Biology Lecture 6: The Digestive System; The Excretory System

Front 1

Basic Anatomy of the Digestive Tract

Back 1

Mouth; esophagus; stomach; small intestine; large intestine; rectum; anus

Front 2

α-amylase

Back 2

Digestion begins with α-amylase contained in saliva

Front 3

Esophagus

Back 3

Part of the alimentary canal between the pharynx and the stomach

Front 4

Peristalsis

Back 4

Wavelike muscular contractions in tubular structures, especially organs of the digestive system

Front 5

Chyme

Back 5

Mass of partly digested food expelled by the stomach into the duodenum

Front 6

Four Major Cell Types in the Stomach

Back 6

1. Mucous cells

2. Chief (peptic) cells

3. Parietal (oxyntic) cells

4. G cells

Front 7

Mucous cells

Back 7

Secrete mucous to lubricates the walls of the stomach and protects the epithelial lining from the acidic environment

Front 8

Chief (peptic) cells

Back 8

Secrete pepsinogen, the zymogen precursor to pepsin which begins protein digestion

Front 9

Parietal cells

Back 9

Secrete HCl which diffuses into the lumen which lowers the pH of the stomach and raises the pH of the blood

Front 10

G cells

Back 10

Secrete gastrin (peptide hormone) into the interstitium which stimulates parietal cells to secrete HCl.

Front 11

90% of digestion occurs in the

Back 11

Small intestine

Front 12

Most of digestion occurs in the

Back 12

Duodenum

Front 13

Most of absorption occurs in the

Back 13

Ileum

Front 14

Villi

Back 14

Finger-like projections that increase the surface area of the intestinal wall for greater digestion and absorption

Front 15

Microvilli

Back 15

On the apical side (lumen side)

Front 16

Brush border

Back 16

Fuzzy covering of microvilli that contain membrane bound digestive enzymes

Front 17

Goblet cells

Back 17

Secrete mucous to lubricate intestine and help protect the brush border from mechanical and chemical damage

Front 18

Pancreatic enzymes

Back 18

Trypsin, chymotrypsin, amylase, and lipase; all act as zymogens

Front 19

Bile

Back 19

Produced in the liver, stored by the gall bladder; breaks up fat into smaller particles to be absorbed by enterocytes

Front 20

Large intestine

Back 20

Ascending colon, transverse colon, descending colon and sigmoid colon; water and electrolyte absorption

Front 21

Albumin

Back 21

Heat-coagulable, water-soluble proteins that occur in blood plasma or serum, muscle, the whites of eggs, milk, and other animal substances and in many plant tissues and fluids

Front 22

Fat is insoluble and typically requires a carrier

Back 22

Lipoproteins or albumin

Front 23

Globulin

Back 23

A group of proteins that contain antibodies

Front 24

When the liver mobilizes fat or protein for energy...

Back 24

It produces acids called ketone bodies which often results in ketosis or acidosis; Blood acidity increases

Front 25

Liver functions

Back 25

Blood & filtration, carbohydrate, fat, & protein metabolism, detoxification, erythrocyte destruction, and vitamin storage

Front 26

Kidney

Back 26

Excrete waste products, maintain homeostasis, help control plasma pH

Front 27

Renal corpuscle

Back 27

Where filtration occurs

Front 28

Proximal tubule

Back 28

Reabsorption and secretion

Front 29

Loop of Henle

Back 29

Concentrates solute in the medulla

Front 30

Collecting duct

Back 30

Concentrates the urine

Front 31

The amount of filtrate is related to

Back 31

The hydrostatic pressure of the glomerulus

Front 32

Descending loop of Henle

Back 32

Permeable to water

Front 33

Ascending loop of Henle

Back 33

Impermeable to water and actively transports Na in and K out.

Front 34

Juxtaglomerular apparatus

Back 34

Monitors filtrate pressure in the distal tube