heart2 Flashcards
1
Q
Types of Vessels
A
- heart - elastic artery - muscular artery - arteriole - continuous capillary
- fenestrated capillary - venule - medium size vein - large vein - heart
2
Q
Change in Size of Arteries?
A
- near heart: most change in pressure so lots of elastic fibers
- muscular arteries: less elastic fibers, more smooth muscles to preciesly control diameter and thus direction of blood fkiw
- drop in pressure: venous side has thinner vessel walls
3
Q
Structure of Capillaries - two types? influence?
A
- continuous capillary and fenestrated capillary
- incluence rate at which exchange will occur
4
Q
Continuous vs. Fenestrated Capillary?
A
- continuous: wall made of squamous endothelial cells, no smooth muscle, no CT, so small it could just be a single layer of endothelial cells wrapped around itself
- fenestrated: fenestra = window/doorway, instead of simple epithelial cells, there are holes to get more rapid exchange from open channels
5
Q
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6
Q
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7
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8
Q
Cardiac Cycle - Atrial Systole and Diastole? (steps 1 and 2)
A
- atrial contraction forces a small amount of additional blood into relaxed ventricles
- atrial systole ends, atrial diastole geins: relaxes as ventricle contracts which will close AV valves
9
Q
Cardiac Cycle - Step 3/4 - Ventricular Systole
A
- first phase: ventricular contraction pushes AV valves closed, but not enough pressure to open semilunar valves
- second phase: venticular pressure rises and exceeds pressure in arteries - semilunar valves open, blood is ejected
10
Q
Cardiac Cycle - steps 5/6 - ventricular diastole
A
- early: ventricle relax, pressure in v drops, blood flows back against semilunar valve cusps, forces them closed, blood flows into relaxed atria
- late: all chambers are relaxed, ventricles fill passively
11
Q
Conduction System - Sinoatrial node?
A
- found in Right Atrium, where it meets the superior vena cava
- aka pacemaker
- will spontaneously depolarize
- rate can be modulated with nervous/hormonal/drug input
- because of gap junctions, will spread out through atrium but can’t get to ventricle because of disk of CT
12
Q
Conduction System - Atrioventricular node?
A
- between right atrium/ventricula
- when depolarizing input hits it from atrium, it depolarizes
- impulses sent through bundle of his, which will devide into left and right then travel down to apex to Purkinje fibers
13
Q
Conduction System - Bundle of his and Purkinje fibers?
A
- BoH: specialized for conduction, branches into left and right bundle branches
- Purkinje fibers: heart contracts at apex up to base
- if it contracts base to apex, blood would flow the wrong way
14
Q
A
15
Q
Cardiac Muscle - gap junctions?
A
- gap junctions on one cell will align perfectly with next cell - holes for metabolites to pass through
- allows ions to pass from one cell to the next, so depolarization spreads out like a wave
- branching and pores allows heart to beat - depolarize cells in one region, but heart is branched so it spreads out in a wave
20
Q
Coronary Sulcus, Anterior Interventricular Sulcus
A
- coronary: runs around division b/w atriums and ventricles
- anterior IV: depression/indentation where septum is
- dperession covered with fat, not really seen
