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Practice flashcards based on lecture notes for BS 121, covering the skeletal system, including divisions, specific bones of the axial skeleton (skull, vertebrae, sternum, ribs), and fetal skull characteristics.

What are the two major divisions of the skeleton?

Axial skeleton and Appendicular skeleton

How many bones make up the axial skeleton and what does it include?

The axial skeleton consists of 80 bones of the head, neck, and torso, including six tiny middle ear bones.

How many bones make up the appendicular skeleton and what does it include?

The appendicular skeleton consists of 126 bones forming the appendages to the axial skeleton, specifically the upper and lower extremities.

What are the two major divisions of bones within the skull?

Cranial bones and facial bones

Which cranial bone forms the forehead, anterior part of the top of the cranium, and contains the frontal sinuses?

The frontal bone

Which cranial bones form the bulging top of the cranium and several sutures, including the lambdoid, squamous, and coronal sutures?

The parietal bones

Which cranial bone forms the lower, posterior part of the skull and forms a movable joint with the first cervical vertebra?

The occipital bone

What is the bat-shaped bone located in the central portion of the cranial floor that anchors several other cranial bones?

The sphenoid bone

Which complex, irregular bone lies anterior to the sphenoid and posterior to the nasal bones, forming part of the anterior cranial floor and medial orbit walls?

The ethmoid bone

Which two facial bones form the keystone of the face, forming parts of the orbital floors, roof of the mouth, and contains the maxillary sinuses?

The maxillae (upper jaw)

What is the largest, strongest bone of the face that forms the only movable joint of the skull with the temporal bone?

The mandible (lower jaw)

Which facial bones shape the cheek, form the outer margin of the orbit, and form the zygomatic arch?

The zygomatic bones

What are fontanels?

Fontanels, or 'soft spots,' are unique anatomical features in the fetal skull that allow the skull to 'mold' during birth and permit rapid brain growth.

What is unique about the hyoid bone compared to other bones in the body?

The hyoid bone is the only bone in the body that articulates with no other bones.

What does the vertebral column consist of?

The vertebral column consists of 24 vertebrae plus the sacrum and coccyx.

What is the upward projection on the second cervical vertebra (axis) that allows for head rotation?

The dens

What are the three parts of the sternum?

Manubrium, body, and xiphoid process

How many pairs of ribs are there, and how do they articulate with the vertebral column?

There are twelve pairs of ribs, each articulating with the body and transverse process of its corresponding thoracic vertebra.

What are floating ribs?

Floating ribs are ribs 11 and 12, which do not attach, even indirectly, to the sternum.