The digestive system

Question 1

What are the four basic digestive processes?

Answer 1

Digestion
Absorption
Secretion
Motility

Question 2

What are the two types of digestion?

Answer 2

Mechnaical digestion

Chemical digestion

Question 3

Absorption

Answer 3

Passage of the end - products of chemcial digestion from the digestion tract into blood or lymph for distrubution to tissue cells

Question 4

Secretion

Answer 4

Enzymes and digestive fluid secreted by the digestive tract and its accesory organs facilitate chemcial digestion

Question 5

Elimnation

Answer 5

Undigested material will be release through the rectum and anus by defecation

Question 6

features of the GI wall structure

Answer 6

Muscosa
Submucosa
Muscularis externa
Serosa

Question 7

Mucosa

Answer 7

Lining of the lumen of the GI tract

3 layers - mucuous membrane, Lamina propria, muscualris mucosae

Question 8

Submucosa

Answer 8

Contains connective tissue which adds to the elastcicity of the tact

Question 9

Muscualris externa

Answer 9

Smooth msucle

Responisble for motility along the GI tract

Question 10

Serosa

Answer 10

Continous with the messentery

Thick layer of connective tissue offers structural support of the tract

Question 11

Palate - rood of the mouth

Answer 11

2 distnct pottion
Hard palate- anterior portion, tongue forces food againts it during chewing
Soft palatae - posterior portion, soft flap which blocks the nasopharynx during swallowing

Question 12

The beginning - Mastication

Answer 12

Digestion begins with mastication

Salivary galnds - partoid gands, sublingual gland, submandibualr gland

Question 13

Salivary amylase

Answer 13

catalyses the hydrolysis breakdown of polysaccharides like starch into smaller molecules
Beginning process of digestion

Question 14

Pharynx

Answer 14

Food passes nasopharynx - closure by soft palate during swallowing
Upper esophgeal sphincter - protects against reflux of food into the airways

Question 15

Stomach

Answer 15

Food passes through the cardiac sphincter into the stomach

Stomach lined with simle columnar epithelial cells

Question 16

Parts of the stomach

Answer 16

Fundus - top part of the stomach
Body - large mid - protion of the stomach
Antrum - lower part of the stomach
Pyloric region - terminal region of the stomach
Pyloric sphincter - control entry of chyme into the small intestine

Question 17

Acidic environemnt of stomach

Answer 17

pH = 2 
Necessary for activating pepsingoen 
Denatures proteins 
Kills bacteria 
Gastric mucosal barrier

Question 18

Gastric pits

Answer 18

Located in stomach lining; lead to gastric glands

Question 19

Secretory products then Gastric pits

Answer 19

Pepsinggen - secreted by chief cells
HCI - secreted by pariteal cells
Intrinsic factor - secreted by parietreal cells
Gastrin - hormone secreted from enteroendocrine cells
Mucus - secreted from neck cells

Question 20

Small Intestine

Answer 20

Coiled, hollow tube
Primary site of digestion and absorption
Lined with simple columnar epithelium
Three division - Duodenum, Jejunum and Ileum

Question 21

Microvilli

Answer 21

Finger - like projections
Villi increase surfaces areas of epithelium
Form brush border

Question 22

Crypts of Lieberkuhn

Answer 22

Present between villi
secreted in duodenum
Absorbed in ileum

Question 23

Role of liver in absorption

Answer 23

Absorbed nutrients travel in blood to the liver before entering the general circulation
liver functions to detoxify substances and processes certain nutrients

Question 24

Large Intestine

Answer 24

Consists of cecum, colon and rectum
Illececal sphincter is between ileum and colon
Teniae coil are bands of longitudinal smooth muscle

Question 25

What are the four types of accesory glands?

Answer 25

Slaivary galnds - secrete saliva Pancreas - secretes pancreatic juice Liver - secretes bile Gallbladder - stores bile produced by the liver

Question 26

The pancreas

Answer 26

Has endocrine and exocrine pancreas | pancreas tissue consist of exocrine acinar cells and duct cells. Endocrine cells dispersed in the islets of Langerhans

Question 27

Pancreatic juice contains -

Answer 27

Bicarbonate which neutralizes acidic pH of the stomach acid to pH 8.0 Pnacreatic amylase - hydrolyses carbohydrates like maltose to glucose molecules lipases Proteases Nucleases

Question 28

The liver

Answer 28

Secretes bile Bile enter duodenum Processes nutrients

Question 29

Functions of the liver

Answer 29

Secretion and modification of hromones Removal of old red blood cells Synthesis of plasma proteins Elimination of waster and toxins

Question 30

The biliary system

Answer 30

``` Liver synthesizes bile Gallbladder stores bile Common bild duct transports bile from liver Joins with panvcreatic duct to form Spincter of Oddi ```

Question 31

Carbohydrate digestion

Answer 31

Only monosaccharides are absorbed Disaccharides and polysaccharides must be digested to monosaccharides Digestion of starch

Question 32

Enzymes of carbohydrate digestion

Answer 32

``` Dextrinase Salviary and pancreatic amylase Sucrase Lactase Maltase ```

Question 33

Protein digestion

Answer 33

Amino acid Dipeptides Tripeptides

Question 34

Types of protease used in the body to dugest protein

Answer 34

Endopeptidases Exopeptides Zymogens

Question 35

Absoprtion of amino acids

Answer 35

Cross the apical membrane by sodium - linked secondary active transport or facilitated diffusion Cross the basolateral membrane by facilitated diffusion

Question 36

Lipid digestion

Answer 36

Lipids face special problm in digestion and absorption Enzymes of digestion Secreted from pancreas Lipases can only act on molecules near the edge of a fat droplet

Question 37

Bile salts

Answer 37

Synthesized in liver from cholesterol Sceretd in bile to duodenum Amphipathic molecule Emulsify fat

Question 38

Absorption of vitamins

Answer 38

Fat soluble vitamins Vitamin B12 Water - soubule vitamins

Question 39

Absorption of minerals

Answer 39

Sodium Chloride Potassium

Question 40

Hormones involved of GI tract

Answer 40

Leptin Gastrin Secretin CCK

Question 41

Peristalisis

Answer 41

Seris of wave - like muscle contraction that move food through the digestive tract Causes movement of the wall of the GI tract