Anatomy

Question 1

Role of mouth and pharynx

Answer 1

to chop and lubricate food, starting carbohydrate digestion, delivering food to the oesophagus

Question 2

Role of the oesophagus

Answer 2

to propel food to the stomach

Question 3

Role of the stomach

Answer 3

Stores/churns food, continues carbohydrate digestion, initiates protein digestion, regulates delivery of chyme to duodenum

Question 4

Role of small intestine

Answer 4

principle site of digestion and absorption of nutrients

Question 5

Role of large intestine

Answer 5

Colon reabsorbs fluids and electrolytes, stores faecal matter before delivery to rectum

Question 6

Role of rectum anal canal and anus

Answer 6

regulates expulsion of faeces

Question 7

What are the accessory structures?

Answer 7

Salivary glands, the pancreas, the liver and gall bladder

Question 8

What is the mucosa of the digestive tract?

Answer 8

the inner part of the wall, it is a mucous membrane containing epithelial cells, exocrine and endocrine glands

Question 9

what is the submucosa?

Answer 9

thick later of loose connective tissue that surrounds the mucosa, it contains larger blood vessels, lymphatic vessels and the submucosa plexus (neurone network)

Question 10

What is the muscular external?

Answer 10

it has an inner circular muscle layer and a longitudinal outer muscles layer, it contains the myenteric plexus which is a neutron network and is responsible for the segmental contractions and peristaltic movement in the GI tract

Question 11

What is the serosa?

Answer 11

the outermost layer, made up of loose connective tissue

Question 12

What are the four major functions of the alimentary canal?

Answer 12

Motility, secretion, digestion and absorption

Question 13

What is meant by motility in the alimentary canal?

Answer 13

Mechanical activity mostly involving smooth muscle (skeletal at mouth, pharynx, upper oesophagus and external anal sphincter)

Question 14

What is meant by secretion in the alimentary canal?

Answer 14

Into the lumen of the digestive tract from itself and accessory structures in response to the presence of food, hormonal and neural signals. Required for digestion, protection and lubrication.

Question 15

What is meant by digestion in the alimentary canal?

Answer 15

The chemical breakdown of enzymatic hydrolysis of complex food to smaller absorbable units.

Question 16

What is meant by absorption in the alimentary canal?

Answer 16

transfer of the absorbable products of digestion (with water, electrolytes and vitamins) from the digestive tract to the blood or lymph

Question 17

What occurs to the lumen during circular muscle contraction

Answer 17

the lumen becomes narrower and longer

Question 18

What occurs to the intestine during longitudinal muscle contractions

Answer 18

intestine become shorter and fatter

Question 19

How does spontaneous electrical activity occur in the stomach, small and large intestines ?

Answer 19

It occurs as small waves

Question 20

What does slow wave electrical activity determine?

Answer 20

the frequency, direction and velocity of rhythmic contractions

Question 21

What cells control the electrical activity and where are they located?

Answer 21

ICC cells and they are located largely between the circular and longitudinal muscle layers but may be found elsewhere

Question 22

What do ICCs form gap junctions with?

Answer 22

Each other and smooth muscle cells

Question 23

What is needed for contraction to occur in the intestines?

Answer 23

The depolarising slow waves must have a sufficient amplitude to reach a threshold to trigger smooth muscle cell calcium potentials

Question 24

what’s another name for slow waves?

Answer 24

Basic electrical rhythm

Question 25

What determines whether slow wave amplitude reaches threshold?

Answer 25

neuronal stimuli, hormonal stimuli and mechanical stimuli

Question 26

Excitatory effect that parasympathetic has on the GI tract

Answer 26

increased gastric, pancreatic and small intestinal secretion, blood flow and smooth muscle contraction

Question 27

Inhibitory effect that parasympathetic has on the GI tract

Answer 27

relaxation of some sphincters, receptive relaxation of stomach

Question 28

What is more important the sympathetic or parasympathetic?

Answer 28

parasympathetic

Question 29

excitatory effects that sympathetic has on GI tract?

Answer 29

some sphincter contract

Question 30

inhibitory effects sympathetic has on GI tract?

Answer 30

decreases motility, secretion, blood flow

Question 31

what us the enteric nervous system?

Answer 31

the system of nerve cells located in the gut wall

Question 32

What is peristalsis

Answer 32

Wave of relaxation followed by contraction that normally proceeds a short distance along the gut in an aboral direction

Question 33

What is segmentation?

Answer 33

rhythmic contractions of the circular muscle layer that mix and divide luminal contents

Question 34

where does segmentation occur?

Answer 34

the small and large intestine

Question 35

What is colonic mass movement?

Answer 35

The powerful sweeping contraction that forces faeces into the rectum (occurs a couple times a day)

Question 36

What is tonic contraction

Answer 36

sustained contractions

Question 37

Where does low pressure tonic contraction occur?

Answer 37

organs with a major storage function such as stomach

Question 38

where does high pressure tonic contraction occur?

Answer 38

sphincters

Question 39

What are the six sphincters?

Answer 39

Upper eosophageal sphincter (UOS), lower oesophageal sphincter (LOS), Pyloric sphincter, Ileocaecal sphincter, the internal and external anal sphincters

Question 40

What is the function of the upper oesophageal sphincter?

Answer 40

made up of skeletal muscle, relaxes to swallow and closes during inspiration to prevent air in stomach

Question 41

What is the function of the pyloric sphincter?

Answer 41

regulates gastric emptying, usually prevents duodenal gastric reflux

Question 42

What is the function of the ileocaecal sphincter?

Answer 42

regulates flow from ileum to caecum, distention of ileum it opens and distention of proximal colon is closes

Question 43

What is the function of the internal and external anal sphincters?

Answer 43

are regulated by defaecation reflex

Question 44

What are the three parts of the small intestine?

Answer 44

duodenum, jujunum and ileum

Question 45

What are the three types of salivary glands?

Answer 45

parotid, submandibular and sublingual

Question 46

What are the parts of the large intestine?

Answer 46

the appendix, caecum, the ascending colon, transverse colon, descending colon and sigmoid colon

Question 47

What joint is used to open the mouth?

Answer 47

temporomandibular joint

Question 48

what are the 'closing' muscles of the mouth?

Answer 48

masseter, temporalis and medial pterygoid

Question 49

What is the 'opening' muscle of the mouth?

Answer 49

the lateral pterygoid

Question 50

What nerve facilitates the opening of the mouth?

Answer 50

The mandibular division of the trigeminal nerve CN V3

Question 51

What nerve supplies the posterior 1/3rd of the tongue?

Answer 51

glossopharyngeal

Question 52

Is the posterior 1/3rd of the tongue in the oral cavity?

Answer 52

no

Question 53

What direction does the posterior 1/3rd of the tongue face?

Answer 53

vertical