L1 - Introduction to GI Flashcards
Summarise the GI tract intrinsic sensory pathways
- submucosal and myenteric plexus
- enteric reflexes regulating motility, secretion and blood flow
Describe what stimuli will activate the extrinsic vagal afferents?
Low mechanical stimuli
- thermal
- chemical
Cell bodies of vagal afferents are situated
Nodose ganglion
Central terminal of vagal aferents is found in the…
Brainstem nucleus tractus solitarius
Stroking of gastric mucosa will trigger the release of…
Serotonin (5HT) into the lamina propia of the epithelium.
Small amount into lumen of the gut
What type of innervation is the visceral peritoneum
under
- autonomic innervation
Describe pain felt in the visceral peritoneum
pain is deep, dull and poorly defined
What type of innervation is the parietal peritoneum under
Somatic innervation
Describe pain felt in the parietal peritoneum
pain is sharp, well localised rebound tenderness - pain felt even after hand is lifted guarding - board like rigidity
Explosive onset of pain indicative of…
Perforation of viscus (appendix or colon) or sudden ischaemia (e.g. mesenteric)
Rapid onset on pain may be indicative of…
Acute inflammatoin
e.g. appendicitis, cholecystitis
Gradual progress pain may be indicative of..
Peritonitis
Describe colic pain
Contraction of smooth muscle against an obstruction causes a cyclical on-off pain.
Intervals are severe.
Patient may roll around in pain
Descirbe biliary colic
Gradual onset, then constant.
So not true colic
Peritonitis
- inflammation of peritoneum
- general or localised
- tenderness, guarding and rebound tenderness
- caused by acid form perforated ulcer
- caused by bile from biliary system
Compare and contrast somatic pain and visceral pain
Somatic
- later onset
- more specific location
Visceral
- dull and / or cramping
- intermittent
- poorly localised
- pain in organ
Position of foregut
Pharynx to Ampulla of Vater
Midgut
Ampulla of vater to first 1/3rd of the transverse colon.
Hindgut
Mid transverse colon to dentate line in rectum.
What would you look out for in an abdominal examination…
Scars, distension, discoloration, rashes, trauma, striae, caput medusa
Caput medusae
Portal venous drainage back to liver impaired.
Channels through previously closed down periumbilical veins are opened.
Allowing portal blood going to the viscera to drain back into larger systemic circulation.
Hesselbach’s triangle
Defined by edge of rectus abdominis muscle, inguinal ligament and inferior epigastric artery.
Direct Hernia
- can exit through superficial ring but cannot extend into scrotum
- weakness in posterior fascia
- medial to inferior epigastric muscles
Indirect hernia
- travels both deep and superficial ring
- can extend into scrotum
- most likely to occur as a result of deep inguinal ring not closing properly.
Blumberg sign
Pain, rebound tenderness, guarding
- indicative peritonitis
How to arrive at a diagnosis using tincanbeds?
T - trauma I - infection N - neoplasm C - congential A - acquired N- nervous B - blood E - endocrine D - drugs S - syphillus
Murphpy’s sign
Pressure applied to right upper quadrant during inspiration. Causes very large pain.
Indicates gall bladder inflammation.
Kehr’s sign
left shoulder pain form diaphragm.
Suggestive of free intraperitoneal blood.
McBurney’s sign
Tenderness with palpation of abdomen 2/3rd of the way between the umbilical and right iliac crest
Psoas
Patient flexes right hip against resistance and experiences RLQ pain, suggestive of appendicitis
Grey-turners sign
- ecchymosis of left flank
- suggest haemorrhage pancreatitis
