lecture 7

Question 1

Function of capillaries

Answer 1

site of exchange between blood and tissues

Question 2

Features of capillaries?

Answer 2

thin walls
large total cross sectional area of capillary bed
slow and smooth blood flow

Question 3

Function of precapillary sphincters?

Answer 3

Control blood flow into capillary beds of certain organs

Question 4

What are precapillary sphincters made up of?

Answer 4

smooth muscle

Question 5

Small lumen of capillaries allows how many red blood cells through at a time?

Answer 5

One red blood cell

Question 6

Why do capillaries allow one red blood cell at a time?

Answer 6

Slows and smooths blood flow
Allows time for gas exchange to occur
blood contact with vessel walls

Question 7

Purpose of thin walls in capillaries?

Answer 7

allow for faster diffusion and large cross sectional area as there are many capillaries.

Question 8

Three types of capillary structures?

Answer 8

continuous
menstruated
sinusoidal

Question 9

Most common type of capillary in the body?

Answer 9

continuous

Question 10

Size of continuous capillary

Answer 10

8-10um

Question 11

Which types of capillaries have intact basement membranes?

Answer 11

Continuous and fenestrated

Question 12

What is the most ‘leaky’ type of capillary?

Answer 12

sinusoidal

Question 13

what is an example of where a fenestrated capillary might be found?

Answer 13

Kidneys and small intestine

Question 14

Where would you find a sinusoidal capillary?

Answer 14

Liver

Question 15

size of a fenestrated capillary?

Answer 15

8-10um

Question 16

size of a sinusoidal capillary?

Answer 16

30-40um

Question 17

What substances can diffuse through capillary cell membrane?

Answer 17

Lipid soluble

Question 18

How do water soluble substances get transported through capillaries?

Answer 18

through the intercellular clefts found in all capillaries or the fenestrations

Question 19

Function of the lymphatic system?

Answer 19

Act as an immune response by screening the drainage of excess tissue fluid and plasma proteins before they return to the blood

Question 20

What is the structure of a lymphatic capillary?

Answer 20

Large and thin, blind ended with valves

Question 21

Where would you find lacteals?

Answer 21

In the small intestine

Question 22

what is the function of lacteals?

Answer 22

they are specialised lymphatic vessels that drain fatty lymph into the cisterna chyli

Question 23

What is the cisterna chyli?

Answer 23

Dilated sac of the thoracic duct

Question 24

Where do cervical and axillary nodes on the right hand side drain into?

Answer 24

The right subclavian vein (into the blood) Via the right lymphatic duct

Question 25

Where do the lymphatic nodes excluding the RHS cervical and axillary nodes drain into?

Answer 25

The thoracic duct and then the left subclavian vein

Question 26

4 functions of the lymph vascular system?

Answer 26

Drains excess tissue fluid and plasma proteins before returning to blood
filters foreign material from the lymph
screens for foreign antigens and conducts an immune response
absorbs fat from intestine and transports it to the blood