Topic 14 Flashcards

1
Q

Digestion involves..

A
  • digestive tract

- accessory organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Digestion

A

breakdown of large food pieces into smaller molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Absorption

A

from human to enterocytes (small intestinal cells) of villi to blood/lymph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Motility

A

smooth muscle contractions in tract. mix (segmentation, churning) move (peristalsis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Secretion

A

digestive juice into lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Mouth contains..

A

salivary glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Salivary glands

A

saliva moistens and prevents cavities (lysozyme and antibodies)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

PSNS stimulate secretion of what saliva

A

thin, enzyme rick saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

SNS stimulate secretion of what saliva

A

much rich saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Mouth aids in what processes

A

digestion and absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Mouth digestion

A

mechanical (chewing) and chemical.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Mouth breaks down carbohydrates into..

A

disaccharides and oligosaccharides. (using salivary amylase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Mouth breaks down triglycerides into..

A

fatty acids and monoglycerides (using lingual lipase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Mouth absorption

A

no food just some drugs (ex: nitroglycerine for angina/ vasodilator)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Pharynx and esophagus aids in..

A

swallowing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Swallowing occurs in 3 phases

A
  • buccal phase
  • pharyngeal phase
  • esophageal phase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Buccal phase

A

voluntary. food is compacted by the tongue into a bolus and moves pharynx by tongue pressing on hard palate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Pharyngeal phase

A

involuntary. food in pharynx triggers signals to swallowing centre (medulla) and initiates swallowing reflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Esophageal phase

A

food mols down esophagus (peristalsis). somatic motor neurons to skel. muscle (upper 1/3). middle is mix of PSNS and motor. lower 1/3 is PSNS to smooth muscle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Food can’t enter or re enter..

A
  • mouth: tongue on hard palate
  • nasopharynx: uvula, soft palate elevated.
  • trachea: glottis and epiglottis closed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Stomach mechanical digestion

A

churning/motility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Stomach chemical digestion consists of..

A
  • carbohydrates
  • lipids
  • proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Stomach chemical digestion of carbohydrates

A

salivary amylase unti pH <7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Stomach chemical digestion of lipids

A

lingual lipase (tongue), gastric lipase (chief cells), until pH <5-6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Food in stomach digestion =

A

buffer: pH doesn’t change right away

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Stomach chemical digestion of proteins

A

HCl (pariental cells) denatures proteins and acts on pepsinogen (chief cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Stomach protected from self digestion by..

A

alkaline mucus (mucus cells) barrier can be penetrated by alcohol, aspirin, vinegar, bile.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Stomach absorption

A

very little absorption of food. some drugs like alcohol and aspirin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Small intestine mechanical digestion

A

segmentation and peristalsis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Small intestine chemical digestion involves..

A
  • pancreas
  • gallbladder/liver
  • intestinal wall
31
Q

1st step of chemical digestion in the small intestine

A

neutralize acid so pancreatic enzymes can work. alkaline fluid (HCO3) from duct cells of pancreas and gallbladder.

32
Q

2nd step of chemical digestion in the small intestine

A

pancreatic enzymes into intestinal lumen from pancreatic acinar cells

33
Q

Regulation of pancreatic enzyme secretion

A

fatty acids and amino acids in duodenum increase cholecystokinin (CKK = hormone)

34
Q

Effects of CCK

A
  • high pancreatic enzyme secretion
  • stimulate gallbladder contractions/release bile.
  • low gastric motility (slow emptying) and low gastric secretion
35
Q

In small intestine we have..

A
    • di- and oligosaccharides – too big to be absorbed
    • amino acids – can be absorbed peptides (most too big to be absorbed)
  • -fatty acids and monoglycerides (can be absorbed)
36
Q

3rd step of chemical digestion in the small intestine

A

intestinal wall enzymes further break down on microvilli of enterocytes

37
Q

Lactase deficiency

A

lactose intolerance. remains undigested and bacteria in large intestine ferment lactose (gas, diarrhea)

38
Q

Celiac disease

A

gluten damages villi. low absorptive area for everything so bacterial fermentation in large intestine (gas diarrhea)

39
Q

Lipids/fats in intestinal wall digestion

A

none! no digestion

40
Q

Absorption of the small intestine is the main site due to..

A
  • large surface area (folds, villi)

- nutrients = small molecules

41
Q

H2O in the small intestine

A

approx. 8500 mL/ day absorbed at small intestine, assuming that..
- -H2O ingested in food/ drink = ~2000 mL/day
- -H2O from secretions = ~7000 mL/day
so. . 9000mL/day enters small intestine, ~500 mL/day lost to large intestine

42
Q

Absorbed nutrients from small intestine go to..

A
  • liver via hepatic portal vein (blood

- into lacteals (lymph) from thoracic duct from left subclavian vein

43
Q

Fat digestion/absorption in small intestine requires bile from..

A
  • liver (synthesizes)

- gallbladder (stores)

44
Q

Bile consists of..

A
  • H2O
  • bile salts (from cholesterol)
  • cholesterol (only excretory route)
  • bile pigments (bilirubin from rbc breakdown)
  • ions
  • detoxified/ inactivated drugs, toxins, hormones
45
Q

Function of bile salts: emulsification

A

breaks up larger globules of fat into many small droplets

46
Q

Function of bile salts: micelle formation

A

keeps fat digestion products in solution

47
Q

Micelle

A

bile salts and phospholipids. interior is hydrophobic. exterior is hydrophilic.

48
Q

3 regulatory phases of gastric motility/secretion

A
  • cephalic phase
  • gastric phase
  • intestinal phase
49
Q

Cephalic phase

A

prepares stomach for food. triggers are thought site, smell, taste of food. if no food enters stomach there is low pH inhibits secretion

50
Q

Gastric phase

A

food in stomach distension, activates starch receptors. food buffer pH slowly, reaches 3 when stomach nearly empty when pH < 3. shuts down NS (enteric) and low gastrin so low acid and enzymes.

51
Q

Intestinal phase

A

controls rate of chyme (=food and gastric juice) entry into duodenum.

52
Q

Gastric emptying is regulated so that..

A
  • acid can be neutralized in small intestine (or enzymes won’t work)
  • tonicity doesn’t overwhelm small intestine
  • there is time for dig/abs in small intestine
53
Q

During intestinal phase initially for a short time..

A

get high gastric secretion. duodenal gastrin release (due to duodenal stretch)

54
Q

During intestinal phase inhibitory signals cause low gastric motility/slow emptying due to:

A
  • CCK released due to presence of fa, aa
  • enterogastric reflex (enteric NS). triggered by aa/peptides, acid, duodenal stretch, hypertonicity decrease motility directly and signals CNS to SNS
55
Q

During intestinal phase inhibitory signals cause low gastric secretion (acid, enzymes) due to..

A
  • secretin: release due to acid

- CCK: released due to aa and fa

56
Q

Digestion from stomach and duodenum hormone

A

gastrin: high acid, gastric enzyme secretion (lipase and pepsinogen)

57
Q

Digestion from duodenum only hormones

A
  • secretin causes HIGH alk. flood secretion from ducts of pancreas and gallbladder and LOW gastric secretion
  • CCK causes HIGH pancreatic enzyme secretion and contraction of gallbladder and LOW gastric motility, secretion
58
Q

Large intestine haustral contractions

A

slow, weak. allow mixing, absorption of salts and H2O

59
Q

Large intestine mass movements

A

due to food in stomach via gastrocolic reflex (powerful waves of contractions from transverse colon to rectum). move fecal mass into rectum

60
Q

Rectal (defecation) reflex stimulation

A

feces in rectum (stretch receptors in rectal wall)

61
Q

Rectal (defecation) reflex CNS

A

sacral segment of spinal cord (PSNS)

62
Q

Rectal (defecation) reflex effectors

A
  • smooth muscle of rectum (contract) and internal anal sphincter (relaxes)
  • external anal sphincter (skel. muscle) under voluntary control
63
Q

Digestion of large intestine

A

none but get bacterial fermentation of undigested nutrients. bacterial synthesize some vitamins (B6 B5, K, folate, biotin)

64
Q

Absorption of the large intestine

A
  • H2O: 400 mL/day via osmosis
  • Na active transport
  • fermentation products (vitamins)
  • drugs (anaesthetics)
65
Q

Secretion of the large intestine

A

K, HCO3

66
Q

Glucose absorbed

A

from blood into body cells to insulin increase uptake into skel. muscle and fat.

67
Q

Glucose in cell is used for..

A
  • catabolism by cells (ATP)

- anabolism: glycogen (75% in skel. muscle, 25% in liver) and 1% of body’s energy stores

68
Q

Lipids absorbed: Cholesterol

A

used to make steroid hormones, bile salts, cell membranes

69
Q

Lipid absorbed: triglyceride in blood then to tissue cells than fa..

A
  • oxidized produces ATP
  • stores as TG in adipose tissue (99% body energy store)
  • used to synthesize
70
Q

Amino acids absorbed

A

enter cells by 2 AT or facilitated transport. GH high entry into most cells. insulin high entry into skel. muscle. in cells AA used mainly for protein synthesis (not store) used for energy when glucose low

71
Q

Metabolic rate

A

bodys rate of energy use: sum of all chemical reactions and mechanical work

72
Q

Factors effecting MR

A

1) SNS ⇑ MR
2) hormones e.g. epi, TH ⇑ MR
3) body temp - 1⁰C rise ⇒ 10% ⇑ in MR
4) exercise ⇑ MR
5) food ingestion ⇑ MR
6) sleep ⇓ MR

73
Q

Basal metabolic rate (BMR)

A

energy body needs for essential activities e.g. HR, kidney function, breathing.