Anatomy of Gastrointestinal System Flashcards
GI Tract
long, continuous tube that stretches from mouth to anus
-pharynx > esophagus > stomach > small intestine > large intestine > recturm
Digestion Process
Ingestion
-process of putting food in mouth, chewing, and swallowing
Digestion
- physically and chemically breaking chucks and large molecules of food into small chunks were cells can use it
- digestive enzymes=substances that will break down complex nutrients (proteins into smaller amino acids, sugars into simple sugars, fats into fatty acids + triglerids)
Absorption
-the process of transferring digested food from intestinal membranes, into the blood circulation, which take most straight to the liver for processing and/or storage
Elimination
-process of passing undigested and unabsorbed food out of the body in the form of stool
Assessory Organs
- help in mechanical and chemical digestion of food as it passes through gastrointestinal tract
- salivary glands, liver and pancreas
Mouth
Food -> Mouth -> Teeth, Tongue, Saliva
- ingest food prepare it for digestion
- referred to as oral cavity/buccal cavity
Pharynx
- back of mouth
- channel through which air, food, and liquids must pass through to either to go to the larynx, the trachea, or esophagus
- epiglottis=flap of cartilage that fold down to cover larynx during swallowing to prevent food from entering the larynx and therefore the lungs
Esophagus
- 10-12 inches long tube that extends from pharynx to the stomach
- Food passes -> pharynx -> esophagus
- peristalsis= muscle movement that move the food down into stomach
- the lower esophagus contains enough pressure to prevent stomach content from refluxing
Stomach (Part 1)
-esophagus empties’ food straight into the stomach
-over eating can cause stomach to push against diagram causing discomfort that takes a while to wear off
-resembles eggplant
-food stays in stomach 3hrs.
fundus=broad portion near esophagus
body=central portion
pylorus-lower narrow section that joining w/ the small intestine
Stomach (Part 2)
Rugae=series of ridges that the musosa folds into and unfolds to stomach can stretch
Mucosa=membrane that lines various cavities in the body it surrounds internal organ
-composed of layers of epithelial cells surrounds a layer of loose connective tissue
Muscle
- longitudinal
- oblique
- circular
- as food is churned, two spinsters prevent food spilling out from either end of stomach
- lower esophageal
- allows stomach to mechanically break dwon food
Small Intestine
20 ft. long, 1 inch in diameter
- duodenum
- top part of small intestines that extends to stomach
- 12 inches long
- curves around near pancreas
- pancreatic duct + common bile from liver empty digestive jucies - Jejunum
- 8 ft. long
- covered in villi projection that help absorb nutrients - ileum
- 10-12 ft. long
- absorbs nutrients that aren’t absorbed in jejunum
Pancreas
- located behind stomach
- nested in curve of duodenum
- pancreatic juice= rich enzyme that digests all 3 major kinds of food
1. trypsin=breaks down protein
2. lipase=breaks down fat
3. secreted by salivary glands break down carbohydrates - also secretes sodium bicarbonate to neutralize the gastric acid
Liver
- largest gland
- complex
- weighs 3.5 pounds
- produces more than 1,000 enzymes
- has a lot of freedom for it delegates nutrimental duties
- convert excess: fats, protein into fat and ship them off to storage
- hepatic portal system=blood vessels that take blood to liver from intestine comprise
->can regenerate if damages it only needs 1/4 of cells to completely regenerate
Liver Jobs
- store blood and filter out toxic element
- convert sugars into glycogen
- maintain normal blood sugar level
- maintain normal sex hormone level in blood
- break down fats + temporarily store fatty acids
- store vitamins B12, A,D, E, and K
- Destroy old RBCs, store useful component and send others to kidney for disposal in urine
- produce fibrinogen and prothrombin (protein that falcate blood clotting)
Large intestine
5 ft. long, larger in diameter than small intestine
-receive waste material from small intestine
-absorb water + sodium from the waste material before it passes out of the body
-incubate bacteria that is essential for producing vitamins
-3 sided frame around small intestine
1. cecum=pouch joint of small and large intestine
2. ileocecal valves=regulates the passages of material from ileum to the cecum
chyme became fecal matter (1-3 days to move from ileocecal valve -> rectrum)
Large intestine (part 2)
cecum=between cecum and rectum
- ascending colon= “climbs” straight up from the cecum to liver
- transverse colon-goes across the abdomen
- descending colon=goes down along frank
- sigmoid colon=(makes s shape) empties into rectum
