Chapter 18 Cardiovascular System

Created by swheeler1115 

Upgrade to
remove ads

23 terms

Orientation of Heart

Base of heart=superior
Apex=inferior

Fibrous Pericardium

outermost covering, dense CT, protects, achors, prevents overfilling

Serous Pericardium

deep to fibrous pericardium
parietal=lines internal surface of fibrous pericardium
visceral=epicardium=covers external surface fo heart

Epicardium

same as visceral epicardium
outermost layter, simple squamous epithelium and loose areolar CT

Myocardium

bulk of heart; cardiac muscle
arranged in spiral bundles, causes a wringing effect when heart contracts

Endocardium

innermost layer
simple squamous epithelium
lines heart chambers, continues with blood vessels to become endothelium

Seperation from Atrium from Ventricle

Externally: Coronary Sulcus seperates each atrium from its ventricle
Internally: Atrioventricle (AV) vavle

Seperates ventricles from blood vessels

Semilunar valves (SV)

Pulmonary Circuit

Right side pump.
right side of heart->lungs->left side of heart

Systemic Circuit

left side of heart->body->right side of heart

Respiratory Membrane

the pulmonary capillaries surround the alveoli and includes a basement membrane
-blood in capillaries becomes oxygenated as it passes by alveoli
-O2 from alveoli into caps.
-CO2 diffuses from caps into aveoli
simple squamous epithelium

Pathway of Blood

Right Atrium > Tricupsid Valve > Right Ventricle > Pulmonary Semilunar Valve > Pulmonary Trunk > L and R Pulmonary arteries > Pulmonary Capillaries (lungs) > Pulmonary Veins (oxygenated) > Left Atrium > Bicuspid valve > Left Ventricle > Aortic Semilunar Valve > Aorta > Systemic Ciculation > RA

Heart Valves

Atrioventricular (AV): tricuspid and bicuspid seperates atrium from ventricle
semilunar (SL): pulmonary (R) and aortic (L) sperate ventricle from blood vessel

AV Vavles

Open when ventricles are relaxed and filling with blood
Closed when ventricles contract to prevent backflow

Chordae Tendineae

Anchor the cusps of the AV valve to papillary muscles

SL Valves

Closed as ventricles filling with blood (relaxed)
Open as ventricles contract to allow ejection of blood

Coronary Circulation

heart requires 5% of the blood supply to nourish itself
coronary arteries and cardiac veins
saphenous vein from leg and cut into grafts-connect from the aorta to the coronary arteries to bypass the blockage

Coronary Arteries

Right and left coronary arteries arise from base of aorta
encircle heart in coronary sulci
anastomoses: junctions of vessels allow collateral routes for blood flow in case of blockage.
blockage may require bypass surgery

Cardiac Veins

Join to form the coronary sinus which drains deoxygenated blood into the RA

Cardiac Muscles

cells are highly interdependent
gap junctions at intercalated discs
short, fat branched cells
gap junctions-ions pass
desmosomes-keep cells from separating as muscle contracts

Contractile Cells

99% of heart cells
contract, carry out pumping action

Autorhythmic cells

1%, don't contract
fire action potentials that spread thru heart via gap junctions
localized along intrinsic conduction system that coordinates contraction of heart chambers

Cardiac Intrinsic Conduction System

Sinoatrial (SA) node pacemaker-initiates pulse > atrioventricular AV node > atrioventricular bundle > connects atria to ventricles > bundle branches (septum) > Purkinje Fibers (depolarize contractile cells for ventricles)

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.

NEW! Voice Recording

Click the mic to start.

Create Set