Digestion: Process of breaking down food molecules so

nutrients can be absorbed

Mechanical Digestion: *teeth chewing breaks ↓ food into

smaller pieces (prepares for chemical

digestion by ↑ing SA for enzymes to work

in chemical digestion)

*churning of stomach (sm muscles)

Chemical Digestion: Enzymes further break ↓ food particles

so nutrients can be absorbed

4 Layers of Digestive Tract

*Frenulum: attaches tongue to floor of mouth

Epiglottis: closes off trachea and bolus passed into

esophagus (behind trachea) when you swallow

Salivary Glands: In mouth start chemical digestion of carbs

Pharynx (throat)

Esophagus

and Cardiac Sphincter

cardiac sphincter

Stomach

*

*

Small Intestine: ABSORPTION of

nutrients

Duodenum

1st part of sm intestine is where most digestion takes place

Rest of sm intestine

absorption

Villi/Microvilli

Of Sm Intestine

↑ SA for absorption of nutrients

Liver and Gall Bladder

Lg Intestine:

Fx Absorption of H2O

jejunum

Peritoneum: Serous moist membrane lines abdominal cavity

& covers organs

(remember Epi membranes serous, cutaneous, mucous

connective tissue membranes synovial

no Epi component

Shiny surface of the organs is the visceral peritoneum; shiny  lining the abdominal wall is the parietal peritoneum

Mesentary: Extension of Parietal Peritoneum

Anchors Sm Intestine to abdominal wall

Greater Omentum: Extension of parietal peritoneum

Envelopes inflamed appendix

CAT

M

E

O

W

Digestion of Carbs: major source of energy

Starts in mouth w/salivary amylase

Sm Intestine: pancreatic & intestinal juices digest starch & sugars

____________ase (enzyme for what it works on)

Amylase breaks ↓starch & sugars

Maltase breaks ↓maltose (gal + gal)

Sucrase breaks ↓ sucrose (glu + fru)

Lactase breaks ↓ lactose (glu + gal)

* Starches polysaccharides disaccharides monosaccharides

Carbs: preferred energy food

Glycolysis: glucose metabolism (catabolic)

CR: w/ O2 = lots of ATP

Glycogenolysis: glu glycogen for storage (an anabolic)

Pancreas: Alpha Cells glucagon hormone

glycogen glucose ↑’s BS

Beta Cells insulin hormone

carries glucose across CM ↓BS

Antagonists

Hypoglycemia: low BS vs Hyperglycemia: high BS

Diabetics metabolize fats vs glucose byproduct ketones

Ketoacidosis affects blood pH diabetic coma

Proteins: Growth & development, repair, enzymes (catalysts)

Can be broken ↓ for energy

Starts in stomach

Enzymes Renin & Pepsin in gastric juice

Sm Intestine: Trypsin in pancreatic juice

Pepsidase in intestinal juice

Fats: store energy (2x more than carbs) impt in cm’s

Saturated, Unsaturated, Polyunsaturated

No C=C 1 C=C >1 C=C bond

Animals Plants

Solid @ RT Liquid @ RT

Gastric lipase in gastric juice digests some fat in stomach

Most fat undigested until of sm Intestine

Bile salts (aid enzyme Fx) made in liver stored in gall bladder, released into duodenum to emulsify fats (mechanical)

Pancreatic enzymes splits fats into glycerol & 3 fa’s

Food Undergoes: Digestion, Absorption (↑ SA) Metabolism

*Metabolism = anabolic + catabolic Rx’s (dehy synth & hydro)

H2O = most of body wt (blood plasma >90% H2O

Minerals: Inorganic & req’d by body

(to make Hgb, DNA, RNA, ATP)

Ca: teeth, bones, nerve, muscle fx

Vitamins: Help enzymes fx

K & some B complex made in liver

D made in skin (w/ sunlight)

A, D, E, K, fat soluble & stored in fatty tissue

C & B H2O soluble, need daily