S1 Flashcards
What divides the gut into its various functional areas?
sphincters
Which two abdominal viscera have gland like function with respect to the GI tract?
pancreas
liver
Approximately how long is the duodenum?
25cm
On a gross anatomical level how does the jejunum differ from the ileum?
jejunum- more folds, wider, longer
What marks the junction of the jejunum and ileum
no obvious junction
continuous
reduction in folds seen
At what point along the GI tract does it enter the pelvis?
end of sigmoid colon going into rectum
what is the function of acid within the stomach?
denature proteins to inc surface area for proteases
kill microorganisms/pathogens
How are the acidic stomach contents neutralized when they enter the duodenum?
HCO3- secreted from pancreas and liver (bile)
enters through common bile duct
Which section of the GI tract is responsible for most nutrient absorption?
jejunum
Which section of the GI tract is responsible for reabsorbing bile salts?
terminal ileum
What is the function of mucus within the large intestine?
provide nutrients to support microbiome
protective layer between epithelia and gut bacteria
What is a mass movement?
rapid peristalsis of faeces from distal large bowel to empty rectum
What process triggers the sensation to defaecate?
stretching of rectum after its filled
What could happen if sphincters in the GI tract do not function effectively?
Incontinence- Anal sphincter
Reflux disease- lower oesophageal sphincter
Vomiting- failure of lower oesophageal sphincter
Diarrhoea- pyloric sphincter fails to control rate at which chyme enters duodenum
dysphagia meaning? when can it occur?
difficulty swallowing
- failure of pyloric sphincter to relax/ lower oesophageal sphincter failure
why isn’t all water removed in small intestine?
some required for frictionless movement.
no water when dehydrated therefore constipation, moving against friction
which muscle aids churning and peristalsis for physical break down?
extra layer of oblique muscle in muscular propria
why is small intestine narrow with large SA?
large SA as most digestion and absorption takes place here
narrow so nutrients come into contact with the epithelial wall to be digested/ absorbed
why is it beneficial for colon to be wider?
storage site for faeces
list innate protection against pathogens GI
- mucus in colon
- stomach acid
- saliva (antibacterial agents)
- peristalsis>moves toxins along and out
- rapidly dividing epithelia > provide healthy and intact barrier against pathogens
