Chapter 7 Axial Skeleton

Identify the articulation site that allows us to rotate our head, e.g. shaking the head "no". Atlas - axis Axis - C3 Occipital bone - axis Occipital bone - atlas

Atlas - axis The prominent projection known as dens on the axis forms a pivot joint with the atlas, allowing the atlas to rotate around the axis. The axis is a very sensible name for C2 since it serves as a central axis for rotation of the atlas.

In the fetus, ________. a) the head is proportionally smaller than the body b) the limbs are proportionally longer than the trunk c) the head is proportionally larger than the body d) the limbs are proportionally shorter than the trunk

c) the head is proportionally larger than the body page 136

How many pairs of ribs are there? 24 12 10 14

12

What is the name of the first cervical vertebra? Atlas Axis Superior articular process Occipital condyles

Atlas The atlas is essentially a ring of bone. Its structure is highly specialized to articulate with the skull.

Identify the major weight bearing part of a vertebra. Lamina Vertebral foramen Transverse process Body

Body The disk shaped bodies of vertebrae are stable and stackable. Most weight is distributed in this region.

Individual vertebrae articulate with each other forming the vertebral column. Identify the part of a vertebra that articulates immediately with the vertebra below it. Superior articular processes Inferior articular processes Spinous process Transverse processes

Inferior articular processes The inferior articular processes contact the superior articular process of the vertebra below it, forming a moveable synovial joint.

Which of the following structures would not be found within a vertebral foramen? Spinal nerve roots Spinal cord Dura mater Intervertebral discs

Intervertebral discs The intervertebral discs are located in between the vertebral bodies. They form a symphysis with the bodies and act as a shock absorber.

Identify the articulation site that allows us to nod our head "yes". Occipital bone - axis Occipital bone - atlas Atlas - axis Occipital bone - C2

Occipital bone - atlas The padlike occipital condyles found on both sides of foramen magnum sit on top of the plate like superior articular processes of the atlas, forming the atlanto-occipital joint. The articular surfaces permit nodding of the head in a "yes" motion (flexion and extension).

Identify the region of the skull that articulates with the atlas. Occipital condyles Foramen magnum Mastoid processes Superior articular facets

Occipital condyles The occipital condyles found on both sides of foramen magnum sit on top of the atlas, forming the atlanto-occipital joint.

________ are the telescoping tubes of matrix (concentric lamellae) with their central canals that form a large part of compact bone. Osteons Osteocytes Lacunae Trabeculae

Osteons

Name the vertebral projection found in a median plane. Transverse process Superior articular process Inferior articular process Spinous process

Spinous process The spinous process extends posteriorly in a median plane. It serves as a site of muscle and ligament attachment.

Bones of the skeleton are connected at junctions called ________. articulations appendiculars associations axials

articulations

These are the cheek bones of the face. a) maxillae b) zygomatics c) sphenoids d) temporals

b) zygomatics page 128

The skeleton is constructed of two types of tissue, ________. bone and cartilage dense connective tissue and bone muscle and bone nervous and bone

bone and cartilage

Bones are somewhat flexible due to ________. calcium salts in the ground substance collagen fibers in the matrix elastic fibers in the matrix soft, pliable ground substance of the matrix

collagen fibers in the matrix page 111

Fontanels are ________. rings of bone in a fetal skull bones encased in cartilage conical projections on a fetal skull fibrous membranes in a fetal skull

fibrous membranes in a fetal skull

The epiphyses of long bones are ________. filled with spongy bone solid hollow

filled with spongy bone page 110

Which of the fetal cranial bones may appear to be two bones in the fetus? parietal frontal occipital temporal

frontal

This is the most common type of skeletal cartilage. hyaline fibrocartilage elastic

hyaline page 108

Vertebrae belong to this category of bones. flat irregular long short

irregular

The transverse processes of vertebrae point ________, while the spinous process points ________. medially, posteriorly medially, anteriorly laterally, anteriorly laterally, posteriorly

laterally, posteriorly page 132

The foramen magnum is located in which bone of the skull? sphenoid temporal occipital frontal

occipital

Label the upper body skeletal system

page 108

Label microscopic structure of compact bone

page 113

The axial skeleton includes all of the following except the ________. A) vertebral column B) pectoral and pelvic girdles C) bony thorax D) skull

vertebral column pectoral and pelvic girdles bony thorax skull

Locate the type of bones in the body Long bone Short bone Sesamoid bone Flat bone Irregular bone

page 110 example: long bone - femur flat bone - sternum irregular bone - vertebra sesamoid bone - patella short bone - heel

Label the bones of the skull, anterior view

page 125

Label the bones that form the orbit

page 128

Locate parts of the axial skeleton on a fetal skeleton Parietal bone Ossification center Mastoid fontanelle Occipital bone Temporal bone Frontal bone Sphenoidal fontanelle

page 137

An example of a sesamoid bone is the ________. clavicle patella pubis radius

patella

Which bone(s) might be absent in the fetus? clavicle fibula distal phalanges patella

patella

The diaphysis of a long bone is covered by ________. endosteum articular cartilage perforating fibers periosteum

periosteum page 111

The midline suture marking the articulation of the two parietal bones is called the ________ suture. sagittal squamous coronal lambdoid

sagittal

The ________ is a median posterior projection arising at the junction of two laminae of the vertebral body. vertebral arch pedicle spinous process lamina

spinous process page 133

In adults, some of the single bones are made of several fused bones. In the fetus, such bones may not yet be fully fused (ossified). These bones include the ________. radius femur tibia sternum

sternum

The cranial bones that house the organs of hearing are the ________ bones. temporal occipital sphenoid parietal

temporal

Look at Iten 7 - Label spinal column

Page 133

Locate parts of a thoracic cage

Page 135

Label parts of the skull, right side

page 121

What is the name of the second cervical vertebra? Atlas Axis Dens Vertebra prominens

Axis C2 is known as the axis. It has a bony projection called the odontoid process that articulates with C1. C1 can pivot around C2, allowing us to rotate our head/shake head "no".

Label the Axial Skeleton

Page 121

Identify a lateral projection of a vertebra. Lamina Superior articular process Transverse process Spinous process

Transverse process The transverse processes of a vertebra project laterally from the junction of the lamina and pedicle.

This is a passageway for blood vessels and nerves. a) facet b) meatus c) tubercle d) foramen

d) foramen page 127

Which of the following bone markings helps form joints? fossa crest head epicondyle

head