Chapter 7 Axial skeleton

Identify the typical number of vertebrae that fuse during development to form the coccyx.

3-5

Name the number of vertebrae that fuse together to form the sacrum.

5

The cranial sutures begin to form at about what age?

5

What is the name of the first cervical vertebra?

Atlas

Identify the articulation site that allows us to rotate our head, e.g. shaking the head "no"

Atlas - axis

What is the name of the second cervical vertebra?

Axis

Identify the tailbone.

Coccyx

Identify the region of the coxal bone that articulates with the sacrum.

Ilium

Identify the articulation site that allows us to nod our head "yes".

Occipital bone - atlas

Identify the region of the skull that articulates with the atlas.

Occipital condyles

Identify the bony posterior wall of the pelvis

Sacrum

The orbital rim is strong, composed of thick, protective bone. But the very thin medial wall and floor of the orbit were literally blown out by the intact eyeball itself when the boxer was struck with such a forceful blow. Which bones compose the orbital rim?

The maxilla and zygomatic bone both articulate with the frontal bone to form the orbital rim.

Surrounding the orbits are the four paranasal sinuses. What are these structures?

The paranasal sinuses are air-filled chambers lined with mucus-producing epithelium that open into the nasal cavities.

When fontanelles close prematurely, the skull shape becomes distorted. This condition is known as craniostenosis. If the anterior fontanelle closes prematurely, which of the following sutures is most likely involved?

coronal suture

Sinusitis, an inflammation of the paranasal sinuses, is brought on by a viral, bacterial, or fungal infection. The most commonly affected paranasal sinuses are the most inferior ones, which are called __________.

maxillary sinuses

The axial skeleton provides an extensive surface area for the attachment of muscles that __________.

perform respiration move the head position the appendicular skeleton perform all of these functions

While skateboarding, a young person suffered a fracture of the nose that resulted in a deviated septum. Which of the following bones or bone markings is most likely attended to during corrective surgery following this accident?

perpendicular plate of the ethmoid

The maxilla also frequently sustains fractures from blunt trauma to the face. Which structures support and house the upper teeth in this bone?

the alveolar process

The young boxer has sustained a "blowout" fracture of his left orbital complex. The orbit that contains the eye is formed by seven facial bones. Which skull bone forms the roof of the orbit?

the frontal bone