BMS13 Flashcards
Describe the ion channels in the colon (5)
Left side
Na in
H out and Na in
HCO3 out and Cl in
Right side
Na out and K in using ATP
Cl out
What may cause malabsorption? (4)
Bile salts not circulating properly, failure of pancreatic enzyme delivery, lack of vitamins or too much water being retained
What takes bile back to the liver?
Portal vein
Describe a villi (5)
Goblet cells, ion channels and enterocytes line it
Lacteals and capillaries are in the centre
Intestinal crypts
What happens in intestinal crypts?
Stem cells move up and differentiate
What does lipase do?
Cut 2 FA from TAG
What do lacteals do?
Absorb fat in the form of chylomicrons
What do enterocytes do?
Make enzymes e.g. enterokinase
What happens to lipids?
Lipoprotein B packages lipids into chylomicrons which the lipids absorb
What does bile do and where does the end of the journey come?
Emulsify lipids so they form micelles which contain bile salt and lipases so they can be cut up and diffuse into enterocytes
What happens when FA diffuse into enterocytes?
SER resynthesizes them
Where does protein digestion start and finish?
In the stomach with HCl and pepsin and then to the duodenum
What does enterokinase do?
Convert inactive enzymes into their active form e.g. tripsinogen to trypsin
What does trypsin do?
Activate inactive enzymes
What makes intrinsic factor for B12?
Parietal cells
What stimulates water absorption in the colon?
Aldosterone
What is the importance of microflora?
It can’t cross the epithelium which helps make vit K and folic acid
What may cause not enough water absorption?
Bacterial infections
Where is the main site of water absorption?
Small intestine
What pumps does the small intestine have?
Fructuose, Na/glucose, Na/K/ATP and then Glucose/Fructose
Describe the tissue of the oesophagus (3)
Smooth & skeletal muscle
connective tissue makes the adventitia
Non-keratinized stratified squamous epithelium makes the mucosa
How many sphincters does the oesophagus have?
2
What do parotid glands excrete?
Serous
What do submandibular glands excrete?
Serous and mucosal
What do sublingual glands excrete?
Mucosal
What shuts the stomach off from the duodenum?
Pyloric sphincter
What does the large intestine do?
Absorbs water and vitamins to finish digestion
What does CKK cause?
Contract the gall bladder and relax the sphincter
What stimulates gastric secretions?
Histamine, gastrin and Ach
What makes up gastric secretions?
HCl
What is chyme?
Gastric juice and partially digested food
What gland makes saliva?
Acinar
What inhibits gastrin?
Low pH
When is CCK released?
In response to fat
What does CCK do? (3)
Stop feeling hungry
Enzyme secretion
Gastric motility
Contracts the sphincter between duo and pancreas
How is saliva modified?
Its passed along a duct and has ions added and removed
What is the cephalic phase?
1
Food in the mouth causes saliva and gastric secretions
What is the intestinal phase?
3
Food enters SI and hormones are released to stop gastric secretions
Nutrients are absorbed
Bile and pancreatic secretions occur
What is the gastric phase?
2
Acids and enzymes are made when food is in the stomach
Gastric motility
What cells release H? (2) What stimulates them to make H?
Enterochromaffin and parietal
ACh
What else does ACh do?
Get mast cells the make histamine
What does gastrin do? (2)
Get mast cells to make histamine and stimulate parietal cells to make H
What does histamine do?
Get parietal cells to make H
What do delta cells do? (3)
Make somatostatin which get enterochromaffin cells to make histamine and get parietal and g cells to make gastrin
What do brunners glands make?
Mucus and HCO3
What do crypts make?
Saline
When is secretin released and by which organ?
Duodenum
Releases when chime gets acidic
Increases bile release
What are enterocytes?
Cells lining the small intestine
What do chief cells make?
Pepsinogen
What does GIP and GLP do?
Inhibit glucagon and make insulin
What type of cells make enzymes and alkali?
Acinar cells
What is the hunger hormone?
Ghrelin
What makes up the back of the tongue?
Smooth oral epithelium
What seperates the front and the back of the tongue?
V shaped sulcus terminalis surrounded by moats
What type of cells make up the front of the tongue?
Fungiform for taste; mushroom shape
Filiform; keratinized spiky shape
Circumvallate for taste; table like
What glands are in the circumvallate? What type are they?
Von ebners; serous
What glands are in the duodenum?
Brunners
What are peyers patch?
In the SI they are lymph
What do plicae circulares do?
Absorption
Name the 3 layers of muscle in the stomach
Longtitudinal, circular and oblique
Name the sections of the stomach (4)
Fundus
Body/corpus
Antrum
Pylorus
What secretion do exocrine glands do?
Merocrine
What is serous VS mucous?
Serous is more liquid while mucous thick and slimy
Name the 3 glands in the mouth?
Sublingual
Submandibular
Parotid
What is a gland called if it is both serous and mucosal?
Serous demilume
What type of gland is parotid?
Serous
What type of gland is the mandibular?
Serous and mucosal
What type of gland is the sublingual?
Mucosal
What are myoepithelial cells?
Around acini to squeeze excretion out
Where are paneth cells?
Under crypts with lysosomes
What part of the gastric pits make what?
The bottom makes enzymes and the top makes mucus
