Human Physiology - Digestion Flashcards Preview

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Flashcards in Human Physiology - Digestion Deck (68)
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1

What is physical digestion?

Digestion through chewing (mastication) and churning in stomach

2

What is chemical digestion?

Digestion through enzymes, juices,

3

What controls digestion?

Hormones, phypothalanus, pepsinogen, trypepsinogen

4

What enzymes are used in digestion?

CCK, Gastrin, Enterogasterone, Secretin, Glucagon, Insulin,

5

What does CCK do?

Causes gall bladder to contract, and release bile salts

6

What are the 4 components of the digestive system?

Ingestion
Digestion
Absorbtion
Egestion

7

What are the layers of the alimentary canal?

Lumen
Mucosa
Submucosa
Muscle layer
Serosa

8

What does Enterogasterone do? Where does it come from?

Excreted from duodenum from high concentration of fats in large intestine, slows peristalsis for more time to digest lipids

9

Where are bacterial flora? What do they do?

Found in large intestine, ferment indigestible carbohydrates, releasing acids and gases. Also synthesize vitamins B and K

10

What is egestion?

undigestible cellulose fibres stores until pressure against colon causes bowl movement

11

What are hormones?

Chemical messenger that travels through the blood stream

12

What is exocrine?

releases hormones through ducts

13

What is endocrine?

releases hormones directly into blood stream

14

What is secretin?

hormone that regulates secretions by pancreas in digestion

15

What is gastrin?

hormone released from the smell or sight of food, releases gastric juice

16

What is Insulin?

hormone released by pancreas and causes liver to absorb glucose from blood and convert it into glycogen for storage, can reduce blood sugar levels

17

What is glucagon?

hormone released in the pancreas for the liver to convert stored glycogen into glucose to increase blood sugar

18

What is the structure of the small intestine?

Villi and microvilli, used to increase surface area

19

What is a lacteal?

lymphatic vessels of the small intestine that absorb digested fats

20

What are some adaptations of the villi?

tight junctions between cells ensure molecules will pass through villi, long structures increase surface area, epithelial cells have more mitochondria to ensure cells have enough ATP to run active transport, lots of pinocytes are present, different kinds of proteins on apical and basal sides to assist in diffusion

21

How are nutrients moved out of the villus?

simple diffusion, facilitated diffusion, active transport, exocytosis

22

How are monosaccarides absorbed?

sodium - potassium pump, requires low concentration of sodium in the epithelium

23

How are lipids absorbed?

monoglycerides and fatty acids through emulsification with bile salts are turned into miscelles, these bile salts carry miscelles into the epithelial cells. They are then converted into triglycerides and combined with cholesterol to become a chylomicron

24

How are amino acids transported into epithelial cells?

active transport into, facilitated diffusion into capillary

25

What happens to the things absorbed in the small intestine?

transported to the liver, which filters and protects our bodies from the harmful stuff we eat

26

What is dietary fibre?

Cellulose

27

What is a primary structure / polypeptide?

formed in dehydration synthesis, amino group from 1 amino acid bonds to carboxyl group of another amino acid (peptide)

28

What is a secondary structure?

formed from polypeptide when H bonds cause chain to coil or fold, caused by R group

29

What is a quaternary structure?

interaction of 2 or more polypeptides

30

What are the steps of protein digestion?

1. Denaturation - mastication / change in pH
2. Deamination - remove amino acids