MA - Digestive System I

Question 1

What is the Gastro-intestinal system?

Answer 1

Continuous tube about 30 feet long from mouth to anus

Question 2

What are some of the main functions of the GI system? (5)

Answer 2

• Ingest food
• Transport food
• Digest food into smaller usable components
• Absorb necessary nutrients into the bloodstream
• Elimination of waste products from the body

Question 3

What are some digestive organs in the GI system? (6)

Answer 3

1. Oral Cavity
2. Pharynx and Oesophagus
3. Stomach
4. Small Intestine
5. Large Intestine
6. Rectum and Anal Canal

Question 4

What are accessory digestive organs and what are some examples?

Answer 4

Organs that secrete substances needed for the chemical digestion
* e.g. Salivary glands and the pancreas

Question 5

What 4 layers make up the digestive tract?

Answer 5

INNER
* Mucosa
* Submucosa
* Muscle
* Serosa

OUTER

Question 6

How is the oral cavity involved?

Answer 6

Involved in the manual breakdown of food

Question 7

What are some functions of saliva? (5)

Answer 7

1. Begin digestion to starches
2. Keep mouth moist
3. Lubricate food
4. Prevents tooth decay
5. Control bacterial flora of the mouth

Question 8

What are the 3 main glands present in salivary glands?

Answer 8

1) Parotid- serous

2) Submandibular- serous and mucous

3) Sublingual- mucous

Question 9

What are the 3 types of secretory units and what do they secrete?

Answer 9

1) SEROUS - Secretes Proteins

2) MUCOUS - Secretes Mucin

3) MIXED - Secretes Serous and Sialomucins

Question 10

What does the oesophagus do?

Answer 10

Transports food and fluid from the pharynx through the thorax and diaphragm to the stomach

Question 11

What does the stomach do?

Answer 11

Acidifies food during digestion and contains mucous-secreting cells to protect the mucosal surface

Question 12

What is the function of the small intestine?

Answer 12

The primary site of absorption of nutrients
* The wall has a huge absorptive surface area due to Microvilli

Question 13

What are the 3 layers in the small intestine?

Answer 13

1. Duodenum- Secrete alkaline to protech from stomach acid
2. Jejunem- Contain villi and goblet cells
3. Ileum- Presence of lipid aggregations

Question 14

What is the function of the large intestine?

Answer 14

Absorbs fluid (water and electrolytes)

Question 15

How much smooth muscle is present on each structure?

Answer 15

Oesophagus: 2 – circular and longitudinal
Stomach: 3 – oblique, circular and longitudinal
Small Intestine: 2 – circular and longitudinal
Large Intestine: 2 – circular and longitudinal