Lecture 33

Question 1

what are the 6 main parts of the Gastrointestinal tract?

Answer 1

• mouth
• esophagus
• stomach
• small intestine
• large intestine
• rectum and anus

Question 2

What are the 4 main GIT accessory organs, and how they help digestion?

Answer 2

• salivary glands
• liver
• gall bladder
• pancreas

Question 3

name the three macronutrients and describe what they are used for by our cells.

Answer 3

• Carbohydrates (energy/ ATP)
• Proteins (building blocks)
• lipids/ fats (energy/ ATP, building blocks)

Question 4

what are the two types of digestion that food undergoes in the GIT, and what is their function?

Answer 4

physical/ mechanical digestion and chemical/ enzymatic digestion

Question 5

how does food move trough the GIT, and what prevents it from going the wrong way?

Answer 5

trough a long tube that goes from the mouth to anus

things that prevents the food moving the wrong way:

• peristalsis ( waves of smooth muscle contraction )
• Sphincters ( a ring of muscle around the junction (join) between parts of the GI tract

Question 6

what is the role of the stomach in digestion, and how is it controlled?

Answer 6

its controlled by the Enteric nervous system (ENS)

• controls movement of food
• secretion of mucus and enzymes
• absorption of water, ions and nutrients

the stomach is used for storage and allows time for food to be physically and chemically digested.

Question 7

what is the role of the small intestine in digestion, and how is it controlled?

Answer 7

chemical digestion of carbohydrates and absorption of 90% of the nutrients. it is controlled by segmentation (a rhythmic contraction and relaxation) and peristalsis

Question 8

what is the role of the large intestine/ colon in digestion?

Answer 8

• Absorption of vitamines and water

- microbial fermentation