intro Flashcards
the function of the CV system is to
maintain homeostasis
the heart acts as a
pump
the blood acts as
transportation mechanism
the vasculature acts as
tubing/exchange system
which acts in series?
pulmonary circulation
which acts in parallel?
systemic circulation
pulmonary circulation is
- lower pressure
- single pathway through a single set of capillary bed
- in series
systemic circulation is
- higher pressure
- mostly parallel
- oxygenated blood only visits one organ system before returning to the heart
- blood flow to different organs can be regulated independently to match metabolic demand
at rest blood flow is: brain: skeletal muscle: GI system: Kidney:
14%
15%
21%
22%
during exercise blood flow to exercising muscles
80%
left side vs. right side of the heart
left side: higher pressure, systemic circulation
right side: lower pressure, serves pulmonary circulation
there is no direction connection between
right and left heart
why must the right and left sides of heart be closely matched?
because its a loop
how many chambers?
4 chambers
2 atria: smaller, priming chambers
2 ventricles: main pumping chambers
valves are
- consist of 2 or 3 cusps
- all 4 valves are in the same plane of the heart
- valves are one way, control direction of blood flow through the heart
- pressure operated–passive
cusps are
flaps of fibrous tissue and endothelium
atrioventricular valve
- tricuspid and mitral (bicuspid)
- between atria and ventricles
- have chordae tendonae
chordae tendonae attach to
papillary muscles in ventricles and help stabilize valves and prevent prolapse of valves
semilunar valves
- aortic and pulmonary
- between ventricles and great arteries
- no chordae tendonae
describe the layers of the heart from outside in
outermost:
- pericardium
- epicardium
- myocardium
- endocardium
the pericardium is made up of
outermost:
- pericardial membrane
a. fibrous layer outer
b. parietal pericardium inner - pericardial fluid
- visceral pericardium
Automaticity
- heart beat is myogenic
2. originates within the heart itself
sinoatrial node
- specialized myocytes
2. initiates the heartbeat
atrioventricular (AV) node is located
- between atria and ventricles
2. slows con
AV node function
slows conduction to allow atrial contraction to precede ventricular contraction
the budle of his is between
AV node and left and right bundle branches in ventricles
purkinje fibers are located in
inner walls of the ventricles
purkinje fibers are
specialized cardiac myocytes cells that allow fast conduction
the his-purkinje system functions to
coordinated contraction of ventricles
