Cardiovascular System

imissyou419's version from 2017-01-30 22:32

Section 1

Question Answer
FunctionsHomeostasis 1. transport O2/nutrients in, CO2/waste out, 2. regulate body temp, 3. transport hormones
Components Heart, 2 circulatory systems, blood
Pulmonary artery"arteries leave heart, veins go back to heart"; deoxygenated blood go to lungs to get O2 and drop off SOME CO2
Pulmonary veinoxygenated blood go back to heart to left atrium to be pumped through systemic circulation
Advantage of parallel vascular beds1. amount of blood flow to individual vascular beds controlled separately [liver gets most blood flow] 2. lowers pressure needed for blood flow to distant organs so less workload on the heart (low resistance to blood flow)
Total blood volume5L
Heart and pulmonary circulation % of TBV15% (of 5L)
Systemic arterial system, % of TBV, vessel?10% (of 5L) - distribution vessels, arterioles = resistance vessels
Systemic capillaries % of TBV, vessel?5% (of 5L) - exchange vssels
Systemic veins % of TBV, vessel?70% (of 5L) - capacitance vessel
Which wall is thicker, left or right?Left ventricle wall is thicker
Pulmonary semilunar valve, aortic valve, tricuspid, bicuspidtricuspid (right AV valve), bicuspid (left AV valve), pulmonary semilunar valve (blood flow into lungs)
Chordae tendonae, papillary musclesPapillary muscles contract to keep tension on chordae tendonae which holds AV valve so it doesn't blow up into atria when ventricles contract

Section 2

Question Answer
What are the 2 types of myocardial cells?1. contractile cells (atrial and ventricular muscle) [contract like skeletal], 2. specialized excitatory (SA, AV node) and conducting cells (His-Purkinje) [contract weakly, self-excitable]
Contractile cells difference to SkeletalContractile cells (shorter, branched, arranged in series; 1/3 volume occupied by mitochondria; extract 80% of O2 from blood; joined by intercalated discs that contain gap junctions; 2 separate syncytia for atrial and ventricular)

Skeletal (1 motor neuron innervating muscle cells in motor unit, no synctium or else cannot do graded contractions)
Contractile cells Similarities to SkeletalCa2+ release from SR, Striated and contain actin & myosin, sliding filament
Gap junctionsallow free movement of ion currents (APs) between cells by joining the intracellular environment; reduces electrical resistance through membrane
SyncytiumWhen one cell contracts, they all contract (there are atrial and ventricular syncytia separated by AV ring)