AP I Tst 3 Tissues of the Heart/Coronary cir

Created by slcar 

Upgrade to
remove ads

AP I Test 3 Tissues of the Heart Coronary circulation mar 4

Pericardial Layers

-heart is enclosed in a double-walled sac called the pericardium
Parietal Pericardium (pericardial sac)
Visceral Pericardium (epicardium)

Parietal Pericardium

thick, fibrous layer-outer wall of the heart
-anchors to diaphram and major vessels
-won't allow the heart to overfill

Visceral Pericardium

thin layer
associated with myocardium

Myocardium

cardiac muscle between the epicardium and endocardium
-the thickest layer and performs the work of the heart

Pericardial cavity

between the parietal and visceral membranes
-contains fluid that lubricates the heart
-allows it to beat with minimal friction

Pericarditis

inflammation of the pericardium
-they grow in toward each other so then have limited space with higher pressure making it hard to lubricate
-causes painful hearbeat b/c of rubbing-friction rub with each heartbeat

Valves

has two or three fibrous, endothelial lined cusps
-prevent backflow (one way pump)

How are the valves opened and closed?

passively
-not muscular

What dictates the valves being opened and closed?

ventricular pressure
-they are pushed open and closed by changes in blood pressure that occur as the heart chambers contract and relax

Phases of the Cardiac cycle 1-Relaxed ventricle

Atrial pressure is greater than ventricle pressure
causing the AV vlaves to open and blood to flow into the ventricles

What happens after blood flows into the ventricles?

the ventricular pressure starts to rise above the atrial pressure

When semilunar -aortic valvews are closed how is the pressure aligned?

Pulmonary and aorta pressure is greater than the ventricular pressure

When the ventricles are contracted what happens?

the AV valves close

How is the pressure aligned when the AV valves are closed?

the ventricle pressure is greater than the atrial pressure

What happens when the ventricular pressure becomes greater than the pulmonary and aorta pressure?

it causes the semilunar valves to open

Isovolumetric contraction

this is when the ventricles are starting to contract and the AV valves are closed
-is called isovolumetric b/c even though the ventricles are contracting they do not eject blood yet and their is no change in their volume
-the ejection of blood will only begin when the ventricular pressure exceeds arterial pressure and forces the semilunar valves open

Chordae tendineae and Papillary muscle

-they are like strings on a parachute--what keeps the pressure from inverting is the strings applying down tension pressure on the edges
-these keep the heart from prolapsing

What does it mean if a heart prolapses?

-the valves bulge excessively into the atria or turn inside out like a windblown umbrella
you have a heart mumur
-which means blood is leaking the wrong direction

Septisemia

can hurt valves
bacterial infection that goes septic
-can disfigure the cusp of the valve and cause imperfection on seams and leak blood thru
-can cause congestive heart failure if it gets bad

Coronary circulation

the blood vessels of the heart wall

Where do the right and left coronary arteries originate?

the base of the aorta and branch into several arteries

What do the arteries that branch off do?

supply blood to myocardium

What are the only arteries to fill during diastole?

relaxed
-the R and L coronary arteries

What is hard on the vessels?

high systolic pressure-it damages them
bypass surgery involves these

Myocardial infarction

heart attack caused by a fatty deposit or blood clot building up plaques in a coronary artery

Ischemia

deficiency of blood flow to the cardiac muscle
-typically occurs when a partially blocked coronary artery constricts-produces lactic acid and stimulates pain

Ischemic tissue

receives limited blood flow
goes necrotic-decays

Anastomoses

connection of 2 arteries
they can supply the same tissue
-can provide some protection from myocardial infarction
-combine their blood flow to points farther downstream
-provide an alternate route called collateral circulation that can supply the heart tissue with blood if the primary route becomes obstructed---knees and joints also have these

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set