Chapter 19

Front 1

Heart chambers

Back 1

right atrium-receiving chamber for oxygen-poor blood returning from the systemic circuit (receives blood via superior vena cava and inferior vena cava)

right ventricle-receives blood from the right atrium and pumps it into the pulmonary circuit via pulmonary trunk.

left atrium-receives oxygen-rich blood returning from the lungs through two right and two left pulmonary veins.

left ventricle-pumps blood into the systemic circuit to other structures of the body.

Front 2

pulmonary circuit

Back 2

blood returning from the body enters the right atrium and passes into the right ventricle

-the ventricle pumps the blood to the longs via the pulmonary trunk

-blood is oxygen poor and carbon dioxide rich

-once in lungs, blood unloads carbon dioxide and picks up oxygen

Front 3

systemic circuit

Back 3

-oxygenated blood leaving the lungs enter the left atrium and passes into the left ventricle

-the left ventricle pumps blood into the aorta and from there into many distributing arteries

-smaller distributing arteries carry blood to all parts of the body
-gases, wastes, and nutrients are exchanged across capillary walls
-blood then returns to the right atrium of the heart via systemic veins and the cycle continues

Front 4

major vessels entering the heart

Back 4

pulmonary vein-oxygenated blood

vena cava- deoxygenated blood

Front 5

major vessels leaving the heart

Back 5

aorta- oxygenated blood
pulmonary artery- deoxygenated

Front 6

Right Side heart circulation

Back 6

-enters through superior/inferior vena cava
-into right atrium
-through tricuspid valve
-into right ventricle
-through pulmonary semilunar valve
-out pulmonary trunk
-to lungs

Front 7

left side heart circulation

Back 7

-enters through four pulmonary veins
-into left atrium
-through mitral valve
-into left ventricle
-through aortic semilunar valve
-out through aorta
-to body tissues

Front 8

heart valves

Back 8

right: tricuspip, pulmonary semilunar valve

"lub" sound is produced by the closing of the AV valves at the start of ventricular contraction (closed until blood enters the ventricles again-beat then takes place again once closed)
"dub" is produced by the closing of semilunar valves at the ventricle contraction

left: mitral, aortic semilunar valve

Front 9

lining of the heart

Back 9

-enclosed in a triple-walled sac called pericardium
-the loose fitting outer layer of the sac is the fibrous pericardium which is a dense connective layer that: protects the heart, anchors the heart, and prevents overfilling

next layer: fibrous pericardium, contains two layers- parietal layer and visceral layer

the visceral layer (epicardium) is an integral part of the heart wall

Front 10

myocardium

Back 10

-the layer of cardiac muscle that forms the bulk of the heart

-layer that contracts

-the elongated circularly spirally arranged muscle cells squeeze the blood through the heart

-contains interlacing bundles that effectively link all parts of the heart together

Front 11

endocardium

Back 11

-a glistening white sheet of endothelium (squamous epithelium) resting on a thin layer of connective tissue

-lines the heart chambers

Front 12

trabeculae carneae

Back 12

-marking the internal walls of the ventricle chambers are irregular ridges of muscle

Front 13

papillary muscles

Back 13

project into the cavity and play a role in valve function

Front 14

pericardial membranes

Back 14

visceral pericardium, myocardium,
endocardium