4. Blood Vessels and Nerves

Question 1

What are the 8 layers of arteries?

Answer 1

• Lumen
• Endothelium
• Basement membrane
• Intima
• Internal elastic lamina
• Media
• External elastic lamina
• Adventitia

Question 2

What are the elastic arteries?

Answer 2

Arteries near the heart- aorta and pulmonary arteries

Question 3

What is a key feature of elastic arteries?

Answer 3

The media contains abundant concentric sheets of elastin

Question 4

What are muscular arteries?

Answer 4

Most arteries with media comprising layers of smooth muscle and little elastin in the media

Question 5

What are arterioles?

Answer 5

Resistance vessels having 3 or fewer muscle layers in their media

Question 6

Describe the elastic laminae of arterioles.

Answer 6

Poorly defined

Question 7

What are the 2 layers of capillaries?

Answer 7

• Basement membrane
• Endothelium

Question 8

What are present at intervals along capillaries?

Answer 8

Pericytes

Question 9

How do fenestrated capillaries differ from normal capillaries?

Answer 9

They have tiny openings called pores which allow larger molecules and proteins to move from the blood into organs and glands

Question 10

Name 2 examples of where you might find fenestrated capillaries.

Answer 10

• Kidney
• Liver

Question 11

What are the 7 layers of veins?

Answer 11

• Lumen
• Endothelium
• Basement membrane
• Intima
• Internal elastic lamina
• Media
• Adventitia

Question 12

Describe venules.

Answer 12

Thin walled and associated with arterioles with contractile pericytes wrapped around the outisde of endothelial cells

Question 13

What is the difference between venules and veins?

Answer 13

Pericytes are replaced by smooth muscle as venules become veins

Question 14

Compare vein wall thickness to venules and arteries.

Answer 14

Large veins are thick walled compared to venules and thin walled compared to corresponding arteries

Question 15

What might smooth muscle in vein walls be?

Answer 15

Circular or longitudinal

Question 16

Describe lymphatics.

Answer 16

Thin walled, similar to capillaries and veins with valves

Question 17

What do lymphatics contain?

Answer 17

Eosinophilic lymph (possibly lymphocytes too)

Question 18

What are peripheral nerves composed of?

Answer 18

Axons

Question 19

What are peripheral nerves supported by?

Answer 19

Schwann cells and most are myelinated

Question 20

What is myelin produced by?

Answer 20

Schwann cells

Question 21

What are the 3 components of myelinated peripheral nerves?

Answer 21

• Endoneurium
• Perineurium
• Epineurium

Question 22

Where is endoneurium located in myelinated peripheral nerves?

Answer 22

Present between individual axons

Question 23

Where is perineurium located in myelinated peripheral nerves?

Answer 23

Surrounds the groups of axons to form fascicles

Question 24

Where is epineurium located in myelinated peripheral nerves?

Answer 24

Binds fascicles together to form nerve fibres

Question 25

What are small peripheral nerve fibres?

Answer 25

Bundles of axons interspersed with endoneurium and surrounded by perineurium and epineurium

Question 26

What is a small neuro-vascular bundle?

Answer 26

Nerve, arteriole and venule

Question 27

What does myelin do?

Answer 27

Insulates axons

Question 28

What are gaps between Schwann cells?

Answer 28

Nodes of Ranvier

Question 29

How do impulses in myelinated and unmyelinated axons differ?

Answer 29

Myelinated axons transmit impulses faster

Question 30

Where are motor neurones located?

Answer 30

Cell bodies in grey matter of the spinal cord

Question 31

Where are sensory neurones located?

Answer 31

Cell bodies in dorsal root ganglion

Question 32

Where are sympathetic neurones located?

Answer 32

In grey matter of cord and in adjacent sympathetic ganglia

Question 33

Where are parasympathetic neurones located?

Answer 33

Cell bodies in brain and local ganglia