Digestive system

Question 1

What are the basic processes of digestion?

Answer 1

1. ingestion
2. mechanical and chemical digestion
3. absorption
4. elimination

secretion, mixing and propulsion

Question 2

How is food broken down?

Answer 2

Physically- chewing and grinding

Chemically- enzymes in the stomach and small intestine
- microbes in the stomach and large intestine

Question 3

Describe a simple digestive tract.

Answer 3

1. Mouth
2. Pharynx
3. Oesophagus
4. Stomach
5. Small Intestine
6. Large intestine
7. Rectum

Question 4

What are the related structures of the digestive system?

Answer 4

Salivary glands- enzymes eg; lysozyme and amylase
Pancreas- secretes hormones and enzymes into the small intestine
Liver- forms bile and secretes it into the small intestine via the sphincter

Question 5

What are the parts of the mouth?

Answer 5

Lips
cheeks
hard and soft palate
tongue
teeth
pharynx
oesophagus

Question 6

What is the function of the tongue?

Answer 6

mastication
taste
thermoregulation
papillae for grooming

Question 7

What are teeth made up of?

Answer 7

above gum;
- enamel
- dentine
- pulp
below the gum;
- root
- neck
- crown
- alveolus
- periodontium

Question 8

What are the functions of the incisors?

Answer 8

• cutting and grasping

Question 9

What are the functions of the canines?

Answer 9

tering and grasping

Question 10

What are the functions of the premolars?

Answer 10

sharp edges for crushing

grinding surface

Question 11

What are the functions of the molars?

Answer 11

grinding

Question 12

What happens in swallowing?

Answer 12

1. soft palate rises
2. epiglottis lowered to close trachea
3. pharynx directs food into the oesophagus aided by the tongue
4. peristalsis propels food down towards the stomach

Question 13

What are the three phases of swallowing?

Answer 13

Buccal Phase- voluntary
Pharyngeal phase- involuntary
Oesophageal phase- involuntary

Question 14

What is tunica mucosa?

Answer 14

epithelium
connective tissue (muscular mucosa)

Question 15

What is tunica submucosa?

Answer 15

loose connective tissue
blood vessels
nerves

Question 16

What is tunica muscularis?

Answer 16

smooth muscle

nerve fibre network

Question 17

What is tunica serosa or adventitia?

Answer 17

serosa- abdominal cavity membrane that secretes serous fluid eg; liver, spleen and stomach
adventicia- loose connective tissue or retroperitoneal organs eg; kidney, bladder aorta or oesophagus

Question 18

What is the oesophagus?

Answer 18

collapsible muscular tube
bolls into stomach
made up of tunica mucosa, submucosa, adventitia, muscularis

Question 19

What secretory epithelial cells cover the lining of the stomach?

Answer 19

1. Mucous cell; secrete alkaline mucous to protect the epithelium against stress
2. G cells; secret hormones gastrin and stimulates parietal and chief cell contractions
3. Parietal cells; secrete hydrochloric acid and intrinsic factor
4. Chief cells; secrete pepsinogen