(06) 3-22

Question 1

Just read this slide

ANP from atrium, BNP from ventricle (counteract activity of angiotensin II)

Question 2

(Hormonal (Humoral) Regulation of Circulation

(Renin-Angiotensin-Aldosterone System)

1. regulates bp by mainly regulating what?
2. AT II is also a potent what?

Answer 2

1. blood volume
2. vasoconstrictor

Question 3

(REnin-Angiotensin-Aldosterone System in Long Term BP regulation)

1. AT II directly affects kidneys to cause retention of what?
2. AT II causes adrenal glands to secrete what? which doe s what?
3. Is an auotmatic feedback system to keep BP regulated despite changes in what?

Answer 3

1. salt and water
2. adlosterone –> Na (and thus, H2O retention by renal tubules)
3. dietary salt intake

Question 4

this shows time course of different mechanims to control blood pressure

Question 5

(Long-Term Blood PRessure Regulation)

1. longer to become active - effective for long term - can it return arterial BP back to normal?
2. Which mechanism is most important?
3. if BP increases –> direct increase in renal output of what? leads to what? leads to?
4. If BP is too low –> decrease in Na and H2O output –> ? —> ?

Answer 5

1. yes
2. renal-body fluid
3. Na and H2O; decreased extracellular fluid and blood volume; decreased BP (pressure diuresis)
4. fluid retention –> increased BP

Question 6

(Renal - Body Fluid Mechanism)

1. pressure at which equilibrium occurs can change –> affects what?
2. shift in what?
3. change in level of intake of what?

Answer 6

1. long term BP level
2. renal output curve
3. salt and water

Question 7

(Properties of the Heart)

1-4. what are the four

5. do these properties occur without extrinsic innervation?

Answer 7

1. Automaticity, rhythmicity - ability to generate electrical impulse (chronotropy)
2. Conductiivty - ability to depolarize and conduct electrical impulse (dromotropy)
3. Contractility - ability to shorten and do work (inotropy)
4. Lusitropy - ability to relax and fill
5. yes (although autonomic innervation can modify them)

Question 8

Answer 8

Question 9

she talked a decent amount about these valves on the right image

she does a whole hand routine that might be helpful 23:00 in 4/16 9:00 AM

Answer 9

Question 10

(Cardiac Conduction System)

1. composed of what?

(sinoatrial node - pacemaker of the heart)

2. near what?

(Atrioventricular node)

3. near what?
4. 1 Av node conducts slowly - why is this good?

(Av bundle - budle of his)

4. Av node to what?

(R and L bundle branches)

5. endocardium

(Purkinje Fibers)

6. penetrate into what?

Answer 10

1. modified muscle cells
2. cranial Vena cava and right auricle
3. right side of intra atrial septum, ventral to coronary sinus
4. 1 allows for filling of ventricles
5. intra ventricular septum (goes through fibrous base)
6. myocardium

Question 11

1. myocytes are most common
2. purkinje fiber cells are big cells - conduct rapidly - good electrical conductivy
3. AV node cells are smaller - makes for much slower conduction (same with SA node)
4. Heart acts like a functional what?

Answer 11

4. syncytium (acts like a single cell) - due to gap junctions

Question 12

Cariac Innervation

two points she wants to make

1. sympatheic nervous innervation goes to what part of heart?
2. how about parasympathetic?

this is all we need to know about this

(we don’t need innervation for heart to function)

Answer 12

1. Sa node, Av node, atrial and ventricular tissue (all over the heart)
2. alot to SA node and AV, and a little to atrial tissue - but not to ventricles

Question 13

(Cardiac Cell Electrophysiology)

(Cardiac action potential duration)

1. much longer or shorter thatn APs of nerve and skeletal muscle?

(Cardiac Action potentials differ among different types of heart cells)

(Two main types of cardiac APs)

2. fast response: what have these?
3. slow response: what have these?

Answer 13

1. longer
2. atrial and ventricular muscle cells, and purkinje fibers
3. sinus and A-V nodal cells

Question 14

(Cadiac Cell Electrophysiology)

(Sarcolemma)

1. maintains what?
2. responds to depolarizing wave by doing what?
3. at rest the sarcolemma is impermable or permeable to Na and Ca?
4. At resting membrane potential, what is important in ion maintentance?
5. During depolarization, controlled entry of ions through what?

(Conductance)

6. permeability of the mebrane to what?
7. conductance helps determeine what?

Answer 14

1. ion gradients
2. opening and closing specific ion channels (voltage-activated channels)
3. impermeable (some background leakage of K out)
4. Na, K-ATPase —> 2 K in, 3 Na out
5. their specific voltage -activated channels
6. a particular ion
7. the rate of current flow

Question 15

(Cell Membrane Potential)

1. electrical and chemical forces important
2. ions –> across sarcolemma only by some type of carrier: channel, exchanger, or pump - channel must be open
3. Ion movement depends on what two things?

Answer 15

3. electrical driving force (potential) and concentration gradient

Question 16

(Resting Membrane Potential)

1. Electrical potential difference across sarcolemma when cell at rest is around what?
2. Mainly related to what? as defined by what? small contribution from what other ions?
3. What defines relation between ion concentration gradient and membrane potential forces?

Answer 16

1. -80 to -90 mV (inside is negative - sarcolemma is polarized)
2. electrochemical gradient for K+; nernst equation; Na and Cl
3. Nernst equation

Question 17

(Resting Membrane Potential)

1. maintained by what two things?

Answer 17

1. passive outward K current
2. Na/K ATPase activity (intracellular proteins contribute to negative intracelluar charge as well)

Question 18

(REsting –> Activaton)

1. cell actively maintains RMP
2. At rest, sarcolemma is realatively permeable to K, but no to Na or Ca
3. For normal depolarizaiton, what must occur?
4. for repolarization, what must occur?

Answer 18

3. Na and Ca must enter in a controlled what (–> membrance becomes less negative (depolarized))
4. K+ must exit

Question 19

1-3. What are the three configurations?

Answer 19

1. closed (“resting”)
2. open (“activated”)
3. inactivated (“recovering from activation”)

Question 20

she talekd about this picture a decent amount

1. Why is the inactivaiton state important?

Answer 20

1. if you overstimulate a muscle you get tetany

Question 21

1. overal ionic conductance at a given time reflects what?
2. K+ currents: what are two types of channels?

Answer 21

1. the number of channels open
2. voltage operated; ligand (G protein and non-G prtoin dependent) what she wants us to focus on is the fact that K going out of cell to bring it back to resting membrane potential

Question 22

(“Fast Response” Action Potential)

1. characteristic of what?

phase 0 = Na coming in

phase 1 = Ca in

phase 2 (plateau phase) = K out

phase 3 = repolarization phase

phase 4 = resting membrane potential

Answer 22

1. working muscle, atrial and ventricular, purkinje cells

Question 23

1. subthreshold (A and B) = ?
2. Threshold reached (C) –> ?

Answer 23

1. local response
2. regenerative response

Question 24

(Vascular Action Potential)

1. answer the question

Answer 24

if alot of sodium channels are still in recovery pahse - not enough sodium will be able to go thorugh channel therefore upstoke ins’t as rapid

Question 25

(Refractory Period) she got cut off here - so figure this out