberty

21. Low estrogen and negative feedback GnRH secretions switch to positive  when estrogen levels increase in the body. Hypothalamic sensitivity to negative  feedback by testosterone and estradiol decreases

23. Estrogen, GnRH. LH. Estrogen, feedback, tonic. Estrogen, LH/FSH, follicle  development, positive, GnRH. LH.  

24. Tonic center

25. Secrete hormones. Hypothalamus- Oxytocin & GnRH, Pituitary- FSH/LH,  Gonads- Male-Sertoli and Leydig, Female- theca and granulosa  

26. No, it’s a tissue

27. Genetics, nutrition, environmental cues

28. Age of puberty in male and female in various species; Influence of breed on  age at puberty. Bos Indicus- cow  

29. Body size of male/female, development of muscle, bone, fat/degree of  fatness

30. Enhances puberty; delays puberty  

31. GnRH neurons secrete GnRH which is regulated by Kisspeptin neurons. These  are in contact with neurons that say how much glucose there is, fat, and leptin in  the blood which then sends signals to the hypothalamus saying if body is or is not  ready to start puberty  

32. Glucose, free fatty acids. Glucose and fatty acids in the blood

33. Hormonal peptide, tells how much adipose tissue (fat) is in the blood stream.  Adipocytes

34. Glucose and fatty acids; GnRH sensitive neurons positive LH release. Directed by level of nutrition  

35. Amount of body fat (remember cow example wit increasing feed, increase  puberty onset)

36. Anterior Pituitary and Hypothalamus  

37. High LH secretion; fatness and onset of puberty  

38. Higher production rates, produce more milk

39. Change the diet, select genetically advanced animals, and use sunlight/light  to “trick” animal into thinking it is a different time of the year (spring)  

40. Season of birth and social cues

41. Optic and olfactory sensory neurons  

42. Start GnRH secretion. Positive feedback for puberty to start or negative  feedback which will reduce GnRH secretion

43. Spring born ewes only have a 6 month long period before they start puberty  due to the sunlight cue(long photoperiods) which stimulates it to start (reach in fall). Fall born ewes have to wait 6 months after being born until they reach spring then 6 months after that they will begin puberty due to the same cue.  

44. Rams, bulls. Minimal seasonal effect on puberty. Increased photoperiod (more light) hastens onset of puberty  

45. Olfactory recognition of pheromones in urine (rat, ewe, sow, and possibly  cow)

46. Chemical compounds secreted by body, are volatile and detected by olfactory system of same species  

47. It is on the roof of the mouth, its two dots that have fluid inside of them that  travel to the nasal cavity to send signals to the brain  

48. Dictated by number of gilts in a pen and exposure to intact males

49. Normal puberty onset. Delayed puberty onset. Accelerated puberty onset,  can be physical or non-physical interaction, large and small groups

50. More accelerated. Even more accelerated than high growth without bull. Most accelerated  

51. A process involving sequential mitotic and meiotic divisions and concludes  after differentiation of spherical spermatids into highly specialized spermatozoa

52. Final product of meiosis (spermatid). Remodels sperm

53. New sperm leave Sertoli cells  

54. Adequate secretion of GnRH from hypothalamus; FSH and LH secretion from  the anterior lobe of the pituitary; Secretion of gonadal steroids (testosterone,  estradiol)

55. GnRH is discharged from hypothalamus in intermittent episodes and target  the Anterior pituitary. This causes discharge of LH which only occur 4-8times every  24 hours. LH secretions are high but short lived. Unlike the discharge of FSH which  last longer due to constant secretion of inhibin and longer half-life. FSH targets  Sertoli cells for production of inhibin and other hormones for spermatogenesis. LH  targets the Leydig cells that synthesize progesterone and convert it to testosterone. The testosterone is then converted to estrogen by Sertoli cells.

56. LH pulses are related with GnRH pulses. Is important for normal testicular  function. It prevents sustained concentrations of LH which would cause the Leydig  cells to become refractory (unresponsive). If Leydig cell secretion is stopped and not coming periodically, severe down regulation of GnRH and LH feedback system  occurs, and soon testosterone will run out, they will be infertile and  spermatogenesis stops

57. Testosterone

58. Pulsatile GnRH secretion (4-6hours), High concentrations of testosterone in  seminiferous tubules, low concentrations of testosterone in systemic blood,  adequate LH receptors in Leydig cells  

59. Endocrine regulation of testis, mitotic divisions of spermatogonia, meiotic  divisions resulting in haploid spermatids, morphologic transformation of spermatids  

60. Endocrine system of male

61. 205 review

63. FSH. Estradiol. Hypothalamus. FSH

64. Continual gamete supply vis stem cell renewal, provide genetic diversity,  provide billions of sperm daily to maximize production, provide an immunologically  privileged site so germ cells are not destroyed by immune system

65. Seminiferous tubules  

66. Proliferation phase, meiotic phase, differentiation phase

67. All mitotic divisions of spermatogonia. A-spermatogonia undergo mitotic  divisions which generate a large number of B-spermatogonia. An important part in  this is the stem cell renewal which is where there is loss of intracellular bridges.  Some type B cells continue on to meiosis but some also are replacements of the A1  spermatogonia. DIPLOID cells

68. 1 maternal and 1 paternal chromosome in the cell. They then duplicate and  divide into two daughter cells

69. Start off as diploid cells. The cells undergo meiosis 1 which replicate the DNA  through crossing over and homologous pairing which produce secondary  spermatocytes. No two cells are alike! They then undergo meiosis 2 which produces  HAPLOID (1N) spermatids

70. No further cell division take place. Transforms spermatids to spermatozoon  (single sperm) which contains a head (nuclear material), flagellum with midpiece  (mitochondrial helix) and principal piece. Has four phases: Golgi, Cap, Acrosomal,  Maturation

71. To connect spermatogonia, spermatocytes or spermatids by intercellular  bridges so the cytoplasm of an entire cohort is interconnected

72. Between Sertoli cells- blood testis barrier. If you destroy them, the male  becomes infertile

73. Leydig cells, lymph, macrophages, blood vessels

74. Review notebook

75. Initial stage of acrosomal formation. Spermatids contain a golgi apparatus  which is the intracellular packaging system in all secretory cells and gives rise to  the acrosome. First, proacrosomic vesicles are formed and they fuse together to  create a larger vesicle called acrosomic vesicle. Centrioles develop the tail out of

microtubules. The proximal centriole is the attachment point of the nucleus to the  flagellum. The distal centriole creates the central portion (tail) or axoneme.

76. Bed of lipids with digestive hydrolytic enzymes inside that digest a pat  through the “jelly coat” of the oocyte  

77. The acrosomic vesicle flattens and “caps” the nucleus. The primitive  flagellum (tail) grows from distal centriole and projects towards lumen of  seminiferous tubules. Acrosome membrane formed (outer and inner), Production of  hydrolytic enzymes (acrosin, hyaluronidase, zona lysin, esterases, acid)

78. Exocytosis during fertilization, digest zona pellucida

79. Nuclear and cytoplasmic elongation. Acrosome covers 2/3 of nucleus and  nucleus elongates. Manchette microtubules form and become the postnuclear cap  which helps the tail form. Neck and annulus form (junction between midpiece and  principle) and spermatids become embedded in Sertoli cells.  

80. Mitochondria form a spiral assembly around the flagellum which creates the  midpiece. Completion of all tail parts (mid-piece, principal piece, terminal piece).  Spermatid is now a spermatozoon and covered with a plasma membrane. Finally,  spermatozoa released from Sertoli cells into lumen of seminiferous tubules (called  spermiation)  

81. Review sperm structure  

82. Precopulatory behavior, copulatory behavior, post copulatory behavior  

83. Search for a sexual partner (look for female signals)- use olfactory, visual,  auditory and tactile responses. Courtship behaviors- sniffing vulva and phonation  (female urination), Flehmen response, Sight (main drive, leads to sexual arousal).  Sexual Arousal- erection and penile protrusion (CNS control).  

84. Learned by behavior. Mounting a female that shows lordosis (mating posture,  stands to be mounted)  

85. Seminal fluid and sperm movement into pelvic urethral. Entrance of penis  into vagina. Expulsion of semen into female tract  

86. Dismounting, refractory period (no further copulation), Memory (positive and  negative experiences)  

87. Male and female reproductive behavior charts  

88. Attractivity- behaviors that attract male like posture, vocalization,  pheromones, and searching for a male (high physical activity). Proceptivity- female  behaviors that encourage male to copulate- posturing with male, homosexual  behavior. Receptivity- copulation behavior of female- limited duration in female,  species variation

89. Sensory cues come in from visual, olfactory, auditory, or tactile stimulants  which send signals to the hypothalamus. The hypothalamus must be sensitized to  respond to sensory signals. In the male testosterone is aromatized to estrogen in

brain and promotes reproductive behavior. Constant hormone supply, initiates repro behavior at any time. In the female, excessive estrogen only prior to estrus  (receptiveness). It then goes to the midbrain “receiving zones” where it acts on  neurons and speeds up impulses. It then goes to the medulla which initiates  postural adaptation for lordosis and mounting. It then goes to the to the spinal cord  which generates signals to the muscles for lordosis and mounting. Simple neural  reflex.  

90. Vaginal and urinary secretions that serve to attract male. Secretions different: estrus female vs no estrus

91. Flehman response for short range investigative behavior. Characterized by  head elevation and lip curling. Detect less volatile pheromones by vomeronasal  organ

92. Produces sex pheromones which attract female. Boars have preputial pouch  secretions, saliva secreted by submaxillary gland (foamy saliva, must odor).  Stimulate sows in estrus. Dogs identify females in estrus by olfactory discrimination. Detect odors in vaginal secretions, urine, milk, blood

93. Auditory stimulation for long range signals indication sexual readiness.  Females- cows increase bellowing, sows grunt with estrus, queens yeow. Males- beef and dairy increase bellowing, elk bugling during breeding season  

94. Sexual posturing. Observe others mating increases stimulation. Semen  collection in bulls via AV, have a warm-up period and increases number of sperm in  ejaculate  

95. Invokes sexual and/or standing posturing by females. Biting neck  

96. Elevated arterial blood inflow, contractions of ischiocavernosus muscle,  dilation of corporal sinusoids, restricted venous outflow, elevated intrapenile  pressure, relaxation of the retractor penis muscle

97. Review penile erection figure  

98. Complex series of neural and vasomotor events that are stimulated by  extrinsic external and erotogenic stimuli  

99. Increases stimulation of nerves in behavior center of hypothalamus  100. Neurons synapse with parasympathetic and sympathetic efferent neurons  101. Review diagram on page 239

102. Two dorsal-lateral corpora cavernosa plus corpus spongiosum. Corpus  sinusoids are supplied by helicine arteries and deep dorsal vein and superficial vein  drain erectile tissue

103. Sinusoids flatten due to adrenergic neurons secreting norepinephrine that  causes vasoconstriction. Blood flow to the cavernous tissue is low so no erection. No erection stimuli is present so NANC neurons do not fire (release nitric acid)

104. Nonadrengenic noncholinergic parasympathetic neurons. Nitric oxide  

105. Erotogenic stimuli is present and the NANC neurons fire and release nitric  oxide. This activates guanylate cyclase which converts GTP to cGMP and causes  sinusoids to relax and cause erection (vasodilation). The cavernous sinusoids  engorge with blood and intracorporal pressure increases. This compresses venules  and prevents exit of blood.

106. Inhibits cGMP to GTP by blocking action of PDE. Prolongs cGMP effect for  prolonged erection, must be in erotogenic state. (review flow diagram)  

107. Mounting- positions male for intromission. Intromission- entrance into vagina.  Emission- movement of seminal fluid and sperm into pelvic urethra, occurs prior to  and during ejaculation, driven by neuroendocrine reflex. Ejaculation- reflex  expulsion of sperm/seminal plasma from tract, response to sensory stimuli (pressure & temp) on glans penis.

108. Emission is triggered by optic, olfactory, tactile or auditory stimulation. These send signals to the afferent neurons and to the spinal cord. From there it sends  signals to the brain and stimulates the nerves in the supraoptic and paraventricular  nuclei which signal the release of oxytocin from the posterior pituitary which cause  contractions of the smooth muscle in tail of epididymis and transports sperm to  ejaculatory position.  

109. Starts with intromission, then the pressure and temp stimulation on the glans  penis sends a stimuli response to the afferent neurons which send signals to the  spinal cord to initiate motor neuron response to the urethralis, bulbospongiosus and  ischiocavernosus muscles to contract suddenly and powerfully. This causes  expulsion of semen.  

110. Ram & bull- 1 fraction. Stallion- 2 fractions, First- sperm rich (3-4jets), Last gel (3-4jets). Boar- 3 fractions, First- accessory fluid, gelatinous pellets, few sperm,  Second- sperm rich, Third- gel portion. Dog- 3 fractions, First- pre sperm, prostate  (first stage coitus), Second- sperm rich, Third- prostate fluid (second stage coitus)  during tie thought to push sperm rich fraction in  

111. Male mounts female, female hold tail to the side and penis is introduced by  several thrusts (intromission). Lasts for 1-2min, first and second fractions of semen  are ejaculated  

112. Transition between first and second stage. Male dismounts and turns around  will lifting one leg over the female. Now facing away.  

113. Now facing away in “the tie”, third fraction of semen is deposited, may last 5- 45min. The tie is kept by bulbus glandis on penis which is engorged with blood and  contractions of muscles near base of penis keep the blood there. Along with  sphincter muscles of vagina. This pushes semen into the uterus, and tie should  never be broken or may compromise fertility and cause injury

115. Period before next ejaculation. Part of satiation rather than exhaustion.  Degree of sexual rest prior to copulation, age and species of male, degree of female novelty, and number of previous ejaculations.  

116. Further stimuli will not cause immediate responsiveness or motivation.  Restimulation may occur after refractory period

117. No further sexual behavior can be induced, even with sufficient stimulation 118. Introducing novel stimulus animals and changing stimulus settings  

119. Restoration of mating behavior in sexually satiated males, when original  female is replaced by novel female.  

120. The presentation of a stimulus that will achieve mounting and ejaculation. To  obtain ejaculation or mating in the shortest time possible so that manpower  involved in managing the mating is minimized.  

121. Extending the period of sexual stimulation beyond what is needed for  mounting and ejaculation. Its purpose is to prolong precopulatory stage of behavior  and collect semen containing the greatest possible number of spermatozoa per  ejaculation. False-mounting, restraint and both.  

122. Deviating penis during a mount so that intromission can not occur. Prevents  male from mounting even though he wants to. Results in the greatest improvement  of spermatozoa output.  

123. Cow, sheep, dog, cat. Rodents. Rodents: gel plug for vagina, prevents  retrograde sperm loss. Pig- gel fraction, lowers retrograde sperm loss. Horse squirted through cervical lumen, gel fraction- lowers retrograde sperm loss  

124. Transcervical. Intracervical. Intravaginal  

125. Retrograde transport and phagocytosis by neutrophils  

126. Female tract is under high estradiol influence during estrus and neutrophils  are all in the mucosa of the vagina and uterus. Their job is to prevent  microorganisms introduced during copulation from colonizing female tract.  Unfortunally, it sees spermatozoa as foreign and they phagocytize or engulf  spermatozoa. No real negative effect on fertility.

127. Barrier to spermatozoa (non-motile, abnormal, dead) transport and a  reservoir for spermatozoa through mucus secretions.  

128. Sialomucin- low viscosity, secreted by basal areas of cervical crypts. Creates  “privileged pathways” for sperm to swim. Those that are not able to swim, are  washed out by the sulfomucin- high viscosity, secreted by apical portion of cervical  epithelium of crypts.  

129. Non-motile spermatozoa

130. Elevated tone (level of contractions that repro tract has under estrogen) and  motility of muscularis of the female tract. Usually non-viable and un-capacitated  sperm

131. Sustained flow of viable sperm to oviduct in a “trickle like” effect from cervix  to uterotubal junction. Sperm temporally “dock” in uterotubal junction (second  reservoir) because it I the first region they encounter. Docking is important for  sperm survival because it promotes viability.  

132. Estradiol (female tract) and prostaglandins (semen)

133. Seminal plasma proteins on the sperm are stripped away by the female tract  environment. Rate and location differs between species. Occurs during sperm  transport of upper tract, fully capacitated in the oviduct and acquire hyperactive  motility in ampulla which facilitates sperm-oocyte contact.  

134. Zona pellucida has 3 glycoproteins (ZP1, ZP2, ZP3). ZP1 and ZP2 provide  structural integrity of the zona. ZP3 has receptor like activity and binds to proteins  on spermatozoal membrane, most important for fertilization. There are two binding  regions, primary zona binding region and acrosomal reaction promoting ligand. The  first binding site is responsible for adherence of sperm to zona. Second is when  ARPL binds with ZP3 molecule and initiates acrosomal reaction  

135. Sperm head

136. Is an orderly fusion of the spermatozoal plasma membrane and the outer  acrosomal membrane. First vesiculation occurs which is when the plasma  membrane forms multiple fusion sites with acrosomal membrane, two membranes  fuse and form vesicles. After the reaction, the nuclear cap (acrosome) is open and  fusion proteins are left on the outer layer.

137. Acrosin- hydrolyzes zona proteins and enhances the sperms ability to bind the zona. Proacrosin- inactive form of acrosin, aids in binding the spermatozoon to the  zona as the acrosomal reaction proceeds. Flagellar action of tail moves sperm  though zona, exposure of sperm equatorial segment occurs which fuses with oocyte plasma membrane and causes fertilization.  

138. Spermatozoon enters perivitelline space and is engulfed by plasma  membrane. This requires fusion of equatorial segment and oocyte plasma  membrane by fusion proteins.  

139. Granules on periphery of oocyte cytoplasm undergo exocytosis. Causes a  zona block, where the zona undergoes biochemical changes so no further sperm  can penetrate it. Also induces vitelline block, which prevents additional sperm  binding to oocyte membrane. Prevents polyspermy.

140. Fertilization by more than one spermatozoon which results in embryo death

141. Reduction of disulfide cross links and nuclear material is released. Formation  of male pronuceli occurs and syngamy occurs which is fusion of male and female  pronuclei.

142. Female dog is mated by several males during estrus, the sperm from all  males can fertilize oocyte and cause litters of different breeds.

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