2. physiology of the lower GI tract

the lower GI tract is responsible for:

• water and electrolyte absorption

• storage and formation of faecal matter

• absorption of vitimins produced by gut bacteria *(Vit K n D)

• protecting the body from harmful microorganisms

• the coordination of defecation

the lower GI tract contunues the process of digestion

in the colon the human microbiome futher digests any remaining carbs producing short chain fatty acids, gases and vitamines

the digestion of carbs n complex sugars

formulates gases n farts

this fermentation process is crucial for the managment of gut health

jujunum and ileum are where the final absorption of nutrients occurs

particularly vitamin B12 and bile acids

the colon is responsible for absorbing water and electrolytes

from indigestible food matter, a key process for maintaining fuild and electrolyte balance in the body

as water is absorbed the remaining matter becomes more solid forming stool

the collons function in absorbing water ensures the stool is properly formed and not too liquid rpeventind diareohah

bowel movements

• preistalsis

• mass movment

• defecation reflex

peristalsis

rhythmic contracitons which oush the contents through the intestine. this movmene tis essenntla for the progression of digested food and waste products towards the rectum

mass movement

strong coordinated contractions that occur in the large intestine. the main funcion is to push waste material throught the colon towards the rectum usually after eating

defecation reflex

the bodys automatic response when stool reaches the rectum. it triggers the urge to empty the boweld by releasesng the anal sphincter allowing to to be expelled

mass movements involve

enteric nervous system, modulated by the ANS

Stomach distention triggers

the Gastrocolic reflex through the PNS

When the rectum is distended the rectosphincteric reflex is initiated and relaxes the internal sphincter

-This is followed by the contraction of abdominal wall muscles and the relaxation of the pelvic wallv

-Peristaltic waves then facilitate the movement of faeces through the anal canal.

Breath in then stop yourself form beathing out it puts pressure on colon and aids defication process

•Immune system % in the gut is 70%- gut associated lymphoid tissue GALT

•Tries to prevent trauma to the gut