Vascular biology II

Question 1

What are the three types of capillaries?

Answer 1

1. Continuous
2. Fenestrated
3. Sinusoidal

Question 2

What type of junctional complexes do continuous capillaries have?

Answer 2

Tight junctions (complete or incomplete)

Question 3

What are the main characteristics of continuous capillaries?

Answer 3

1. Tight junctions
2. Lack pores or fenestrae
3. Numerous pinocytotic vesicles
4. Well-developed basal lamina

Question 4

Where are continuous capillaries found?

Answer 4

1. Brain
2. Muscle
3. Connective tissue
4. Exocrine glands

Question 5

What are the characteristics of fenestrated capillaries?

Answer 5

1. Fenestrae / pores
2. Pores closed by thin diaphragm
3. Continuous basal lamina

Question 6

Where are fenestrated capillaries found?

Answer 6

Areas of rapid exchange:

1. Kidney, nonglomerular
2. Endocrine glands
3. Intestines
4. Kidney, glomerulus - diaphragms absent

Question 7

What are the characteristics of sinusoidal capillaries?

Answer 7

1. Discontinuous endothelial lining - large openings
2. Discontinuous or absent basal lamina
3. Macrophages present

Question 8

Where are sinusoidal capillaries found?

Answer 8

Areas of rapid exchange where cells can be exchanged:

1. Red bone marrow
2. Liver
3. Spleen
4. Adrenal cortex

Question 9

Which veins possess longitudinal bundles of smooth muscle in the adventitia?

Answer 9

IVC, SVC, brachiocephalic, renal, iliac

Question 10

Vasculogenesis: definition

Answer 10

De novo vessel formation

Question 11

De novo vessel formation

Answer 11

Vasculogenesis

Question 12

Angiogenesis: definition

Answer 12

Growth from pre-existing EC-derived channels

Question 13

Growth from pre-existing EC-derived channels

Answer 13

Angiogenesis

Question 14

Arteriogenesis: definition

Answer 14

Formation of arteries, arterioles and collateral vessel remodeling

Question 15

Formation of arteries, arterioles and collateral vessel remodeling

Answer 15

Arteriogenesis

Question 16

Neovascularization: definition

Answer 16

Overarching term to include vasculogenesis, angiogenesis, and arteriogenesis

Question 17

Overarching term to include vasculogenesis, angiogenesis, and arteriogenesis

Answer 17

Neovascularization

Question 18

Vascular remodeling: definition

Answer 18

Vascular response to alterations in the environment

Question 19

Vascular response to alterations in the environment

Answer 19

Vascular remodeling

Question 20

What are the two mechanisms of blood vessel formation?

Answer 20

1. From endothelial precursor cells

2. From pre-existing vessels

Question 21

Where do EPCs reside?

Answer 21

Red bone marrow of adults and non-bone marrow niches

Question 22

What are the functions of the EPC mechanism for vessel formation?

Answer 22

1. Replace lost endothelial cells
2. Re-endothelialization of vascular implants
3. Neovascularization of ischemic organs, wounds, and tumors

Question 23

What are the steps for vessel formation from pre-existing vessels?

Answer 23

1. Vasodilation (via NO) and increased permeability (via VEGF)
2. Proteolytic degradation of basal lamina (via MMPs)
3. Loss of intercellular junctions (via plasminogen activator)
4. Migration and proliferation of endothelial cells (via VEGF, ANG-2)
5. Endothelial cells mature into endothelial capillary tube
6. Elaboration of basal lamina (via FGF) and recruitment of periendothelial cells

Question 24

What protein do tumor endothelial cells express?

Answer 24

Tumor endothelial marker 8 (TEM8)