Quiz 1 Flashcards
MAP=
COxTPR
Heart is connected to the lungs in series or in parallel?
How is the heart connected to everything else?
- series
- Parallel
Draw out the Cardiovascular system
What is normal CO
5L/minute
Where are resistance vessels?
Small arteries before capillaries
What are 2 main functions of resistance vessels?
- The provide a site to regulate blood pressure
- The protect blood capillaries from high pressure
Is pressure low in veins or arteries
veins
Most of blood volume is in veins or arteries?
veins
Blood pressure is highest in?
Aorta
True or false: When the heart stops beating, blood pressure becomes equal in the arteries and veins at ~ 9 mm Hg
–Where does this pressure arise from?
False: When the heart stops beating, blood pressure becomes equal in the arteries and veins at ~7 mmHg
–pressure exerted by the volume of blood in the vascular system
What is the “normal” blood pressure,
What is the new recommended blood pressure
120/80
115/75
Organ flow is regulated by
Changes in local resistance
What substance do tissues use to regulate blood
local vasodilators
What is considered high blood pressure?
140/90
What two factors influence blood pressure
- Body Weight
- Height of head above heart
The primary purpose of the cardiovascular system is to…
Provide blood flow to the tissues
CO is regulated by what
By autonomic nervous system
what is TPR regulated by (2 things)
autonomic nervous system and local tissue factors
MAP is regulated ______; blood flow is regulated _______
systematically
locally
Flow =
(Partery-Pvein)/R1
P wave
- what’s happening in AP
- What’s happening in the body
Atrial Depolarization
Atrial contraction
PR Interval
- what’s happening in AP
- What’s happening in the body
Initial Atrial Depol to Initial depol of Ventricles
-conduction time from atria to ventricle
PR Segment
AV node conduction
QRS
- what’s happening in AP
- What’s happening in the body
Ventricular Depol
Ventricular Contraction
T wave
Depolarization of ventricles
QT interval
Initial ventricular depol to last ventricular repol
Time for ventricualr contraction and relaxation
ST inverval
plateau of ventricular action potential
What are intra and extra cellular concentrations of K+
145 mM inside,
4mM outside
What are intra/extra cellular concentrations of Na+ inside/outside the heart
Inside- 5mM
Outside- 140 mM
What are intra/extra cellular concentrations of Ca2+ inside/outside the heart
Inside –10-7 mM
Outside– 2 mM
Sodium Potassium Pump, Pumps how many Na out/k in?
3 Na out
2 Na in
Na/Ca pump how many Ca out/ how many Na in
1 Ca out, 3 Na in
T/F Na/K pump uses ATP
T
T/F Na/Ca uses ATP
F, passively follows [] gradient
What causes rapid depolarization/ 0 phase of action potential in fast type AP
Na moving into the cell
What causes plateau/ phase 2 of action potential in fast type AP ?
Ca coming into cell/ K going out
What causes repolarization/ phase 3 of action potential in fast type AP ?
Decrease in Ca entry and increase in K extrusion
What triggers depolarization in fast type AP
Rapid voltage gated sodium channels that open and close in a way that they can’t be excited for a long time period
T/F If you poison NA/K ATPase the cell can still be excited many times
T
What does the Goldman-Katz equation calculate?
Membrane Potential that takes into acount differences in [] and permeability
The current that leads to slow type depolarization comes from where?
Funny sodium channel
Repolarization/Plateau (phase 2) in slow type AP comes from where
Calcium current
Phase 3 in slow type / repolarization…comes from where?
K current
Absolute refractory period
no stimulus can excite
effective refractory period
no conducted stimulus can excite
relative refractory period
a large stimulus can excite
supranormal recovery period
a less than normal stimulus excites
ARP caused by
inactivation of Na channels
RRP caused by
opening of voltage gated potassium channels
ERP caused by
some Na channels are open, but not enought current for potential to be conducted
Heart rate is increased/decreased by sympathetic
Heart rate is increased/decreated by parasympathetic
- increased
- decreased
How does sympathetic stimulation increase heart rate?
Speeds up rate of phase 4 depolarization via norepinephrine release that increases inward Na and Ca current
How does parasympathetic stimuation decrease heart rate?
Acetylcholine increases K+ permeability so:
1) hyperpolarizes the cell
2) slows spontaneous phase 4 depol
6 process that cause dropsey
- heart disease
- lung disease
- kidney disease
- liver diesease
- starvation
- Blood vessel disease
Draw/Name blood flow through the heart
sum of all blood moved to the arteries is called
cardiac output
sum of all blood coming from veins back to heart is called
venous return
- The normal heart moves blood into the arteries (CO) at a rate sufficient to _____________
- The normal heart accepts blood from the veins (VR) at a rate sufficient to _________
- supply the needs of the body
- prevent the venous system from overfilling
What is [Ca] in ECM?
>1 mM
What is [Ca] in cytosol of myocytes?
<1 micromolar
heart ____ when Ca enters the cytosol from extracelluar space and intracellular stores via ____ ______ down ~1000 fold gradient
Ca
passive diffusion
The heart ____ when calcium is removed form the cytosol via ____ _____
relaxes
active transport
Inward currents are genterated by Ca influx through
voltage-gated channels
What are the two calcium cycles?
Extra and Intra Cellular
What does the sarcotubular network do?
pumps Ca out of cytosol into SR
What do subsarcolemmal cisternae do
release Ca into cytosol
What are the two structures of the SR?
sacrotubular network and subsarcolemma cisternae
Label
What are t-tubules/ transverse-tubules
plasma membrane extensions that are filled with Ca and that can rapidly propagate action potentials into cell interior
What is a dyad and what does it do
structure formed by membranes of the t-tubules and subsarcolemmal cisternae of hte SR
Meidate the ability of an action potential to trigger the release of activator calcium from teh sarcotubular network
Which protein allows Ca to enter cytosol from ECF?
L-type Ca channel
Which two proteins allow Ca to leave cytosol into ECF
plasma membrane Ca pump
Na/Ca exchanger
Which protein/stuructuer allows Ca to entery cytoosol from SR?
SR Ca Release Channel
Which portein/structuer allows Ca to leave cytosol into SR
SR Ca Pump
What are 3 functions of Chemial signals from Ca that enters cell from L-type Ca Channel
- some plays a part in contraction (provides around 1/3 of activator Ca)
- Some activates intracellular Ca release channels
- some is retained in the SR where it augments Ca release in later contractions
What is function of electrical signals from Ca that enters cell from L-type Ca Channel
inward depolarizing current
Does Plasma Membrane Ca Pump Provide active/passive transport
active–going up [Ca] gradient
What powerms PMCA
ATP hydrolysis
NCX is active/passive
active
Where does energy come from for NCX
energy provided by Na moving down gradient
for NCX how many Na/Ca in/out
What kind of current is created
3Na in, 1 Ca out
inward depolarizing
Na/K Pump
- active/passive
- if active/ where does energy come from
- What’s being moved
- What kind of current is created
- is current significant?
- active
- ATP
- 3 Na out for 2 K in
- outward, repolarizing/hyperpolarizing
- Not significant, small and relatively unchanging through out Cardiac cycle
Troponin C
- What does it do
- What kind of protein is it?
- Ca receptor of contractile protein/ initiates contraction
- EF hand protein
SERCA/ Sarcoplasmic Reticulum Ca Pump
- What does it do
- Active/Passive
- If Active where does energy come from
- pumps Ca into SR
- active
- atp hydrolysis
What does phospholamban do? Mediates what
- regulates SERCA
- mediates action of sympathetic nervous system
- dephosphorylated Phospholamban does what to relaxation, resting tension, contractility
- phosphorylated Phospholamban does what to relaxation, resting tension, contractility
- slows relaxation, increases resting tension, decreases contractility
- accelerates relaxation, decreases resting tension, and increases contractility
Is phospholamban activiated when dephosphorylated/phosporylated state
phosphorylated
