digestive system part one Flashcards
what are the 7 main organs involved with the GI tract process?
mouth (oral cavity) Pharynx Esophagus Stomach small intestine large intestine anus
What are the 6 accessory structures that help digestion?
Tongue Salivary gland liver gallbladder pancreas spleen
What is ingestion?
selective intake of food and drink
What is propulsion?
moving food along the digestive tract from one part to the next
What are some different types of secretion?
water, HCL, salts, buffers, digestive enzymes
What is mechanical digestion?
the physical breakdown of food into smaller pieces
What is chemical digestion?
the breakdown of food by digestive enzymes and acids
If carbohydrates are broken down they become…
sugars
if proteins are broken down they become…
amino acids
if fats are broken down they become…
fatty acids
If nucleic acids are broken down they become..
nucleotides
What are the four tissue layers which make up the Alimentary canal?
- Mucosa
- Submucosa
- Muscularis
- serosa/ adventitia
what is mucosa and its function?
- innermost layer of the GI epithelium
- surrounds the lumen
- secretes mucus/ digestive enzymes/ hormones
- absorbs the end products of digestion to blood
- protect against infectious disease
what is submucosa and its function?
- aveolar connective tissue layer
- highly vascular: contains blood vessels
- contains most of GI nerves
- attaches the mucosa layer to muscularis layer
what is the structure and function of the muscularis?
- consists generally of two layers : inner circular layer and outer longitudinal layer
- the contraction of the muscularis moves food along the digestive tract
What is the serosa and what is its function?
- it is the outermost tissue layer
- attaches the organ to surrounding structures
- secretes serous fluid which reduces friction as it moves over other structures
what type of epithelium tissue lines the mouth, pharynx and oesophagus?and why?
thick stratified squamous epithelium
to resists abrasion
What is type of muscle id the tongue composed of?
skeletal muscle
the pharynx connects the ……. to the……..and the…….
- mouth
- oesophagus and trachea
Degluition is ….
swallowing
mastication is ….
chewing
small intrinsic glands found under mucous membrane of mouth, lips. cheeks and tongue are called…..
saliva glands
functions of saliva
moistens to aid swallowing cleanses teeth binds food together into bolus neutralizes acidic foods dissolves foods
what is bolus:
a soft slippery easily swallowed mass
what are the four regions of the stomach?
- cardia
- fundus
- body
- pylorus
what does the stomach secretion Hydrochloric Acid do?
- breaks up connective tissue and plant cell walls
- liquifies food to form chyme
- converts ingested ferric ions (fe3+) to ferrous (Fe2+)
What is pepsinogen? what does it do?
the inactive form of pepsin - requires HCL for activation
- splits proteins into poly peptides and peptides
What does the stomach secretion Lipase do?
it is an enzyme that starts the breakdown of fats (lipids) into fatty acids and Glycerol
what does Rennin do?
coagulates milk
What is Intrinsic factor essential for?
the absorption of B12 by small intestine.
