Digestive System Unit 4

Question 1

What is metabolism?

Answer 1

all chemical reactions within cells whether that be catabolic or anabolic

Question 2

What do we take in to our digestive system?

Answer 2

Nutrients- carbohydrates, lipids, proteins, vitamins, minerals, and water

Question 3

Why are we hungry? What stimulates hunger?

Answer 3

The hypothalamus regulates the feeding and satiety hormones. There are both neural and hormonal controls to stimulate hunger.

Question 4

What is food broken into?

Answer 4

It is broken from complex to simple units in the digestive system.

Question 5

Cells use _ to make ATP

Answer 5

small carbon chains (this yields 36 ATP/glucose)

Question 6

Aerobic cellular respiration equation?

Answer 6

C6H12O6 + O2 -> CO2 + H2O + energy (ATP)

Question 7

Aerobic cellular consists of 4 steps:

Answer 7

Glycolysis, preperatory reaction, citric acid cycle/krebs cycle, and oxidative phosphorylation

Question 8

How will energy from nutrients be used?

Answer 8

muscle contraction, nerve impulse conduction, glandular secretions, cell growth, division, and repair and store energy

Question 9

Innermost -> Outermost layers of the GI tract.

Answer 9

Mucosa, submucosa, muscularis, serosa

Question 10

What is the function of the Digestive system?

Answer 10

transfers nutrients from external to internal environment

Question 11

How does transport of nutrients happen (processes)

Answer 11

Ingestion, digestion, egestion, secretion, and absorption.

Question 12

what is absorption?

Answer 12

simple molecules pass into blood or lymph vessels

Question 13

small intestine..
large intestine..

Answer 13

-absorbs all nutrients
-absorbs water and vitamins

Question 14

What are the types of digestion?

Answer 14

Chemical digestion and mechanical digestion

Question 15

what is chemical digestion?

Answer 15

catabolic process, enzymes break complex molecules into simple molecules

Question 16

what is mechanical digestion?

Answer 16

physical movements of digestive tract. (peristalsis and segmentation)

Question 17

what is peristalsis?

Answer 17

unidirectional, forward propulsion

Question 18

what is segmentation?

Answer 18

multidirectional mixing

Question 19

What are the secretions of the digestive system?

Answer 19

Mucus, bile salts, HCL, pepsin, bicarbonate, enzymes

Question 20

Mucus…

Answer 20

comes from GI tract, coats food, protects GI tract

Question 21

Bile salts…

Answer 21

comes from liver and gallbladder, emulsify lipids

Question 22

HCL and pepsin…

Answer 22

HCL (parietal cells), Pepsin (chief cells), both come from the stomach and aid in protein digestion

Question 23

bicarbonate…

Answer 23

comes from pancreas, neutralizes acid

Question 24

enzymes…

Answer 24

comes from salivary glands, stomach, pancreas, brush border. facilitates the break down of food, work best at specific pH

Question 25

what does amylase break down?

Answer 25

starch/sugar

Question 26

what does lipase break down?

Answer 26

fat

Question 27

what does protease break down?

Answer 27

protein

Question 28

Extrinsic neural controls...

Answer 28

occur along long reflexes, parasynthetic stimulation increases motility and secretion

Question 29

Intrinsic neural controls...

Answer 29

Occurs along short reflexes, known as the enteric nervous system (gut brain)

Question 30

intrinsic neural controls structure and function?

Answer 30

-nerve plexuses in muscle wall -feedback loop regulates motility

Question 31

oral cavity consists of what?

Answer 31

cheek muscles, tongue, uvula, teeth

Question 32

what do the cheek muscles do?

Answer 32

aid in mastication (chewing)

Question 33

what does the tongue do?

Answer 33

shapes food into bolus, contains taste buds

Question 34

what does the uvula do?

Answer 34

seals nasal cavity so no food enters

Question 35

what are the types of dentitions?

Answer 35

deciduous (baby) and permanent (adult)

Question 36

how is mechanical digestion achieved in the oral cavity?

Answer 36

mastication

Question 37

how does absorption occur in the oral cavity?

Answer 37

no nutrients are absorbed in the oral cavity, though some drugs are

Question 38

how does chemical digestion occur in the oral cavity?

Answer 38

occurs with saliva which contains water, enzymes, electrolytes, and proteins.

Question 39

functions of saliva?

Answer 39

begin starch digestion, cleanses mouth, moistens to articulate while speaking and ease swallowing.

Question 40

what causes you to salivate?

Answer 40

salivary nuclei in medulla + pons, feedback with ANS

Question 41

structure of the throat (pharynx)

Answer 41

muscular tube and sphincter at both ends

Question 42

function of the pharynx

Answer 42

deglutition (swallowing)

Question 43

1st phase of deglutition

Answer 43

1) Buccal: bolus moves from mouth to pharynx, tongue pushes bolus back, uvula raises to seal nasal cavity

Question 44

2nd phase of deglutition

Answer 44

2) Pharyngeal: bolus moves from pharynx to esophagus, stretch receptors signal swallowing center (medulla) causing breathing halts. Larynx rises, epiglottis folds over glottis. Upper esophogeal sphincter relaxes.

Question 45

3rd phase of deglutition

Answer 45

3) esophogeal: bolus moves from esophagus to stomach, peristalsis pushes bolus, gastroesophageal sphincter opens

Question 46

stomach structure

Answer 46

rugae (folds of mucosa) when collapsed, gastric pits leads to gastric glands, 3 layers of muscle

Question 47

stomach function

Answer 47

begins protein digestion. mix, churn, and pummel food. Absorption does not occur for nutrients yet

Question 48

mucous cells

Answer 48

secrete mucus for stomach's protective coating

Question 49

enteroendocrine cells

Answer 49

secrete chemical messengers

Question 50

chief cells

Answer 50

-secrete pepsinogen (activates pepsin, aids protein digestion) -secrete gastric lipase, aids lipid digestion

Question 51

parietal cells

Answer 51

secrete hydrochloric acid (HCl) (creates acidic conditions that activate pepsinogen)

Question 52

how is HCl acid produced

Answer 52

comes from breakdown of carbonic acid. products are H+ and HCO3-. Antiporter shifts HCO3- into blood as Cl- enters into parietal cell

Question 53

How does gastrin relate to regulating the stomach/intestines?

Answer 53

from the G cells (enteroendocrine) of stomach. Activated by presence of protein, high pH, or stretch of the stomach. Increases gastric secretions, stimulates protein digestions.

Question 54

How does secretin relate to regulating the stomach/intestines?

Answer 54

from the enteroendocrine cells and duodenum. Activated by presence of chyme. Decreases gastric secretions/movements and increases bicarbonate ions which neutralizes acid.

Question 55

How doe cholecystokinin (CKK) relate to regulating the stomach/intestines?

Answer 55

from the enteroendocrine cells and duodenum. Activated by presence of fatty chyme. Decreases gastric secretions, increases bile and pancreatic juice

Question 56

phases of digestion in order

Answer 56

1) Cephalic 2) Gastric 3) Intestinal

Question 57

Cephalic phase of digestion

Answer 57

initiated by taste/smell of food. neural stimulation causes gastric secretion

Question 58

Gastric phase of digestion

Answer 58

food enters stomach, churning occurs. Gastrin stimulates gastric secretion and motility

Question 59

Intestinal phase of digestion

Answer 59

about 4 hours after meal, small amounts of chyme released into duodenum. CCK + secretin inhibit gastric secretion and motility

Question 60

small intestine regions in order

Answer 60

duodenum, jejunum, ileum