The Excretory System

Question 1

What is the excretory system ?

Answer 1

A system which is designed to remove waste products from the body.

Question 2

How are waste products removed from the body in mammals ?

Answer 2

Urine

Question 3

How are waste products removed from the body in reptiles and birds ?

Answer 3

Uric acid

Question 4

What is excretion ?

Answer 4

The removal of metabolic waste products from the body

Question 5

What is Elimination ?

Answer 5

The removal of indigestible foods from the body.

Question 6

What are the 3 sections of which the kidney can be divided into ?

Answer 6

Pelvis , Medulla and Cortex

Question 7

Name the functional units within the kidney

Answer 7

Nephrons

Question 8

What is the function of the cortex section of the kidney ?

Answer 8

A space for the arterioles and venules from the renal artery and viren to perfuse to the nephrons of the kidney.

Question 9

What is the function of the medulla section of the kidney ?

Answer 9

Regulate the concentration of urine

Question 10

What is the function of the Ureters ?

Answer 10

To carry urine from the kidney to the bladder

Question 11

What is the structure of the Ureters ?

Answer 11

Made up of a tube of smooth muscle which forces the urine into the bladder via the use of peristaltic waves.

Question 12

What are the main functions of the bladder ?

Answer 12

Storage of urine before excretion

Question 13

What is the structure of the bladder ?

Answer 13

Built up of transitional epithelium which allows for stretching
Folds of material flatten out when it is full
Covered with a smooth muscle to help with expelling of urine.
Exit is sealed by a sphincter

Question 14

What is the function of the urethra ?

Answer 14

Carries urine from the bladder to the exterior of the body.

Question 15

Describe the structure of the urethra

Answer 15

Made of fibrous tissues and muscle and is lined with mucous membranes
In males it runs through the penis to the environment
In females it is shorter and will lead directly to the outside or will joint the vagina

Question 16

How does the avian excretory system differ to the mammalian excretory system ?

Answer 16

Birds do not have a bladder and they have an excretory system which contains two kidneys a ureter and a colcaca. Birds have a ureter and mammals have a urethra.

Question 17

How is water absorption within the body controlled ?

Answer 17

Water absorption is controlled by ADH ( antidiuretic hormone) in the blood.

Question 18

What is ADH (antidiuretic hormone) ?

Answer 18

A hormone which causes the membrane in the collecting duct to become more permeable to water and therefore this allows for more water to be absorbed resulting in the formation of concentrated small amounts of urine.

Question 19

How is the water potential of the blood detected ?

Answer 19

Sensory cells called osmoreceptors in the hypothalamus

Question 20

What happens when the water potential in the blood is low ?

Answer 20

Water moves out of the osmoreceptors by osmosis which causes the cells to shrivel. Which causes ADH to be made which is then released into the bloodstream by the posterior pituitary gland .