16.2 Mouth Flashcards
What is the other name of the mouth?
Oral cavity
What forms the opening of the mouth
muscular lips
What is the function of lips?
It helps procure, guide, and contain the food in the mouth
The palate forms the?
arched roof of the oral cavity
What is the function of the palate?
It separates the mouth from the nasal passage allowing for breathing and chewing or sucking to take place simultaneously
Where is the uvula located
it hangs from the palate in the rear of the throat
What is the function of the uvula?
To close the nasal passage during swallowing
The floor of the oral cavity is formed by?
the tongue
What type of muscle does the tongue have?
Skeletal muscle (voluntary)
What is the function of the tongue?
It guides food within the mouth during chewing and swallowing and also plays a role in speech.
Where are the taste buds located and what are their function?
they are located on the tongue and have a role of providing the sense of taste.
What is the function of teeth?
To mechanically break down food
What is the first step in the digestion process and explain it
Mastication (chewing): mouth motility that involves tearing, slicing, grinding and mixing of ingested food by the teeth.
where are teeth embedded and protruding from?
the jawbones
What is occlusion?
it is how well the upper and lower teeth fit together when the jaw is closed.
what is the most important factor when determining the efficiency of chewing?
occlusion
What is malocclusion?
It is when the upper and lower teeth do not make proper contact with one another hence they cannot accomplish normal cutting and grinding.
What causes malocclusion and what can fix it?
It can be caused by overcrowding of teetgh or displacement of the jaw. This can be rectified by braces
What covers the exposed part of the tooth and is considered the hardest structure of the body?
Enamel
Enamel cannot be regenerated so any teeth defects that occur in the enamel must be………….
patched by artificial filings or else the surface will continue to erode into the underlying living pulp.
The act of chewing can be voluntary but……….
Most chewing during a meal is a rhythmic reflex-like activity accomplished without conscious effort.
What are the three functions of chewing?
- To mechanically break down food into smaller pieces to facilitate swallowing and to increase the food surface area on which salivary enzymes can act.
- To mix food with saliva
3.To expose food to taste buds
What are the 2 functions of taste bud stimulation?
- gives the pleasurable sensation of taste
- it reflexly increases salivary,gastric,pancreatic, and bile secretions to prepare for the arrival of food
What type of digestion begins in the mouth due to salivary amylase?
Carbohydrate digestion
What produces saliva?
The three salivary glands that secrete saliva into the mouth by their short ducts.
What is the composition of saliva?
99.5% water , 0.5% electrolytes and protein
How much saliva is secreted daily?
1-2 L
What are the three most important salivary proteins?
salivary amylase, mucus and lysozymes.
What are the 3 salivary glands and their locations?
- Sublingual gland- under the tongue on the floor of the mouth
- Submandibular gland-beneath the mandible
- Parotid gland- Situated in front of and just below each ear, on the sides of the face. (largest)
List the 7 functions of saliva:
- Digestion of starches (breaks down dietary carbs into maltose and a-limit dextrins)
- Facilitates swallowing
- Antibacterial action
- Solvent for taste molecules
- Aids in speech
- Oral hygiene
- Dental protection
Despite the many functions of saliva………………..
It is not required for digestion and absorption because the pancreatic and small intestine are more than capable of performing digestion without salivary and gastric secretions.
What is xerostomia
it is a condition characterised by dry mouth due to diminished salivary secretion. This causes difficulty in chewing and swallowing, inarticulate speech unless there are frequent sips of water taken when speaking, and an increase in dental cavities unless special precaution is taken.
In the absence of food-related stimuli, what other factor stimulates salivary secretion?
Low-level parasympathetic stimulation induces production of basal salivary secretion
what is the importance of basal salivary secretion?
It ensures that the mouth and throat are always lubricated.
Besides food stimulation and parasympathetic stimulation, what other two reflexes stimulate the secretion of saliva?
Simple reflex and conditioned reflex
Explain simple salivary reflex?
This is when chemoreceptors and pressure receptors within the oral cavity respond to the presence of food. They then initiate impulses in afferent nerve fibers which carry this information to the salivary center in the medulla oblongata. The salivary center in turn sends impulses via the extrinsic autonomic nerve to the salivary glands to promote increased salivation.
Why do we salivate so much during dental procedures?
Due to pressure receptors being activated
Explain conditioned salivary reflex?
It occurs without oral stimulation but rather due to the stimulation of the other senses. This reflex is a learned response. The cerebral cortex processes the sensory input and then stimulates the medulla oblongata salivary center which sends impulses to the salivary glands to increase salivation via the autonomic nerves.
What does the salivary center do?
it controls the degree of salivary output by means of the autonomic nerves that supply the salivary glands.
What is different about sympathetic and parasympathetic stimulations when it comes to salivary compared to other parts of the body
They are not antagonistic! Rather both of them increase salivary secretions but the difference is that the quantity and characteristics differ.
Explain parasympathetic stimulation of salivating
It exerts the dominant role in salivary secretion, it produces a prompt abundant flow of watery saliva rich in enzymes.
Explain sympathetic stimulation of salivating
It produces a smaller volume of thick saliva rich in mucus. It is for this reason that the mouth feels drier when it is dominant during a fight or flight response.
Salivary secretion is the only digestive secretion entirely under…………..
neural control
Where does the majority of the function of salivary amylase occur?
In the stomach after the food and saliva have been swallowed and before HCl inactivates it in between the food mass.
