digestive system
general functions & structures
anatomy of stomach
peritoneum &mesentery
anatomy of accessory organs play a role in digestive activities, but are not part of the G I T
anatomy of large intestine, rectum & anal canal
anatomy of small intestines
stuctures
gross & microscopic
microscopic
gross
structures and functions
gross and microscopic
gross & microscopic
gallbladder
pancreatic acini - exocrine gland
liver
features
rectum( terminal part of G I T)
anal canal
large intestine
others features & functions
haustra
epiploic appendages
tenia coli
general functions
stores and concentrates bile
secretion digestive enzymes
general functions
chemical digestion-secrete enzymes
absorption
mechanical digestion (segmentation)
duodenum( first part)
jejunum second portion
laterally, attached to pancreas and common bile duct
joins stomach via pyloric sphincter
laterally, attached to proper mesentery
ileum last portion
laterally, attached to proper mesentery
joins large intestine at ileocecal junction
ileum contents enter large intestine via ileocecal valve in the cecum
transverse colon
descending colon
ascending colon
start at cecum
ileocecal valve in cecum prevent back flow of contents
attached to greater omentum & transverse mesocolon
sigmoid colon(s-shaped region)
attached to sigmoid mesocolon
connects to the anus
temporary storehouse for feces
surrounded by internal and external anal sphincters,
internal anal sphincters,
external anal sphincters
inner (involuntary) smooth muscles
(outer) voluntary skeletal muscles
function
transmit fecal matter outside of body
longitudinal 3 band muscle layer
contract causing colon to protrude out
extensions formed by protruding colon walls
small fat filled pouches hang on colon surface
function
absorb water and electrolytes such as ion(Ca+, Na +, K + & Cl-)
transmit useless waste out of body
has well developed muscle to expel feces
duodenal glands secretes
mucus
alkaline
to neutralize acid from stomach
wall protection
intestinal glands secretes
watery intestinal juice
neutralize hydrochloric acid & aid in digestion
Peyers patches (lympatic nodules)
for immune system
pyloric sphincter( attached to duodenum)
pyloric region
body
cardiac sphincter(attached to esophagus)
fundus
cardiac region
rugae
folds in the inside to increase surface area for storage
greater curvature(outside curve)
lesser curvature(inside curve)
attached to greater omentum
attached to lesser omentum
lumen (inside)
mechanical digestion
chemical digestion
churning
addition of enzymes and chemical (eg HCl)
gastric glands
parietal cells/glands
chief cells/glands secretes
HCl
intrinsic factors
acid eg HCl
pepsinogen
absorption of vitamin B12
produces erythrocytes
has mucosa layer for protection
pepsin enzyme breaks down protein
prevent reflex of acid into esophagus
regulate amount of chyme moving into small intestines
muscle layer
circular layer
oblique layer
muscular externa longitudinal layer
peritoneum- serous membrane (thin membrane) that lines the abdominal and pelvic cavities, and covers most abdominal viscera
functions
store food
mechanical digestion - churning
mesentery
- double folds of peritoneum.
- hold organs in place
- stores fat & provide a place for blood vessels and nerves to attach to.
intraperitoneal organs - lie within peritoneum
retroperitoneal organs** - lie behind the intraperitoneal space
jejunum
ileum
stomach
sigmoid colon
liver
ascending colon
descending colon
pancreas
rectum
duodenum
mesocolon
greater omentum
mesentery proper
lesser omentum
attached to jejunum and ileum
attached to transverse colon & sigmoid colon
attached to cardiac region and liver
attached at greater curvature and to left side of large & small intestines
ability to wrap around an infected organ
mechanical and chemical process
general functions
Digestion - breaks down food for ease absorption into the circulatory system
eliminates what cannot be broken down
gastrointestinal (GI) tract
accessory digestive - organ that helps with digestion but is not part of the digestive tract
mechanical- cut food into small pieces
chemical- add chemicals (enzymes)
mouth, oropharynx, esophagus, stomach, small intestine, large intestine, and anus
liver
pancreas
salivary gland
gall bladder
continuous tube with two openings: the mouth and the anus.
stomach(churning process)
small intestine
teeth
food mixing (segmentation movement)
mouth
small intestine
stomach
esophagus (peristalsis movement)- no mixing
peristalsis movement forward movement through large intestines
make blood protein (globulin, fibrinogen, & albumin)
stores some vitamins
process fats and amino acids
store glucose as glycogen
filter toxins out of blood e.g alcohol, iboprofen
making bile- that emulsify fats
produce & secrete 22 + enzymes
enter duodenum via duct
blood circulation
hepatic circulation
hepatic portal circulation
heart
hepatic artery
capillaries of liver ( filters harmful toxins )
hepartic vein
inferior venacava
heart via right atrium part
heart
digestive tract arteries
capillaries of digestive tract ( stomach, intestine, pancreas & spleen).
hepatic portal vein (contains most nutrients)
eg appendix
to duodenum via pancreatic duct
produce bicarbonate(alkaline)
neutralize stomach acid
chemical digestion
transverse colon
kidney
increase storage capacity
features and functions
villi
micro villi
circular folds
slow down movements & increase surface area for absorption.
appendix hollow tube that is closed at one end and is attached at the other end to the cecum
has mucus glands for lubrication