Chapter 17 Digestive System Part 2

Small intestine receives?

chyme from stomach, liver, and pancreatic secretions

Small intestine function for digestion?

complete digestion of the nutrients in chime

Small intestine function for absorption?

absorbs products of digestion

Small intestine function for transportation?

transports the remaining residue to the large intestine

Small intestine consists of 3 parts which are?

duodenum, jejnum, and illeum

Duodenum is the?

shortest and most fixed portion of small intestine

Jejunum is the?

middle portion and thicker and more active than ileum

illeum is the?

distal portion and contains peyers patches (lymph nodes)

Jejenum and ileum are suspended by a double layered fold of peritoneum called a?

mesentery which transports blood and lymphatic vessels and nerves to wall of intestine

A double fold of peritoneum called the greater omentum drapes down from the stomach and over the?

large intestine and folds of small intestine

Intestinal villi is the?

tiny projections that increase surface area for nutrient absoprtion

Microvilli is the increase?

surface area for absorption

Structures of the intestinal wall are?

intestinal wall, mircovilli, blood vessels, lacteals, intestinal glands, and plicae circulares

Blood vessels in the intestinal wall are?

absorb most nutrients

Lacteals?

absrob most fats into the lymphatic system

Intestinal glands are/crypts of Lieberkuhn are?

glands located between the viilli

Pilcae circulares are?

circular folds that increase surface area fro absorption

Mucus is secreted by goblet cells and also secreted by?

specialized Brunners glands that secrete a thick alkaline mucus in response to certain stimuli

Watery fluid is secreted by intestinal gland and picks up?

digestion products and transport them to villi

Enzymes in the membranes of the microvilli includes?

peptidases, sucrase, maltase, and lactase, lipase

Peptidases do what?

break down peptides into amino acids

Sucrase, maltase, and lactase do what?

break down disaccarides into monosaccardies

Lipase does what?

breaks down fatty into fatty acids and glycerol

Regulation of small intestine secretion occurs by these methods?

mucus released when intestine irritated or stimulated

chyme secrete mucus and glands secrete watery fluid

stretch activate nerve

parasympathetic release intestinal enzyme

Villi increases?

surface area for absorption

Small intestine is most important absorbing organ of the?

alimentary canal

Absorption is so effective that very little absorbable material reaches the?

organs distal end

Carbohydrate digestion and absorption:

amylase break down starch

intestinal enzyme break sugars into simple sugars

simple sugars enter blood

Pepsin in the stomach break down?

proteins into polypeptides

Pancreatic proteases (trypsin, chymotrypsin, etc) break down?

proteins and polypeptides into smaller peptides

Intestinal peptidases break peptides into?

amino acids

Amino acids are absorbed by?

active transport into blood vessels of villi

Fat digestion and absorption is emulsified by?

bile salts

The small intestine is digested mainly by?

enzymes from pancreas and small intestine

Micelles are?

loose complexes of fatty acids and bile salts, from which fatty acids can migrate to microvilli and be absorbed

The fatty acids and glycerol are absorbed by a process involving several steps and then absorbed into?

blood or lymphatic capillaries (lacteals)

Chylomicrons?

package fats sos they can be transported

Chylomicrons are?

absorbed by lacteals

The small intestine carries these movement:

peristalsis, segmentation, parasympathetic impulses

Peristalsis is?

wave like pushing movements that propel chyme in proper direction down the small intestine

Segmentation is?

ring like contractions that move chyme back and forth (mixing movement)

Parasympathetic impulses is?

stimulate both mixing and peristaltic movements, and sympathetic impulses inhibit them

If small intestine becomes over distended or irritated a strong peristalic rush may sweep contents to what area causing?

moves to large intestine causing diarrhea

IIeocceal sphincter joins the?

ileum of small intestine to cecum of large intestine and help regulate flow of chyme

The large intestine stores?

feces

The large intestine absorbs some water and electrolytes and reabsorbs and recycles?

water and digestive secretions

The large intestine has a?

cecum, colon, rectum, and a. canal

The cecum is a pouch that forms at the beggining of the large intestine and what is attached to it?

appendix

Colon contains both?

right and left colic flexures

Rectum is extends from the?

sigmoid colon to a. canal and next to sacrum

A. canal has internal and external?

a. sphincter guard anus

The large intestinal wall has 4 layers as other tubular organs of the?

alimentary canal

The large intestinal wall does not have?

villi and plicae circulares

Longitudinal muscle is organized into 3 bands which is called?

taeniae coli that runs down entire length of colon

Muscle bands create pouches called what?

haustra which help form feces

The large intestine has little to no?

digestive function

The large intestine contains tubular glands containing?

goblet cells that secrete mucus the only significant secretion

Large intestine absorbs water and electrolytes but can also create feces and carry out?

defecation

Large intestine houses intestinal flora which is a bacteria that does what?

break down contents such as cellulose and produce vitamins K and B12 and thiamine

Movements of the large intestine are similar to the small intestine but they are what?

slower and less frequent

Types of movements for large intestine?

mixing movements

Mass movements which is?

peristaltic waves usually 2-3 times a day after meals

Defactation reflex is?

elimination of feces from body

What are the steps of defecation?

holds deep breath and contract abdominal muscles then the feces moves to rectum

Feces are composed of?

materials not digested or absorbed and also contain water, electrolytes, mucus, bacteria, and bile pigments

The pungent odor is produced by bacterial compounds including?

phenol, hydrogen sulfide, indole, skatole, ammonia

Salivary amylase is a salivary gland what is the action?

begins carbohydrate digestion by breaking down starch to disaccharide

Pepsin is a gastric chief cell and what is the action?

begins protein digestion

Pancreatic amylase source is the pancreas what is the action?

breaks down starch into disacharides

Pancreatic lipase source is pancreas what is the action?

breaks down fats into fatty acids and glycerol

Proteolytic enzymes (trypsin, chymotrypsin, carboxypeptidase) source is pancreas what is the action?

break down proteins or partially digested enzymes into peptides

Nucleases source is pancreas and the action is?

break down nucleic acids into nucleotides

Peptidase source is intestinal mucosal cells and action is?

breaks down peptides into amino acids

Sucrase, maltase, and lactase source is intestinal mucosal cells and action is?

breaks down disacharides into monosaccharides

Intestinal lipase source is intestinal mucosal cells and action is?

breaks down fats into fatty acids and glycerol

Enterokinase source is intestinal mucosal cells and action is?

converts trypsinogen into trypsin