1.1 Anatomy of gut Flashcards
List 3 functions of the abdomen
1) Protects and supports viscera within
2) Assists in breathing
3) creates changes in intra-abdominal pressure
Where is McBurney’s point and what is its significance in appendicitis?
Location: 1/3 along a line from the right ASIS to the umbilicus
Significance: In appendicitis pain initiates near the umbilicus in the epigastric region. This is because Infection begins irritating the visceral peritoneum -> poorly localised pain that is felt where the organ was embryologically derived.
Over- time, as the infection spreads to the surrounding abdominal wall, it begins to irritate the parietal peritoneum -> more localised pain that is felt closer towards the appendix’s adult position -> migrates towards McBurneys point
What are the 4 quadrants of the Abdomen? Which significant abdominal organs lie in each quadrant?
R Upper: Liver, gallbladder
R Lower: Appendix
L Upper: Stomach, spleen
L Lower: descending colon, sigmoid colon
Label the 2 planes shown below
What are the boundaries of the abdomen?
Superior: diaphragm
Inferior: Pelvic inlet
Lateral: serous membranes
What are the 9 regions of the abdomen?
Lable the planes shown below
List the 3 types of mesentery in the abdomen
- Mesentery proper
- Trasverse mesocolon mesentery
- Sigmoid mesocolon mesentery
What is mesentery and what is its significance?
Double layer of the peritoneum: tissue that houses blood vessel, nerves, and lymphatics to gut as vessels cannot directly penetrate the peritoneum
What is the peritoneal cavity and what is its clinical significance?
A potential space between parietal and visceral peritoneum ➞ contains serous fluid that lubricates the GI tract allowing for movement during digestion
Inflammation and infection can lead to increased production of fluid which can put pressure on the organs ➞ ascities
Compare the parietal vs visceral peritoneum
Parietal ➞ lines abdominal walls
Visceral ➞ covers suspended organs
(These layers slide freely against one another)
What is the nervous innervation to the Parietal peritoneum?
What impacts does this have on “feeling pain” in the abdomen?
Innervated by somatic afferent fibres, sensitive to well localised pain ➞ can feel pain here and perceive it being there
What is the nervous innervation to the Visceral peritoneum?
What imapact does this have on “feeling pain” in the abdomen?
Innervated by visceral afferent fibres, activation of these can lead to referred pain ➞ poorly localised sensations of discomfort
(reffered pain localises to region of embryological origin)
What is meant by an intraperitoneal organ?
Give 4 examples of organs which are intraperitoneal
Intraperitoneal: completely invested by visceral peritoneum and suspended by mesenteries
- stomach, spleen, jejunum, ileum, caecum, appendix, transverse colon, sigmoid colon
What is meant by a retroperitoneal organ?
Give 4 examples of organs which are retroperitoneal
Retroperitoneal: NOT suspended in the abdominal cavity by mesentery, lay between visceral peritoneum (anteriorly) and abdominal wall (posteriorly)
- kidney, adrenal glands, ureters, IVC, abdominal aorta
Give 4 organs which are considered ‘Inbetween’ structures (retro/intraperitoneal)
Duodenum, ascending colon, descending colon, pancreas