Lecture 27 Flashcards
GI secretions are classified into 2 parts. What are they?
endocrine secretions and exocrine secretions
What is the purpose of endocrine secretions? Give examples
They are for the regulation of __________ and ____________ eg. _________ stimulation of stomach ________ and _________ acid secretion. __________ and _______ inhibition for _______ motility and stimulation of _______ secretions
They are for the regulation of motility and secretion eg. gastrin stimulation of stomach motility and gastric acid secretion. CCK and secretin inhibition for stomach motility and stimulation of pancreatic secretions
What are the purposes of exocrine secretions?
Prepare ________ for __________ by:
- diluting it to the _________ of the plasma
- altering _________ for optimal ________
- digesting ________
- protection/________
Prepare food for digestion by:
- diluting it to the osmolarity of the plasma
- altering pH for optimal digestion
- digesting food
- protection/lubrication
What are the 4 major components of GI secretions?
- mucus
- enzymes
- electrolytes
- serous solutions
How many litres of saliva do we secrete per day?
1.5 L
Is saliva hypertonic, hypotonic or isosmotic? What is its osmolarity?
hypotonic with an osmolarity of 100 mOsmolL-1
What is the main ion in saliva?
Na+
What are five functions of saliva?
- oral hygiene
- helps with talking
- chewing and swallowing by moistening and dissolving food
- makes food isosmotic
- has amylase for starch digestion
What condition happen as a result of a lack of saliva?
xerostomia
Is food acidic or basic?
acidic
What is in saliva that protects us from the acidic food?
HCO3-
Does the sympathetic system increase or decrease saliva secretion.
Decrease
What are 6 examples of things we can analyse using saliva?
- DNA
- cancer
- heart attack
- infections (HIV)
- homeopathy
- COVID-19 testing
How many pairs of salivary glands are there?
3
What are the three main pairs of salivary glands? What sort of secretion do each of these have?
- parotid (serous)
- submandibular (mixture of mucous and serous)
- sublingual (mucous)
As well as the three main pairs of salivary glands, where are the minor ones located?
there are minor buccal glands in the mouth, pharynx and oesophagus
Where are the parotid salivary glands located?
behind the ears