Alimentary controls

Question 1

2 categories which control the alimentary system

Answer 1

Nervous (somatic and autonomic) and hormonal

Question 2

2 categories of autonomic nervous control

Answer 2

Sympathetic and parasympathetic

Question 2

2 categories of somatic (voluntary) nervous control

Answer 2

Sensory (sensation) and motor (innervate muscles)

Question 3

Function of sympathetic nervous system

Answer 3

Fight or flight response, increase heart rate and breathing, reduce gut motility

Question 4

Function of parasympathetic nervous system

Answer 4

Rest and digest, reduce heart rate and breathing, increase gut motility

Question 5

Example of GIT hormones

Answer 5

Cholecystokinin (CCK), gastrin, Gastrin Inhibitory Polypeptide (GIP), Secretin

Question 6

Function of cholecystokinin (CCK)

Answer 6

Stimulates contraction of gall bladder to release bile, stimulates synthesis and secretion of enzyme-rich pancreatic juice, relaxes Sphincter of Oddi, and has a weak inhibitory effect on bicarbonate secretion.

Question 7

Where is cholecystokinin (CCK) released from?

Answer 7

Secreted from endocrine cells in the duodenum in response to high fat and protein in diet.

Question 8

Function of gastrin

Answer 8

Stimulates HCl production by parietal cells in the stomach gastric glands.

Question 9

Where is gastrin released from?

Answer 9

Secreted by G cells in the gastric pits of the stomach.

Question 10

Function of Gastric Inhibitory Peptide (GIP)

Answer 10

Main role is to increase insulin secretion, and is a weak inhibitor of acid secretion.

Question 11

Function of secretin

Answer 11

Reduces gastric acid secretion from the stomach and increases bicarbonate (HCO3) from the pancreas.

Question 12

Where in the alimentary system is there mostly somatic nervous control?

Answer 12

Nearer to mouth and anus (choose when to chew and defaecate). Autonomic control in between (e.g. secretions, peristalsis)

Question 13

In which area of the alimentary system are hormones primarily dominant?

Answer 13

In stomach and duodenum (upper SI)

Question 14

What secretions occur in the mouth?

Answer 14

Saliva

Question 15

What motility occurs in the mouth and pharynx?

Answer 15

Chewing and swallowing (mastication and deglutination)

Question 16

How are saliva secretions controlled?

Answer 16

Entirely neural by cranial nerves

Question 17

Which cranial nerve innervates anterior 2/3 of the tongue for gustation?

Answer 17

Facial nerve - CN VII

Question 18

Which cranial nerve innervates the posterior 1/3 of the tongue for gustation and sensation?

Answer 18

Glossopharyngeal nerve CN IX

Question 19

Which cranial nerve is responsible for olfaction?

Answer 19

Olfactory nerve CN I

Question 20

Which cranial nerve controls chewing?

Answer 20

Trigeminal nerve CN V in the loading periodontal ligaments

Question 21

Example of psychic stimuli for saliva secretion

Answer 21

Visual

Question 22

What is classical conditioning?

Answer 22

Associated unconditioned stimulus (sight of food) with a new conditioned stimulus (bell) to bring about the same response (salivation) - Pavlov’s dog

Question 23

Order of strengths of salivatory stimuli from weakest to strongest

Answer 23

Visual, olfactory, mechanical (chewing), chemical (taste)

Question 24

Which taste is the strongest salivary stimuli?

Answer 24

Acid

Question 25

Which structures are involved in chewing?

Answer 25

Jaw, facial and tongue muscles (muscles of mastication)

Question 26

Which cranial nerves control chewing?

Answer 26

Trigeminal nerve (CN V) innervates muscles of mastication. Facial nerve (CN VII) innervates facial muscles. Hypoglossal nerve (CN XII) innervates tongue motor function (muscles).

Question 27

Which structures are involved in swallowing/ deglutination?

Answer 27

Jaw, tongue, pharyngeal muscles (superior, middle, inferior constrictors)

Question 28

Which part of the nervous system controls swallowing / deglutination?

Answer 28

Skeletal muscle therefore controlled by somatic nerves; however, there is an automatic and reflex component.

Question 29

Which cranial nerves control swallowing?

Answer 29

Trigeminal nerve (CN V), hypoglossal nerve (CN XII). Pharyngeal plexus is innervated by the glossopharyngeal (CN IX) and vagus nerve (CN X).

Question 30

What is the swallowing centre?

Answer 30

An area in the medulla oblongata that inhibits respiration while swallowing.

Question 31

Which types of muscles are found in the oesophagus?

Answer 31

Superior 1/3 is skeletal, middle 1/3 is mixed, lower 1/3 is smooth muscle

Question 32

Which cranial nerve innervates the muscles in the oesophagus?

Answer 32

Vagus nerve (CN X)