Salivary Glands And Secretion

Question 1

Xerostomia

Answer 1

Persistent sensation of dry mouth due to decreased secretion of saliva

Question 2

Secretory glands sub serve 2 main functions

Answer 2

1. Digestive enzymes from mouth to distal end of ileum

2. Mucous glands from mouth to anus for lubrication and protection.

Question 3

Mucous glands perform main functions

Answer 3

Adherent Property- adheres to food particles hence lubrication
Adheres fecal particles together
Sufficient Body- coats the gut wall
Low resistance- prevents slippage of food and aids easy sliding of food along gut wall
Strongly resistant to digestion by GI ENZYMES
Buffering action

Question 4

Complex glands of GIT

Answer 4

Salivary
Pancreas
Liver

Question 5

How do complex glands differ from rest of the glands in alimentary canal?

Answer 5

These glands lie outside the walls of the alimentary tract while the other three- single cell mucous glands, pits and deep tubular glands are either invagination or lie on the surface epithelium of alimentary canal.

Question 6

What are pits in alimentary canal?

Answer 6

In the small intestine invagination of epithelium into the sub mucosa form crypts of lieberkuhn. Contain specialised secretory cells.

Question 7

Deep tubular glands are present where and function?

Answer 7

Stomach and upper duodenum

Oxytocin gland

Question 8

Basic mechanism of stimulation of alimentary tract glands

Answer 8

1. Contact of food with the gut epithelium which activates the ENTERIC NERVOUS SYSTEM
2. Autonomic Stimulation
   
   2. 1 Parasympathetic
   3. 2 Sympathetic
   4. 3 Hormonal

Question 9

The 3 types of stimuli that activate the ENTERIC NERVOUS SYSTEM

Answer 9

Tactile stimulation
Chemical irritation
Distension of the gut wall
These stimulate the mucous cells on the GUT EPITHELIUM and DEEP GLANDS IN THE GUT WALL to release secretion.

Question 10

Effect of Parasympathetic stimulation

Answer 10

Increases secretion of salivary, oesophageal, gastric, pancreas and Bruner glands.
Distal portion of large intestine inner gated by pelvic parasympathetic nerves.

Question 11

Dual effect of sympathetic stimulation

Answer 11

1. Alone increases slightly
2. If parasympathetic and hormonal stimulation is already causing copious secretion by the glands, superimposed parasympathetic stimulation decreases it

Question 12

How does sympathetic stimulation decrease secretion

Answer 12

Vasoconstrictive reduction of blood supply to the glands

Question 13

What is a hormone

Answer 13

Chemical polypeptide or their derivatives

Question 14

What is mucus?

Answer 14

A thick secretion composed mainly of water,electrolytes and a mixture of several glycoproteins which themselves are composed of large polysaccharide bound with much smaller quantities of proteins.

Question 15

Buffering action of mucus

Answer 15

The glycoproteins of mucus have amphoteric properties which mean that they are capable of buffering small amounts of either acids or alkalis;
Mucus also contains moderate quantities of HCO3 which specifically neutralise acids

Question 16

Daily secretion of saliva and ph

Answer 16

800-1500ml Av 1000ml

Ph 6.0-7.0