oral cavity

Question 1

tongue intrinsic muscles, what they do, and which nerve innervates them

Answer 1

Superior longitudinal – curls tongue superiorly and shortens

Inferior longitudinal – curls tongue inferiorly and shortens

Vertical – flattens tongue

Transverse – narrows tongue

Question 2

Name the attachments and action of the genioglossus muscle. Also, name the nerve which innervates it.

Answer 2

Genioglossus
Superior fibers
Attachments: Genial tubercles (sup. mental spine) to body of tongue
Action:Retract tip of tongue

	Middle fibers 
		Attachments: Genial tubercles (sup metal spine) to body of tongue
		Action:  Depress dorsum of tongue, protrude tongue

	Inferior fibers 
		Attachments: Genial tubercles (sup. mental spine) to hyoid
		 Action: Protrude tongue, advance hyoid

	N: CN XII

Question 3

Hyoglossus. Attachments, action, and innervation

Answer 3

Hyoglossus
Attachments: Hyoid bone to lateral surface of tongue
Action: Retrude tongue and draw sides downward, raise hyoid
N: CN XII

Question 4

Styloglossus. Attachment, Action, Innervation.

Answer 4

Attachments: Styloid process, lateral surface of tongue
Action: Retrude tongue and draw sides upward
N: CN XII

Question 5

Palatoglossus. attachment, action, innervation.

Answer 5

Attachments: Palatal aponeurosis to dorsum and lateral surface of tongue
Action: Elevate tongue, depress palate
N: CN X

Question 6

innervation of the tongue. What nerve innervates the palatoglossus?

Answer 6

Vagus nerve

Question 7

The Somatic motor innervation of the tongue begins in which portion of the brain?

Answer 7

Cell bodies of LMN in Hypoglossal nucleus

Question 8

Name the General Sensory nerve and pathway that innervates the anterior 2/3 of the tongue

Answer 8

GENERAL SENSORY –
Anterior 2/3 – CN V3
Sensory cell bodies in trigeminal ganglion → V3 branches from the ganglion in cranial cavity  foramen ovale  infratemporal fossa  lingual nerve branches from V3 and goes on to innervate the tongue.

Question 9

Name the General Sensory nerve and pathway that innervates the posterior 1/3 of the tongue.

Answer 9

GENERAL SENSORY
Posterior 1/3 – CN IX, CN X
Sensory fibers exit the brain jugular foramen  sensory cell bodies in superior and inferior
glossopharyngeal and vagal ganglia fibers branch to tongue

Question 10

Name the Special Sensory nerve and pathway of the anterior 2/3 of the tongue

Answer 10

SPECIAL SENSORY (TASTE) –
		Anterior 2/3 – CN VII
	Sensory fibers exit the brain  internal acoustic meatus  sensory cell bodies in geniculate ganglion  facial canal  chorda tympani nerve branches in the facial canal and passes through the middle ear  petrotympanic fissure  infratemporal fossa  joins lingual nerve of V3 tongue

Question 11

Name the special sensory nerve and pathway of the posterior 1/3 of the tongue

Answer 11

Posterior 1/3 – CN IX
Sensory fibers exit the brain jugular foramen  sensory cell bodies in superior and inferior glossopharyngeal ganglion fibers branch to tongue

Question 12

what is the Parasympathetic pathway of salivary gland innervation?

Answer 12

Parasympathetic – CN VII
Preganglionic cell bodies in Superior Salivatory Nucleus (pons)  internal acoustic meatus  facial canal  chorda tympani nerve branches in the facial canal and passes through the middle ear  petrotympanic fissure  infratemporal fossa  joins lingual nerve of V3  pre-ganglionic fibers synapse with post-ganglionic fibers in submandibular ganglion  postganglionic fibers continue on to submandibular and sublingual glands

Question 13

what is the sympathetic pathway of salivary gland innervation?

Answer 13

Sympathetic:
Preganglionic fibers originate T1 – L2  enter chain  ascend chain to superior cervical ganglia  synapse 
postganglionic fibers hitchhike on facial artery and lingual arteries to arrive at glands

Question 14

What is stage one of swallowing and deglutition? Is it Voluntary or involuntary?

Answer 14

Voluntary
Following mastication, the food is pressed into a bolus on the dorsum of the tongue against the hard palate. The swallow is initiated by pushing the food posteriorly into the oropharynx by the tongue.

Question 15

What is stage two of swallowing and deglutition?Is it Voluntary or involuntary?

Answer 15

Stage Two (Involuntary) 
The soft palate elevates to seal the oropharynx from the nasopharynx and prevents regurgitation of food into the nasal cavity. The stylopharyngeus and palatopharyngeus muscles and the suprahyoid muscles contract to raise the larynx.

Question 16

What is stage three of swallowing and deglutition?Is it Voluntary or involuntary?

Answer 16

Stage Three (Involuntary) 
The three constrictor muscles contract in a sequential fashion as peristaltic waves. From superior to inferior, each pair of muscles contracts for approximately 0.33 second. Just as the muscles physically overlap, so do their contractions overlap from superior to inferior.

Question 17

What is stage four of swallowing and deglutition?Is it Voluntary or involuntary?

Answer 17

Stage Four (Involuntary) 
The bolus enters the esophagus and is propelled downward by peristaltic action. 
The cricopharyngeus muscle (lower fibers of the inferior constrictor muscle) is in a constant state of contraction and prevents passage of air to the esophagus below. During the act of swallowing, the cricopharyngeus relaxes to allow passage of the bolus into the esophagus below. The bolus is propelled to the stomach by peristaltic waves of the esophagus.