Appendicitis and diverticulosis/diverticulitis Flashcards
1
Q
What is the appendix?
A
- A diverticulum off the caecum
2
Q
Describe the anatomy of the appendix
A
- Has a complete longitudinal layer of muscle (colon has incomplete bands called taenia coli)
- Location of appendix is important because it changes how acute appendicitis presents
3
Q
Outline the blood supply to the appendix
A
- Separate blood supply to caecum
- From a mesentery (mesoappendix)
- Ileocolic branch of SMA
4
Q
What are the potential locations of the appendix?
A
- Retro-caecal
- Pelvic
- Sub-caecal
- Para-ileal (pre or post)
5
Q
When does the classic presentation of appendicitis occur?
A
- When appendix comes into contact with parietal peritoneum in right iliac fossa
6
Q
What are the broad categories of appendicitis?
A
- Acute (mucosal oedema)
- Gangrenous (transmural inflammation and necrosis)
- Perforated - contents of appendix enter peritoneum
7
Q
What is the classic explanation for appendicitis?
A
- Blockage of appendiceal lumen creates higher pressure in appendix
-Venous pressure rises - Oedema in walls of appendix
- Makes it harder for arterial blood to supply appendix
- Ischaemia in walls of appendix
- Bacterial invasion follows
8
Q
What kind of things can cause blockage to the appendiceal lumen?
A
- Faecolith
- Lymphoid hyperplasia
- Foreign body (swallowed)
9
Q
What are the symptoms in a classic presentation of appendicitis?
A
- Poorly localised peri-umbilical pain
- Anorexia
- Nausea/vomiting
- Low grade fever
- After 12-24 hours pain is felt more intensely in right iliac fossa
10
Q
Outline what happens to the appendix as it becomes inflamed and causes pain
A
- When appendix first starts to swell, it stretches visceral peritoneum
- This has visceral afferents
- Pain is referred to T9/T10 dermatomes
- Once appendix swells large enough it comes into contact with parietal peritoneum (somatic origin)
- Has more specific nervous system
- Pain becomes localised
