Cardiovascular System

Question 1

What is the average amount of circulating fluid in the adult human body?

Answer 1

16 L

Question 2

What is the average volume of plasma in an adult human?

Answer 2

3.5 L

Question 3

What are the functions of the circulatory system?

Answer 3

Transport of nutrients and waste, acid.base regulation, immune response, and water balance

Question 4

Where in the body is most blood volume at any given time?

Answer 4

Peripheral veins (65%)

Question 5

Where in the circulatory system is the major site of gas exchange?

Answer 5

Capillaries

Question 6

What is the innermost layer of all blood vessels?

Answer 6

Tunica intima

Question 7

What is the tunica intima composed of?

Answer 7

Endothelium and basal lamina, smooth muscle cells (sometimes), connective tissue

Question 8

What are the components of the tunica media?

Answer 8

Smooth muscle cells, connective tissue, internal elastic lamina

Question 9

What structures are included in the tunica adventitia?

Answer 9

Connective tissue, vasa vasorum, nervi vascularis, external elastic lamina

Question 10

What seperates the tunica intima from tunica media in large arteries?

Answer 10

Internal elastic membrane

Question 11

What is the thickest layer of large arteries?

Answer 11

Tunica media

Question 12

What feature of the eleastic sheets in the tunica media facilitate nutrient and gas exchage?

Answer 12

Fenestrations

Question 13

What is the source of the elastin, collagen, and other ECM molecules within the tunica media?

Answer 13

Smooth muscle cells

Question 14

What layer of large arteries contain unmyelinated nerves and macrophages?

Answer 14

Tunica adventitia

Question 15

What seperates tunica media from tunica adventitia in muscular arteries?

Answer 15

External elastic lamina

Question 16

How big are arterioles?

Answer 16

10-100 micrometers diameter

Question 17

What is the size of named/muscular arteries?

Answer 17

2-10 mm diameter

Question 18

What is the site of the greatest peripheral resistance in the circulatory system?

Answer 18

Arterioles

Question 19

What are the functions of Weibel-Palade bodies?

Answer 19

Recruitment of platelets to form clots, secrete particular factors that lead to blood clotting

Question 20

What is the general term for moving things from the lumen through the cell and to the basolateral surface? What are the mecanisms by which this is achieved?

Answer 20

Transcytosis; Pinocytosis, Receptor-mediated endocytosis, and channels

Question 21

Where does microcirculation begin and end?

Answer 21

Begins at arterioles and ends at venules

Question 22

What are precapillary sphincters? What is their physiologic function?

Answer 22

Smooth muscle sphincters at the junction of the arteriole and capillary; Occlude the lumens of capillaries, forcing blood through a given channel toward the venous side

Question 23

What are pericytes and what is their function?

Answer 23

Stem cells that surround capillaries, venules, and arterioles; give rise to smooth muscle cells and endothelial cells if damage or injury occurs

Question 24

What layers are within the walls of the capillaries?

Answer 24

Just endothelium- no tunica media or adventitia

Question 25

What are the three types of capillaries?

Answer 25

Continuous capillaries, fenestrated capillaries, and sinusoidal capillaries

Question 26

Where are continuous capillaries found?

Answer 26

Brain, heart, muscle, blood organ barriers

Question 27

Where are fenestrated capillaries found?

Answer 27

Endocrine organs/glands, kidneys

Question 28

Where are sinusoidal capillaries found?

Answer 28

Liver, spleen, bone marrow

Question 29

What is the general function of fenestrated capillaries?

Answer 29

Filtration

Question 30

What is the general function of continous capillaries?

Answer 30

Gas exchange, transcytosis

Question 31

What contributes to the formation of the sinusoids in capillaries?

Answer 31

Incomplete or absent basal lamina

Question 32

What is the general function of sinusoidal capillaries?

Answer 32

Passage of large molecules

Question 33

What is the name of the membrane that may or may not cover fenestrations?

Answer 33

Diaphragms

Question 34

What is a thoroughfare channel?

Answer 34

A microcirculatory structure that has no sphincters and allows blood to avoid some part of the capillary bed

Question 35

What supplies the blood from the arteriole to the thoroughfare channel?

Answer 35

A metarteriole

Question 36

What structure provides a pathway to bypass microcirculation, shunting blood directly from arteries to veins w/o going through the capillary network?

Answer 36

Arteriovenous shunt

Question 37

What is the path of blood flow in an arterial portal system?

Answer 37

Afferent arteriole--> capillary network--> efferent arteriole--> capillary network on other side of organ--> venule

Question 38

What is the path of blood flow in a venous portal system?

Answer 38

Arteriole--> capillary--> vein--> capillary or sinusoid--> vein

Question 39

Regarding the thickness of the wall layers, how could distinguish between an artery and vein?

Answer 39

The tunica adventita is thicker than the tunica media in veins

Question 40

The presence of what in the tunica adventitia indicates the vessel is a vein?

Answer 40

Longitudinal smooth muscle cells

Question 41

How are smooth muscles arranged in the tunica adventitia of large veins?

Answer 41

One layer parallel to blood flow and another layer perpindicular