4.2.1 Excretion

Question 1

define the term excretion;

Question 2

explain the importance of removing metabolic wastes, including carbon dioxide and nitrogenous waste, from the body

Question 3

describe, with the aid of diagrams and photographs, the histology and gross structure of the liver

Question 4

describe the formation of urea in the liver, including an outline of the ornithine cycle

Question 5

describe the roles of the liver in detoxification

Question 6

describe, with the aid of diagrams and photographs, the histology and gross structure of the kidney;

Question 7

describe, with the aid of diagrams and photographs, the detailed structure of a nephron and its associated blood vessels

Question 8

describe and explain the production of urine, with reference to the processes of ultrafiltration and selective reabsorption

Question 9

explain, using water potential terminology, the control of the water content of the blood, with reference to the roles of the

• kidney, osmoreceptors in the hypothalamus and
• the posterior pituitary gland;

Question 10

outline the problems that arise from kidney failure and discuss the use of

• renal dialysis and
• transplants for the treatment of kidney failure (HSW6a, 6b, 7c);

Question 11

describe how urine samples can be used to test for pregnancy and detect misuse of anabolic steroids (HSW6a, 6b).