chapter 3 - metabolism Flashcards
what is metabolism
use of food as fuel, resulting in energy
what is digestion
process of food broken down into smaller parts, chemically changed, and moved through GI system
begin at mouth end at anus
mechanical digestion
break food down w teeth
peristalisis
rhytmic contraction fo muscular walls of tract
chemical digestion
composition of carb potein and fats are changed through addition of water, resulting in splitting offood molecules (hydrolysis)
what organs screte digestive enzymes
mouth stomach pancreas and small intestien
what is saliva
secretion of salivary glandes containing water salts and salivary amylanse (ptyalin)
parts of the stomach
fundus (upper), middle (body), end (pylorus)
what happens to food in stomach
enters fundus, in body of stomach muscles knead food and mix it w gastric juices and intrinsic factor necessary for absorption of b12
what does gastirc juices containe?
HCL, pepsin, and mucus
role of HCL in gastric juices
prepare protein molecules for partial digestion by pepsin, destroys most bacteria in food and makes iron and calcium more soluble
order of small intestine
duodenum jejunum ilieum
what does secretin do
hormone that causes pancras to secrete sodium bicarbotine to neutralize acidity of chyme
what does cholecystokinin (CKK) do
produced by intenstinal mucosal glands when fat enters; triggest gall bladder to release bile
what does pacnreatic juices contain
trypsin, chymotrypsin, carboxypepidase (pancreatisc proteases)
pancreatic amylase
pancreatic lipase
small intesine intential juice contains:
lactase maltase sucraze
peptidase
what is function of cecum
cecum: the blind, pounch-like beginning of colon in RLQ; absorbs water and salts
- muscular wall that knead content to enhance absorption
- one of end products is volatile fatty acids: acetate, rpopionate, butyrate; absorbed by large intestine and used as source of energy
what is absorption
passage of nurients into blood or lypmhatic system (lympathic vessels carry fat-soluble particles and too large molecules to pass through capillaries)
length of small intestine
20 ft
length of esophagus
10 in
colon lengh and diametier
5ft long, 3 in in diameter
tasks of large intestine
absorb water, synthesisze some vitamin bs and vitamin k, collect food residue like dietary fiber
what is absorpeped by capillaries
glucsoe fructose galactose amino acids minerals water-soluble vitamins
what is carried to liver
fructose and galactose, comverted to glucsoew
hat do lacteals do
absorb glycerol and fatty acids in additio not ofat-soluble vitamins
percent of feces
99% of carb
95% of fats
92% of proteins
overall transmit time from ingenstion to elimination
16 to 27 hours
what is aerobic metabolism
nutrients are combined w oxygen within each cell (oxidation - reduced carb to CO2 and H2), protein to CO2, H@O, N)
what is anaerobic metabolis m
reduce fat wo using oxygen
what is anabolism
build new substances from simpler ones
what is catabolism
reduce sybstance to simpler ones
what hormoes regulate metabolism
Triiodothyronine (T3) and thyroxine (T4)
too much and hyperthyroidism (too fast metabolisM)
to little and hypothyroidism (too slow metabolism )
t1 kilocal = ____kJ
4.184
what is 1 calorei
amount of heat needed to raise temp of 1 kg of water by 1 degree celsius
1 g carb = __ cal
4
1 g protein = __ cal
4
1 g fat = __ cal
9
1 g alc = __ cal
7
what is bomb calorimeter
determine energy values of food with inner part having food and outer having water. food is burned andcaloric value is determined by incr in temp of surrounding water
what is basal metabolism
energy needed to carry out involuntary vital processes while at rest
respiration circulations regof body temp, and cell activity and maintenance
basal metabolism rate (BMR)
rate needed only for body maintenance
aka resting energy expenditure (REE)
factors that affect ones BMR
lean body mass body size, sex, age, hereditry, physical condition, climate
bacteria crucial in probiotics
lactobacillus, bifidobacterium, and saccharomyces
what is lean body mass
muscle
muscle need more call then fat or bone
thermic effect of food
body requires energy to process food (digestion, absorption, transportation, metabolism, and storage)
rep 10% of daily energy
what equation is commonly used to determine BMR for those above 18
harris-benedict equation
what do gastric juices conssit of?
hydrochloric acid, diges-tive enzymes, and mucus.
what is chyme
mixture of gastric juices and chewed and swallowed food combine in the stomach
when empty what is stomzch size
1/8 cup
function of rugae
folds in stomach that allow it to expand when odd Is consumedexpands to 1-2 quarts of food
how much of digestion fone in small inesti e
95%
sections of small intestine + length
duodenum - 12in
jejunum - 4ft
ileum - 5ft
20 ft total (small intestine) in length and 1 in in diameter
how long does it take for food to travel from mouth top small intestine
5 to 14 hours
function of bile
helps disperse (distribute) fat in the water-based digestive fluids, giving enzymes in the fluids access to the fat so they can break it down.
colon lenght
3.5 ft in body
5-6 ft in length
how long does chyme stay in colon
1 to 3 days before elimination
what are feces made of
mucus,
bile pigments, fiber, cells that have been sloughed (shed) from the lining of the large intestine, and water
inside surface area of the small intestine is about_______ times larger than
that of a smooth tube.
600
wha absorbs fat-soluble nutrients
. Lymph vessels in the villi, called lacteals
how does fiber strengethen intestinal tract
forms a mass in the digestive tract that creates resis-tance against which the muscles of the intestine can push
