extended response

Question 1

Urinary System:

three hormones that affect reabsorption and excretion of water and sodium in the collecting ducts (5 marks).

Answer 1

Aldosterone
ADH
Atrial natriuretic peptide

Question 2

describe aldosterone

Answer 2

Aldosterone – produced in the adrenal cortex, stimulates the reabsorption of water and sodium ions in the kidney which results in increased blood pressure and volume

Question 3

ADH

Answer 3

ADH – controls the amount of water lost in the urine, reabsorbing the water through cells into the blood

Question 4

Atrial natriuretic peptide

Answer 4

Atrial natriuretic peptide which is produced by the heart, it opposes aldosterone -increase the amount of sodium lost, this affects the blood volume especially the water, so the blood volume will decrease because less sodium and the water will follow the sodium and more water lost
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Question 5

Kymphatic and Immunity

1. Name two physical barriers that contribute to the body’s defence (O.5 marks each total 1 mark).

Answer 5

skin and mucous membrane

Question 6

2. List and briefly describe six internal non-specific defences (6 marks).

Answer 6

fever
inflammation 
complement 
phagocytes 
immune surveillance 
interferons

Question 7

3. A) Name the four cell types that T cells differentiate into (2 marks)

Answer 7

Cytotoxic
memory
helper
regulatory

Question 8

memory T cell

Answer 8

responds to a previousy encountered antigen

Question 9

cytotoxic

Answer 9

attacks foreign cells or body cells infected by viruses

Question 10

HELPER

Answer 10

helper stimulates the activation and function of T and b CELLS

Question 11

Regulatory

Answer 11

moderate activity of T and b cells

Question 12

Describe the roles of two of these cell types in the specific immune response (3 marks)

Answer 12

B cells secrete antibodies that neutralize the virus.

T cells react directly against a foreign antigen that is presented to them on the surface of a host cell.

Question 13

a) List and briefly describe three ways that the respiratory system defends itself against pathogens and particles. (3 marks)

Answer 13

Macrophages

mucous escalator

Question 14

b) Name one specific cell that plays a key role in defending the respiratory system and describe how it does this. (2 marks)