HPA Digestive System Pancreas Liver Small Intestine Part II Koopstyle

7/28/2019 HPA Digestive System Pancreas Liver Small Intestine Part II Koopstyle

1/29


2/29

Pancreatic Juice

pancreatic amylase splits glycogen into disaccharides

pancreatic lipase breaks down triglyceridestrypsin, chymotrypsin, and carboxypeptidase digest proteins

nucleases digest nucleic acids

bicarbonate ions make pancreatic juice alkaline

17-30


3/29

Regulation of Pancreatic

Secretions

acidic chyme stimulates

release ofsecretin

secretin stimulate release of

pancreatic juice

17-31


4/29

Liver

17-32


5/29

Hepatic Lobule

17-33


6/29

The Paths of Blood and Bile in

Hepatic Lobule

17-34


7/29

Liver Functions

builds glycogen from smaller units of glucose as energy storage

breaks down glycogen into glucose for use by the bodys cells

converts non-carbohydrates to glucose (gluconeogenesis)

oxidizes fatty acids (ketoacidosis is the over oxidation of fat, seen in DM)

synthesizes lipoproteins, phospholipids, and cholesterol converts carbohydrates and proteins into fats

removes functional groups off amino acids to use for new proteins

forms urea ( a metabolic waste of protein metabolism)

synthesizes plasma proteins

converts some amino acids to other amino acids (transamination)

stores glycogen, vitamins A,D, B12, iron, and blood

phagocytizes worn out RBCs and foreign substances

removes toxins from blood

produces and secretes important enzymes for digestion

these are just several of the 1,000s of jobs that the liver performs

17-35


8/29

Production &Composition of Bile

secreted by the hepatocytes of the liver

Made of bile salts, which are responsible for

1. emulsification (breakdown) of fats

2. aids the absorption of fatty acids, cholesterol, and

fat-soluble vitamins in the jejunum and ileum

bile pigments (bilirubin and biliverdin)

bicarbonate ions

cholesterol

electrolytes (Na, K and Ca)

water

17-36


9/29

Gallbladder

17-37


10/29

Regulation of Bile Release

fatty chyme entering duodenumstimulate gallbladder to release

bile

17-38


11/29

Gall Stones


12/29

Gall Stones


13/29

Three Parts of Small Intestine

17-39


14/29

Mesentery

suspends portions of the small

intestine from the posterior

abdominal wall

composed of loose areolar C.T.

supports vessels, nerve and

lymphatic vessels that supply theintestinal wall

Greater Omentum: a double fold

of mesentery that covers the

stomach thru the L.I.= protection of

viscera

will be very prominent in the cat

17-40


15/29

Structure of the Small Intestinal Wall

Velvety appearance internally

Due to the many tiny projections of mucosa called villi

i) most numerous in the duodenum

ii) greatly increase the surface area of the lumen for absorption of nutrients

Each villus contains:

i) thin layer of simple columnar epi.

ii) core of C.T. containing blood capillaries and a lymphatic capillary called a

lacteal and nerve fibers

iii) at free surface are numerous microvilli that form a brush border on the inside

of the S.I. further increasing surface area for maximum absorption

Between adjacent villi are deep intestinal glands called the crypts of Lieberkuhn

which many enzymes are secreted from the mucosa

S.I. lining has numerous folds called the plica circulares which further increase the

surface area of the lumen


16/29

Intestinal Villus

17-41


17/29

Intestinal Epithelium

17-42


18/29

Wall of Small Intestine

17-43


19/29

Secretions of Small Intestine

peptidase breaks down peptides into amino acids

sucrase, maltase, lactase break down disaccharides into

monosaccharides

lipase breaks down fats into fatty acids and glycerol

enterokinase converts trypsinogen to trypsinsomatostatin hormone that inhibits acid secretion by stomach

cholecystokinin hormone that inhibits gastric glands, stimulates

pancreas to release enzymes in pancreatic juice, stimulates

gallbladder to release bile

secretin stimulates pancreas to release bicarbonate ions in

pancreatic juice

17-44


20/29

Regulation of Small

Intestinal Secretions

Goblet cell secretion of mucus is stimulated by presence of chyme in

small intestine

distension of intestinal wall activates nerve plexuses in wall of small

intestine to increase peristalsis and

parasympathetics trigger release of intestinal enzymes

17-45


21/29

Absorption in the

Small Intestine

monosaccharides and amino acids

through facilitated diffusion and

active transport

absorbed into blood

electrolytes and water

through diffusion, osmosis, and

active transport

absorbed into blood

17-46


22/29

Movements of the

Small Intestine

mixing movements

peristalsis pushing movements segmentation ring-like contractions

over-distended wall triggers peristaltic rush resulting in diarrhea

17-48


23/29

Large Intestine

17-49


24/29

Large Intestinal Wall

17-50


25/29

Functions of Large Intestine

little or no digestive function

absorbs water and electrolytes

secretes mucus (lots of it!!!)

houses intestinal flora (E. coli)

i) some bacteria in the gut synthesize Vitamin K for clotting mechanism

forms feces

carries out defecation

17-51


26/29

Movements of Large Intestine

slower and less frequent than those of small intestine

mixing movements

peristalsis mass movements usually follow meals (Bowel Movement, B.M.)

Appendicitis: rupture of the vermiform appendix. Can lead to peritonitis, which is an

infection of the peritoneum and can lead to death

17-52


27/29

Composition of Poop

water

electrolytes

mucus

bacteria

bile pigments altered by bacteria provide color

smell produced by bacterial compounds (methanogens)

17-53


28/29

Life-Span Changes

teeth become sensitive

gums recede

teeth may loosen or fall out heartburn more frequent

constipation more frequent

nutrient absorption decreases

accessory organs age but the effects are less noticeable

17-54


29/29

Clinical Application

Hepatitis

inflammation of the liver

most commonly caused by viral infection

can be caused by reactions to drug, alcoholism or autoimmunity

Signs and Symptoms

headache

low fever

fatigue

vomiting rash

foamy urine

pale feces

jaundice

pain

Hepatitis A not washing hands or eating

raw shellfish

Hepatitis B chronic; serum

Hepatitis C serumHepatitis D very severe; only produces

symptoms if infected with B; serum

HepatitisE, F, G more rare

17-55

Documents

HPA Digestive System Pancreas Liver Small Intestine Part II Koopstyle