Week 8

Question 1

What runs close to and superior to the hyoid bone?

Answer 1

Anterior belly of digastric.

Question 2

What are the two bellies of digastric connected by?

Answer 2

A central tendon.

Question 3

What is the central tendon of digastric attached to the hyoid bone with?

Answer 3

A tunnel of fascia.

Question 4

When the digastric muscle contracts what happens to the central tendon and the hyoid bone?

Answer 4

They move up.

Question 5

What is the attachment of the superior belly of digastric?

Answer 5

Attaches to the base of the skull medial to the mastoid process.

Question 6

What muscle gives a tendon that wraps around the central tendon?

Answer 6

Stylohyoid.

Question 7

What are the two parts of the submandibular salivary gland?

Answer 7

Superficial part in submandibular region and the smaller parts lie in the floor of the mouth.

Question 8

What muscle is used to stick the tongue out?

Answer 8

Genioglossus.

Question 9

Where are the circumvallate pappilae located?

Answer 9

On the posterior third of the tongue.

Question 10

What nerve gives sensory innervation to the anterior tongue?

Answer 10

Lingual nerve.

Question 11

What is the pathway of sensory information from the taste buds of the tongue to the brainstem?

Answer 11

Sensory from taste buds from anterior two thirds of tongue- leave tongue in lingual nerve and pass into chordi tympani-takes to facial nerve and enter the brainstem in this nerve.

Question 12

What nerve gives sensation to the back of the hard palate?

Answer 12

Greater palatine nerve.

Question 13

What nerve innervates the soft palate?

Answer 13

Lesser palatine nerve.

Question 14

What nerve innervates the skin on the posterior part of the cheek?

Answer 14

Buccal branch of the trigeminal.

Question 15

What does the hyoglossus do?

Answer 15

Depresses the tongue.

Question 16

What does the styloglossus do?

Answer 16

Pulls tongue up and back.

Question 17

What does the palatoglossus do?

Answer 17

Bring soft palate down.

Question 18

What nerve supplies the muscles of the tongue?

Answer 18

Hypoglossal nerve. THE VAGUS NERVE SUPPLIES THE PALATOGLOSSUS MUSCLE.

Question 19

What does the geniohyoid muscle do and what innervates it?

Answer 19

Pulls hyoid bone forward so there is more space in the lower part of the pharynx for a bolus to go down (fibres of C1 supply).

Question 20

Why is a swelling in the parotid gland more painful than the submandibular gland?

Answer 20

Parotid gland has dense fascia around it. Submandibular gland can swell and not be painful as has looser connective tissue around it around it.

Question 21

Where is the bifurcation of the common carotid in reference to the thyroid cartilage?

Answer 21

Upper body of thyroid cartilage.

Question 22

What might be damaged when doing surgery to fix atheroma in the carotid arteries (internal and external)?

Answer 22

Hypoglossal nerve- the tongue would deviate to the affected side.

Question 23

What is the circle of willis and why is it important?

Answer 23

The circle of Willis allows blood to flow across the midline of the brain if an artery on one side is occluded. The circle of Willis thereby serves a safety valve function for the brain, allowing collateral circulation (or flow of blood through an alternate route) to take place if the flow is reduced to one area.

Question 24

What artery is deep to the hyoglossus muscle?

Answer 24

Lingual artery.

Question 25

What is the pathway from the submandibular ganglion to the infratemporal fossa?

Answer 25

Parasympathetic supply for submandibular/lingual and lacrimnal, receive supply and these fibres leave brainstem in facial nerve (superior salvatory nucleus). Facial nerve to chordi tympani and leaves facial nerve in infratemporal fossa.

Question 26

What are the intrinsic muscles of the tongue?

Answer 26

1. superior longitudinal muscle of the tongue
2. inferior longitudinal muscle of the tongue
3. transverse muscle of the tongue
4. vertical muscle of the tongue.

Question 27

What muscle is immediately deep to the digastric?

Answer 27

Mylohyoid muscle.

Question 28

What muscle runs in front of the internal jugular vein (this vein is deep to the sternocleidomastoid muscle)?

Answer 28

Omohyoid muscle.

Question 29

What are the branches of the superior thyroid artery?

Answer 29

1. infrahyoid artery,
2. superior laryngeal artery.
3. sternocleidomastoid artery,
4. cricothyroid artery.

Question 30

Where are the baroreceptors located within the neck?

Answer 30

In the carotid sinus.

Question 31

What lymph nodes are tucked in the soft tissues behind the chin?

Answer 31

Submental lymph nodes.

Question 32

Where could the pathology be if the submandibular lymph nodes are inflamed and there were no pathologies in the mouth?

Answer 32

Paranasal sinuses and the nasal cavity.

Question 33

What are the lymph nodes called that are around the internal jugular vein and where do they receive lymph from?

Answer 33

Deep cervical nodes. They receive lymph form superficial lymph node groups and from deep areas of the head (oropharynx and nasopharynx).

Question 34

What does the jugulo-digastric node drain (it is one of the deep cervical nodes)?

Answer 34

Very big node that drains the palatine tonsil seen in the oropharynx.

Question 35

What does the jugulo-omohyoid lymph node drain?

Answer 35

Drains the lingual tonsil- it is one of the deep cervical nodes.

Question 36

What lymph nodes are pathologies in the upper abdomen/chest likely to metastasise in?

Answer 36

Supra-clavicular lymph nodes.

Question 37

What lymph nodes are present around the ear?

Answer 37

Parotid nodes (in front of ear) or posterior auricular nodes (behind the ear).

Question 38

What is the difference between Hodgkins and Non-Hodgkins lymphoma?

Answer 38

A doctor can tell the difference between Hodgkin’s lymphoma and non-Hodgkin’s lymphoma by examining the cancer cells under a microscope. If in examining the cells, the doctor detects the presence of a specific type of abnormal cell called a Reed-Sternberg cell, the lymphoma is classified as Hodgkin’s. If the Reed-Sternberg cell is not present, the lymphoma is classified as non-Hodgkin’s.

Question 39

What is the function of the digastric muscle?

Answer 39

If the hyoid bone is fixed in place- the digastric can held to open the jaw. If jaw is fixed by other muscles- digastric helps to move the hyoid bone up.

Question 40

What way do the mylohyoid fibres run from the mylohyoid line?

Answer 40

They run medially and backwards and slightly downwards.

Question 41

What muscle in the neck has a posterior free edge?

Answer 41

The mylohyoid muscle.

Question 42

What is the function of the medial pterygoid muscle?

Answer 42

Origin
Superficial part: Tuberosity of maxilla, Pyramidal process of palatine bone;
Deep part: Medial surface of lateral pterygoid plate of sphenoid bone

Insertion
Medial surface of ramus and angle of mandible
Action Bilateral contraction - Elevates and protrudes mandible
Unilateral contraction - Medial movement (rotation) of mandible

Innervation
Medial pterygoid nerve (of mandibular nerve (CN V3))

Blood supply Pterygoid branches (maxillary artery, buccal artery, facial artery).

Question 43

What is the origin, action, innervation and blood supply of the temporalis?

Answer 43

Origin
Temporal fossa (up to inferior temporal line), Temporal fascia
Insertion
Apex and medial surface of coronoid process of mandible

Action
Anterior fibres: Elevates mandible
Posterior part: Retracts mandible

Innervation
Deep temporal branches (of mandibular nerve (CN V3))

Blood supply
Deep temporal branches of maxillary artery, middle temporal branches from superficial temporal artery.

Question 44

What is the origin, action, innervation and blood supply of the masseter?

Answer 44

Origin
Superficial part: maxillary process of zygomatic bone, Inferior border of zygomatic arch (anterior 2/3)
Deep part: deep/inferior surface of zygomatic arch (posterior 1/3)

Insertion Lateral surface of ramus and angle of mandible

Innervation Masseteric nerve of mandibular nerve (CN V3)

Blood supply Masseteric artery

Function Elevates and protrudes mandible.

Question 45

What is Vincent’s angina and how can it be caused?

Answer 45

Vincent’s angina is a pharyngeal infection with an ulcerative gingivitis caused by: Borrelia vincentii - a spirochaete. Fusiformis fusiformis - a Gram -ve bacillus. It can be caused by a dental absess if it bursts above or below the mylohyoid muscle.

Question 46

What nerve disappears deep to the submandibular salivary gland?

Answer 46

Hypoglossal nerve.

Question 47

Where does the internal carotid artery start and where does it go to?

Answer 47

Internal carotid runs from bifurcation at neck (upper body of thyroid cartilage)- goes into carotid canal at base of skull- gives off branches to brain and eye (ophthalmic) here.

Question 48

What nerve runs lateral to the internal and external carotid arteries?

Answer 48

Hypoglossal nerve.

Question 49

Where does the facial artery come off the external carotid artery?

Answer 49

At the level of the posterior belly of digastric.

Question 50

What shape is the facial artery and where does it enter the face?

Answer 50

It is a twisted vessel and runs over submandibular salivary gland and enters face at front of masseter muscle.

Question 51

Why is the facial artery twisted?

Answer 51

It is twisted so you can open and close mandible and still maintain blood supply to the face. It runs a groove in the submandibular salivary gland.

Question 52

Where does the lingual artery dissapear when in the mouth?

Answer 52

Lingual artery- grooving course and disappears deep to submandibular gland- heads into the tongue.

Question 53

What is the passageway to make the submandibular salivary glands secrete?

Answer 53

Chordia tympani gives preganglionic parasympathetic supply which joins lingual nerve. Fibres that are going to make glands secrete travel from brainstem in facial nerve- leave this nerve to join lingual nerve in the infratemporal fossa. Parasympathetic fibres run down to submandibular ganglion- synapse with cell bodies in this ganglion. Bundles of fibres come out from this ganglion and go to submandibular salivary glands- parasympathetic post ganglionic fibres. Follow lingual nerve down- might see little nerves running forwards to sublingual gland- these parasympathetic fibres running forwards.

Question 54

What is the origin, insertion and action of the genioglossus muscle?

Answer 54

Origin Superior part of mental spine of mandible (symphysis menti)

Insertion Underside of tongue and body of hyoid
Artery Lingual artery
Nerve Hypoglossal nerve

Actions Inferior fibers protrude the tongue, middle fibers depress the tongue, and its superior fibers draw the tip back and down.

Question 55

What muscle attaches to the inferior part of the mental spine?

Answer 55

The geniohyoid muscle originates from the inferior mental spine, located on the posterior surface of the mandible near the lower part of the mandibular symphysis. From there, the muscle fibers radiate posteroinferiorly, close to the central line and insert to the superior border of the body of the hyoid bone.

Question 56

What is the function of the geniohyoid muscle?

Answer 56

This muscle pulls hyoid bone forward when we swallow to create space for bolus to go down.

Question 57

What do the intrinsic muscles of the tongue do? Name them all and their function.

Answer 57

Intrinsic muscles of the tongue are simply arranged- front to back called superior and inferior longitudinal muscles. Skeletal muscle under voluntary control. They shorten the tongue- superior contracts then would curl the tongue (change its shape- intrinsic muscle functions). There are vertical muscles (make the tongue thin and flat) and transverse muscles (pulls sides in- fatter and taller). All skeletal and supplied by hypoglossal nerve.

Question 58

What does the palatoglossus muscle do?

Answer 58

Palatoglossus muscle- runs between tongue and soft palate. RIGHT AND LEFT ACT TOGETHER- pulls soft palate down towards tongue. Nerve supply is the vagus nerve (vagus nerve supplies some muscles of the soft palate).

Question 59

What is the nerve supply of the soft palate?

Answer 59

The greater and lesser palatine and nasopalatine branches of the maxillary nerves and the glossopharyngeal nerve supply the sensory innervation. The lesser palatine nerve also contains taste fibers of facial nerve origin, which supply the taste buds in the oral surface of the soft palate. The parasympathetic postganglionic secretomotor fibers that arise from the facial nerve via the pterygopalatine ganglion run with these nerves to the palatine mucous glands. Sympathetic fibers run from the carotid plexus along the arterial branches.

Question 60

What nasal concha is a bone in its own right?

Answer 60

Inferior nasal concha.

Question 61

What is the origin, blood and nerve supply, action and insertion of the palatopharyngus muscle?

Answer 61

Origin
Within the soft palate, it is composed of two fasciculi, which arise from the upper surface of the palatine aponeurosis in the same plane, but it is separated from each other by the levator veli palatini. From the posterior border of the hard palate and the aponeurosis there is the thicker anterior fasciculus where some fibers interdigitate across the midline. The thinner posterior fasciculus is in contact with the mucosa of the pharyngeal aspect of the palate; it joins the posterior band of its opposite muscle in the midline. The two layers unite at the postero-lateral border of the soft palate; here they are also joined by fibers of the salpingopharyngeus. The muscle passes laterally and downwards behind the tonsil, it then travels postero-medial and in close contact to stylopharyngeus.

Insertion
It attaches with the stylopharyngeus muscle to the posterior border of the thyroid cartilage; some fibers blend with the constrictor muscles. The upper fibers interdigitate with the opposite number, to form ‘Passavant’s ridge’.

Vasculature
The blood supply of this muscle is derived mainly from the pharyngeal branch of the ascending pharyngeal artery and the tonsillar branch of the facial artery.

Nerve supply
The pharyngeal branch of the vagus nerve (X cranial nerve) with its motor fibers from the cranial accessory nerve (XI cranial) supply this muscle.

Action
Palatopharyngeus elevates the pharynx and larynx forwards and medially, thus shortening it while swallowing. Passavant’s muscle closes nasopharyngeal isthmus in swallowing.

Question 62

What is the origin, blood and nerve supply, action and insertion of the tensor veli palatini muscle?

Answer 62

The tensor veli palatini muscle is a broad, thin, ribbon-like muscle found lateral to the levator veli palatini muscle in the soft palate (see below).

Origin
It arises by a flat lamella from the scaphoid fossa at the base of the medial pterygoid plate, from the spine of the sphenoid bone and from the lateral wall of the cartilage of the auditory tube.

The muscle descends vertically between the medial pterygoid plate and the medial pterygoid muscle to end in a tendon that winds around the pterygoid hamulus. The muscle is kept in that position by some of the fibers of origin of the medial pterygoid. A bursa can be found between the tendon and the hamulus.

Insertion
The tendon then passes medially and inserts into the palatine aponeurosis and into the surface behind the transverse ridge on the horizontal part of the palatine bone.

Nerve supply
The motor innervation of the muscle is derived from the mandibular nerve via the nerve to the medial pterygoid muscle.

Vasculature
The arterial blood supply is derived from the ascending palatine branch of the facial artery and the descending palatine branch of the maxillary artery.

Action
When the tensor veli palatini muscles act together, the palatine aponeurosis becomes taut and horizontal and provides a platform upon which other palatine muscles may act to change the position of the soft palate. Acting alone, the muscle pulls the soft palate laterally.

Question 63

Describe the hard palate.

Answer 63

The hard palate consists of the horizontal plate of the palatine bone and the palatine process of the maxillary bone. Its superior surface forms the floor of the nasal cavity and its inferior surface forms the roof of the oral cavity.

The oral surface of the hard palate is covered with oral mucosa, a tough keratinized epithelium designed to withstand the mechanical demands of chewing and swallowing. This mucosa is light pink in color and displays a number of identifiable features:

• Incisive papilla is a midline elevation located directly behind the central incisors over the incisive canal.
• Palatine fovea are two orifices located, either side of the midline palatine raphe just distal to the junction between the hard and soft palate.
• Palatine raphe is a narrow elevation that passes along the median plane from the incisive papilla anteriorly to the uvula posteriorly.
• Transverse palatine folds or rugae are wrinkled mucosal folds that extend laterally from the palatine raphe.
• Vibrating line is the transverse boundary between the hard and soft plates.

Question 64

What is the origin course and supply of the lingual arteries?

Answer 64

Origin
The lingual artery is the third branch of the external carotid artery and gives off the dorsal lingual branches the sublingual artery and the deep lingual artery in the floor of the mouth.

Course
It reaches the floor of the mouth by passing between the hyoglossus muscle and the middle constrictor of the pharynx.

Supplies
The dorsal lingual branches supply the back of the dorsum of the tongue and the region around the pillars of the fauces.

Question 65

What is the origin and supply of the sublingual arteries?

Answer 65

Origin
The branches of the lingual artery in the floor of the mouth are: the dorsal lingual branches, the sublingual artery and the deep lingual artery.

Supplies
The sublingual artery supplies the sublingual gland and other structures in the floor of the mouth. The deep lingual artery is the terminal part of the lingual artery, which is found on the inferior surface of the tongue near the lingual frenulum.

Question 66

Describe the pathway of the lingual nerve.

Answer 66

The lingual nerve is derived from the posterior trunk of the mandibular nerve within the infratemporal fossa. It receives the chorda tympani branch of the facial nerve beneath the lateral pterygoid muscle. At the level of the mandibular foramen, the lingual nerve lies on the medial pterygoid muscle and is anterior to the inferior alveolar nerve. The nerve then leaves the infratemporal fossa, passing downwards and forwards to lie close to the lingual alveolar plate of the mandibular third molar tooth. Before curving forwards into the tongue, the nerve is found above the origin of the mylohyoid muscle and lateral to the hyoglossus muscle. On the superficial surface of the hyoglossus muscle, the lingual nerve twists twice around the submandibular salivary duct, first on the lateral side of the duct and then on the medial side. It enters the tongue behind the sublingual salivary gland. Suspended from the lingual nerve as it runs across the hyoglossus muscle is the submandibular parasympathetic ganglion.

Question 67

What does the lingual nerve supply?

Answer 67

The lingual nerve itself supplies the mucosa covering the anterior two-thirds of the dorsum of the tongue, the ventral surface of the tongue, the floor of the mouth, and the lingual gingivae of the mandibular teeth.

Question 68

What are the branches of the hypoglossal nerve?

Answer 68

Branches:

i) Meningeal branch.
ii) Upper root of ansa cervicalis.
iii) Muscular branches to thyrohyoid and geniohyoid.
iv) Muscular branches to the tongue.

Question 69

What nerve is anastomosed to the facial nerve to correct a facial palsy?

Answer 69

This nerve may be anastomosed to the peripheral facial nerve as a method of rehabilitating facial nerve palsy.

Question 70

Laxity of what muscle may contribute to snoring in old age?

Answer 70

Laxity of the genioglossus muscle in old age may contribute to snoring.

Question 71

What is the origin, insertion, blood, nerve supply and action of the genioglossus muscle?

Answer 71

Origin
It originates from the superior genial tubercle (mental spine) on the medial surface of the body of the mandible.

Insertion
The genioglossus muscle fans out into the substance of the tongue. The two genioglossus muscles cannot easily be separated near their origins. As the muscles enter the tongue, however, a thin strip of connective tissue intervenes. The superior fibers of the genioglossus muscle pass upwards and anteriorly towards the tip of the tongue. Some of the inferior fibers insert onto the body of the hyoid bone.

Nerve supply
Genioglossus receives its motor innervation from the hypoglossal nerve.

Vasculature
The sublingual branch of the lingual artery and the submental branch of the facial artery supply this muscle.

Action
The genioglossus muscle is a protractor and depressor of the tongue.

Question 72

What does the internal jugular vein drain?

Answer 72

Drains
The internal jugular vein receives the inferior petrosal sinus, the facial, lingual, pharyngeal, and superior and middle thyroid veins; the right also receives the right lymphatic trunk and the left the thoracic duct at the union with the subclavian vein. It drains blood from the skull, brain, face and neck.

Question 73

What is the internal jugular vein a continuation of?

Answer 73

The internal jugular vein is a continuation of the sigmoid sinus as it exits the skull via the jugular foramen.

Question 74

What is the course of the internal jugular vein?

Answer 74

At its superior and inferior ends, the internal jugular vein forms dilated bulbs; there are valves within the inferior bulb. It descends in the carotid sheath, found lateral to the internal carotid artery above the third or fourth cervical vertebrae, and the common carotid artery below the third or fourth cervical vertebrae. It unites with the subclavian vein behind the sternal end of the clavicle, anterior to the vagus nerve (X cranial nerve) to form the brachiocephalic vein.

Question 75

What does the ascending palatine artery supply and what is its origin and course?

Answer 75

Origin
The ascending palatine artery is a branch of the facial artery and arises near the origin of the facial artery.

Course
It ascends the lateral pharyngeal wall to the superior border of the superior pharyngeal constrictor and splits into two branches.

Supplies
The ascending palatine artery is the main arterial supply to the palate. One of its branches hooks over the superior constrictor and descends to the palate, and the other pierces the superior constrictor to supply the pharyngotympanic tube and the palatine tonsil.

Question 76

What is the origin, insertion, nerve and blood supply and action of the stylohyoid muscle?

Answer 76

Origin
Stylohyoid arises from the posterior surface of the base of the styloid process.

Insertion
It passes downwards and forwards with the posterior belly of the digastric to insert into the body of the hyoid bone at the junction with the greater horn, just above the attachment of omohyoid. Near its insertion it splits to envelop the digastric tendon.

Nerve supply
In common with the posterior belly of the digastric, the stylohyoid muscle develops from the second branchial arch. Consequently, the digastric branch of the facial nerve innervates it.

Vasculature
It receives its blood supply from the facial, posterior auricular, and occipital arteries.

Action
It elevates and draws the hyoid bone backwards and therefore the floor of the mouth and the base of the tongue.

The digastric and stylohyoid muscles can be classified with the mylohyoid, geniohyoid, hyoglossus and genioglossus muscles as the suprahyoid musculature. The infrahyoid musculature lies within the muscular triangle of the neck.

Question 77

What is the nerve supply of the TMJ?

Answer 77

This is predominantly from the auriculotemporal nerve with a few fibers from the nerve to the masseter.

Question 78

What are the movements of the TMJ?

Answer 78

i) Depression (opening of the mouth from rest).
ii) Elevation (closing of the mouth to rest).
iii) Protrusion (carrying the mandible forwards from rest).
iv) Retraction (carrying the mandible back to rest).
v) Small amount of lateral movement (side-to-side movement from the rest position).

Question 79

What does the buccal branch of the facial nerve supply?

Answer 79

Buccal branch of the facial nerve which transmits motor information to the buccinator muscle.

Question 80

What nerve supplies the mucosa of the cheek?

Answer 80

Buccal nerve. It is also a branch of the mandibular division of the trigeminal nerve (not to be confused with the buccal branches of the facial nerve).

Question 81

If the hypoglossal nerve was damaged how would it show up clinically?

Answer 81

The tongue would deviate to the affected side.

Question 82

What is the submandibular ganglion?

Answer 82

The submandibular ganglion (SMG) is a parasympathetic ganglion, which receives inputs from preganglionic cholinergic neurons and innervates the submandibular salivary gland to control saliva secretion.
(The submandibular ganglion looks like a swelling on the lingual nerve. The fibres coming to this ganglion are coming from the superior salvatory nucleus in the brainstem).

Question 83

What muscle is immediately deep to the digastric muscle?

Answer 83

Mylohyoid.

Question 84

What direction do the fibres of the anterior belly of digastric run?

Answer 84

The fibres run backwards.

Question 85

Where is the central tendon of digastric located?

Answer 85

Medial side of superficial part of the submandibular salivary gland.

Question 86

What vein is deep to the omohyoid muscle?

Answer 86

Internal jugular vein.

Question 87

What branch of the common carotid artery is further forward?

Answer 87

External carotid artery.

Question 88

What are the major branches of the external carotid artery?

Answer 88

The major ECA branches are the superior thyroid, ascending pharyngeal, lingual, facial, occipital, posterior auricular, superficial temporal, and maxillary arteries.

Question 89

What is the pathway of the hypoglossal nerve over the internal/external arteries?

Answer 89

Comes down lateral to the internal/external arteries and crosses over them to go to the tongue.

Question 90

What nerve supplies the tensor veli palatini muscle?

Answer 90

pharyngeal branch of the vagus nerve.

Question 91

What nerve supplies the levator veli palatini muscle?

Answer 91

pharyngeal branch of the vagus nerve.