Blood Vessels

Question 1

Arterioles have ______ resistance and therefore _______

Answer 1

Peripheral, blood pressure

Question 2

Arterioles, capillaries and veins so are lined with

Answer 2

Simple squamous epithelium

Question 3

Continuous capillary features

Answer 3

1. Adjacent endothelial cells connected by junctional complexes
2. Most common type
3. Impermeable

Question 4

Fernestrated capillary features

Answer 4

1. Small pores (ferestrae) connected by junctional complexes
2. Permeable
3. Found in Bowman’s capsule + small intestine villi

Question 5

Basic structural plan of blood vessels

Answer 5

1. Tunica intima (avascular) : inner-endo cells + connective tissue
2. Tunica media : smooth and connective
3. Tunica adventita: connective + outer

Question 6

Tunica media and adventita may be absent from ______

Answer 6

Small vessels

Question 7

Vaso vasorum

Answer 7

Vessels of vessels -> supplies blood to certain media and adventita

Question 8

Structural features of aorta

Answer 8

Intima: collagen + few elastic fibres, thin layer of c.t.
Media: thick s.m. with sheets of elastic fibres
Adventita: thick collagen, vasa vasorum, nerves

Question 9

Structural features of most systemic arteries

Answer 9

Intima: endo.cells, prominent layer of c.t. = inner elastic lamina
Media: thick s.m. limited c.t.
Adventita: thick c.t. EEL, collagen + nerves

Question 10

Structural features of arterioles

Answer 10

Intima: endo.cells, IEL absent from small arterioles
Media: s.m. 3-6 cells
Adventita: merges with C.T. no EEL

Question 11

Structural features of capillaries

Answer 11

Endo cells, no media/adventita

Question 12

Structural features of venules + veins

Answer 12

Intima: endo. cells , no IEL
Media: s.m.
Adventita: absent/indistinct - merges with c.t.

Question 13

Valves are found in ______ and are

Answer 13

Veins > 2mm diameter, 2 leaflets of c.t. covered with endo.