cardiovascular system questions

what other two systems are closely tied to the CV system

respiratory and renal

what generates pressure to circulate blood

heart

what transports blood, regulates blood pressure, and exchanges

blood vessels

what are the 5 types of blood vessels

arteries, arterioles, capillaries, venules, veins

describe the location of the heart in detail

between lungs, behind sternum, top tilted back, and tilted to the right side

name the heart layers in detail

pericardium (parietal pericardium, pericardial cavity), epicardium (visceral pericardium), myocardium, endocardium

what is the serous membrane around the heart

pericardium

what tissue is not present in the heart

neural

what are the 4 chambers of the heart

RA, RV, LA, LV

what separates the ventricles

septum

what separates the atria

atrial walls

are the ventricles the same size

they were as a newborn, but then the LV gets more muscular from pumping harder and so the RV is bigger

what valve: between RA and RV

right AV valve/tricuspid valve

what valve: between LA and LV

left AV valve/bicuspid/mitral valve

what valve: between RV and pulmonary trunk

pulmonary valve/pulmonic semilunar valve

what valve: between LV and aorta

aortic valve/aortic semilunar valve

what supports the AV valves

chordae tendineae attached to papillary muscles

name the pathway of the blood through the heart and body starting in the left ventricle

left ventricle, aortic valve, aorta, arteries, arterioles, capillaries, venules, veins, superior and inferior vena cava, right atrium, tricuspid valve, right ventricle, pulmonary valve, pulmonary arteries, lungs, pulmonary veins, left atrium, bicuspid valve

1 cycle of contraction and relaxation of heart chambers, heartbeat

cardiac cycle

what are the 3 steps of the cardiac cycle

1. diastole: heart relaxed, blood filling atria

2. atrial systole: atria contract, ventricles completely filled with blood

3. ventricular systole: ventricles contract, blood to body, atria relax

what causes cardiac sounds

blood flow turbulence when a valve closes

what causes the lub sound

turbulence when AV valves close

what causes the dub sound

turbulence when semilunar valves close

what is the equation of cardiac output

HR x SV= CO

does the blood in your body always flow turbulently

no, mostly is laminarly

how much is the CO every minute

5 liters

peak of pressure in aorta when blood flows in

systolic

lowest blood pressure in aorta when blood is flowing out

diastolic

what direction do fluids flow

from high pressure to low pressure

how does blood move through arteries

they stretch when blood is pumped in, then elastic recoil pushes it through

what closes a valve

pressure being greater in front of it

what opens a valve

pressure being greater behind it

what does the heart being autorhythmic mean

it generates its own beat

true/false: the heart has neurons 

false

why is the heart autorhythmic

it has specialized myocytes and gap junctions

what do the intrinsic controls of the heart do

establish normal heart beat

pacemaker, upper RA

sinoatrial node

base of RA, causes slight delay

atrioventricular node

where does the electrical signal of the heart go after the AV node

atrioventricular bundle, right and left bundle branches, Purkinje fibers

where does the contraction of the heart

the apex of the heart because it is the shortest distance away from the AV node

why are the contraction origins of the heart beneficial

they start at the apex and move up the heart so it pushes blood up towards the valves and out of the heart

what do the extrinsic controls do

modify heart rate to meet body’s immediate needs, can override intrinsic controls

what 2 cells does the contraction of the heart rely on and what do they do

cardiac myocytes- mechanical pumping, autorhythmic cells- electrical impulses for contractions

in the medulla oblongata, can override intrinsic heart rate, output from autonomic nervous system

cardiomotor center

where do parasympathetic nerves innervate

SA and AV nodes

where do sympathetic nerves innervate

SA node, AV node, and ventricular myocardium

what does the sympathetic nervous system affect

stroke volume, heart rate, cardiac output

what does the parasympathetic nervous system affect

heart rate, cardiac output

what causes contraction of the heart

cell depolarization

what causes relaxation of the heart

cell repolarization

true/false: ECG is a reflection of tissue depolarizing NOT conduction system

true

ECG: what does the P wave show

SA node fires, atria depolarization

ECG: QRS complex show

depolarization of ventricles, atria repolarize but overshadowed

ECG: T wave shows

ventricles repolarize, return to diastole

ECG: P-R interval shows

atrial depolarization to ventricular depolarization

ECG: Q-T interval shows

total time of ventricular depolarization and repolarization

do the mechanical events of the heart exactly match up with the timing of the ECG

no, the mechanical events happen a little after the cell depolarization/repolarization

what is the funny current

calcium, sodium ions into the cells to depolarize them

ECG: P-Q shows

AV node delay, conduction system

can cardiac muscle contract and hold itself there. why or why not

no, the plateau phase of contractile cells involve a refractory period where they can’t contract again for a moment

what does the plateau period of contractile cells ensure

heart diastole and refilling

what is happening in a conduction cell: initial period of depolarization to sub threshold (step 1)

Na+ in, little bit of K+ out

what is happening in a conduction cell: latter period of depolarization to threshold (step 2)

Ca2+ in

what is happening in a conduction cell: rapid depolarization phase (step 3)

Ca2+ in

what is happening in a conduction cell: repolarization phase (step 4)

K+ out

what is happening in a contractile cell: phase 0

rapid depolarization, Na+ in

what is happening in a contractile cell: phase 1

small repolarization, Na+ in decreases

what is happening in a contractile cell: phase 2

plateau, Ca2+ in, K+ out decreases

what is happening in a contractile cell: phase 3

repolarization, K+ out, Ca2+ in decreases

what is happening in a contractile cell: phase 4

resting potential, K+ out, Na+ and Ca2+ impermeable

what structures does the flow of blood naturally go through high to low pressure

artery, arteriole, capillary, venule, vein

where is blood pressure highest

arteries (aorta)

where is blood pressure lowest

veins (inferior vena cava)

where is blood flow fastest

arteries (aorta)

where is blood flow slowest

capillaries, to allow nutrient exchange

what are the 3 layers of an artery from deep to superficial

epithelium, smooth muscle, connective tissue (collagen)

what is the surge of blood flow

pulse

what vessel has the greatest smooth muscle ratio and offers the greatest resistance to flow

arterioles

what are the layers of an arteriole from deep to superficial

epithelium, smooth muscle

how do arterioles regulate blood pressure

constricting or dilating

what are the layers of a capillary

epithelium

what are passages for things that can’t diffuse across capillary lipid bilayer but can dissolve in water

pores

what is it when pressure in capillary is more than outside so water and solutes are forced into extracellular fluid where the lymphatic system picks them up

bulk flow

what are the 3 ways for substances to cross the capillary walls

diffusion, pores, bulk flow

force of fluid on the capillary walls

hydrostatic pressure

describe how fluid ends up in the extracellular space

hydrostatic pressure forces anything small enough through the capillary walls, because of the high concentration of proteins in the capillary, water diffuses back in but a little stays behind, nutrients are left behind for the cells

osmotic pressure because of plasma proteins

oncotic pressure

are there proteins in the interstitial fluid

no

what happens to the little bit of water left behind in the interstitial space

picked up by lymphatic system and returned to bloodstream

what regulates how much blood flows into the capillaries

precapillary sphincter

how does working out affect the precapillary sphincters

working out makes your muscles work harder because your cells are working harder so they/re wasting and releasing more heat, this heat denatures the precapillary sphincters making them relax, so more blood is getting to your working muscles

when there is inflammation where does this happen

venules

what are the 3 layers of venules from superficial to deep

connective tissue, smooth muscle, endothelium

what blood vessels have valves

veins

what are the 3 layers of veins form deep to superficial

endothelium, smooth muscle and elastic fibers, connective tissue

what prevents backflow of blood in veins

valves

how do valves work in veins

skeletal muscles contract which pushes blood through valves

how much of your blood is in your veins

70%

what monitors resting blood pressure

medulla

keeps blood pressure in normal limits in face of sudden changes by sensing when there is less stretch in aorta (low bp) and sends info to medulla to raise heart rate

baroreceptor reflex