Unit III - Temporal bone

Question 1

What are the four parts of the temporal bone?

Answer 1

Squamous

Mastoid

Petrous

Tympanic

Question 2

What are the four parts of the squamous part of the temporal bone?

Answer 2

temporal surface

zygomatic process

mandibular fossa

external auditory meatus

Question 3

What attaches to the temporal surface of the squamous part of the temporal bone?

Answer 3

temporalis muscle

attachment: temporal fossa –> coronoid process and anterior border (temporal crest) of the ramus of the mandible
function: elevation and retraction (posterior aspect of the muscle) of the mandible
innervation: mandibular n.
blood supply: deep temporal a.

Question 4

What attaches to the zygomatic process?

Answer 4

Masseter muscle

attachment: zygomatic arch –> angle of mandible and lateral aspect of the mandibular ramus
function: elevation, protraction, and retraction (deep fibers) of the mandible
innervation: mandibular nerve
blood supply: masseteric, facial and transverse facial a.

Question 5

What are the 5 parts of the mandibular fossa of the squamous part of the temporal bone?

Answer 5

articular eminence and tubercle

petrotympanic fissure

squamotympanic fissure

tegmen tympanii

opening of osseous portion of auditory tube

Question 6

What is transmitted through the petrotympanic fissure?

Answer 6

chorda tympani n.

Question 7

what attaches to the squamotympanic fissure?

Answer 7

articular disc

Question 8

What are the 2 parts of the mastoid part of the temporal bone?

Answer 8

mastoid process

sigmoid sulcus

Question 9

What attaches to the mastoid process?

Answer 9

(1) sternocleidomastoid
attachment: lateral aspect of mastoid process and superior nuchal line –> manubrium and medial 1/3rd of clavicle
function: flexion of head and neck, and contralateral rotation of the head
innervation: accessory n.
blood supply: occipital, posterior auricular, superior thyroid and suprascapular a.

(2) splenius capitis
attachment: ligamentum nuchae and lower cervical and upper thoracic spinous processes –> lateral third of superior nuchal line
function: extension and lateral flexion of the head
innervation: dorsal rami of cervical spinal n.
blood supply: vertebral, occipital, deep cervical and deep branch of transverse cervical a.

(3) longissimus capitis
attachment: upper thoracic transverse processes –> posterior margin of mastoid process
function: extension and ipsilateral rotation of head
innervation: dorsal rami of spinal n.
blood supply: vertebral, occipital, deep cervical, and deep branch of transverse cervical a.

Question 10

What are the two parts of the mastoid process?

Answer 10

mastoid notch

occipital groove

Question 11

What attaches to the mastoid notch?

Answer 11

posterior belly of digastric muscle
attachment: temporal mastoid notch –> intermediate tendon (great cornu of hyoid)
function: depression of mandible or elevation of hyoid
innervation: facial n.
blood supply: occipital and posterior auricular a.

Question 12

What is the function of the occipital groove?

Answer 12

houses occipital artery

Question 13

what is the function of the sigmoid sulcus?

Answer 13

houses sigmoid sinus

Question 14

What are the four parts of the petrous part of the temporal bone?

Answer 14

Anterior surface (trigeminal impression)

Posterior surface (Internal auditory meatus)

Inferior surface (carotid canal, jugular fossa, canaliculus for the tympanic n.)

Superior border (groove for the superior petrosal sinus)

Question 15

What is the function of the trigeminal impression?

Answer 15

houses trigeminal ganglion

Question 16

what is the function of the internal auditory meatus?

Answer 16

transmits facial and vestibulocochlear n.

Question 17

What attaches to the inferior surface of the petrous part of the temporal bone?

Answer 17

levator veli palatini muscle

attachment: petrous temporal bone adjacent to carotid canal and the cartilagenous portion of the auditory tube –> soft palate
function: elevates the soft palate
innervation: vagus nerve (pharyngeal branch)
blood supply: ascending palatine, greater palatine and lesser palatine a.

Question 18

What is the function of the carotid canal?

Answer 18

transmits the internal carotid artery and carotid nerve

Question 19

What is the function of the jugular fossa?

Answer 19

transmits the internal jugular vein, glossopharyngeal nerve, vagus nerve, and accessory nerve

Question 20

What is the function of the canaliculus for the tympanic nerve?

Answer 20

transmits the tympanic nerve

Question 21

What are the two parts of the tympanic part of the temporal bone?

Answer 21

styloid process

stylomastoid foramen

Question 22

What attaches to the styloid process of the tympanic part of the temporal bone?

Answer 22

(1) stylohyoid muscle
attachments: styloid process –> greater cornu of hyoid
function: elevation & retraction of hyoid
innervation: facial n.
blood supply: occipital, posterior auricular & facial n.

(2) stylopharyngeus muscle
attachment: styloid process –> posterolateral aspect of pharyngeal wall
function: elevation of pharyngeal wall
innervation: glossopharyngeal n.
blood supply: ascending pharyngeal a.

(3) styloglossus muscle
attachment: styloid process –> lateral base of tongue
function: elevation and retraction of tongue
innervation: hypoglossal n.
blood supply: sublingual a.

(4) stylohyoid ligament
attachment: apex of styloid process –> lesser cornu of hyoid

Question 23

What is the function of the stylomastoid foramen?

Answer 23

transmits the facial nerve