digestion and absorption pt 2

how long does food stay in small intestine

up to 4 hours

• turns to thin watery mixture

in order for nutrients to be absorbed, every molecule of the nutrient must enter

one of the cells lining small intestine

nutrients absorbed in small intestine will be deposited in

the blood and lymph

what does the small intestine have to increase surface area for absorption

folds, villi, and microvilli

most nutrients are absorbed in

the small intestine

these are finger like extensions in the small intestine

villi

these are microscopic extensions in the small intestine

microvilli

fat soluble nutrients go into

lymph (lacteals)

nutrients that aren’t absorbed int he small intestine go into

the blood (capillaries)

these are extensions of lymph (in small intestine)

• vessels in the villi

lacteals

why does the small intestine have increased surface area

so that all digested nutrients come into contact with the lining

nutrients absorbed in blood go to the

liver

• here they are stored or dispensed into blood

the large intestine is how big

3-5 ft (named for its diameter)

digestion in the large intestine is done by

bacteria (not by you)

what is digested in the large intestine

fiber (digested by bacteria)

what is absorbed in the large intestine

• water

• sodium, potassium, chloride

• vitamin K and biotin (produced by bacteria and absorbed by you)

this is refereed to defecation or bowel movement

elimination

the word bowels refers to

sm and lg intestines

defecation takes how long

1-3 days from mouth to anus

who make faster transit time (men/women)

men

once nutrients are in the cloud, they circulate where

circulate to all cells in the body

• vessel and heart

• carries oxygen and nutrients to tissues

• removes cellular wastes

cardiovascular system

• recaptures fluid escaped from blood in capillaries

• vessels that drain lamp

• dump lamp into blood

lymphatic system

the lymphatic system transports _ from the small intestine into the blood

triglycerides and fatty acids

what 2 systems are involved in the circulation of nutrients

cardiovascular and lymphatic systems

• as well as excretion and elimination

what do the lungs excrete in the elimination process

water and CO2

what do the kidneys do

filter blood

• excrete cellular wastes

• maintain water/ ion balance

• produce urine

what does the liver do in the excretion process

removes other wastes from blood

this happens when too much H2O is removed from the waste bu the large intestine

• reduced fiber, fluid intake, exercise

  • har, dry, infrequent stools

constipation

occurs when too little H2O is removed from the waste by the lg intestine

• frequent stools

• can cause dehydration

• can be sign of disease/ infection/ irritation

diarrhea

outpocketings of the wall of lg intestine

• pouches along colon

  • high fiber diet prevents this

diverticulosis

diverticula that are inflamed causes

diverticulosis

burning in chest caused by acidic stomach contents refluxing into esophagus

• can erode esophagus

• nothing wrong with heart, pain is just close in proximity

heartburn

a very common type of cancer that is caused by low fiber intake and high fat intake

• antioxidants may reduce risk

colorectal cancer (colon cancer)

swallowed air that is nit stinky

gas

vapor produced by bacteria in lg intestine when digesting fiber

• stinky

flatus

flatus passing out of anus

flatulent

these are found in the esophagus, stomach, and duodenum

• used by thin spots in stomach from helicobacter pylori (caused by bacteria)

  • treatment = antibiotics

gastric ulcers

chronic reflux of stomach acid into esophagus

• can lead to esophageal cancer

• reduced by smaller meals with less fat

gasteroesophageal reflux disease (GERD)

irritation of sm intestine (sometimes lg intestine too)

• symptoms: cramping, gas, bloating, diarrhea

• exact cause = unknown

irritable bowel syndrome (IBS)

this may be influenced bu species oft bacteria

metabolic syndrome