H and N 1.1

Question 1

What is the name of the 1st cervical vertebra?

Answer 1

The atlas

Question 2

What is the structure of the atlas?

Answer 2

• No body or spine
• Made of anterior and posterior arches
• The transverses processes contain a foramen that transmits the vertebral vessels

Question 3

What is the 2nd vertebra?

Answer 3

The axis

Question 4

What is the dens?

Answer 4

• The most characteristic feature of the axis is the dens (odontoid process)
• The dens articulates with the anterior arch od the atlas, providing a pivot about with the atlas and head can rotate (side-to-side action of the head, as in indicating “no”)
• The axis is the strongest of the cervical vertebrae.

Question 5

What can fracture the axis and atlas?

Answer 5

1. A blow to the top of the head may fracture the atlas, usually across the anterior and posterior arches
2. Such a fracture is called a Jefferson fracture.
3. Fractures of the axis often involve the dens. 4. A fracture may cross the neural arch between the superior and inferior articular facets.
4. This is referred to as a “hangman” fracture.

Question 6

What is the atlantooccipital joint on each side covered with?

Answer 6

1. The atlantooccipital joint, on each side, is covered with an articular capsule and posteriorly reinforced by the posterior atlantooccipital membrane
2. It permits flexion and extension (the action of nodding one’s head up and down to signify “yes”)

Question 7

What is the ligament nuchae?

Answer 7

1. A strong median fibrous septum
2. It is an extension of the thickened supraspinous ligaments that arise from the spinous process of C7 and extend to the external occipital protuberanc

Question 8

What fusions can occur?

Answer 8

• While there are usually 7 cervical vertebrae, fusion of adjacent cervical vertebrae can occur
• Most commonly, this fusion in the cervical region is seen between C1 and C2 (the atlas and axis) or between C5 and C6.

Question 9

What could trauma to the upper cervical region result in?

Answer 9

the axis being displaced anteriorly over the C3 vertebra, causing injury to the spinal cord and quadriplegia (loss of movement of the upper and lower limbs bilaterally)

Question 10

What type of joint is the atlantoccpitial joint?

Answer 10

a biaxial condyloid synovial joint between the atlas and the occipital condyles

Question 11

What does the atlantoaxial joint permit?

Answer 11

-flexion and extension as when the head is nodded up and down and some lateral bending

Question 12

What type of joins are the atlantoaxial joint?

Answer 12

Uniaxial synovial joints

Question 13

What do the atlantoaxial joints consist of?

Answer 13

They consist of plane joints associated with the articular facets and a median pivot joint between the dens of the axis and the anterior arch of the atlas

Question 14

What does the atlantoaxial joint permit?

Answer 14

The atlas and head to be rotated as a single unit as when the head is turned from side to side

Question 15

What are these joints reinforced by?

Answer 15

• By ligaments, especially the cruciate and alar ligaments

- The alar ligaments limit rotation

Question 16

How can osteoarthritis affect these joint?

Answer 16

1. Osteoarthritis is the most common form of arthritis and often involves erosion of the articular cartilage of weight-bearing joints, including the cervical spine
2. Extensive thinning of the intervertebral discs and of the cartilage covering the facet joints can lead to hyperextension of the cervical spine, narrowing of the intervertebral foramen, and the potential for impingement of the spinal nerves exiting the intervertebral foramen

Question 17

What do the cartilges of the larynx include?

Answer 17

1. thyroid cartilage (Adams apple_
   2 cricoid cartilage
2. epiglottis,
3. paired arytenoid, corniculate, and cuneiform cartilages.

Question 18

where are the cuneiform cartilages?

Answer 18

These paired elastic cartilages lie in the aryepiglottic folds and have no articulations with other cartilages or bones

Question 19

How is sensory innervation provided?

Answer 19

The thyrohyoid membrane has an opening through which the internal branch of the superior laryngeal nerve (branch of the vagus nerve) enters the larynx to provide sensory innervation above the vocal folds

Question 20

What trauma to the cartilages in the larynx can result in?

Answer 20

1. Trauma to the cartilages of the larynx may result in fractures
2. Consequently, the underlying laryngeal mucosa and submucosa may hemorrhage, resulting in significant edema and the potential for airway obstruction
3. Ultimately, such an injury may result in hoarseness as the vocal folds swell and/or are compromised by the damage (muscle or nerve damage), making speaking difficult or impossible

Question 21

Where do the three auditory ossicles reside?

Answer 21

-In the middle ear or tympanic cavity

Question 22

What do the three auditory ossicles do?

Answer 22

-They amplify sonic vibrations from the tympanic membrane and transmit them to the inner ear.

Question 23

What are the 3 ear ossicles?

Answer 23

1. Malleus (hammer)
2. Incus (anvil)
3. Stapes (stirrup)

Question 24

How are the three auditory ossicles fused?

Answer 24

1. The handle of the malleus is fused with the medial aspect of the tympanic membrane; the head articulates with the incus.
2. The incus articulates with the stapes, whose footplate is attached to the oval window.

Question 25

What are different types of hearing loss?

Answer 25

1. Two small muscles attach to the auditory ossicles; the tensor tympani muscle attaches to the malleus and the stapedius muscle to the stapes
2. These very small skeletal muscles dampen large vibrations resulting from excessively loud noises
3. Sensorineural hearing loss suggests a disorder of the internal ear involving the cochlea and/or the cochlear division of the vestibulocochlear nerve (CN VIII)
4. Conductive hearing loss suggests a disorder of the external or middle ear, often involving the tympanic membrane (eardrum) and/or the middle ear ossicles.