Activity 3
(Exercises)
1. 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 yellow bone being referred to is the “sphenoid bone,” which is centrally located and joins with most of the other bones of the skull.
2. 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?
The two mechanisms of bone formation (ossification) are endochondral ossification and intramembranous ossification. In endochondral ossification, a bone is formed through the hyaline cartilage, which progressively transitions to become a hard bone. Moreover, it is through this mechanism that the formation of long bones is involved. On the other hand, another mechanism of bone formation is intramembranous ossification, which directly forms the bone on the mesenchyme, a precursor tissue, without the association of cartilage. Through this mechanism, the flat bones of the skull, face, clavicle, and jaw are formed.
3. 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?
The synovial joints presented in the video are:
Ball-and-socket joint for the shoulder.
Hinge joint for the knee.
Pivot joint for the cervical vertebrae.
Condyloid joint for the wrist.
Saddle joint for the fingers.
Gliding joint for the spine/vertebrae.
- Which type of synovial joint allows for the widest ranges of motion?
The type of synovial joint that is freely movable and allows for the greatest range of motion is the ball-and-socket joint.