Exam 1 Study guide
**Disclaimer: This is intended to help you solidify your understanding of the concepts in the class. The questions are there to guide you as you study. I will not be posting answers; by filling them out and double checking if they’re right, you are learning :) I will be making a study guide for each exam, including the final.
Also, please check the “Figures for class” handout on Blackboard
Numbers to know:
Arterial (blood pH): 7.357.45
Blood glucose: 75 110mg/mL Don't forget about the age old question of How do you calculate atomic mass?
Body Temp: 37.5 dg. Celcius
300 mOsm = normal blood osmolality
Physiology : study of the functions of living things. Structures are used to help us study how they function
Homeostasis: why physiology is important
Nearly all physiological functions are regulatory mechanisms to help maintain homeostasis. Primary focus of this class!
1. What does homeostasis mean?
2. How does it work?(Negative feedback, antagonistic processes, integration and coordination)
Physiological systems are the products of evolution; developed over great timespan, adaptations.
Biological Membranes and Transport
1. What are the major types of macromolecules and characteristics of each? (organic molecules)
2. Lipids: insoluble in water, reduced polarity. 2 types: triglycerides and phospholipids. What is special about phospholipids, how are they structured and how do they work to form a cell membrane?
Other components of cell membranes:
Proteins: integral If you want to learn more check out ear wax tuscaloosa
3. What are some functions of proteins in the cell membrane (what can they act as?) 4. What is the fluid mosaic model?
5. What are the main functions of the plasma membrane?
● allows there to be different chemical environments inside and outside cell
6. What types of molecules can move through ( are permeable) to cell membrane? Which ones aren’t?
7. What are aquaporins?
Diffusion and Osmosis
1. What is the direction of diffusion (what must be there for diffusion to occur?) Osmosis:
1. What is the relationship between solute and water concentration? 2. what does osmolarity (osmolality) mean?
a. What is the normal osmolality of blood?
3. Difference between osmolality and tonicity
Transport across membranes
What are two ways a channel can be gated?
2. Carrier mediated transport (CMT) :
what type of molecule is helped through?
Difference between active and passive transport
Characteristics of transport protein (carrier)
Types of CMT:
What is the importance of Na/K pumps?? What type of transport are they? Draw and explain We also discuss several other topics like cognitive psychology study guide
How is glucose transported from lumen of nephron into blood? (several different types of transport Hint:Na+ cotransport)
3. Bulk transport
Receptor mediated endocytosis
What is it? What is it caused by? What are the symptoms?
Osmoregulation: balancing of fluid and solutes to maintain homeostasis Kidney is the main organ for osmoregulation!!
Why is water important to living things?
Water stats can be found in lecture handout (how much, where its located) How do we lose water? Gain it?
General : maintain homeostasis (stable osmolality, volume, composition and pH) of body fluids Specific: regulate (control)amount of water and ions
remove metabolic waste from blood
regulate pH (secreting H+, absorbing H+ and bicarbonate)
remove foreign chemicals (toxins, drugs)
Biosynthesis (making molecules that are used in biological processes)
` Example: gluconeogenesis→ producing glucose from vit. D and Ca++ Anatomy of the Renal system We also discuss several other topics like fsu health and wellness
Draw a diagram of both the kidney and nephron and label the parts. What is the pathway the filtrate takes through the nephron?
Kidney: cortex, medulla, calyces, renal pelvis, ureters
Nephron: glomerulus, Bowman’s capsule, PCT, DLOH, ALOH, DCT, collecting duct
3 key processes of nephron (tubule): filtration, reabsorption, secretion Note how the osmolality of filtrate changes and what is happening at each place!
1. Filtration= glomerulus
a. capillaries are fenestrated(little holes, leaky) which allows molecules to be pushed out of blood. However, large things (proteins, blood cells) can’t get through. Ultrafiltrate= everything initially filtered out. 99% of this is reabsorbed
b. Filtration slits: created by holes in capillaries and podocytes(overlap glomerular capillaries). Podocytes have “fingers” that interdigitate (like holding hands) and together with the fenestra (holes) create a filtration screen known as the slit diaphragm We also discuss several other topics like What is risk aversion?
c. GFR = glomerular filtration rate: how much is filtered within a given amount of time
i. produce 180 L filtrate a day but only excrete 1.5 liters of urine.
ii. MUST secrete 400mL urine to eliminate wastes → obligatory water loss d. flow of blood to the glomerulus is regulated by constricting or dilating the afferent arteriole.
i. Sympathetic nervous system = emergency, “survival mode”. Blood supply channeled to survival organs (heart, muscles) and away from less
important. Constriction of blood flow (vasoconstriction)
ii. renal autoregulation is what occurs under normal conditions → body’s natural response to adjust to the normally changing blood pressure
throughout the day (ex. when you stand up from laying down, your blood pressure changes). Afferent arteriole constricts/dilates accordingly.
iii. macula densa senses the volume of filtrate being pushed through ALOH, and if it’s too much it signals the afferent arteriole to constrict. We also discuss several other topics like psyc 457 textbook notes
2. Reabsorption = taking things from filtrate back into blood
a. Most occurs in PCT and DLOH
i. PCT = proximal convoluted tubule. Entering filtrate is isosmotic (.3 Osm) with surrounding tissues
1. In PCT, 65 % water and NaCl and all glucose and amino acids
2. Exiting filtrate is also isosmotic you’re removing both salt and
water, so there is no net change
ii. DLOH takes a dive into hypertonic medulla.
DLOH = unregulated water reabsorption
ALOH= unregulated salt reabsorption
NaCl removed, water retained, filtrate becomes hyposmotic
Reabsorption NaCl, secretion of K+. Main site of Na/K regulation
filtrate becomes isosmotic again
Collecting duct (CD)
impermeable to salt, regulated water reabsorption
urea leaves CD and goes into medulla, contributing to hyperosmolality What role does urea play? (hint: reabsorption)
Medulla hyperosmolality :
proximity of DLOH and ALOH → countercurrent multiplier
What is the countercurrent multiplier system? (draw diagram!)
How does the vasa recta contribute to the hyperosmolality of the medulla?
What is pH and what do the numbers stand for?
What is an equilibrium reaction?
What do buffers do? Why do we need them (physiologically)? What are important buffers in the body?
What are two ways the renal system works to regulate pH?
What is the law of mass action? How does it apply to the bicarbonate buffer system? (Hint: see diagram given in class notes about how kidney and lung work together)
What is the bicarbonate shuttle system (draw diagram!) and why is carbonic anhydrase (CA) important?
Normal conditions: nearly all bicarb. reabsorbed in PCT, lots of H+ secreted (PCT)
Acidosis: low blood pH→ increased secretion H+, lots of new bicarb produced, if . lots of buffering in urine, hyperventilation (more CO2 breathed out)
Alkalosis: high blood pH; decreased bicarb reabsorption, decreased excretion of H+, hypoventilation (retain CO2 to try and make blood more acidic)
What causes altitude sickness?
Other regulatory aspects of renal system: reabsorption Na+/secretion K+ (maintain osmolality), water reabsorption in collecting duct
What is the difference between diabetes insipidus and diabetes mellitus? Why is this?
Hormonal control of renal regulation
Aldosterone: Regulates Na+ reabsorption directly, blood volume indirectly steroid hormone = slower acting.
Stimulated by baroreceptorsin aortic arch, carotid sinuses of carotid arteries= measure stretch of artery walls → blood pressure
Aldosterone released to help more Na+ be absorbed increasing blood osmolality so water can move into blood by osmosis→ ncreasing blood volume and B/P Where does renin come from?
Renin/angiotensin system: See the diagram from class! Draw it here!
ADH=anti diuretic hormone: Regulates total body water
● peptide neurohormone = fast acting
● Relase triggered by osmoreceptorsin hypothalamus (see Fig. 17.20) ● Diuresis:
● Site of action = collecting duct.
● Production and insertion of aquaporins in CD membrane to aid in water reabsorption. ● Inhibited by alcohol, caffiene, diuretic drugs; this is why you pee a lot when you drink!
ADH and aldosterone work together
Atrial natriuretic peptide: inhibits ADH, opposite effects of aldosterone (trying to lower blood volume whereas ADH and aldosterone work to raise blood volume)
Diuretics = drugs that cause diuresis
When are they needed?
What are two different types and how do they work?
Nervous System (NS)
Neuron: functional unit of nervous system. Neuron:nervous system::nephron:renal system How are neurons classified?
Draw a neuron, label its parts, and draw arrows in the direction a nerve impulse would travel.
Why are the myelin sheath and nodes of ranvier important in neuron function?
Central NS: brain and spinal cord
Peripheral NS: everything else
Afferent = Away from receptor (toward CNS)=sensory
Efferent = Exiting CNS (toward effectorgland, organ etc.)= motor
Somatic = conscious control
Autonomic = involuntary
Interneurons= entirely in CNS, relay and integrate info.
Nerve = bundles of axons
Bioelectricity: What is it and why is it important? What are current and voltage and how are they related?
Resting membrane potential:
*****What is it in a neuron? _____ mV*****
Why is it this number (why is there a charge difference)?
Ion Equilibrium: What do the numbers mean? How are they found (what equation)?
What directions will Na+ and K+ move if ion channels are open? Why is Na+ movement different (stronger)?
Define terms (draw diagram from your notes in a way that makes sense to you!) Depolarization
Action vs. Graded potentials (AP vs. GP)
What are the differences between the two? Any similarities? What cells are each found in? Graded potentials can combine to produce stronger potentials to reach threshold= summation
AP cannot do this
What is the importance of summation?
Draw graphs to illustrate GP and AP!
(From GP handout)
GP determine whether or not a cell will generate an action potential. They can be excitatory and inhibitory. What type of change in membrane potential is happening with each? Define each term below and explain what is happening to cause this.
What is the threshold? (50 mV)
Think of a nerve impulse as an orgasm (seriously, it makes sense! Go to next page for explanation)
→ Stimulation keeps building and building (GP) until it reaches a certain point (threshold) and an orgasm happens (AP). Slowly, the feeling goes away (repolarization) and there is a certain period of time where you can’t have one (refractory period). But once the refractory period is over, the process begins again (if you want it to!)
***You can use this analogy to explain a lot about membrane potentials (concept of summation, excitatory, inhibitory etc.) if you think about it!***
But back to the more scientific stuff...
How does a Graded potential happen (i.e. mechanisms) and end?
By definition, what is an action potential? What is happening to the ions leading up to and during the action potential?? How is the cell repolarized?
What is the refractory period?
After Monday’s lecture, I will post the remainder of the study guide as well as lecture and reading notes. So stay tuned!