Large Intestine function Flashcards
Describe the muscular structures of the Large Intestine?
Circular muscle complete
Longitudinal muscle incomplete
What are Haustra?
Pouches of the large intestine
What are teniae coli?
Bands running the length of the colon
What is the function of crypts in the Large intestine?
Lubrication for faecal movement
How does the rectum differ from the anal canal?
Muscularis thicker in canal
Simple columnar becomes stratified squamous
How do the internal and external anal sphincter differ?
External anal sphincter is skeletal muscle
What is the function of the colon?
Osmotic absorption of water to dehydrate chyme
What is the benefit of colonic microflora?
Cellulase - breakdown of undigested carbohydrate
What nutrient is absorbed in the colon?
Short chain fatty acids
Vitamin K
What gases make up flatus?
Nitrogen CO2 Hydrogen Methan Hydrogen sulphide
Mass movement of faecal material into the rectum triggers what?
Mechanoreceptor activity –> defection reflex
Which nerves control the defecation reflex?
Pelvic splanchnic nerves (parasympathetic)
The defecation reflex causes what?
Contraction of the rectum
Relaxed internal anal sphincter
Contracted external
Increased colonic peristalsis
What are the symptoms of constipation?
Headaches
Nausea
Loss of appetite
Abdominal distension
Diarrhoea is responsible for what proportion of deaths <5y/o?
25% (1.5m p.a.)
