blood, tissue fluid & lymph

Question 1

what is carried in the plasma?

Answer 1

• dissolved glucose, amino acids, mineral ions, hormones and plasma proteins
• red and white blood cells
• platelets

Question 2

state 3 examples of plasma proteins

Answer 2

• albumin: maintains osmotic potential of blood
• fibrinogen: role in blood clotting
• globulins: role in transport and immunity

Question 3

describe platelets

Answer 3

fragments of megakaryocytes found in red bone marrow

Question 4

what process are platelets involved in?

Answer 4

clotting mechanism of blood

Question 5

what % of blood volume is made up of plasma

Answer 5

55%

Question 6

what are fenestrations

Answer 6

small openings / pores in capillary wall that allow substances to pass through

Question 7

what effect do plasma proteins have?

Answer 7

osmotic effect - gives blood in capillaries a high solute potential (low water potential) compared to surrounding fluid

Question 8

what is tissue fluid

Answer 8

fluid that fills gaps between cells after being squeezed out of the capillaries

Question 9

describe the composition of tissue fluid

Answer 9

• water
• dissolved glucose, amino acids, mineral ions, hormones
• red and white blood cells
• platelets

Question 10

what is oncotic pressure?

Answer 10

the tendency of water to move into the blood by osmosis

Question 11

what is the oncotic pressure in capillaries

Answer 11

-3.3kPa

Question 12

what is hydrostatic pressure?

Answer 12

the pressure exerted by the blood of walls of blood vessels (due to heart contractions)

Question 13

what is the hydrostatic pressure at the arterial end of the capillary?

Answer 13

4.6kPa

Question 14

what happens to water at the arterial end of the capillary?

Answer 14

hydrostatic pressure is higher than oncotic pressure, water moves in by osmosis so fluid is squeezed out of the capillaries

Question 15

what happens as blood moves through the capillaries?

Answer 15

balance changes - hydrostatic pressure falls to 2.3 kPa as fluid has moved out, oncotic pressure is still -3.3 kPa so is stronger than hydrostatic

Question 16

what happens to water in the venous end of the capillary?

Answer 16

water moves back into the capillary by osmosis

Question 17

what % of tissue fluid is in the blood vessels once blood has returned to the veins

Answer 17

90%

Question 18

what % of tissue fluid does not return to the capillaries - where does it go?

Answer 18

10% - drains into lymph capillaries

Question 19

what is the composition of lymph

Answer 19

similar to plasma + tissue fluid with less oxygen and fewer nutrients - contains fatty acids absorbed from villi of small intestine

Question 20

how is lymph transported?

Answer 20

through lymph capillaries that get squeezed by body muscles - contain one way valves

Question 21

how does lymph rejoin the blood

Answer 21

flows into subclavian veins (under clavicle/collar bone)

Question 22

what are lymphocytes

Answer 22

type of WBC that is part of the immune system

Question 23

what is a lymph node

Answer 23

small, bean-shaped structure part of immune system

Question 24

what do lymph nodes do?

Answer 24

filter substances that travel through the lymphatic fluid (eg. bacteria and other debris) from lymph to be ingested by phagocytes