Principles of organisation

Question 1

What is the order of organisation in the body?

Answer 1

Cell –> tissue –> organ –> organ system –> organism

Question 2

What is a cell?

Answer 2

The basic building blocks of all living things.

Question 3

What is a tissue? (2)

Answer 3

A group of similar cells which work together to carry out a particular function. It can contain more than one type of cell.

Question 4

What is an organ?

Answer 4

A combination of tissues carrying out a specific function.

Question 5

What is an organ system?

Answer 5

Group of organs working together to carry out a particular function.

Question 6

What is epithelial tissue?

Answer 6

Covers some parts of the body, like the inside and outside of your stomach.

Question 7

What is glandular tissue?

Answer 7

Makes and secretes chemicals like enzymes and hormones, in the stomach it makes digestive juices to digest food.

Question 8

What is muscular tissue?

Answer 8

Contracts to move whatever it’s attached to, in the stomach it moves the stomach wall to churn the food.

Question 9

What does the digestive system do?

Answer 9

Breaks down food, large insoluble molecules, into smaller soluble molecules which we absorb into our blood and gives us energy.

Question 10

What is the PH in the mouth?

Answer 10

7 (neutral)

Question 11

What does the mouth do? (2)

Answer 11

Salivary glands make saliva which moistens food to help travel down the oesophagus. Saliva contains amylase to digest starch into sugar.

Question 12

What do the glands do? (3)

Answer 12

Secrete chemicals like enzymes. Produce amylase in the saliva to break starch into sugar. Produce enzymes and stomach acids in the stomach.

Question 13

What does the stomach do? (4)

Answer 13

Glands in the stomach lining produce hydrochloric acid and protease (pepsin). The hydrochloric acid kills bacteria and gives the right ph (1-2) for the protease enzyme to work. The protease breaks down proteins into amino acids. The muscular walls then churn the food.

Question 14

What is the PH in the stomach?

Answer 14

1-2 (acidic)

Question 15

What tissues are the stomach made of?

Answer 15

Epithelial, glandular and muscular.

Question 16

What does the pancreas do?

Answer 16

Produces amylase, protease and lipase, releases all 3 in pancreatic juices into the small intestine.

Question 17

What does the liver do?

Answer 17

Produces bile to be stored in the gall bladder.

Question 18

What does bile do? (3)

Answer 18

Made in the liver, stored in the gall bladder. Added to the small intestine which helps digestion by emulsifying fat into smaller droplets. Neutralises stomach acid to provide correct conditions for the enzymes present in the small intestine.

Question 19

What does the gallbladder do? (2)

Answer 19

Stores bile between meals. When you eat, it squeezes bile through bile ducts into your small intestine.

Question 20

What does the small intestine do? (3)

Answer 20

Has all three enzymes, including lipase which digests lipids into fatty acids. Bile is added into it through gall bladder. The small molecules are absorbed into the blood here from the digestive system.

Question 21

What is the large intestine?

Answer 21

Where excess water is absorbed into the blood from the food, leaving indigestible food to be faeces.

Question 21

What is the PH in the small intestine?

Answer 21

8-9 (alkaline)

Question 22

What is the rectum?

Answer 22

Where faeces is stored until it leaves the anus.

Question 23

IMPORTANT SUMMARY NOTES: (5)

Answer 23

1. starch –> amylase –> sugar
2. protein –> protease –> amino acids
3. lipids –> lipase –> fatty acids and glycerol
4. Mouth has amylase, stomach has protease and HCL, small intestine has all 3 enzymes.
5. Food does not pass through the pancreas, but it adds enzymes, the gall bladder, but it stores bile, and the liver but it creates bile.