Digestion

Question 1

What is the function role of the Mouth?

Answer 1

Breaking up food into smaller pieces via mastication and mix with saliva to aid with digestion and swallowing

Question 2

What is Mastication?

Answer 2

The act of chewing food, the first stage of digestion

Question 3

What is Pretension?

Answer 3

Gathering

Question 4

What is Deglutition

Answer 4

Swallowing

Question 5

What is the main function of the Salivary Gland?

Answer 5

Lubricate and facilitate packaging a food bolus for its passage down the oesophagus

Question 6

What are some other functions of the Salivary Gland/Saliva?

Answer 6

Thermoregulation, oral cavity cleaning, buffering of weak acids, reduction of oral bacteria growth + protection

Question 7

How many layers are there in a tooth?

Answer 7

4

Question 8

What are the four layers of the teeth?

Answer 8

Enamel, Dentin, Cementum and Pulp

Question 9

What are the function of the teeth?

Answer 9

Aid in initial digestion stage by helping break up the food

Question 10

What are the types of teeth in a Carnivore?

Answer 10

Incisors, Canines, Premolars, Molars and Carnissials

Question 11

What are the types of teeth in a Herbivore?

Answer 11

Eleodontal Incisors, 2nd Incisors, Premolars and Molars

Question 12

What is the function of the Molars?

Answer 12

Grinding

Question 13

What is the Oesophagus?

Answer 13

Tubular, elongated organ of the digestive system which connects the pharynx to the stomach

Question 14

What is the main function of the Oesophagus?

Answer 14

Transport food entering the mouth through the throat and into the stomach

Question 15

How long does it usually take the food to travel from the mouth to the stomach?

Answer 15

4-8 Seconds

Question 16

How does the food go down?

Answer 16

Peristalsis of the circular muscle contracts and relaxes to push food down.

Question 17

What takes place in the Monogastric stomach?

Answer 17

Mechanical digestion

Question 18

What is Mechanical digestion?

Answer 18

Churning of the stomach makes food break down in size giving it a larger surface area

Question 19

What do the gastric juices produced by churning consist of?

Answer 19

• Pepsinogen
• Hydrochloric acid (HCL)
• Mucus

Question 20

What is produced by stimulus of the stomach wall?

Answer 20

Gastrin

Question 21

What is produced to slow churning and reduce pH?

Answer 21

enterogastrone

Question 22

What is Mucus produced for?

Answer 22

Protection from excess stomach acid and most of all autolysis. It also acts as a lubricant, reducing friction

Question 23

What are the three cells that the stomach wall also contains?

Answer 23

Oxyntic cells, goblet cells and peptic cells

Question 24

What do Oxyntic cells do?

Answer 24

Secrete hydrochloric acid (HCL)

Question 25

What do goblet cells do?

Answer 25

Mucus

Question 26

What do peptic cells do?

Answer 26

Secrete Pepsin

Question 27

What is the Duodenum?

Answer 27

The first 20cm of the small intestine

Question 28

Where does the duodenum receive secretions from?

Answer 28

Liver and Pancreas

Question 29

What happens in the Duodenum?

Answer 29

- Further digestion takes place. - Input of pancreatic juices. - Lipids are broken down into fatty acids. - Protein is broken down into amino acids. - The digestion of carbohydrates takes place inside cells.

Question 30

Why is there a large surface area in the Duodenum?

Answer 30

Large number of villi

Question 31

What does the liver do?

Answer 31

Produce bile

Question 32

What is Bile made up of?

Answer 32

Bile salts and Mineral salts

Question 33

What do Bile salts do?

Answer 33

Help with the digestion of fats by breaking them down from large globules to smaller globules, lowering surface tension and making a larger surface area

Question 34

What do Mineral salts do?

Answer 34

Neutralise the stomach acid (HCl) to around 7/8 pH in the small intestine

Question 35

What does the Pancreas do?

Answer 35

Produces pancreatic juices which contain pancreatic amylase, pancreatic lipase and trypsinogen (or trypsin in its active form)

Question 36

What does Pancreatic amylase do?

Answer 36

Converts the remaining amylose (starch) into maltose

Question 37

What does Pancreatic lipase do?

Answer 37

Converts lipids into fatty acids and glycerol

Question 38

What does Trypsinogen do?

Answer 38

Trypsinogen, upon meeting with the enzyme enterokinase, is activated and is called trypsin. Trypsin then continues to break down proteins in digestion.

Question 39

What does the Jejunum and Ileum do?

Answer 39

The longest part of the small intestine, secretes endopeptidases and exopeptidases. Nutrients and water are absorbed here aided by villi.

Question 40

What happens to Sucrose?

Answer 40

Sucrose is hydrolysed into fructose and glucose by sucrase

Question 41

What happens to Maltose?

Answer 41

Maltose is also hydrolysed into two glucose by maltase

Question 42

What happens with the walls of the intestines here?

Answer 42

Here the walls of the small intestine begin to thin and narrow, and the blood supply is reduced

Question 43

What does the Mucosa do in the jejunum and ileum?

Answer 43

Secretes small amounts of digestive enzymes and lubricates mucus while absorbing nutrients

Question 44

95% of what is absorbed by the small intestine?

Answer 44

Carbohydrates and Proteins

Question 45

What else does the small intestine absorb?

Answer 45

About 90% of the water that it receives during digestion

Question 46

What does the large intestine do?

Answer 46

Absorbs water (by osmosis), minerals and vitamins

Question 47

What does Chyme, at the start of the large intestine, consist of?

Answer 47

Water, bile, mucus, dead cells, bacteria and undigested food

Question 48

What is different in the large intestine than the small intestine?

Answer 48

- larger lumen - smaller in length - thinner wall

Question 49

Where are faeces stored and excreted?

Answer 49

Faeces are stored in the rectum and then egested through the sphincter muscle called the anus