Digestive System Flashcards
Muscular tube extends…
From oral cavity to anus
Another name for digestive tract?
GI Tract Alimentary canal
4 layers of digestive tract:
1) Mucosa
2) Submucosa
3) Muscularis externa
4) Serosa : Visceral Peritoneum
Mucosa
Inner lining of digestive tract
Contains epithelium + lamina propria
Aids in secretion and absorption
Lamina Propria
Loose areolar connective tissue in mucosa along with Muscularis mucosae
Arranged in two concentric layers
Submucosa
Dense, irregular connective tissue with large blood vessels
Muscularis externae
Has smooth muscle cells, arranged in an inner circular layer with a longitudinal outer layer
Peristalsis
Waves of muscular contractions (using both inner circular and longitudinal muscles) that move bolus along tract
4 types of teeth
Incisors
Cuspid
Bicuspids
Molars
Two types of dentition teeth
Primary dentition teeth: 20 temporary teeth
Secondary dentition teeth: 32 permanent teeth
3 functions of saliva
Lubricate mouth
Dissolve chemicals that stimulate taste buds
Initiates digestion with salivary amylase
What is part of the nervous system and makes mouth water at the thought food?
Parasympathetic.
It accelerates secretion.
3 phases of swallowing:
Buccal phase
Pharyngeal phase
Esophageal phase
What kind of tissue is located in the esophagus?
Stratified squamous epithelium in the mucosa
Because it deals with roughage
Regions of the stomach
Cardia
Fundus
Body
Pylorus
Major functions of the stomach
Storage
Mechanical breakdown
Disruption of chemical bonds
Production of intrinsic factor
What is intrinsic factor?
Glycoproteins required for absorption of vitamin B12
What kind of tissue is in the stomach?
Simple columnar epithelium
Good for secretion
What are parietal cells?
Secrete intrinsic factor and hydrochloric acid
What is pepsin?
Active enzyme that breaks down protein
What is pepsinogen?
An inactive proenzyme.
Needs acidic, or low pH by HCl to convert to pepsin.
3 phases of gastric activity:
Cephalic
Gastric
Intestinal
3 segments of small intestine:
Duodenum
Jejunum
Ileum
Which 2 are retroperitoneal?
Pancreas and duodenum
6 Functions of Digestive Tract
Ingestion Mechanical processing Digestion / Chemical Breakdown of food Secretion Absorption Excretion
What is the hepatopancreatic sphincter (Sphincter of Oddi)?
Assists bile and pancreatic juices into the duodenum
