GI tract Flashcards
What is GI tract.
From mouth to anus
Adventitia
Outermost layer surrounding the tract
Types of Smooth muscle in tract
Longitudinal muscle layer (under adventitia)
Circular muscle layer (under longitudinal muscle layer)
(Under involuntary control)
Plexus
Web of nerves
Myenteric plexus (underneath circular Muscle layer)
Submucosal plexus (underneath myenteric plexus)
Submucosa
Underneath the submucosal plexus
Contains nerves,blood vessels and collagen
Epithelium
Under submucosa
Secretes mucus to reduce friction between food and wall
Function of Lumen
Constantly contracting to push food through
Types of contractions
Peristalsis- moves forwards
Segmentation- back and forth to break up food
Mass movement- rapid movements forwards
Peritoneum
Serous membrane sac encasing the abdominal organs to prevent movement and provide structure and prevents organs coming into contact with each other so reduces inflammation due to serous fluid
Goblet cell
In the epithelial cells
Secretes mucus for lubrication
Mouth
Physical breakdown of food by chewing (mastication)
Anterior roof is hard palate made from bone
Posterior roof is soft due to muscle
Amylase released here by salivary glands
Pharynx
Throat
Food goes from mouth to oesophagus via pharynx
Oesophogus
Long tube which transport bolus to stomach
Sphincter
Thickened rings of circular muscles keeping the tract a one way stystem
Tounge
Voluntary muscle
Needed for swallowing (deglutition)
Anchored to mouth by frenulum
Papillae contains taste buds
How many parts is the Salivary glands
Three parts