Pancreas Exocrine function:

secretes pancreatic juice into small intestines

Pancreatic juice includes buffers to increase pH of chyme

Pancreatic enzymes Lipase Amylase Proteases

Liver Reddish-brown, ~3.3lb 4 lobes: left, right,

caudate, quadrate Hepatocytes: liver cells

that secrete bile into the common bile duct (duodenum) or the cystic duct (gallbladder)

Gallbladder pear-shaped organ;

functions in storage of concentrated bile

ACCESSORY ORGANS (PANCREAS, LIVER, & GALLBLADDER)

Metabolic regulation: monitor levels of nutrients in blood from digestive tract

Hematological regulation: removes aged and damaged RBCs, debris and pathogens from circulation Bile production: bile salts

emulsify lipids into small droplets for absorption

FUNCTION OF THE LIVER

Cirrhosis: fibrous (scar) tissue replaces healthy tissueAlcoholismHepatitis A & C : viral infections

Symptoms: jaundice, liver failure, etc…

CLINICAL NOTE: LIVER DISEASE

Horse-shoe shaped, from end of ileum to anus (~5ft)

Functions: Water absorption Vitamin absorption Compaction and storage of feces

3 sections Cecum: compaction; attached to

appendix Colon: 4 segments (ascending,

transverse, descending, sigmoid) Rectum: temporary storage of

feces Internal anal sphincter (involuntary) External anal sphincter (voluntary)

THE LARGE INTESTINE

Polyps form in colon and become malignant

Second most common form of cancer

Prevention and early detection can save your life!!

CLINICAL NOTE: COLON CANCER

Carbohydrates: salivary amylase begins breakdown; continued by pancreatic amylase in small intestine; form simple sugars which are transported into the bloodstream via the liver.

Lipids: triglyceride emulsified into small droplets; bile salts from micelles which are then transported into the bloodstream

Protein: HCl and digestive enzymes (proteases) break proteins into single amino acids which are absorbed into the bloodstream

DIGESTION AND ABSORPTION

Inability to breakdown lactose (lipid in milk)

At adolescence, lactase production can decrease/stop

Causes digestive problems

Possible treatments: probiotics

CLINICAL NOTE: LACTOSE INTOLERANCE

Water & Electrolytes: water flows from high to low [C] of water; easily moves into surrounding tissues to maintain osmotic equilibrium

Vitamins: fat-soluble (A,D, E and K) absorbed in micelles; water-soluble (B vitamins and vitamin C) are easily absorbed by epithelium (vitamin B12 needs intrinsic factor)

DIGESTION AND ABSORPTION

Epithelium becomes thinner as division rate of stem cells decreases

Smooth muscle tone decreases making contractions weaker

Cumulative damage from exposure to toxins, etc… (i.e. liver disease, tooth decay)

Increase in cancer rateDomino effect from other systems (i.e.

dental health or dietary change)

AGING & THE DIGESTIVE SYSTEM

Chapter Objectives 1-5 (p. 515)Vocabulary: mucosa; submucosa; muscularis externa; serosa; peristalsis

Due: Wednesday, 4/10Chapter Objectives 6-11Due: Monday, 4/15Chapter 16 Test: Monday, 4/15

HOMEWORK