the digestive system

Question 1

What are the five main phases that of digestion?

Answer 1

ingestion - taking food into the mouth
fragmentation- mechanically breaking down larger peices
digestion- breaking small pieces down chemically
Absorption - through cell membrane
elimination - of waste products

Question 2

What are the parts of the G.I. tract?

Answer 2

The G.I. tract is 9 meters long and contains:
Oral cavity
pharynx 
esophagus 
stomach 
small intestine 
large intestine 
anus

Question 3

What are the accessory organs of the G.I. system?

Answer 3

Salivary glands
gallbladder
liver
pancreas

Question 4

What begins in the Oral cavity?

Answer 4

Ingestion
fragmentation
digestion

Question 5

how many teeth does children have and adults have?

Answer 5

Children -20

adults- 32

Question 6

Name the teeth?

Answer 6

from front to bacK;
two incisors- for cutting 
One cuspid (canine) - for tearing 
two bicuspids (premolars) - for crushing 
three molars - for grinding

Question 7

what are the salivary glands?

Answer 7

parotid
sublingual
submaxillary

Question 8

what are the products secreted by the salivary glands?

Answer 8

amylase- breaks starch and glycogen into disaccharides

mucous - lubricates food for swallowing

Question 9

describe the process of swallowing?

Answer 9

Tongue and pharyngeal muscles roll the bolus of food into the esophagus. The epiglottis close the airway (glottis) while swallowing. Peristalis and gravity moves it out the esophagus to the stomach.

Question 10

What is Peristalsis?

Answer 10

The muscular movement of the G.I tract. It is controlled by the ANS.

Question 11

What breaks the food further in the stomach?

Answer 11

muscular activity and the production of gastric juices.

Question 12

What are the gastric juices made from?

Answer 12

The hormone gastrin and the impulses from the parasympathetic system.

Question 13

What is the makeup of gastric juices?

Answer 13

HCL- kills organisms and keeps the pH of the stomach 2

pepsinogen - inactive enzyme. activated form is pepsin which break down peptides in the presence of low pH

Question 14

What is chyme?

Answer 14

it is the product of food degradation in the stomach

Question 15

what are globlet cells?

Answer 15

cells found in the stomach and the intestine the secrete mucous

Question 16

What is the path of chyme?

Answer 16

it is secreted through the stomach muscular sphincter (pylorus) into the first part of the small intestine (the duodenum)

Question 17

What is the function of the liver?

Answer 17

it occupies the upper right portion of the abdominal cavity. It function in:
converts glucose to glycogen
glucose from non carbohydrates
plasma protein production
deamination of proteins
formation of urea
storage of iron and vitamins
detoxification
production of bile -produce by hepatocytes in liver

Question 18

What is bile?

Answer 18

a yellowish green fluid composed of water, cholesterol, pigments(detroyed red blood cells) and salts.

Question 19

What is the function of bile salts?

Answer 19

emulsification of fats- the dissolving of fat globules into micelles.
emulsification helps the absorption of Vitamins A, D, E, K

Question 20

What is the function of the gallbladder?

Answer 20

it stores bile and secrets it into the duodenum via the bile duct.

Question 21

Function of pancreas in exocrine system?

Answer 21

it secretes pancreatic juices into the pancreatic duct which joins to the bile duct.
pancreatic juices are made up of alkaline bicarbonate ( it neutralizes acidic chyme) and digestive enzymes

Question 22

What stimulates the secretion of pancreatic juices?

Answer 22

It is due to parasympathetic and hormonal response.

The duodenum produces and release secretin and CCK in the prescence of chyme.

Question 23

What are the pancreas digestive enzymes?

Answer 23

pancreatic amylase - break down carbohydrates
pancreatic lipase- fat braekdown
nucleases- breakdown nucleic acids
trypsin, chymotrypsin, carboxypeptidase- breakdown proteins.

Question 24

What are the components of of the small intestine?

Answer 24

Duodenum
jejunum
ileum

Question 25

What is the role of the small intestine in the digestive system?

Answer 25

completes the digestion of chyme
absorbs nutrients
passes of remains to large intestines
peristalsis is the main mode of tranportation

Question 26

describe absorption of the small intestine?

Answer 26

Because of the surface area and villi and
microvilli
both project into the lumen and contain lacteals and blood capillaries

Question 27

what are lacteals?

Answer 27

they are lymph capillaries in villi. they absorb fats into the lyphatic system in the small intestine

Question 28

What is the role of the capillaries?

Answer 28

They carry nutrients from small intestines to liver for processing via The hepatic portal vein (carries blood from one capillary bed to another)

Question 29

What are the divisions of the large intestine?

Answer 29

the cecum- connects to the ileum and projects to a closed end tube
Colon
rectum- store feces
anal canal- expel feces

Question 30

What are the divisions of the colon?

Answer 30

ascending
transverse
descending
sigmoid

Question 31

How are feces formed?

Answer 31

The LARGE INTESTINE HAS NO digestive function.

feces are formed from water and electrolytes from residual chyme

Question 32

What is feces made up of?

Answer 32

60% bacteria, mucus, bile pigments, water, undigested material