1. Which bone (yellow) is centrally located and joins with most of the other bones of the skull?
Sphenoid bone. It is shaped like a butterfly or saddle (depending on how you look at it), the sphenoid forms the floor of the cranium and the sides of the eye sockets (orbits). A central, sunken portion of the sphenoid bone called the sella turcica shelters the pituitary gland, which is very important in controlling major functions of the body.
2. What are the two mechanisms by which the bones of the body are formed and which bones are formed by each mechanism?
The two (2) mechanisms are the intramembranous ossification and endochondral ossification. Intramembranous ossification produces the flat bones of the skull and most of the clavicle (collarbone). Centers of ossification during this process form when mesenchyme cells change into osteogenic cells and osteoblasts. On the other hand, endochondral ossification produces most other bones, including the vertebrae, pelvic bones, and bones of the limbs. It is a method in which mesenchyme first transforms into a hyaline cartilage model that resembles the shape of the bone to come, and then the cartilage is broken down, reorganized, and calcified to form a bone.
3. What are the synovial joints being described in the video?
The synovial joints that were described in the video are the following: ball-and-socket joint, hinge joint, pivot joint, condylar/condyloid joint, saddle join, and gliding joint.
4. Which type of synovial joint allows for the widest ranges of motion?
The ball-and-socket join allows for the widest range of motion. The ball-shaped head of one bone fits into a depression (socket) in another bone. It has a circular movement; joints can move in all planes, and rotation is possible. The ball-and-socket joint can be found in the shoulder and hip.
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Reference:
- Norris, M., & Siegfried, D. (2011). Anatomy & Physiology for Dummies (2nc ed.). New Jersey: Wiley Publishing, Inc.