Cardiovascular: Anatomy of the Blood Vessels

Question 1

BLOOD VESSELS include:

Answer 1

ARTERIES, VEINS, and CAPILLARIES

Question 2

How many layers do BLOOD VESSELS have?

Answer 2

1) TUNICA EXTERNA aka ADVENTITIA
2) TUNICA MEDIA
3 TUNICA INTERNA aka INTIMA

Question 3

L and S of the TUNICA EXTERNA (ADVENTITIA)

Answer 3

L - Most superficial layer of a BLOOD VESSEL

S - FIBROUS CT, COLLAGEN, and ELASTIC FIBERS

Question 4

L and S of the TUNICA MEDIA

Answer 4

L - Middle layer of a BLOOD VESSEL
S - SMOOTH MUSCLE and ELASTIC CT
*VASCULAR SPASMS occur here

Question 5

L and S of TUNICA INTERNA (INTIMA)

Answer 5

L - Deepest layer of a BLOOD VESSEL
S - 3 layers:
1) ENDOTHELIUM = SIMPLE SQUAMOUS 
2) BASEMENT MEMBRANE = LOOSE AREOLAR CT
3) ELASTIC MEMBRANE = ELASTIC CT (not in veins)

Question 6

T or F: CAPILLARIES have only 1 layers

Answer 6

T, ENDOTHELIUM with thin BASEMENT MEMBRANE

Question 7

S and 3 Fs of ARTERIES

Answer 7

S - Thick TUNICA MEDIA (smooth muscle allows constriction and dilation)
F -
1) Carry BLOOD away from the HEART
2) Most carry Oxygenated BLOOD
3) ELASTIC MEMBRANE facilitates stretching for BLOOD under high pressure

Question 8

3 types of ARTERIES

Answer 8

1) ELASTIC ARTERIES
2) DISTRIBUTING/MUSCULAR ARTERIES
3) ARTERIOLES

Question 9

S of ELASTIC ARTERIES

Answer 9

S - Large, thick layer of ELASTIC TISSUE; high pressure

e.g. AORTA

Question 10

S of DISTRIBUTING/MUSCULAR ARTERIES

Answer 10

S - Mid-sized (several mm); thick SMOOTH MUSCLE LAYER

Question 11

S of ARTERIOLES

Answer 11

S - Smallest (0.5 mm); no externa

Question 12

2 Fs of VEINS

Answer 12

1) Carry BLOOD towards the HEART

2) Most carry DEoxygenated BLOOD

Question 13

T or F: BLOOD is under high pressure while in VEINS

Answer 13

F; BLOOD is under low pressure while in VEINS

Question 14

S of VEINS

Answer 14

S - Thin TUNICA MEDIA (less SMOOTH MUSCLE and very little ELASTIC FIBER)
- Valves to prevent backflow

Question 15

What is the smallest VEIN?

Answer 15

A VENULE

Question 16

S and F of VENULES

Answer 16

S - No SMOOTH MUSCLE

F - Drain BLOOD into VEINS

Question 17

How does the VENOUS system return BLOOD to the HEART if pressure in low?

Answer 17

By using the SKELETAL and RESPIRATORY PUMPS

Question 18

How does the SKELETAL PUMP work?

Answer 18

MUSCLE contraction massages VEINS (valves prevent backflow)

Question 19

How does the RESPIRATORY PUMP work?

Answer 19

Changes in THORACIC and ABDOMINAL pressure

Question 20

What are the smallest BLOOD VESSELS called?

Answer 20

CAPILLARIES, about the diameter of a single RBC

Question 21

What is a network of CAPILLARIES called?

Answer 21

A CAPILLARY BED

Question 22

S and F of CAPILLARIES

Answer 22

S - Only ENDOTHELIUM, thin and permeable

F - Site of exchange between BLOOD and TISSUES

Question 23

What are 3 types of CAPILLARIES?

Answer 23

1) CONTINUOUS CAPILLARIES
2) FENESTRATED CAPILLARIES
3) SINUSOID CAPILLARIES

Question 24

S and F of CONTINUOUS CAPILLARIES

Answer 24

S - ENDOTHELIUM continuous = moderately permeable

F - Main exchange VESSELS in TISSUES (exchange of nutrients, wastes, blood gases, hormones)

Question 25

S and F of FENESTRATED CAPILLARIES

Answer 25

S - ENDOTHELIUM has pores/fenestrations, therefor more permeable
F - For absorption or filtration in KIDNEYS and INTESTINES

Question 26

S and F of SINUSOID CAPILLARIES

Answer 26

S - ENDOTHELIUM has large gaps, therefore the most permeable CAPILLARY
F - Allows the passage of large molecules/cells (in SPLEEN, LIVER, and BONE MARROW)

Question 27

What is a CAPILLARY BED?

Answer 27

A network of CAPILLARIES connecting ARTERIOLES with VENULES

Question 28

What regulates flow through CAPILLARY BEDS

Answer 28

Rings of SMOOTH MUSCLE called PRECAPILLARY SPHINCTERS

Question 29

Give a basic overall summary of CAPILLARIES

Answer 29

• Thin-walled
• Permeable
• Huge surface area