Control of UGF Flashcards
Sympathetic neurotransmitter
Noradrenaline
Sympathetic receptors
Adrenoceptors (alpha + beta)
Parasympathetic neurotransmitter
Acetylcholine
Parasympathetic receptors
Muscarinic
In the sympathetic nervous system, what does Acetylcholine act on?
Nicotinic receptor
Sympathetic agonist
Noradrenaline @ alpha + beta-adrenoceptors
Sympathetic antagonist
Atenolol @ Beta-adrenoceptors
Parasympathetic agonist
Acetylcholine @ muscarinic receptors
Parasympathetic antagonist
Atropine @ muscarinic receptors
Salivation + benefits
Glandular production of saliva
- aids speech
- promotes dental hygiene
- allows mastication (chewing)
- adds fluid
- starts digestion of starches (amylase)
Production of saliva is under _________ control
Autonomic control - parasympathetic (acetylcholine at muscarinic receptors)
Stomach secretes __ litres per day
2
What pH is the Stomach + benefit
Low = 1 - 1.5 = acidic
- acidity sterilises food to prevent food poisoning
- optimal pH for enzyme
Chief cells of gastric mucosa secrete
Pepsinogens
What does the acid environment activate
pepsinogens to form pepsins
What is pepsins
Endopeptidase - proteolysis of (breaks down) proteins to polypeptides
Cephalic phase
prepares stomach for food arrival - begins prior to food entry
What nervous system is stimulated by cephalic phase
Parasympathetic
Cephalic phase is stimulated by…
Sight, smell, taste
(Cephalic phase) What does parasympathetic system stimulate
Acid release
Gastrin release into blood
What releases gastrin
G cells
Gastric phase
Occurs while food is in the stomach
- Stretch receptors detect distension of stomach
- Release of ACh, histamine + gastrin
What is secreted in gastric phase
Acid, pepsinogen, mucus