intro to digestive

Question 1

typical recomended diet

Answer 1

500g carbs
125g proteins
50g lipids

50% veggies and fruits
25% whole grain foods
25% proteins

Question 2

function of digestive systems

Answer 2

break down food to release thier nutrients and absorb those nutrients

Question 3

GI tract includes

Answer 3

organs of the alimentary canal as well as accessory glandular tissues

Question 4

alimentary canal

Answer 4

muscular tube made up of diff organs that coordinate their activity to move unidirectionally from mouth to anus

Question 5

examples of the alimentary canal organs

Answer 5

mouth
pharynx
esophagus
stomach
small intestine
large intestine
anus

Question 6

exocrine organs

Answer 6

lie outside the digestive tract and empty their secretions through ducts into the digestive tract lumen

Question 7

example of exocrine organs

Answer 7

salivary glands
exocrine pancreas
biliary system
liver
gallbladder

Question 8

what is the alimentary canal lined by

Answer 8

from outside in

serosa
muscularis
submucosa
mucosa

Question 9

submucosa

Answer 9

anchors mucosa

connective tissue layer that anchors the epithelia to the rest of the alimentary canal

Question 10

mucosa

Answer 10

contains:
epithelium
laminal propria
muscularis mucosae

direct contact with food

lines the alimentary canal
epithelial cell layer is directly in contact with food or chyme and physically separates the food from the inner environment of the body

organized diff based on part of the alimentary canal

Question 11

muscularis mucosae

Answer 11

smooth muscle contracts the mucosa
circular muscle
longitudinal muscle

Question 12

serosa

Answer 12

another layer of connective tissue which anchors GI tract to other organs in the body

areolar connective tissue
epithelium

Question 13

what is the alimentary canal exposed to

Answer 13

the external enviroment

Question 14

what protects the body from external assaults in the alimentary canal

Answer 14

GI tract barrier

tight junctions bw the epithelial cells
mucus and other secretion production by mucosa

Question 15

what are the external assaults that might affect the alimentary canal

Answer 15

acidic pH of the somach
digestive enzymes
gut flora

Question 16

what does the mucus secreted by epithelial cells and mucous cells do

Answer 16

serves as protective barrier against several forms of potential injury to the gastric mucosa

alkaline (basic)

also serves as padding from physical damage by sharp food

Question 17

what are the types of cells that are joined by tight junctions- luminal membrane of the gastric mucosa

Answer 17

chief cell and parietal cell

Question 18

what do the luminal membrane of the gastric mucosa do

Answer 18

impermeable to H+ so HCl cant penetrate

and mucus coating offers further protection

Question 19

what are the four main GI functions

Answer 19

secretion
motility
digestion
absorption

Question 20

GI function- secretion

Answer 20

digestive jioces are secreted into the digestive tract lumen by exocrine glands

gastrointestinal hormones help control digestive motility and exocrine gland secretion

Question 21

GI function- motility

Answer 21

muscular contractions that mix and move forward the contents of the digestive tract through
propulsive movements that push the contents forward through the digestive tract
and
mixing movements facilitate the absorption by exposing intestinal contents to the absorbing surfaces of digestive tract

Question 22

GI function- digestion

Answer 22

biochemical breakdown of complex foodstuffs into smaller absorbable units
large food molecules are converted to simple absorbable untis as the digestive tract contents are propelled forward

Question 23

GI function- absorption

Answer 23

small absorbable units that result from digestion along with water, vitamins, and electrolyes are trasnferred from the digestive tract lumen into blood or lymph

Question 24

mechanical and chemical digestion in the mouth

Answer 24

mechanical- chewing and swallowing
chemical- carbs and fats

Question 25

mechanical and chemical digestion in the stomach

Answer 25

mechanical- perstaltic mixing and propulsion chemical- proteins and fats absorption- lipid soluble substances such as alchohols and aspirin

Question 26

mechanical and chemical digestion in the small intestine

Answer 26

mechanical- mixing and propulsion primarily by segmentation chemical- carb, fat, polypeptides, nuc acids absorption- peptides, aa, glucose, fructose, fats, water, minerals, vitamins

Question 27

mechanical and chemical digestion in the large intestine

Answer 27

mechanical- segmental mixing and propulsion no chemical digestion exception by bacteria absorption of ions, water, minerals, vitamins, and organic molecules

Question 28

what are the 3 types of sensory receptors that respond to local changes in the digestive tract

Answer 28

chemoreceptors mechanoreceptors osmoreceptors

Question 29

chemoreceptors

Answer 29

sensitive to chemical components within the lumen

Question 30

mechanoreceptors

Answer 30

sensitive to stretch or tension within the wall

Question 31

osmoreceptors

Answer 31

senstitive to the osmolarity of the luminal contents

Question 32

regulation of digestion function and relation to the CNS

Answer 32

1. duodenum fills with chyme 2. sensory stretch receptors are stimulates 3. sensory nerve impulses travel to central nervous system 4. nerve impulses inhibit peristalsis in stomach wall

Question 33

what do sensory receptors in digestive tract do and what do they trigger

Answer 33

monitor luminal content and wall tension triggers neural reflexes or hormonal secretion to influence digestive effector cells

Question 34

what are the digestive effector cells

Answer 34

smooth muscle cells exocrine gland cells endocrine gland cells

Question 35

smooth muscle effector cells

Answer 35

modify gut motility

Question 36

exocrine gland effector cells

Answer 36

secrete digestive juices

Question 37

endocrine gland effector cells

Answer 37

secrete gastrointestinal hormones

Question 38

local stimulus in digestive function

Answer 38

pH, stretch, osmolarity, products of digestion

Question 39

external stimulus of digestive function

Answer 39

sight, smell, etc