Gastrointestinal System
Jenna Stellato, Lauren Gomez, and Marissa LaLuna
Esophagus
❖ Used to pass food to the stomach
❖ Stratified squamous epithelial tissue
❖ Secretes mucus
❖ Mucus glands help the passage of food
Stomach
Structure of Stomach
❖ J-shaped
❖ Two openings➢
esophageal and duodenal
❖ Four regions
Function of Stomach
❖ Fundus
➢
collects digestive gases
❖ Cardia
➢
opening of the esophagus, into stomach
❖ Body
➢
secretes acid with enzymes that digest food
❖ Pylorus
➢
responsible for mucus, gastrin, and pepsinogen
Gastric Secretions
❖ Mucus
➢ coats & lubricates the gastric surface and protects epithelium from
acidic substances
❖ Acid
➢ important for activation pepsinogen and inactivation of bacteria
❖ Protease
➢ type of protein that speed up the breakdown of others
❖ Hormones
➢ a hormone called gastrin is secreted from the gastric epithelium and
it controls acid secretion
Mixing and Emptying Actions
❖ Chyme- a semifluid paste of food particles and gastric
juice
❖ Peristaltic waves push the chyme toward the pyloric
region
❖ The stomach’s contractions push the chyme to the
small intestine
❖ Most food will pass through the stomach fast and
easily, but some fatty foods may stay in the stomach
longer
Pancreas
❖ Glandular organ
Structure of Pancreas
❖ Located below the stomach
❖ Three parts
➢ head, body, and tail
Function of Pancreas
❖ Endocrine gland that produces several important
hormones, like insulin and glucagon
❖ Contains digestive enzymes which help to break down
carbs, proteins, and lipids
Pancreatic Juice
❖ A watery fluid secreted by the pancreas which
contains enzymes that break down partially digested
food in the small intestine.
Liver
❖ Detoxifies blood to get rid of harmful substances
Liver Structure
❖ A triangular organ which extends across abdominal
cavity
❖ Made up of pinkish-brown tissue and connective tissue
❖ Contains bile ducts which are tubes that carry bile
through the liver and the gallbladder
Liver Functions
❖
❖
❖
❖
Stores vitamins and iron
Stores glucose
Converts stored sugar into usable sugar
Destroys old red blood cells
Gallbladder
❖ Pear-shaped sac
❖ composed of three parts:
➢ neck,body,fundus
❖ Stores and concentrates bile:
➢ a liquid that the body uses to digest fat and
neutralize acid
http://www.youtube.com/watch?v=JnzwbipJuAA&saf
e=active
Small Intestine
❖ Where most of the chemical and mechanical digestion
is carried out
Structure of Small Intestine
❖ Smooth muscle wall
Function of Small Intestine
❖ Peristalsis- Rhythmic contraction to digest food
➢ Duodenum: Neutralizes acidic gastric materials to
continue the digestive process
➢ Jejunum: Handles absorption of carbohydrates and
proteins, vitamins, minerals, and iron
➢ Ileum: Coiled parts of the small intestine that
absorbs nutrients from digested food
Large Intestine
❖ Far larger than small intestine
❖ Digestion already took place in small intestine
❖ Gets rid of wastes in the body
Structure of the Large Intestine
❖ Is 5ft. long
❖ 6 regions:
cecum,ascending colon, and
rectum, Transverse colon,
descending colon, sigmoid colon
Function of the Large Intestine
❖ Salt and water absorption takes place here
❖ Maintaining fluid balance
❖ Some vitamins are absorbed here
Diseases of Gastrointestinal System
❖ Acid reflex- SymptomsHeartburn,Regurgitation,Nausea
Treatment- Medications (antacids),Diet,
surgery in extreme cases
Diseases of Gastrointestinal System
❖ Gallstones➢ pieces of solid material that form in the gallbladder
➢ develop because cholesterol and pigments in bile which sometimes form into
hard particles
❖ Cholesterol Stones- yellow-green (most common)
❖ Pigment Stones- small and darker color
❖ Symptoms not present in most cases
Diseases of Gastrointestinal System
Gastritis➢ inflammation or irritation of the stomach lining
➢ caused by alcohol use, bacterial or viral infections, or the use of certain
medications
❖ Symptoms- abdominal pain/bloating, vomiting, indigestion, loss of appetite
❖ Treatments- upper endoscopy, blood tests, stool tests, antacids (to reduce
stomach acid)
❖ Crohn’s Disease➢ inflammatory bowel disease which can cause inflammation of the digestive
tract
❖ Symptoms- abdominal pain, diarrhea and malnutrition
❖ Therapy can help the pain
Video
http://youtu.be/URHBBE3RKEs