M10S1: Componets Of The Digestive System

Question 1

Digestive system is a multi-organ system as organs are divided into what 2 groups

Answer 1

1. Digestive Tract (Alimentary canal):
   -mouth, oral cavity, pharynx, esophagus, stomach, small intestine, large intestine, and anus
2. Accessory Digestive Organs
   -tongue, teeth, salivary glands, liver, biliary ducts and gallbladder and pancreas

Question 2

Functions of the digestive tract

Answer 2

-aka alimentary canal
-continuous tube that starts in oral cavity and ends inferiorly with anal canal
-each organ of digestive tract plays an integral role in breakdown of food and uptake in nutrients

*refer to goodnote images for function of digestion, absorption, secretion, motility, elimination of waste

Question 3

What is defecation

Answer 3

-removal of fecal matter from rectum

Question 4

General histology organization of the digestive tract wall

Answer 4

-although individual parts of digestive tract perform distinct functions, there are similarities when comparing histology

Mucosa
-innermost layer of digestive tract wall and composed of 3 elements
Surface epithelium: reflects the expected function of organs and functions include secretion, absorption and protection
Lamina propia: layer of loose connective tissue under surface of epithelium
Muscularis Mucosa: composed of smooth muscle fibres under the lamina propia

Submucosa
-below mucosa
-dense irregular connective tissue and contains blood vessels, lymphatics, glands and nerve plexuses

Muscularis externa
-composed of circular and longitudinal laters of smooth muscle with nerve plexuses in between the layers
-plexuses are responsible fro muscle contraction to propel food through digestive tract

Serosa/adventitia
-outermost layer of digestive tract either serosa or adventitia
Outer layer is serous membrane (single layer of thin, flat cells that form membranous sheet and secrete lubricating fluid)= serosa
Outer layer is loose connective tissue = adventitia

• refer to goodnote images

Question 5

Name each layer of digestive tract and its definition

Answer 5

*refer to goodnotes