GI Flashcards
What is the function of the pharyngeal constrictor muscles?
They contract sequentially producing peristaltic waves which drive food into the oesophagus.
Do parotid glands have mainly serous or mainly mucous acini?
Mainly serous acini.
What is serous acini secretion composed of?
alpha amylase - this is needed for starch digestion.
Do sublingual glands have mainly serous or mainly mucous acini?
Mainly mucous acini.
What is mucous acini secretion composed of?
Mucin - needed for lubrication.
Do submandibular glands have mainly serous or mainly mucous acini?
They have serous and mucus acini.
Which of the main salivary glands is constantly active?
Submandibular.
What is the function of saliva?
It acts as a lubricant for chewing, swallowing and speech. It is important in oral hygiene; has a role in immunity, wash and it can also act as a buffer.
What is the optimum oral pH?
7.2
What is the pH range of saliva?
6.2 - 7.4
Name 4 factors that can affect the composition of saliva.
- Stimulus.
- Age.
- Gender.
- Drugs.
Are serous acini dark staining or pale staining on a histological slide?
Dark staining.
Mucus acini = pale staining
What is the epithelium lining of intercalated ducts?
Simple cuboidal epithelium.
What is the function of intercalated ducts?
They connect acini to larger striated ducts.
What ions are reabsorbed at striated ducts?
Na+ and Cl-
Is saliva hypotonic or hypertonic?
Hypotonic - water reabsorption and ion secretion.
What is the importance of the striated duct basal membrane being highly folded?
It is folded into microvilli for the active transport of HCO3- against its concentration gradient.
What organelle is abundant in striated ducts and why?
Mitochondria. For the active transport of ions.
Name 2 ions that striated ducts secrete.
K+ and HCO3-
Name 2 ions that striated ducts reabsorb.
Na+ and Cl-
What ducts do striated ducts lead on to?
Interlobular (excretory) ducts.
What is the epithelium lining of interlobular ducts?
Simple columnar epithelium.
What is the parasympathetic innervation of the Parotid gland?
Cn 9 - glossopharyngeal.
What is the parasympathetic innervation of the Sublingual gland?
Cn 7 - facial.