Organ systems 2) Digestive Flashcards
What do carbohydrates provide?
Energy
What are proteins used for?
Building cells and tissues
Fats and lipids
- energy,
- membrane formation,
- hormone production.
Vitamins
molecules that the body cannot make so must be extracted from food.
Minerals and trace elements
used in the assembly of different structures e.g. bones, enzymes.
salts
fundamental to all cells, you are essentially a big bag of salt solution.
what are the 3 types of saliva glands?
parotid, sub-mandibular
and sub-lingual
Name 3 enxymes in saliva?
Amylase Lipaise Lyzozyme
What is Lyzozyme
A bacteriocite
What is the buchal lining made of?
non-keratinised stratified squamous epithelium,
Where does food go after leaving the mouth
Oropharynx then Laryngopharynx
What is degulation?
Swallow reflex
What is the refex that propells food into the stomach when it is in the oesophegus?
peristalsis
What blocks the larynx during swallow?
Epiglotis
Where does the oesophegus pass through the diafram?
The oesophegeal hiartus
Where does the oesophegus join the stomach, and what sphincter if found here?
Cardiac orifice, GASTROESOPHAGEAL SPHINCTER
Why is the GASTROESOPHAGEAL SPHINCTER kept closed?
To prevent stomach acid from rising up and irritating oesphoegus
Describe the layors of the eousophagus from out to in
Serosa – connective tissue membrane surrounding the tube
Muscularis – skeletal muscles running in different orientations
Sub- mucosa - connective tissue layer
Mucosa - smooth muscle, connective tissue and lining epithelium.
Parietal Cells: what do they do?
- Secrete HCI and intrinsic factor
- Intrinsic factor is essential for B12 absorbsion
What do chief cells produce in the stomach?
protein digesting enzyme PEPSINOGEN which is converted to active PEPSIN by HCl, and a lipase.
Enteroendocrine Cells: what do they release?
Chemicals including histamine and seratonin
What is the Duodenum?
first 20-25 cm of the small intestine
Where do sectetions enter the duodenum from?
pancreas and gallbladder
What is the sphincter at the excit of the stomach called
Pyloric sphincter
What are the endocryne secretions of the pancreas?
Insulin and glucagon
What does pancreatic juice contain? (5)
a) HCO3- to neutralise HCl
b) Pancreatic amylase to digest carbohydrate (-CHO)
c) Lipase (fat) to digest lipids
d) Ribonuclease (RNA) and deoxyribonuclease (DNA) to digest DNA and RNA.
e) A number of protease enzymes to continue the breakdown of proteins.
What does the Gallbladder do?
Stores and concentrates bile produced by the liver
What is the role of bile?
- emulsify fats so they can be absorbed.
- enables absorption of fat soluble vitamins and iron in the small intestine.
What is billirubin?
Bile pigment formed from the breakdown of red blood cells
What are the 2 remaining parts of the small intestine?
After the duodenum
JEJUNUM (2m) and ILEUM (4M)
What covers the inner layer of the mucosa in the small intestine and why?
Villi, to increase surface area
Where in the liver does the processing of nutrients take place?
Hepatic vein
What is the role of the large intestine?
Remoove water and electrolytes
Where is the caecum?
One end of the apendix leading from the
What is the role of the liver?
Its role is to process food arriving from the small intestine and to filter blood, extracting toxins and adding important proteins.
What shape is a liver lobule?
What is at each corner?
Hexagonal
- a portal triad
What are the 3 structures of the portal triad?
- A branch of the hepactic artery (supplying oxygen)
- A branch of the hepatic portal vein (carrying nutreous blood)
- A bile duct
What is a liver cell called?
hepatocytes
