Cardiovascular System Hist

Question 1

What are receiving chambers of heart? discharging chambers?

Answer 1

atria

ventricles

Question 2

Layers of heart wall

Answer 2

1) epicardium = outer layer; visceral layer of serous pericardium
2) myocardium = middle; composed of cardiac m and contains fibrous skeleton of hear
3) endocardium

Question 3

Types of atrioventricular valves? semilunar valves?

Answer 3

• tricuspid and bicuspid (mitral)

- aortic and pulmonary

Question 4

When do valves open and close?

Answer 4

response to pressure changes

Question 5

Where are NO valves present?

Answer 5

entrances to venae kava, coronary sinus and pulmonary vv into heart

Question 6

What is unique about cardiac m?

Answer 6

able to depolarize and contract without impulses from nervous system by using intrinsic cardiac conduction system

Question 7

What sets the rate of intrinsic cardiac m contraction?

Answer 7

set by pacemaker cells and altered by sympathetic (accelerates heartbeat) and parasympathetic (decelerates heartbeat) division of ANS; hormones also impact intrinsic rate

Question 8

How are purkinje fibers and other conducting cells connected to one another?

Answer 8

desmosomes and gap junctions

Question 9

Where is the SA node found?

Answer 9

near junction of SVC and right atrium

Question 10

aa vs vv in cross section

Answer 10

aa appear more open and vv more collapsed; lumen of vv much larger

Question 11

Thickest layer of aa vs vv

Answer 11

aa= tunica media
vv= tunica externa

Question 12

Elastic/conducting aa layer features

Answer 12

tunica intima = inconspicuous internal elastic mem
tunica media =multiple layers smooth m cells separated by elastic lamellae
tunica adventitia = thin; may contain vasa vasorum and Nervi vascularis

Question 13

muscular/distributing aa layer features

Answer 13

tunica intimia = thiner than elastic; prominent internal elastic mem
tunica media = multiple layer smooth m separated by limited elastic material; prom external elastic mem
tunica adventitia = thick; may contain vasa vasorum and Nervi vascularis

Question 14

medium vv layer features

Answer 14

tunica intima = endothelium and basal lamina, thin sub endothelial layer with some smooth m.; sometimes thin internal elastic mem
tunica media = thinner than a; severe layer smooth m w/interspersed collagen and elastic fibers
tunica adventitia = thicker than intimacy and media; collagen nd networks of elastic fibers

Question 15

large vv layer features

Answer 15

intima = endothelium and basal lamina along with thin sub endothelial layer and some smooth m cell
media = thin; circularly arranged smooth m cells
adventitia = thicker than intima and media; collagen and elastic fibers with occasional smooth m cell

Question 16

Special feature in vv

Answer 16

vv in limbs have valves (thin folds of tunica intima; endothelial cells over thin layer CT)
- prevent back flow of blood