circulation part one Flashcards
the heart is wrapped in what
fibrous pericardium
pericardium
Protects, anchors, and prevents overfilling
2 layers
what are the two layers of the pericaridum
Parietal layer lines the internal surface Visceral layer (epicardium) on external surface of the heart Separated by fluid-filled pericardial cavity (decreases friction)
layers of heart wall
epicardium
myocardium
endocardium
Epicardium
visceral layer of the serous pericardium
myocardium
Spiral bundles of cardiac muscle cells
Fibrous skeleton of the hear made of crisscrossing connective tissue
myocardium function
Anchors cardiac muscle fibers
Supports great vessels and valves
Limits spread of action potentials to specific paths
endocardium
intermost layer
continuous with endothelial lining of blood vessels
four chambers of the heart
two atria and two ventricles
atria separated by
interatrial septum
junction between atria and ventricle
Coronary sulcus (atrioventricular groove)
two ventricles are separated by
the interventricular septum
what vessels enter right atrium
superior and inferior vena cava
what vessels enter left atrium
right and left pulmonary viens
what vessels leave the right ventricle
pulmonary trunk
what vessels leave the left ventricle
aorta
The heart is two side by-side pumps, the right side is for
pulmonary circuit
Vessels that carry blood to and from the lungs
The heart is two side by-side pumps, the left side is for
Left side is the pump for the systemic circuit
Vessels that carry the blood to and from all body tissues
where do all gas exchanges occur
the capillary beds
pathway of blood through the heart, first pump
right atrium to tricuspid valve to right ventricle to semilunar valve to pulmonary trunk to pulmonary arteries to lungs
pathway of blood through heart, second pump
lungs to pulmonary veins to left atrium to bicuspid valve to left ventricle to aortic semilunar valve to aorta to systemic circulation
differences between pulmonary circuit and systemic circuit
Pulmonary circuit is a short, low-pressure circulation
Systemic circuit blood has a lot of resistance
circumflex artery location
surronds the outside of the heart off of the interventricular artery
anterior interventricular artery
runs down between the ventricles on the front
posterior interventricular artery
runs down between the ventricles on the back
right marginal artery
comes off coronary artery running down the right ventricle
right coronary artery
between right ventricle and artium
left coronary artery
between left ventricle and artium
ischemia
insufficient blood flow to heart muscle , causes angina
between right ventricle and artium
“tight chest” caused by a fleeting deficiency in blood delivery to the myocardium
Cells are weakened
Myocardial infarction
heart attack
Prolonged coronary blockage
Areas of cell death are repaired with noncontractile scar tissue
what do heart valves do
Ensure unidirectional blood flow through the heart
what do Atrioventricular (AV) valves do
Prevent backflow into the atria when ventricles contract
what does Chordae tendineae do
anchor AV valve cusps to papillary muscles to prevent eversion
what do semilunar valves do
Prevent backflow into the ventricles when ventricles relax
Cardiac muscle cells are
striated, short, fat, branched, and interconnected
Intercalated discs
junctions between cells anchor cardiac cells
Desmosomes
prevent cells from separating during contraction
Gap junctions
allow ions to pass; electrically couple adjacent cells
