Body systems

Question 1

State the heirarchy of how cells are organised in a system

Answer 1

Cell, tissue, organ, organ system

Question 2

Define an organ system

Answer 2

A biological system consisting of a group of organs that work together to perform one or more functions

Question 3

Define digestion

Answer 3

The breakdown of large insoluble molecules into small soluble molecules by chemical and physical means

Question 4

State the organ of the digestive system where most nutrients are absorbed

Answer 4

Small intestine (ileum)

Question 5

Describe the function of the pancreas for digestion

Answer 5

Pancreas makes enzymes that break down lipids, proteins and carbohydrates.
No food passes through the pancreas

Question 6

State two organs of the digestive system where physical digestion occurs

Answer 6

Mouth - Teeth mechanically break down food
Stomach - Muscular bag churns food
Duodenum - Bile added, physically breaks down large lipid molecules, emulsifies fats and neutralises stomach acid

Question 7

Order the following organs in order of how food passes through the digestive system:

Ileum
Stomach
Oesophagus
Mouth
Large intestine
Duodenum

Answer 7

1. Mouth, 2. oesophagus, 3. stomach, 4. duodenum, 5. ileum, 6. large intestine

Question 8

Which organs of the digestive system are NOT part of the alimentary canal?

Answer 8

Liver
Gall bladder
Pancreas

All have a function for digestion, but no food passes through

Question 9

Describe how chemical digestion occurs in the mouth

Answer 9

Saliva contains amylase
Amylase is an enzyme which breaks down starch
Only carbohydrates are broken down in the mouth

Question 10

Describe the function of the oesophagus

Answer 10

Connects the mouth to the stomach, moves food by peristalsis (muscle contraction)
No food is digested in the oesophagus

Question 11

Define excretion

Answer 11

The process of eliminating or expelling waste matter

Question 12

List the organs of the excretory system and their functions

Answer 12

Kidney (x2) -
Ureter
Bladder
Urethra

Question 13

Describe the function of the bowmans capsule

Answer 13

To filter the blood

Glucose, salt, amino acids and urea are filtered from the blood

Question 14

State the four main components of a nephron

Answer 14

Bowman’s capsule
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule

Question 15

State the function of the proximal convoluted tubule

Answer 15

Reabsorption of ions

Question 16

State the function of the loop of Henle

Answer 16

Reabsorption of water

Question 17

State the function of the distal convoluted tubule

Answer 17

Selective reabsorption of water

Question 18

State the main compounds excreted in urine

Answer 18

(Water-93-96%)
Urea
Uric acid
Salts

Question 19

Explain the volume and concentration of urine that would be excreted if someone was dehydrated

Answer 19

Because the body needs to retain more water due to dehydration
Then a greater volume of water is reabsorbed from the distal convoluted tubule
Therefore a smaller volume of concentrated urine is produced and excreted