anal canal - neurovascular supply and lymphatics Flashcards
what is the arterial supply above the pectineal line?
Superior rectal artery (branch of inferior mesenteric artery)
Anastomosing branches from the middle rectal artery.
what is the arterial supply below the pectineal line?
Inferior rectal artery (branch of the internal pudendal artery)
Anastomosing branches from the middle rectal artery.
what is the venous drainage above the pectineal line?
Superior rectal vein
what is the venous drainage below the pectineal line?
Inferior rectal vein
what does the superior rectal vein empty into?
inferior mesenteric vein
what does the inferiro rectal vein empty into?
pudendal vein
what is the nerve supply above the pectineal line?
Visceral innervation via the inferior hypogastric plexus.
Sensitive to stretch
what is the inferior hypogastric plexus sensitive to?
stretch
what is the nerve supply below the pectineal line?
Somatic innervation via the inferior anal nerves
what is the inferior anal nerves branches of?
pudendal nerve
what is the inferior anal nerves sensitive to?
pain, temperature, touch and pressure
what is the lymphatic drainage above the pectineal line?
Internal iliac lymph nodes
what is the lymphatic drainage below the pectineal line?
Superficial inguinal lymph nodes
what are haemorrhoids?
Haemorrhoids are vascular cushions found within the anal canal of healthy individuals
what is it called when haemorrhoids become swollen and distended?
they are referred to as pathological haemorrhoids.
what is the function of haemorrhoids?
help with the maintenance faecal continence
how are pathological haemorrhoids observed in people?
suffer from constipation, prolonged straining when defecating, or raised intra-abdominal pressure (e.g pregnancy, ascites).
which position should patients be in upon examination of anal canal?
the patient in the lithotomy position
where are haemorrhoids typically located?
typically located at the 3, 7 and 11 o’clock positions
what can pathological haemorrhoids cause?
They can cause bleeding and pain on defecation
how can pathological haemorrhoids be managed?
managed conservatively or surgically
depending on severity