7. GIT - physiology 1 Flashcards
What is prehension?
the act of moving food into the mouth, directly controlled by the CNS
what nerves are involved in prehension?
- facial nerve
- glossopharyngeal nerve
- the motor branch of the trigeminal nerve
what is mastication?
the first act of digestion
what does mastication allow?
- breakdown of food particles to increase surface area for digestion
- Moisten and lubricate food to prevent it from getting stuck in the oesophagus
what structures are involved in mastication?
- Stratified squamous epithelium
- Terminal branches of sensory neurons
what are the 2 types of saliva?
- mucous
- serous
what salivary glands produces mucous saliva?
- sublingual
- zygomatic
what salivary gland produces serous saliva?
parotid
describe mucous saliva compared to serous
- mucous is thicker/more viscous
- serous is watery and contains amylase
describe mucous saliva compared to serous
- mucous is thicker/more viscous
- serous is watery and contains amylase
what is mucous saliva important for?
binding food into a bolus
what are salivary gland mainly regulated by?
parasympathetic nervous system
describe the salivary gland structure?
- Striated duct (in and out)
- Intercalated ducts (bunches of grapes)
- Acini (secrete saliva)
- Nerve fibres on the outside of the gland - only controlled by neurons
how are salivary glands controlled?
- regulated mainly by the parasympathetic nervous system
- the stimulation of nerve fibres on the end of the acini results in saliva production
- the sympathetic nervous system activates b-adrenergic receptors in salivary secretory cells: occurs in fight or flight and produces a smaller quantity of vicious saliva. stimulation could be carnivores about to attack.
list the constituents of saliva including
- function
- component
- how it works
Function: lubrication
Component: Mucins (glycoproteins)
How: mix with water to form mucous
Function: pH regulation
component: HCO3-
How: neutralisation
Function: antibacterial
Component: Lysozyme antibodies
how: keep the amount of bacteria in check 21
how are Omnivores, Single-stomached herbivores, and some avians saliva specialised
Starch digestion - amylase in saliva - mixed with food before stomach. Acts in stomach