Chapter 3 Flashcards
(49 cards)
1
Q
Digestion
A
- process of breaking down food into components small enough to be absorbed
2
Q
absorption
A
- process of taking substances into interior of body
3
Q
gastrointestinal tract
A
- hollow tube
- mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus
4
Q
transit time
A
- time it takes food to pass length of gi tract
5
Q
functions of gi tract
A
- ingestion - softening of food
- transport - rate varies
- secretion - enzymes, acid, bile, mucus
- absorption - of end products of digestion
- elimination
6
Q
salivary glands
A
- moistens food
- supplies enzymes
7
Q
gallbladder
A
- stores and secretes bile
- bile pH ~7-7.7 (alkaline)
8
Q
pancreas
A
- secretes bicarbonate (alkaline) secretes enzyme
9
Q
mouth
A
- mechanical breakdown through teeth
- enzymes: amylase-carbs (makes starch taste sweet), lingual lipase-fat
- saliva - moistens food for swallowing
10
Q
esophagus
A
- transports food bolus from mouth to stomach
11
Q
epiglottis
A
- covers passage to lungs when swallowing
12
Q
pyloric sphincter
A
- smooth muscle at junction between pylorus of stomach and duodenum of small intestine
- acts as valve to control flow of digested food from stomach to intestine
13
Q
duodenum
A
- proximal (upper) part of small intestine
- most digestion occurs in this part
14
Q
jejunum
A
- middle part of small intestine
- absorbs digested nutrients
15
Q
ileum
A
- distal part of small intestine
- absorbs digested nutrients
16
Q
chyme
A
- thick semi-fluid mass of partly digested food that is passed from stomach to duodenum
- both physically and chemically softened food
17
Q
peristalsis
A
- physical movement
- waves of muscular contractions
- longitudinal muscles relax
stomach: every 2s
small intestines: ever 4 s
large intestines: slower
18
Q
stomach
A
- hydrochloric acid: preps protein for digestion, activates enzymes (pepsinogen to pepsin)
- pepsin: begins protein digestion
- gastric lipase: some fat digestion
- gastrin: stimulates gastric secretions and movement
- water
- mucous
- intrinsic factor
19
Q
illeum
A
- intrinsic factor - needed for absorption of vitb12
20
Q
digestive sectretions
A
- mucus: viscous materail produced by globlet cells, moistens, lubricates, protects gi tract
- enzymes: protein molecules that speed chemical reactions, not changed during reactions
21
Q
chemical breakdown
A
- enzymes (proteins) catalyze reactions, end in ase - ex lipase
- hydrolysis: if water used to break molecule
22
Q
esophageal sphincter
A
- prevents reflux of stomach content that causes heartburn
- gerd and ulcers
23
Q
sphincter of oddi
A
- controls amount of bile and pancreatic secretions into small intestine
24
Q
ileocecal sphincter
A
- prevents large intestine content from backing up into small intestine
25
intrinsic factor
- if a protein that binds ingested vitamin b12; it enables b12 to be absorbed by the intestine
- produced by parietal cells
26
without intrinsic factor
- allows b12 to be absorbed in ileum
- vitb12 needed to produce red blood cells
- can cause pernicious anemia: wekaness, cns damage, psychological disorders
27
age and b12
- absorption decreases with age
28
antacids and b12
- not enough stomach acid may inhibit b12 absorption
29
gi tract role in immune function
- protects body from infection
| - limits absorption of toxins and pathogens
30
microbiota
- 10-100 trillion symbiotic microbial cells in each person
| - mostly bacteria in gut
31
small intestine absroption
- folds, villi, microvilli expand absorptive surface
| - most nutrients absorbed hiere
32
digestion of fat in small intestine
- primary site of fat digestion
- cck released from duodenal cells stimulates pancreas to release pancreatic lipase
- cck also stimluates the relase of bile
- bile helps emulsify fat, which increases surface area of food to aid action of lipase
- pancreatic cplipase is relased to facilitate lipase action
- fat is broken into monoglycerides and fatty acids
- lecithin from gall bladder ans protien colipase (aids lipases attachment to lipid)
33
absorptive mechanisms
- passive diffusion
- facilitated diffusion
- active transport
34
metabolic pathways
- series of reactions to transform food into final product that can be used by body
35
catabolic reactions
- release energy trapped in chemical bonds
| - energy converted to atp
36
alternate feeding methods
- enteral or tube feeding: nutrition enters gut
| - TPN: total perenteral nutrition, doesnt enter gut, ex. by blood stream
37
probiotics
- bacteria or yeast
- aid digestion
- alive
38
prebiotics
- form of fiber
| - from food
39
diverticulosis
- pouches along colon
- high fiber diet reduces formation
- western diet affliction
40
GERD
- gastro-esophageal reflux disease
- reduced by smaller meals, less fat
- use of strong antiacids linked to hip fracture
41
irritable bowel syndrome
- can result in malabsorption of nutrients
- early diagnosis can result in no long term problems
- fodmap diet effective
42
colorectal cancer
- need high intake of vegetables, fruit, folate, ca, vitd
43
gas
- smell due to sulfur
| - not bad
44
peptic ulcers
- bacterial cause
| - h pylori secretes protective enzyme to survive in stomach
45
functional dyspepsia
- chronic pain in upper abdomen for unknown reason
| - once cause known its no longer functional dyspepsia
46
chron's disease
- causes inflammation on lining of digestive tract
| - can lead to abdominal pain, severe diarrhea, fatigue, weight loss, malnutrition, death
47
ulcerative colitis
- causes inflammation of lining of large intestines only
| - innermost lining of colon
48
effects of chromic digestive disorders
- failure to absorb nutrients: osteoperosis, nutritional deificiencies, eventual acute illness, can cause death
choldren: failure to grow, compromised immune systems, deficiencies more pronounced during growth
49
cholecystitis
- inflammation of gall bladder
- cuaes: blockage of cystic duct by gallstones. high fat, low fiber diet
- prevention: slowly lose weight (1-2lbs/week), diet high in fruit, veg, whole grains
