Cardiovascular System

Question 0

what are the 3 heart wall layers?

Answer 0

endocardium
myocardium
epicardium

Question 1

What is the impulse conducting system of the heart do and what makes it?

Answer 1

it is for initiating and propagating electrical impulses for cardiac muscle contraction
formed by purkinje fibers
NOT NERVOUS SYSTEM

Question 2

what is the epicardium?

Answer 2

layer of mesothelial cells on the outer surface of the heart and the underlying connective tissue
= pericardium

Question 3

what synchronizes the contraction of the heart to make the contractions efficient?

Answer 3

specialized cardiac muscle fibers

impulses start in SA node then spread to AV node, bundle of his, then purkinje

Question 4

how does the parasympathetic nervous system affect the heart?

Answer 4

post ganglionic fibers terminate w/ SA and AV nodes and then extend to coronary arteries
Acetylcholine is released at the axon terminals
HR is slowed and coronary arteries constricted

Question 5

how does the sympathetic nervous system affect the heart?

Answer 5

post ganglionic fibers terminate in SA, AV nodes, myocardium, and coronary arteries
release norepinephrine
increases HR and dilates coronary arteries

Question 6

what is the nervi vascularis of the tunica adventitia?

Answer 6

controls the contraction of smooth muscle

Question 7

what is the vasa vasorum of the tunica adventitia?

Answer 7

small blood vessels that nourish the tunica media

Question 8

the cells of the tunica intima in large arteries have inclusions called Weibel-Palade bodies. What do these contain?

Answer 8

von Willebrand factor

Question 9

endothelial cells modulate blood flow and vascular resistance by secreting what?

Answer 9

Vasoconstrictors- ACE + endothelin

Vasodilators- prostacyclin + EDRF/NO

Question 10

how do endothelial cells play a role w/ LDL?

Answer 10

LDL is modified by free radicals produced by endothelial cells
the LDL is then endocytosed by macrophages and forms foam cells

Question 11

what are foam cells characteristic of?

Answer 11

atherosclerotic plaques

Question 12

what is characteristic about the layers of muscular arteries?

Answer 12

prominent internal elastic membrane

more smooth muscle and less elastin in the tunica media

Question 13

where are continuous capillaries found?

Answer 13

muscle, CNS, and lungs

Question 14

what are the 2 main features of continuous capillaries?

Answer 14

they have occluding junctions and pericytes

Question 15

where are fenestrated capillaries found?

Answer 15

endocrine glands, intestinal tract, and gallbladder

Question 16

where are discontinuous capillaries usually found?

Answer 16

in the liver, spleen, and bone marrow (where blood is really slow)

Question 17

what is usually present along the walls of discontinuous capillaries?

Answer 17

macrophages

Question 18

what are precapillary sphincters?

Answer 18

sphincters that control the flow of blood into the capillary bed

Question 19

what are the 2 biggest lymphatic vessels?

Answer 19

thoracic duct and right lymphatic duct