ch 7 questions

Define fontanelle, and identify the major fontanelles.

A fontanelle is a relatively soft, flexible, fibrous region between two flat bones in the developing skull. The major fontanelles are the anterior fontanelle, posterior fontanelle, sphenoidal fontanelles, and mastoid fontanelles.

What purpose does a fontanelle serve?

Because they are not ossified at birth, fontanelles permit the skull to change shape during childbirth, and they allow for enlargement of the brain during infancy and early childhood.

Describe false ribs.

False ribs (ribs 8-12) are the five lower ribs on either side that do not articulate with the sternum directly.

Improper administration of cardiopulmonary resuscitation (CPR) can result in a fracture of which bones?

Improper compression of the chest during CPR can—and commonly does—result in a fracture of the xiphoid process of the sternum or the ribs.

What structures go through the mental foramen?

Structures passing through this opening include the mental nerve, which carries sensory information to the brain, and mental vessels, which supply the chin and lips.

Identify the facial bones.

The 14 facial bones include 2 inferior nasal conchae, 2 lacrimal bones, 1 mandible, 2 maxillae (maxillary bones), 2 nasal bones, 2 palatine bones, 1 vomer, and 2 zygomatic bones.

List the components of the vertebral column.

The adult vertebral column consists of 26 bones: the vertebrae (24), the sacrum (1), and the coccyx.

Why does the vertebral column of an adult have fewer vertebrae than that of a newborn?

The adult vertebral column has fewer vertebrae than a newborn because, in an adult, the five sacral vertebrae fuse to form a single sacrum, and the four coccygeal vertebrae fuse to form a single coccyx.

Identify the bones of the axial skeleton.

The axial skeleton includes the skull (8 cranial bones and 14 facial bones), the bones associated with the skull (6 auditory ossicles and the hyoid bone), the thoracic cage (the sternum and 24 ribs), and the vertebral column (24 vertebrae, the sacrum, and the coccyx).

List the primary functions of the axial skeleton.

The axial skeleton serves as a framework that supports and protects organs, provides an extensive surface area for muscle attachment, and stabilizes and positions parts of the appendicular skeleton that support the limbs.

Joe suffered a hairline fracture (fracture without separation of the fragments) at the base of the dens. Which bone is fractured, and where is it located?

The axis is fractured. The dens is a tooth-like process projecting upward from the body of the axis, or second cervical vertebra, which is located in the neck (cervical region).

Why are the bodies of the lumbar vertebrae larger than those of the cervical and thoracic vertebrae?

The bodies of the lumbar vertebrae are larger because they must support a great deal more weight than do vertebrae that are more superior in the spinal column. The larger vertebral bodies allow the weight to be distributed over a larger area.

Identify the bones of the nasal complex.

The bones forming the nasal complex are the frontal, ethmoid, nasal, maxilla, palatine, and sphenoid.

Identify the bones of the orbital complex.

The bones forming the orbital complex are the frontal, sphenoid, zygomatic, palatine, maxilla, lacrimal, and ethmoid.

Name the fontanelles found on the infant skull. Why aren't they labeled on the adult skull?

The infant skull has six fontanelles: sphenoidal (paired), mastoid (paired), anterior, and posterior. As the skull develops, bones ossify and fuse. In an adult skull, all of the bones are complete and fused, so there aren't any fontanelles on the adult skull.

Which two pairs of ribs are the floating ribs? What distinguishes them from the other false ribs?

The last two pairs of ribs (11 and 12) are the floating ribs and do not attach to the sternum. The other false ribs are indirectly attached to the sternum by costal cartilage.

Identify the bone containing the optic canal, and cite the structures using this passageway.

The optic canal is found in the sphenoid. The optic nerve and ophthalmic artery pass through this structure.

Examining a human vertebra, you notice that, in addition to the large foramen for the spinal cord, two smaller foramina are on either side of the bone in the region of the transverse processes. From which region of the vertebral column is this vertebra?

The presence of transverse foramina indicates that this vertebra is from the cervical region of the vertebral column. These foramina are passageways for important blood vessels that supply the brain.

What is the importance of the secondary curves of the spine?

The secondary curves of the spine allow us to balance our body weight on our lower limbs with minimal muscular effort. Without the secondary curves, we would not be able to stand upright for extended periods.

Looking at all the views of the skull, name the major sutures.

The skull contains four major sutures: the sagittal suture, the lambdoid suture, the squamous suture, and the coronal suture.

Which bone contains the depression called the sella turcica? What is located in this depression?

The sphenoid contains the sella turcica, which in turn contains the pituitary gland.

Identify the bones containing the paranasal sinuses.

The sphenoid, ethmoid, frontal, and paired palatine and maxillary bones contain the paranasal sinuses.

Which two regions of the spine form primary curves?

The thoracic and the sacral regions of the spine form primary curves.

What are the main differences between true ribs and floating ribs?

True ribs (ribs 1-7) attach directly to the sternum by separate costal cartilages; floating ribs (ribs 11-12) are the two lower ribs on either side that are not attached anteriorly to the sternum.

Name the foramina found in the ethmoid bone

olfactory foramina