MGCCC chapter 24 Digestive System

Home

Get App

Create

5 basic activities involved in digestion.
- Ingestion- Taking food in
- Movement- of food along digestive tract
- Digestion- breakdown of food by both mechanical and chemical processes
- Absorption- passage of digested food from the GI tract to the circulatory system.
- Defecation- Elimination of indigestible substances from the body
GI tract AKA?

Alimentary canal
What is the Gastrointestinal tract?

a tubular structure that runs from the mouth to the anus.
Accessory structures of the digestive system
- teeth
- tongue
- salivary glands
- liver
- gallbladder
- pancreas
4 layers of the GI tract
- Mucosa
- Submucosa
- muscularis
- Serosa (visceral peritoneum)
3 sublayers of the submucosa
- epithelial mucosa
- lamina propria
- mucosal muscularis
What is the mucosal muscalris?

sublayer that contains muscle fibers that contract to throw the mucosa into small folds which increase the absorptive area
What does the submucosa consist of?
- arterioles
- venules
- lymphatics
- glands
- nerves
What does the submucosal plexus do?

Regulates blood flow in the intestines.
What does the muscularis layer of the GI tract contain? What does it do?

Myenteric plexus (plexus of auerbach) which contains autonomic nerve fibers that control GI tract mobility.
What is the parietal peritoneum?

serous membrane that lines the wall of the abdominal cavity.
What is visceral peritoneum?

An extension of the parietal peritoneum that covers the serosa of the GI tract and several other organs.
The space between the parietal and visceral peritoneum?

Peritoneal cavity
What are the peritoneal folds?
- mesocolon
- falciform ligament
- lesser omentum
- greater omentum
- mesentery
Mesocolon

supports the large intestine
falciform ligament

attaches the liver to the abdominal wall and diaphram
lesser omentum

supports the stomach
greater omentum (apron

contains many fat and lymph nodes
Mesentery

Supports the small intestine
Mouth AKA

Buccal Cavity
What is the mouth formed by?
- The cheeks
- hard/soft palate
- tongue
Lips AKA

Labia
What forms the boundary of the mouth?

Lips
What kind of tissue are the lips?

Transitional epithelium
What attaches the lips to their respective gums?

labial frenulums
Fauces?

opening between palatoglossal arches leading to the pharynx
What dangles between the palatoglossal arches?

uvula
What initiates the breakdown of starch by reducing long polysaccharides?

Salivary amylase
polysaccharides

carbs
3 sets of salivary glands
- Parotid
- Submandibular
- Sublingual
Parotid glands

located in front of the end underneath the ears
Mumps

viral infection of the parotid glands
Submandibular glands

lie below and inside the mandibular angles
Sublinual glands

Lie immediately underneath the tongue.
3 regions of the tooth
- Crown
- Neck
- Root
Crown

part of the tooth above the level of the gums
neck of tooth

constricted portion between the crown and root. Surrounded by gums
Root of tooth

filled with pulp
Baby teeth

deciduous teeth
Permanent dentition

32 permanent teeth
Front 4 teeth

Incisors- adapted for biting
on each side of the incisors

canine tooth- pointed for tearing
Premolar teeth

(bicuspid)- cut and shear food
molar teeth

3 on each side of the jaw- equipped for grinding
Next major organ involved in swallowing after mouth is?

Esophagus
Esophagus lies

behind the trachea and pierces the diaphram at the esophageal hiatus
What permits food into the stomach?

Esophageal sphyncter
Stomach is divided into ___areas, they are?
4
- Cardia
- Fundus
- Body
- Pyloras
How long does it take the stomach to empty its contents?

2-6 hours
Order of digestion
- Carbohydrates
- Protein
- fats are no digested in the stomach
Which surface of the stomach has large folds called rugae?

Mucosal
Chief (zymogenic) cells secrete?

Pepsinogen
Parietal cells produce
- hydrochloric acid
- intrinsic factor
Enteroendocrine (gastrin) cells produce?

gastrin
A head which has a ____ that joins the _________ to form the _______that empties both bile and pancreatic fluids into the proximal portion of the duodenum through the____?
- pancreatic duct
- common bile duct
- ampula of vater
- sphincter of oddi
Pancreatic amaylase digests?

Carbs
Trypsin digests?

Protein
Pancreatic Lipase digest?

Fat
What and where is fat emulified?

In the live by alkaline bile
The cystic duct connects with the gallbladder, joins the common hepatic duct and, at that point, becomes the common bile duct
Small intestine is divided into?
- Duodenum
- Jejunum
- ileum
How long is the duodenum?
Jejunum?
Ileum?
- 10"
- 8'dead/3'live
- 12'dead/6'live
The lumen of the small intestine is lined with?

Villi
Each villus contains

an arteriole, venule,lymph vessel
Lymph vessel in the villus of the small intestine?

Lacteal
Crypts of Lieberkuhn cells
- Enteroendocrine cells
- paneth cells
Enteroendocrocrine cells
- secrete cholecystokinin
- secretin
- gastric inhibitory peptide
paneth cells

secrete lysozyme
lysozyme

bacterial enzyme
Cecum

blind pouch below the ileocecal valve to which the vermiform appendix is attached.
Colon divided into 4 parts?
- Ascending colon
- transverse colon
- descending colon
- sigmoid colon
Last section of the GI tract?

Rectum
Where is the defecation reflex mediated

Nerve centers in the sacral portion of the spinal cord
Ulcers are usually created by?

Helicobacted pylorae
Appendicitis

Inflammation of the vermiform appendix
Diverticulitis is treated with?

High fiber diets and/or surgery

Author

Anonymous

47568

Card Set

MGCCC chapter 24 Digestive System

Description

Digestive System chapter 24

Updated

2010-11-05T20:06:25Z

Show Answers