GI Flashcards
Is stage 1 of swallowing voluntary or involuntary?
Voluntary.
What happens in stage 1 of swallowing?
Food is compressed against the roof of the mouth and is pushed to the oropharynx by the tongue.
Is stage 2 of swallowing voluntary or involuntary?
Involuntary.
What happens in stage 2 of swallowing?
The nasopharynx closes off due to soft palate elevation. The trachea is closed off by the epiglottis. Elevation of the hyoid bone shortens and widens the pharynx.
Is stage 3 of swallowing voluntary or involuntary?
Involuntary.
What happens in stage 3 of swallowing?
The pharyngeal constrictor muscles sequentially contract producing peristaltic waves. This propels the bolus of food down the Oesophagus. This is followed by depression of the hyoid bone.
Name 6 muscles/groups of muscles that are involved in swallowing.
- Buccinator.
- Suprahyoids.
- Muscles of the palate.
- Muscles of the floor of the mouth.
- Infrahyoids.
- Pharyngeal constrictor muscles.
Which muscle(s) manipulate food in chewing. Elevate the hyoid bone and flatten the floor of the mouth?
Buccinator and Suprahyoids.
What is the function of the muscles of the soft palate in swallowing?
They act to tense and elevate the soft palate.
What is the function of the muscles of the floor of the mouth in swallowing?
They raise the hyoid bone and larynx.
What is the function of the infrahyoids?
To depress the hyoid bone and larynx.
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.