N: digestion, absorption & transport

Question 0

describe how muscular actions aid in food digestions in small intestine:

Answer 0

• 2 layers of muscle: inner circular and outer longitudinal
• muscles work together in 2 ways:
  1) PERISTALSIS: pushes digestive contents along
  2) SEGMENTATION: contractions by circular muscles that squeeze contents to promote mixing with digestive juices

Question 1

describe how muscular actions aid in food digestions in stomach:

Answer 1

• 3 layers of muscle: diagonal, circular, longitudinal

- these layers alternatively contract and relax to churn the chyme and force downward

Question 2

2 muscular actions that happen in the small intestine:

Answer 2

peristalsis

segementation

Question 3

what is the action of peristalsis?

Answer 3

pushes digestive contents along

Question 4

what is the action of segmentation?

Answer 4

contractions by inner circular muscles that squeeze contents to promote mixing with digestive juices

Question 5

describe how muscular actions aid in food digestions in sphincter muscles:

Answer 5

• one at top and bottom of stomach
• regulate movement of food through periodically opening and closing
• prevents reflux(backing up) of material

Question 6

enzyme in mouth that digests food?

Answer 6

amylases

Question 7

what digestive processes occur in small intestine?

Answer 7

• pancreas releases bicarbonate to neutralise stomach acid
• ## receives bile salts from liver via gallbladder

Question 8

function of bile:

Answer 8

acts as emulsifier to suspend fat and facilities its digestion by lipase

Question 9

what does saliva digest?

Answer 9

starch digesting enzymes - AMYLASE

Question 10

what is the starch digesting enzyme in saliva?

Answer 10

amylase

Question 11

what does gastric juice work to digest?

Answer 11

enzymes work to digest proteins - proteases

Question 12

what enzyme digests proteins?

Answer 12

proteases in gastric juice from gastric glands

Question 13

function of goblet cells in stomach?

Answer 13

secrete mucus to protect walls of the stomach from high acidity levels
- HCl

Question 14

where is bile produced and how does it end up where it does?

Answer 14

• produced in liver
• stored in gallbladder
• released into small intestine
  ..HOW?
  via hormonal signals

Question 15

Outline the steps involved in the digestion, absorption and transport of triglyceride fats into the blood stream?

Answer 15

answer in notes book

Question 16

Outline the steps involved in the digestion and absorption of proteins and amino acids into the blood stream?

Answer 16

answer in nutrition note book

Question 17

Outline the steps involved in the digestion and absorption of complex carbohydrates into the blood stream?

Answer 17

answer in nutrition note book

Question 18

why does the body need adequate carb for efficient breakdown of fat for energy?

Answer 18

• describe how fat is broken down for energy
• TCA cycle needs oxaloacetate to combine with acetyl-CoA in step 1
• oxaloacetate is made from pyruvate which in turn is made from glucose
• low carb-depleted glucose-TCA does not function
• acetyl-CoA accumulates, ketosis, ketone bodies-less efficient energy
• therefore… conclude

Question 19

how can the body make fatty acids from carbs but not carb from fatty acids?

Answer 19

• describe how carbs can be made into fatty acids - glycolosis
• describe last step of glycolosis
• acetyle CoA either TCA cycle OR makes fatty acid component
• fat can be converted to acetyl CoA and enter TCA/ETC to make ATP but CANNOT be converted to pyruvate
• pyruvate to acetyl-CoA is an irreversible process