GI: Gross anatomy Basics Flashcards
1
Q
Functions of Digestive System
A
- Ingestion
- Mechanical Processing
- Digestion
- Secretion
- Absorption
- Excretion
2
Q
GI Tract definition
A
- muscular tube extending from oral cavity to anus
- circular and external longitudinal layers
3
Q
Components of GI tract
A
- oral cavity
- pharynx
- esophagus
- stomach
- small intestines
- large intestines
4
Q
Accessory glands of GI tract
A
- salivary glands
- liver
- pancreas
5
Q
Intraperitoneal vs Retroperitoneal
A
- Intraperitoneal
- covered compmletely by peritoneum
- serous membrane
- attached to body wall by mesenteries
- covered compmletely by peritoneum
- Retroperitoneal
- covered by peritoneum on anterior side only
6
Q
Esophagus
A
- Muscular Tube
- 25 cm long
- Primarily in thorax
- begins posterior to cricoid cartilage
- passes through diaphgram
- Cranial 1/3=skeleteal muscle
- middle 1/3=skeletal and smooth muscle
- Caudal 1/3=smooth muscle
- Contains:
- upper esophageal sphincter
- prevent air from entering the esophagus
- Lower Esophageal sphincter
- upper esophageal sphincter
7
Q
GERD
A
- backward flow of stomach acid through the Lower Esophageal sphincter into lower esophagus
- Causes Heartburn or acid indegestion
- painful
- May cause erosion of enamel on teeth
- Tx by:
- drugs
- to reduce excess stomach acid
- Surgery
- reduce lumen size oo strengthen LES
- drugs
8
Q
Stomach: Different parts
A
- Intraperitoneal
- 4 parts:
- Cardia
- surrounds esophageal orifice
- Fundus
- dilated superior part
- related to left dome of diaphgram
- Body:
- majory part
- b/w fundus and pyloric antrum
- Pyloric part:
- pyloric antrum
- pyloric canal
- Cardia
- 2 curvatures:
- greater curvature
- on left
- longer and convex
- Lesser curvature
- on right
- shorter and concave
- greater curvature
9
Q
Shape and size difference depen on?
A
- differs per individual
- between meals
10
Q
Stomach is characterized by:
A
Rugae- longitudinal gastric folds
11
Q
Stomach: Functions
A
- Transorm food into chyme
- Body(corpus)
- Mechanical Breakdown/Digestion
- Break chemical bonds in food by acid and enzymes
- Produces :
- Gastrin
- regulates digestive function
- gastric juices
- Gastric Lipase
- triglycerides
- Pepsin
- proteins
- HCl (chief cells)
- IF (chief Cells)
- helps absorb vitamin B12 in ileum of SI
- Gastrin
- Limited Absorptioin
- certain durgs and alcohol
- Storage
12
Q
Gastrin
A
- Hormone produced by the stomach
- regulate digestive functions
13
Q
Small Intestine
A
- 90% of digestion and absorption of nutrients
14
Q
What are the parts of the small inteste
A
- Duodenum
- Jejunum
- Illeum
15
Q
Small intestine characterized by:
A
Plicae circulares
permanent tranverse folds containing intestinal villi
16
Q
Duodenum
A
- C Shaped
- 1st part of small intestine
- smallest-25 cm
-
retroperitoneal
- except for 1st part
- Has many plicae circulares and intestinal villi
- Receives and mixes:
- chyme from stomach
- digestive secretions from pancreas and liver
17
Q
4 parts of duodenum
A
- Superior
- intraperitoneal (rest is RETROPERITONEAL)
- Descending
- receives pancreatic and bile ducts
- Horizontal
- inferior to superior mesenteric vessels
- Ascending
- curves to join jejunum
18
Q
Jejunum
A
- Locatrion of most chemical digestion and nutrient absorption
- folic acid
- plicae circularis
19
Q
ileum
A
- Last/Distal part of small intestine
- Major location for absorption of vitamin B12
20
Q
Large Intestine
A
- Inverted horseshoe shape organ
- frames small intestine
- 1.5m
21
Q
What are the parts of the large intestine
A
- Cecum
- Appendix
- Colon
- ascending
- transverse
- descending
- sigmoid
- Rectum
- Anal Canal
22
Q
Surface features of large intestine
A
End at Rectum
- Teniae coli
- 3 bands of longitudinal muscles
- Haustra
- punches produced by contraction of teniae coli
- Omental (epiploic) appendices
- fatty outgrowth attached to external wall
23
Q
Major Functions of Large Intestine
A
- Reabsorption of water
- Absorption of vitamins produced by bacteria
- Compact into feces
- Storage of feces
- Produce Lubricant
24
Q
Large Intestine: Cecum
A
- Blind pouch
- intrapeitoneal
- no mesentery
- receives material from ileum through ileocecal valve
- Begins Compaction
25
Large Intestine: Appendix
* aka Vemiform (worm-like) appendix
* Blind diverticulum with minimal lumen
* extends from posteromedial wall of cecum inferior to ileocecal junction
* Intraperitoneal
* Dominated by lymphoid tissue in adolescence
26
Appendicitis
* Acute inflammatioon of appendix
* Initially vague/dull pain in umbilical region
* then severe pain in right lower quadrant=irritated peritoneum
27
Colon
* Ascending:
* narrower than cecum
* **Retroperitoneal**
* continues as transverse colon at right colic (hepatic) flexure
* Transverse
* Largest part
* most movable portion
* intraperitoneal
* continuess as descending colon at left colic (splenic) flexure
* Descending
* much narrower
* **retroperitoneal**
* Sigmoid
* descends into pelvic cavity
* intraperitoneal
28
Diverticulosis
* Mucosal Outgrowths (Diverticula) in middle-aged and elderly
* most common in sigmoid colon
* Can become infected and inflammed=Diverticulitis
29
Rectum
* last 17cm of digestive system in pelvic cavity
* continues as anal canal at anorectal angle (90 degree)
* superior 1/3 covered anteriorly and laterally by peritoneum
* expandable for temporary storage of feces
* characterized by transverse rectal folds
30
Anal Canal
* Terminal 5 cm of digestive tract
* contains anal columns:
* Surrounded by:
* internal anal sphincter
* smooth muscle
* involuntary
* external anal sphincter
* skeletal muscle
* voluntary
