Prehension and Mastication Flashcards
What is food prehension and which 4 organs are involved?
This is the seizing and conveying of food to the mouth.
- lips
- cheek
- teeth
- tongue
What are vibrissae and what is their function?
Hairs - sensitive so can be used to locate food
Which nerve innervated the muscles of the lips?
Facial nerve
What is the name of the group of muscles that act as one to form a diaphragm across the cheek?
Buccinator
What are the functions of the tongue?
- Manipulation of foodstuffs both within and outside of the mouth
- Tasting
- Lapping water
- Grooming
- Vocalisation/articulation of sound
How many pairs of extrinsic muscles pertain to the tongue?
5
What is the name given to the intrinsic muscles of the tongue?
Propria linguae
What type of epithelium lines the tongue?
stratified, squamous keratinised epithelium
What marks the division between the rostral two thirds and caudal one third of the tongue?
Vallate Papillae
Which two joints allow motility in mastication?
Temporomandibular and symphysial joints
What is formed from where the joint capsule of the temporomandibular joint is thickened?
Mandibular ligament
Which process prevents backwards movement of the jaw?
Retroglenoid process
Where is the symphysial joint located?
Between the two halves of the mandible at the rostral end as it unites them
In which species is the symphysial joint most unfused?
Carnivores and cattle
What are the 4 muscles of mastication
- Temporalis
- Masseter
- Pterygoids
- Digastricus
Why is the digastricus muscle innervated by the trigeminal and facial nerves?
It has dual origin - from the 1st and 2nd pharyngeal arches
In carnivores what is the largest and strongest muscle of the head?
Temporalis
What is the largest muscle of the head in herbivores?
Masseter
What are the 4 large salivary glands?
- Parotid
- Mandibular
- Sublingual
- Zygomatic (carnivores only)
How does the sympathetic (fight or flight) system change the production of saliva?
Slows down production
Why do cattle produce up to 150 litres of salvia per day?
It acts as a fermentation medium within the stomach and acts to buffer the fatty acids produced.
What is the main prehensile organ in the following species:
- Horse
- Cattle
- Sheep
- Dog
- Lips
- Tongue
- Tongue
- Teeth
What is the function of the Caninus muscle?
Retractor of the upper lip and nostril
Which muscle retracts the caudal commissure of the lip?
Zygomaticus
Which muscle lifts the upper lip and nostril?
Levator nasolabialis
The sensory supply to the cheek is from which nerve?
Trigeminal nerve
Which muscle lies over the infraorbital foramen?
Lavator labii superioris
Name the 3 pairs of extrinsic tongue muscles
- Genioglossus
- Styloglossus
- Hyoglossus
Which 2 pairs of muscles, associated with the hyoid apparatus also affect the movement of the tongue?
Geniohyoid
Sternohyoid
Motor supply to the tongue is from which nerve?
Hypoglosssal
Sensory supply to the tongue is from which nerves?
Rostral 2/3 - trigeminal mandibular lingual nerve
Caudal 1/3 - glossopharyngeal and vagus
Taste sensation is supplied by which nerves?
Rostral 2/3 = lingual then chorda tympani then facial
Caudal 1/3 = glossopharyngeal and vagus
The temporalis, masseter and pterygoids are innervated by which nerve and arise from where?
- Mandibular branch of trigeminal
- Mesoderm of pharyngeal arch 1
Which nerves innervate the digastricus muscle?
Rostral part = trigeminal
Caudal part = facial
What are the functions of salvia in:
- carnivores
- herbivores
- ruminants
- Lubrication
- Starts digestion and contains enzymes that act as buffers for fatty acids
- Produces fluid for fermentation to start in the rumen
