DIGESTIVE SYSTEM

Question 1

List the 6 features of the gastrointestinal tract

Answer 1

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

Question 2

List the 6 accessory organs to to the digestive system

Answer 2

1. Teeth
2. Tongue
3. Salivary glands
4. Liver
5. Gall bladder
6. Pancreas

Question 3

Define:

1. Ingestion
2. Secretion
3. Mechanical processing

Answer 3

1. taking in foods and liquids
2. addition of water, acids, buffers, and enzymes into GI tract
3. physical breakdown of food, mix with secretions, move contents towards anus

Question 4

Define

1. Digestion
2. Absorption
3. Defecation

Answer 4

1. Chemical breakdown
2. Uptake of nutrients through epithelial cells into blood or lymph
3. elimination of wastes, bacteria and dead cells

Question 5

What are the functions of salivary glands?

Answer 5

• lubricates and flushes surfaces
• dissolves chemicals that stimulate taste buds
• bacterial control
• chemical digestion

Question 6

Pharynx function

Answer 6

• respiratory function: Nasopharynx
• Respiratory and digestive function: oropharynx and laryngopharynx
• Swallowing

Question 7

What are the functions of the oesophagus

Answer 7

-Moves bolus from pharynx to stomach via peristalsis
- Upper oesophageal sphincter: regulates movement into oesophagus
Lower oesophagus sphincter: regulates movement into stomach

Question 8

What is peristalsis?

Answer 8

Waves of muscular contraction

Question 9

What are the 3 subsections of the small intestine?

Answer 9

1. Duodenum: receives chyme and digestive secretions, neutralises stomach acids
2. Jejunum: chemical digestion and nutrient absorption
3. The ileum: ends at ileocecal valve (sphincter)

Question 10

What are the mechanical functions of the small intestine?

Answer 10

• Mixes chyme (food mixed into acidic environment) with secretions
• Increases absorption
• Moves residue forwards
• Begins with segmentation
  Followed by peristalsis

Question 11

What are the functions of the large intestine?

Answer 11

• Absorption of vitamins produced by bacteria
• Reabsorption of remaining water
• Compaction and storage of faeces prior to defecation
• Produces mucous for lubrication
• Motility

Question 12

What is the defecation reflex?

Answer 12

Parasympathetic spinal reflex stimulated when the colon is stretched, possible to postpone

Question 13

The epithelium contains gastric glands made of…

Answer 13

1. Parietal cells - secrete HCl, kills microbes, activates pepsin
2. Chief cells - secrete pepsinogen, converts pepsin by HCl

Question 14

What is the function of the gall bladder?

Answer 14

Stores and concentrates bile

Question 15

What is the function of the liver?

Answer 15

Produces and secretes bile

Question 16

Endocrine cells secrete…

Answer 16

insulin and glucagon

Question 17

Exocrine cells secrete…

Answer 17

pancreatic juice

Question 18

What are the pancreatic enzymes?

Answer 18

• Pancreatic amylase
• Proteases e.g., trypsinogen, prolastase
• Pancreatic lipase

Question 19

How are carbohydrates absorbed?

Answer 19

• as monosaccharides, fructose, glucose and galactose
• They travel in blood to liver, fructose and galactose are converted to glucose, the excess is removed and stored as glycogen

Question 20

How are proteins absorbed?

Answer 20

• As amino acids

- Travel in blood to the liver,

Question 21

90% of absorption occurs in the small intestine, what absorption occurs in the large intestine?

Answer 21

• reabsorption of remaining water
• reabsorption of bile salts
• absorption of vitamins produced by bacteria