ingestion, secretion, motility, digestion, absorption, elimination
Six activities of the digestive system
tubular gastrointestinal tract, accessory organs
What are the two main groups of organs in the digestive:
mouth, esophagus, stomach, small/large intestine, rectum
What are the organs making up the tubular gastrointestinal tract?
liver, gallbladder, pancreas, salivary glands
What are the organs making up the accessory organs of digestion?
mucosa, submucosa, muscularis, serosa
List the four layers(tunics) of the GI tract in the order of inside out
epithelium, lamina propria, muscularis mucosae
List the three layers of the mucosa from inside out
stratified squamous epithelium: protection; simple columnar epithelium: secretion absorption
What is the tissue and function of the epithelial layer?
Found in two areas: mouth, pharynx, upper esophagus, anus
and the other area stomach and intestines
areolar connective tissue; supports epithelium, binds epithelium to muscularis mucosae, contains blood and lymph vesses, MALT
What is the tissue and function of the lamina propria?
thin layer of smooth muscle; folding of mucous membrane of stomach and small intestine increasing surface area for digestion and absorption
What is the tissue and function of the muscularis mucosae?
areolar connective tissue; binds mucosa to muscularis
What type of tissue is found in the submucosa and function?
inner sheet of circular fibers/ outer sheet of longitudinal fibers; involuntary smooth muscle contracts to break food down, mix it with digestive secretions and move it along the GI tract
What's the arrangement of smooth muscle in the muscularis layer and function?
above diaphragm: esophagus adventitia consists of areolar connective tissue only, no epithelial layer is present; below diaphragm visceral peritoneum consists of simple squamous epithelium and connective tissue
How does serosa structure differ above and below the diaphragm?
covers the organs = serosa
What's the location of the visceral peritoneum in relation to the organs of the GI tract?
lines the wall of the abdominpelvic cavity
What's the location of the parietal peritoneum in relation to the organs of the GI tract?
space btwn the visceral and parietal layers
What's the location of the peritoneal cavity in relation to the organs of the GI tract?
fold of the peritoneum that holds small intestine in place by binding it to posterior abdominal wall
Function of the mesentery
fold of the peritoneum that holds large intestine in place by binding it to posterior abdominal wall
Function of the mesocolon
suspends stomach and duodenum from liver
Function of the lesser omentum
largest fold; hangs from stomach over small intestine and transverse colon*fatty protective apron
Function of the greater omentum
attaches liver to anterior abdominal wall and diaphragm
Function of the falciform ligament
RP - organs located on posterior abdominal wall and peritoneum covers only the anterior surfaces eg kidneys, ureters, adrenal; IP - organs completely enclosed by peritoneum
Difference Between Retroperitoneal and Intraperitoneal Organs
parotid, sublingual, submandibular
What's the location of the three main salivary glands?
inferior, anterior to the ears
Where is the location of the parotid salivary gland?
under the base of the tongue
Where is the location of the sublingual salivary gland?
under the mandible
Where is the location of the submandibular salivary gland?
99.5 % water, .5% solutes (mucous, lysozyme, urea, amylase, lingual lipase, bicarbonate ions)
What's the composition of saliva?`
cleanses mouth and teeth, dissolves food to begin digestion, mucous lubricates food for swallowing, lysozyme destroys bacteria; amylase - initiates starch digestion lingual lipase is activated in the stomach
What's the function of saliva?