Watch this video to view a rotating and exploded skull with color-coded bones. Which bone (yellow) is centrally located and joins with most of the other bones of the skull? The link to the video at the study guide.
- Answer: Sphenoid bone. The sphenoid bone is one of the eight bones that make up the cranium, the superior portion of the skull. It holds everything together at the center and helps connect the neurocranium to the facial skeleton.
View another video to review the two processes that give rise to the bones of the skull and the body. Access to the video is in the study guide. Answer this question:
What are the two mechanisms by which the bones of the body are formed and which bones are formed by each mechanism?
- Answer: The two mechanisms are the following: intramembranous ossification and endochondral ossification.
- Intramembranous ossification: Bone formation during early fetal development that occurs on or within fibrous connective tissue membranes. Centers of ossification during this process form when mesenchyme cells change into osteogenic cells and osteoblasts.
- Endochondral ossification: How most skeletal bones are formed; this is the replacement of cartilage, a connective tissue, with bone.
Listed below are the bones formed by each mechanism:
- Intramembranous Ossification: Flat bones of the skull, mandible, and clavicle.
- Endochondral Ossification: All bones of the body, except the flat bones of the skull, the mandible, and the clavicle.
Watch another video (link in the study guide) to see an animation of synovial joints in action. Answer the following questions after watching the video.
What are the synovial joints being described in the video?
- Answer: The following are the synovial joints being described in the video (in order of how they were showcased in the video):
- Ball-and-socket joint
- Hinge joint
- Pivot joint
- Condylar/Condyloid joint
- Saddle joint
- Gliding joint
Which type of synovial joint allows for the widest ranges of motion?
- The synovial joint that allows for the widest range of motion is the ball-and-socket joint. As it has a rounded end of one bone fitting into a cup-like socket of the other bone, allowing motion in all directions. Examples of these would be the hip and shoulder joints.