Discuss and illustrate the importance of intervertebral discs and spinal curvature.
Intervertebral discs (or intervertebral fibrocartilage) lie between adjacent vertebrae in the spine. Each disc forms a cartilaginous joint to allow slight movement of the vertebrae, and acts as a ligament to hold the vertebrae together. The intervertebral discs are fibrocartilaginous cushions serving as the spine's shock absorbing system, which protect the vertebrae, brain, and other structures. The spinal bones and their related structures (such as the intervertebral disk, the ligaments, and the muscles) work together to provide movement, balance, upright posture, protection, and shock absorption to the body.
There are four different types of spinal curves:
- Cervical
- Thoracic
- Lumbar
- Sacral
The spine actually takes up about half of the volume of the torso, from front to back. This may give you an idea of the amount of support the spinal column is capable of giving to the body. The presence of the head, which places weight on the top of the spine, develops the cervical curve to allow us to hold our held upright. The rib-cage adds weight to the front of the body in the area of the mid and upper back. The thoracic spinal curve is in the direction opposite of the rib cage. This means demands placed on the spine by the weight of the ribcage are neutralized by the thoracic curve. Weight of the upper body is neutralized by the lumbar and sacral curves.
http://www.mayfieldclinic.com/PE-AnatSpine.htm
http://www.spineuniverse.com/anatomy/intervertebral-discs
There are four different types of spinal curves:
- Cervical
- Thoracic
- Lumbar
- Sacral
The spine actually takes up about half of the volume of the torso, from front to back. This may give you an idea of the amount of support the spinal column is capable of giving to the body. The presence of the head, which places weight on the top of the spine, develops the cervical curve to allow us to hold our held upright. The rib-cage adds weight to the front of the body in the area of the mid and upper back. The thoracic spinal curve is in the direction opposite of the rib cage. This means demands placed on the spine by the weight of the ribcage are neutralized by the thoracic curve. Weight of the upper body is neutralized by the lumbar and sacral curves.
http://www.mayfieldclinic.com/PE-AnatSpine.htm
http://www.spineuniverse.com/anatomy/intervertebral-discs
Name and illustrate three major categories of joints and compare the amount of movement allowed by each
Cartilaginous Joints
Cartilaginous joints are connected entirely by cartilage (fibrocartilage or hyaline). Cartilaginous joints allow more movement between bones than a fibrous joint but less than the highly mobile synovial joint. An example would be the joint between the manubrium and the sternum. Cartilaginous joints also forms the growth regions of immature long bones and the intervertebral discs of the spinal column.
Synovial Joints
A synovial joint, also known as a diarthrosis, is the most common and most movable type of joint in the body of a mammal. As with most other joints, synovial joints achieve movement at the point of contact of the articulating bones.Structural and functional differences distinguish synovial joints from cartilaginous joints (synchondroses and symphyses) and fibrous joints (sutures, gomphoses, and syndesmoses).
The movements possible with synovial joints are:
The movements possible with synovial joints are:
- abduction: movement away from the mid-line of the body
- adduction: movement toward the mid-line of the body
- extension: straightening limbs at a joint
- flexion: bending the limbs at a joint
- rotation: a circular movement around a fixed point
Fibrous Joints
These joints are also called "fixed" or "immoveable" joints, because they do not move. These joints have no joint cavity and are connected by fibrous connective tissue. The skull bones are connected by fibrous joints. Sutures are found between bones of the skull. In fetal skulls the sutures are wide to allow slight movement during birth. They later become rigid (synarthrodial).
Synovial joints
A synovial joint, also known as a diarthrosis, is the most common and most movable type of joint in the body. As with most other joints, synovial joints achieve movement at the point of contact of the articulating bones.
The movements possible with synovial joints are:
The movements possible with synovial joints are:
- abduction: movement away from the mid-line of the body
- adduction: movement toward the mid-line of the body
- extension: straightening limbs at a joint
- flexion: bending the limbs at a joint
- rotation: a circular movement around a fixed point