Human Physiology - Unit 2 - Cardiovascular

main transport system and temperature regulation

what are the roles of cardiovascular system in homeostasis

heart, blood, and vasculature

what are the 3 components of the cardiovascular system

Blood

Plasma takes up the largest volume in _______

Erythrocytes are the second largest amount

buffy coat (leukocytes and platelets) are the smallest amount

heart

2 pumps (right ventricular and left ventricular)

pumps through the pulmonary system

only goes one way (in series circuit) 

Vasculature

systemic system

parallel vascular beds (redistributing blood flow)

perfusion

passage of blood through a vascular bed

ischemia

lack of oxygen/ blood flow, typically due to an occlusion

it allows the left ventrical to generate greater pressure

why are the walls of the left ventricle thicker than the right

systemic circulation is higher pressure so blood will move

why does the left ventricle need to generate greater pressure

in series circuit

components are connected end-to-end, forming a single path for current to flow

parallel circuit

components are connected side-by-side with multiple paths for current

allows for the same quality of blood to all tissues and better regulation of blood flow

m Ach R

cholinergic receptor in the cardiovascular system?

Alpha and beta receptors

adrenergic receptors for the cardiovascular system

tricuspid

right atrioventricular valve

bicuspid

left atrioventricular valve

pulmonary semilunar

valve between right ventricle and pulmonary artery

aortic semilunar

valve between the left ventricle and aorta

R atrium, tricuspid, R ventricle, pulmonary semilunar, pulmonary artery, lungs, L atrium, bicuspid, L ventricular, aortic semilunar, aorta, body

trace the flow of blood in the cardiovascular system

cardiac output

The volume of blood ejected from each ventricle per minute

the product of HR and SV, expressed in liter/min

70; 70; 5

Average values = ___ beats/min(HR) x ___ mL/min(SV) = ___ L/min (CO)

slowers heart rate, weaker atrial kick, and slower AV conduction

How does the parasympathetic nervous system affect cardiac output

faster heart rate, stronger contraction, increased cardiac output

How does the sympathetic nervous system affect cardiac output

intrinsic firing rate

how much the SA node would fire if it could whenever it wanted

100 action potentials/min

preload

what is another name for end diastolic volume

SV to increase

what does an increase in EDV cause

change in filament overlap, and increase Ca released and sensitivity of troponin to Ca

how does an increase in EDV cause an increase in stroke volume

Frank-starling relationship

As EDV goes up, so does SV

control of end-systolic volume

prevents ESV from increasing, thus preventing clots, explains what part of the Frank-Starling relationship

matching of cardiac output of both ventricles

outflow of R. and L. sides of heart remain equal, explains what part of the Frank-Starling relationship

prevention of rise in venous pressure

prevents blood from backing up into the vein/capillary and regulates the size of the heart, explains what part of the Frank-Starling relationship

an increase in stroke volume

an increase of sympathetic stimulation results in

makes it stronger, faster

what does sympathetic stimulation do to a contraction

mean atrial blood pressure

MABP means??

decreases

High MABP does what to the SV

decreases the ability of ventricles to shorten

increased pressure in arteries …

work rate

heart rate increases linearly with an increase in ___ ____

does not

SV ___ (does/does not) increase linearly with work rate,

50%

SV plateaus at an increase of __% with work rate

lungs

What organ gets the most cardiac output

positive 

_______ inotropes increase the force of contraction in the heart

negative

_______ inotropes decrease the force of contraction in the heart

Chronotropic

__________ effects change the heart rate (positive or negative)

agonist

binds to a receptor and produces a biological response

antagonist

blocks the action of the agonist

a decrease in velocity

an increase in cross-section area = ???

it allows for ample time for diffusion

Why is the low velocity beneficial in capillaries

arteries

Large in radium, low resistance

act as a pressure reservoir

stretches out

during systole, the blood ejected out of the heart ________ the arteries

recoil

during diastole, the _____ of the arteries continues to push blood through the vasculature

arterioles

causes adjustments in blood distribution to the organs by releasing and contracting, which regulates flow through changes in resistance

match flow to local tissue, maintain and protect MAP, and temperature regulation

what are the 3 roles of arterioles

continuous

(type of capillary) endothelial cells are packed together very tightly

most common type

fenestrated

(type of capillary) more porous, allowing for rapid diffusion

mostly renal system

single wall of endothelial cells

Regardless of type, what do all capillaries have, that allows for exchange between blood and ISF

concentration gradient

exchange of materials across a capillary wall is influenced by what

sympathetic firing, skeletal muscl pump, respitory pump

what are the 3 venous return factors

systemic veins

return blood to the heart

high capacitance

very low pressure

one way flow

mean arterial pressure (MAP)

the average pressure experienced by the arterial vessels over the cardiac cycle

pulse pressure

systolic pressure - diastolic pressure =

MAP

1/3 pulse pressure + diastolic pressure =

total peripheral resistance (TPR)

The combined resistance of all blood vessels in the systemic circulation

MAP

CO x TPR =

baroreceptors

pressure sensors located in blood vessel walls that measure blood pressure

they sense the stretch of the vessel walls and relay the info to the brain

cardiovascular control center

what do baroreceptors communicate with in the brain in response to changes in pressure

action potential firing

increase in vessel distension (pressure) leads to an increase in ???

negative feedback

what kind of feedback loop is the response by CVCC to return MAP to regular level

vasodiltion

relaxation of smooth muscle

vasoconstriction

contraction of smooth muscle

SA node, atrial contractile cells, AV node, bundle of hiss, bundle branch cells, Purkinje fibers, ventricular contractile cells

trace the excitation of the heart

Electrocardiogram

a graph of voltage vs time of electrical activity of the heart using electrodes

electrodes detect the small electrical changes that are a result of cardiac muscle depolarization

p-wave

(on ECG) atrial depolarizaiton

QRS complex

(on ECG) ventricular depolarization

T wave

(on ECG) ventricular repolarizaiton

PR interval

(on ECG) shows conduction through the AV node

ST segment

(on ECG) the interval between ventricular depolarization and repolarization

endocardium

outside layer of the heart, closest to blood

myocardium

middle layer of heart, thickest layer of cardiac muscl

pericardium

fluid-filled sac that helps with lubrication of the heart

functional syncytium

heart muscle cells that are sychronized in halth

cardiac myocytes

striated

mostly mononucleated

branched endings

all three types

Which type(s) of muscle have these characteristics?

sliding filaments and cross-bridges

ATP powers the force generation

Elevated Ca trigger contraction

cardiac and skeletal

Which type(s) of muscle have these characteristics?

has sarcomeres

striated

has troponin

t-tubules

cardiac and smooth

Which type(s) of muscle have these characteristics?

pacemaker cells

gap junctions

Ca entry from ECF

autonomic/ hormones modulate activity

involuntary

arteries, arterioles, capillaries, venules, veins

trace the path of blood

SA node

pacemaker of hear

atrial contractile cells

atrial kick

automaticity

ability to generate spontaneous action potentials (SA node, AV node, conducting cells)

sinus rhythum

normal cardiac excitation

latent pacemakers

not actively driving the heart rate, but could is SA node went out

abnormal

What is an ectopic pacemaker

calcium-induced calcium release

calcium enters the cell, which causes calcium to release from the sarcoplamic reticulum

2/3

the cardiac cycle is in diastole __ of the time

ventricular filling

diastole

the ventricles fill with blood during diastole

initial period is passive; atrial kick follows

this contributes 10-20 % of blood to ventricles

open; closed

during ventricular filling, the AV valves are ____ and the Aortic and pulm valves are _____

isovolumetric contraction

systole

ventricles contract

1st heart sound at start of this phase: “lub” - caused by AV valves closing

volume constant at EDV

closed; closed

during isovolumetric contraction and relaxation, the AV valves are ____ and the Aortic and pulm. valves are _____

<; >

(isovolumetric contraction (systole))

pressure in ventricles _ pressure in aorta and pulmonary artery

pressure in ventricles _ pressure in atria

<; >

(isovolumetric relaxation (diastole))

pressure in ventricles _ pressure in aorta and pulmonary artery

pressure in ventricles _ pressure in atria

>

(Ejection (systole))

pressure in the ventricles _ pressure in the aorta and the pulmonary artery