Digestive Tract

Question 1

Constituents of digestive system

Answer 1

Digestive tract_. Oral cavity, esophagus, stomach, small intestine, large intestine,anus and its associated glands , salivary glands, liver, pancreas

Question 2

Functions of gi tract

Answer 2

To obtain molecules from ingested food , that is necessary for the maintenance, growth and energy needs of the body

Question 3

Functions of structures of the digestive tract

Answer 3

Ingestion
Mastication
Motility
Secretion
Hormone release
Chemical digestion
Absorption
Elimination

Question 4

General structure of digestive tract

Answer 4

It is an hollow tube , with a lumen made up of variable diameter, its walls are made up of 4 layers
Mucosa
Submucosa
Muscularis
Serosa

Question 5

Another name for mucosa is

Answer 5

Mucous membrane

Question 6

Describe the mucosa

Answer 6

It has an epithelial lining
With an underlying lamina propria rich in blood vessels, lymphatics lymphocytes, small glands
And a thin layer of smooth muscle called muscularis mucosae

Question 7

Functions of muscularis mucosae

Answer 7

Separates the mucosa from submucosa
Facilities local movement of mucosa

Question 8

Describe the submucosa

Answer 8

It contains denser connective tissues with larger blood and lymph vessels
Contains the submucosa/meissner plexus of autonomic nerves
It may also contain glands and significant lymphoid tissues

Question 9

Another name for muscularis layer

Answer 9

Muscularis externa

Question 10

Describe the muscularis layer

Answer 10

It is a thick layer
Made up of 2 or more sublayers
In the inner layer, the fiber orientation is circular
In the external sublayer, the fiber orientation is mainly longitudinal.

Question 11

The connective tissue between the muscle sublayers contains what

Answer 11

It contains blood and lymph vessels as well as the myenteric/Auerbach nerve plexus of many autonomic neurons aggregated into small ganglia

Question 12

What makes up the enteric nervous system

Answer 12

The myenteric/ Auerbach nerve plexus
And the meissner or submucosa plexus

Question 13

Describe the serosa

Answer 13

It is a thin sheet of loose connective tissue, rich in blood vessels lymphatics and adipose tissue
It is covered with a simple squamous epithelium or mesothelium

Question 14

What is the serosa of small and large intestine continuous with

Answer 14

It is continuous with the portions of the mesentery

Question 15

What is mesentery

Answer 15

It is a large fold of adipose connective tissue covered on both sides by mesothelium that suspends the intestine

Question 16

The mesentery is continuous with what

Answer 16

Peritoneum

Question 17

Is the esophagus suspended in a cavity?

Answer 17

No it is not, it is bound directly to adjacent structures and therefore lacks a serosa having a thick adventita instead

Question 18

Describe the oral cavity

Answer 18

It is made up of stratified squamous epithelium, which may be keratinized, non keratinized or partially keratinized

Question 19

The keratinized cell layers resist damage from abrasion and are best developed where

Answer 19

In the masticatory mucosa on the gingiva(gum)
And hard palate

Question 20

The lamina propria in these keratinized layer rests where

Answer 20

They rest directly on the periosteum of underlying bone

Question 21

The no keratinized squamous epithelium predominates where

Answer 21

In the lining mucosa over the soft palate,cheeks, floor of the mouth and the pharynx or throat, posterior region of the oral cavity leading to the esophagus

Question 22

Surfaces of the lips

Answer 22

The internal mucosa surface, has lining mucosa with thick non keratinized epithelium with many minor labial salivary gland
The red vermilion zone of each lip is covered by very thin keratinized stratified squamous epithelium and is transitional between the oral mucosa and skin
The outer surface , has thin skin consisting of epidermal and dermal layers , sweat glands and many hair follicles with sebaceous glands

Question 23

The tongue is a striated muscle covered by

Answer 23

Mucosa

Question 24

How are the muscle fibers in the tongue oriented

Answer 24

They are oriented in all directions, allowing a high level of motility

Question 25

Which papillae has no taste buds

Answer 25

Filiform papillae