Physiology of Large Intestine

Question 1

Longitudinal muscle in caecum and colon divided into 3 strands called

Answer 1

taeniae coli

Question 2

Longitudinal muscle encircles what

Answer 2

anus and rectum

Question 3

Where does smooth muscle become thickened

Answer 3

internal anal sphincter

Question 4

skeletal muscle encircles what

Answer 4

external anal sphincter

Question 5

Taeniae coli and circular muscle create

Answer 5

Haustra

Question 6

What comes from taeniae coli

Answer 6

Appendices

Question 7

What does the caecum receive

Answer 7

1-2l of undigested material, unabsorbed fluid, unabsorbed biliary contents from the terminal ileum via ileocaecal valve

Question 8

What stimulates the opening of the ileoecaecal valve

Answer 8

CCK and gastrin

Question 9

The gastroileal reflex is influenced by

Answer 9

distention of the stomach –> open
distention of the ascending colon –> close
hormones, parasympathetic, sympathetic, enteric neurones

Question 10

What is the appendix

Answer 10

Blind ended tube with extensive lymphoid tissue

Question 11

How does the appendix attach to the caecum

Answer 11

via appendicael orofice

Question 12

What may cause the appendix to become obstructed leading to appendicitis

Answer 12

faecalith

Question 13

Primary functions of colon

Answer 13

Absorption of sodium, calcium, water = condenses ileoceacal material into solid/semi-solid stool
Fermentes undigested carbohydrates into short chain fatty acids by colonic material
Secretions K, HCO3 and mucus
Reservoir - storage
Periodic elimination of faeces

Question 14

Fluid reabsorption and bacterial elimination occurs till

Answer 14

Distal end of transverse colon

Question 15

Final drying and storage

Answer 15

Descending colon and rectum

Question 16

Periodic elimination of faeces is voluntary or involuntarty

Answer 16

Usually voluntary after early childhood

Question 17

WHat is faeces made up of

Answer 17

100g/100ml = H20
50g = bilirubin, little salt, bacteria, cellulose

Question 18

mucosa of the large intestine lacks what

Answer 18

villi

Question 19

Mucosa of the small intestine possesses

Answer 19

circular folds, crypts and microvilli which increase SA

Question 20

Surface epithelial colonocytes

Answer 20

mediate electrolyte absorption

osmosis driven by H2O absorption

Question 21

Crypts

Answer 21

ion secretion

Question 22

Goblet cells

Answer 22

Mucus

Protein defense

Question 23

Na/K absorption increased by

Answer 23

aldosterone

Question 24

significant loss of what in faeces in secretory diarrhoea

Answer 24

Potassium

Question 25

Haustration

Answer 25

non propulsive movement alternating contraction to circular muscle

Question 26

When do haustra appear and disappear

Answer 26

Appear after mass movement

Question 27

How often does haustration occur

Answer 27

very slowly between 16 and 48 hours to allow for absorption

Question 28

A mass movement involves

Answer 28

large secretions of circular and transverse colon powerfully drives faeces into distal region

Question 29

A mass movement occurs

Answer 29

1-3 times per day

Question 30

What is a mass movement normally stimulated by

Answer 30

Gastroileal response after a meal

Question 31

Mass movement in distal region propels faces into what

Answer 31

Rectum

Question 32

In a mass movement the rectum fills with faeces. What does this activate

Answer 32

Faecal stretch receptors

Question 33

Contraction of the smooth muscle of sigmoid colon and rectum (internal anal sphincter) can cause

Answer 33

Relaxation of skeletal muscle of external anal sphincter = ASSITS DEFECATION Contraction of skeletal muscle of external anal sphincter = DELAYED DEFECATION

Question 34

The colon contains about 500-1000 bacteria the most are beneficial to the gut what are their main functions

Answer 34

Increase intestinal immunity Promote motility Synthesise vit K2 and free fatty acids activate some IBD treatment

Question 35

As well as faeces what else does the anus permit expulsion of

Answer 35

Intestinal gas - flatus

Question 36

Flatus is a result of

Answer 36

swallowed air some carbohydrates require certain bacteria to be absorbed internal and external anal sphincters contract and leave. a narrow exit which doesn't permit solid matter to pass through

Question 37

How does Irritable Bowel Syndrome Present

Answer 37

bouts of diarrhoea, constipation and abdo pain

Question 38

What is the treatment of Irritable Bowel Syndrome

Answer 38

modification of diet anti-diarrhoeals anti-spasmodics laxatives

Question 39

Explain the use of linaclotide

Answer 39

Peptide drug used for the treatment of moderate to severe IBS with constipation in adults

Question 40

How does linaclotide work

Answer 40

Increases secretion of Chloride and bicarbonate | Increases intestinal transmit

Question 41

What is the benefit of linaclotide

Answer 41

Improves bowel movement and alleviates discomfort

Question 42

What are the side effects of linaclotide

Answer 42

diarrhoea

Question 43

Unlicensed low doses of amitriptyline are used for

Answer 43

Abdo pain

Question 44

Inflammatory Bowel Disease is an overarching term for

Answer 44

Crohn's - Entire gut | UC - Colon

Question 45

Acute IBD treatment

Answer 45

Glucocorticoids e.g. prednisolone | Prolonged use --> adrenal suppression

Question 46

Aminosalicylcates include

Answer 46

Sulfasalazine

Question 47

Aminosalicylates are used to

Answer 47

Decrease inflammation in maintenance and mild UC