Lower GI Tract

Question 1

What nerve innervates the ascending colon and most of the transverse colon in terms of parasympathetic supply?

Answer 1

Vagus nerve

Question 2

What is distal parasympathetic supply from?

Answer 2

Pelvic nerves

Question 3

What nerves give sympathetic supply to the lower GI tract

Answer 3

Lower thoracic and upper lumbar spinal cord

Question 4

What is the external anal sphincter controlled by?

Answer 4

Somatic motor fibres in the pudendal nerves

Question 5

What disease occurs when theres no enteric nervous system?

Answer 5

Hirschsprung’s

Question 6

Where is the myenteric plexus ganglia concentrated?

Answer 6

Below the tenia coli

Question 7

What are the 4 layers of the colon

Answer 7

Mucosa
Submucosa
Muscularis (made of 2 layers circular and longitudinal layers)
Serosa

Question 8

Where does nerve supply to the lower GI tract come from?

Answer 8

Centrally AND from the submucosal and myenteric plexus (they are like localised pacemakers)

Question 9

What does the mucosa layer contain? Why is this useful?

Answer 9

Lots of mucin producing glands to allow easy passage of stool and lubrications

Question 10

What are the inflammatory lower GI tract disorders?

Answer 10

IBD and microscopic colitis

Question 11

What are the infective lower GI tract disorders?

Answer 11

C diff

E coli

Question 12

What are the structural lower GI tract disorders?

Answer 12

Diverticular disease
Haemorrhoids
Fissures

Question 13

What are the functional lower GI tract disorders?

Answer 13

Irritable bowel syndrome

Question 14

What are the neoplastic lower GI tract disorders?

Answer 14

Colonic polyps

Colon cancer

Question 15

Who does IBD often affect?

Answer 15

Young people

Question 16

What type of condition is IBD?

Answer 16

Lifelong, chronic and autoimmune

Question 17

What is ulcerative colitis?

Answer 17

Inflammatory disorder limited to the colonic mucosa

Question 18

What is the pattern of inflammation in UC?

Answer 18

Continuous

Question 19

What anatomical area is always involved in UC?

Answer 19

Rectum

Question 20

Does UC affect males or females more?

Answer 20

Effects both equally

Question 21

What is NOT present in UC?

Answer 21

Granulomas

Question 22

What anatomical area does Crohn’s effect?

Answer 22

Any part of the GI tract

Question 23

What is the pattern of inflammation in Crohn’s?

Answer 23

Patchy chronic transmural granulomatous inflammation

Question 24

What structures may be formed in Crohn’s and why?

Answer 24

Tendency to form fistula (penetration between 2 walls) or strictures (narrowing of the lumen, there is non expansive fibrous tissue). They form because deeper layers are affected in Crohn’s compared to UC

Question 25

Out of UC and Crohn's which are painful and why?

Answer 25

Crohn's is more Generally UC is not This is because deeper areas are affected in Crohn's

Question 26

What do IBD symptoms depend on?

Answer 26

Site of bleeding

Question 27

What symptoms will colitis present with?

Answer 27

Bleeding Mucus Urgency Diarrhoea

Question 28

What symptoms will perianal areas being affected present with?

Answer 28

Anal pain Leakage Difficulty passing stool

Question 29

What symptoms will small bowel disease present with?

Answer 29

``` Abdominal pain Weight loss (due to less absorption) Tiredness/lethargy (less absorption causes anaemia) Diarrhoea Abdominal mass ```

Question 30

What are some extra intestinal manifestations of IBD?

Answer 30

``` Arthritis (axial – Ankylosing spondylitis) Peripheral Skin (Erythema nodosum Pyoderma gangrenosum Eyes (Anterior uveitis Episcleritis/Iritis) Liver (Primary Sclerosing Cholangitis (PSC) Autoimmune hepatitis) ```

Question 31

What are the 3 biggest influencers in the development of IBD?

Answer 31

Environmental factors like luminal microbes Genetic susceptibility Immune response

Question 32

What does immune response in Crohn's involve?

Answer 32

Anti-saccaromyces cervisiae (ASCA)

Question 33

What does immune response in UC involve?

Answer 33

pANCA

Question 34

In terms of urination/bowel movements what does urgency mean?

Answer 34

You have control but you have to go

Question 35

In terms of urination/bowel movements what does incontinence mean?

Answer 35

You don’t have control over what you pass and when

Question 36

What IBD is perianal disease associated with?

Answer 36

Crohn's only

Question 37

Why do strictures and fistulations form in Crohn's?

Answer 37

Due to deeper areas being affected whereas UC is superficial

Question 38

Define dysbiosis

Answer 38

Microbial imbalance or impaired microbiota

Question 39

What does poor bacterial community in the microbiota cause?

Answer 39

Inflammation

Question 40

What are the 3 main goals when treating IBD?

Answer 40

Induce clinical remission Maintain clinical remission Improve patient quality of life

Question 41

What is the main action of steroids for IBD?

Answer 41

Diffuses and bind in nucleus to Glucocorticoid Responsive Elements (GRE) which increases anti-inflammatory gene products blocks pro-inflammatory genes

Question 42

How are steroids for IBD administered?

Answer 42

IV, oral or rectal enema

Question 43

How long can steroids be used? Why?

Answer 43

Only short term for acutely unwell patients as they cause lots of side effects and become less effective long term

Question 44

What is the main action of 5 ASA for IBD?

Answer 44

Reduces inflammation via methods such as Inhibition of pro-inflammatory cytokines (IL-1 and TNF-a ) Inhibition of the lipo-oxygenase pathway i.e. prostaglandin and leukotrienes Scavenging of free radicals

Question 45

What is the main action of azathioprine for IBD?

Answer 45

Results in reduced number of B and T lymphocytes, immunoglobulins and interleukins with the overall aim of reducing inflammation

Question 46

What things do we need to monitor/check when giving immunosupressants?

Answer 46

``` Thiopurine TPMT Hep B/C HIV Chickenpox If they gave had all their vaccinations TB Frequently check bloods when starting and also regularly afterwards ```

Question 47

What are some side effects of biologic therapies?

Answer 47

``` Opportunistic infections Infusion or site reactions Neutropenia Demyelinating disease Heart failure (HF) Cutaneous reactions, including psoriasis Malignancy Induction of autoimmunity ```