3.1 GI general anatomy Flashcards
what are the 6 essential activities of the digestive process
- ingestion
- Mechanical breakdown (chewing in mouth, churing in stomach, segmentation in small intestine)
- Chemical digestion
- Propulsion (swallowing in oropharynx, peristalsis in esophagus, stomach, SI and LI)
- Absorption (begins in stomach but most is in SI)
- Defecation
What are the 2 groups of organs in the digestive system?
- Alimentary Canal (gastrointestinal tract)
- oral cavity, teeth, tongue
- pharynx
- esophagus
- stomach
- small intestine
- large intestine (colon)
- Accessory organs
- salivary glands
- liver
- gallbladder
- pancreas
what organs are located in the right hypochodriac region
liber and gallbladder
what organs are found in the epigastric region
liver and stomach
what organs are found in the left hypochondriax region
iaphragm and stomach
what organs are found in the right lumbar region
ascending colon
*draw fram around torso with right hand, first go up thats ascening
what organs are in the ubilical region
small intestine and transverse colon
what organs are found in the left lumbar region
descending colon
what organs are found in the right illiac (inguinal) region
cecum and appendix
what organs are found in the hypogastric (pubic) region
urinary bladder
what organs are found in the left iliac (inguinal) region
sigmoid colon
what are teh 4 basic layers in the alimentary canal
- muscsa (touches the food most deep)
- submucosa
- muscularis externa (smooth muscle layer)
- Serosa/adventitia
describe the parts of the mucosa layer
- epithelium
- stratified squamous (to resist abrasion) or simple columnar (somtimes goblet to absorb or secrete -> if goblet it produces mucus)
- Lamina propria
- loose connective tissue
- capillaries for nourishment & absorption
- lymphoid follicles MALT (potential to ingest pathogens need to be able to fight off)
- Muscularis mucosae
- smooth uscle (moves mucosa)
- not propelling food stuff
what are the functions of the mucosa
- secretes mucus, digestive enzymes and hormones
- absorbed end products of digestion
- protects againt infectious disease
describe the submucosa
*second layer sep by smooth muscle layer
- loose connective tissue
has blood & lymphatic vessels, lymphoid follicles, gland and submucosal nerve plexus
describe the layers of the muscularis externa
- circular layer: smoth muscle (squeezes
- outer longitudinal layer: smooth muscle (will shorten)
- myenteric nerve plexus: autonomic nerves -> coordinates movment of 2 smooth muscle layers
- some alters are more thick (sphincter) controls release and prevents backflow
describe peristalsis
*physically moves food stuff trhu body
- bolus of food arrives in digestive system
- circular muscles contract behind bolus
- longitudinal muscles ahdead of bolus contract
- contraction in circular muscle layer forces bolus forward
describe segmentation
*helps with mixing -> contract and relax, not moving food
- non adjacent segemtns of alimentary tract organs alternatively sontract & relax
- mvoes food forward then backward for food mixing -> slow food propulsion occurs
*like cat making biscutis -> alternative sections like alternating paws
what is the peritonal cavity? waht lines it?
Peritoneal cavity = Between visceral & parietal peritoneum; fluid lubricates mobile organs
Visceral peritoneum: on external surface or organs
Parietal peritonium: lines body wall (permiter)
what surrounds intraperitoneal organs?
describe it
what are intraperitonal organs?
Intraperitonal organs = liver, stomach, ileum, jejunum, transverse colon, sigmoid colon
surrounded by peritoneum (these organs pushed their way into the body cavity)
- have a mesentery: double layer of peritoneum
- > route for blood vessels, lymphatics and nerves
- > holds organs in place and stores fat
what are the retroperitoneal organs?
deacribe what surrounds them
retroperitoneal organs: duodenum (almsot all of it), ascending colon, descening colon, rectum, pancreas
NO MESENTARY -> is resorbed and lost
- these organs are POSTERIOR to peritoneum
0 have an adventitia
attachment/placement of mesenteries
start: ant abdominal wall
- > Falcifrom ligament: anterior liver - anterior ab wall (attaches liver to the udnerside of the diaphagm
- > lesser omentum: liver - lesser curvature of stomach
- > Greater omentum: greater curvature of stomach -> anterior transverse colon
- > transverse mesocolon: attaches transverse colon to post ab wall
*have viseral peritonem (lines organs aka cerosa) and parietal peritoneum (lines body cavity
