MT M3 3.4 Intro to the musculoskeletal sys Flashcards
Orthopedics
Orthopedics is the medical specialty that focuses on the musculoskeletal system.
muscular system
The muscular system is comprised of the muscles in the body and enables the body to move.
skeletal system
The skeletal system is comprised of bones, ligaments, tendons, and cartilage that form the skeleton of the body.
bones
The skeleton is made up of bones, the primary organs of the skeletal system. They are made up of 25% water and 75% hard matter, largely calcium phosphate.
bones
Bones form the framework of the body and serve in structure and movement, protection of internal organs, storage of minerals such as calcium and phosphate, and as the site of blood cell formation.
skeleton can be divided
The skeleton can be divided into the axial skeleton and the appendicular skeleton.
axial skeleton
The axial skeleton consists of the bones at the core of the body: the skull, spine, ribs, and sternum.
appendicular skeleton
The appendicular skeleton consists of the bones of the appendages of body, the shoulder girdle, arms, and hands, the pelvic girdle, legs, and feet.
Long bones
Long bones are located in the arms and legs, and an example would be the femur.
Flat bones
Flat bones are located in the shoulder, skull, ribs, and parts of the pelvis. Examples of these bones would include the sternum or the bones of the skull.
Short bones
Short bones are located in the fingers and toes. The carpal bones of the wrist serve as an example.
Irregular bones
Irregular bones are located in the spine and ear. The vertebrae are irregular bones.
Sesamoid bones
Sesamoid bones are shaped like a sesame seed. The patella or kneecaps are sesamoid bones.
accessory structures of the skeletal system
The accessory structures of the skeletal system are the cartilage, tendons, and ligaments.
Cartilage
Cartilage is fibrous connective tissue that is found at the ends of bones, in the joints, and the tube structures of the body, such as the larynx, air passages, and ears. At birth, most of the skeleton is made up of cartilage that is replaced with bone as the child grows.
Tendons
Tendons are fibrous cords that connect muscles to bones.
Ligaments
Ligaments are fibrous tissues in bands or sheets that connect two or more bones, cartilages, and other structures. They also help to support the fascia and muscles.
muscles
Muscles enable the body to move from one place to another, produce heat, and maintain stability and posture. There are three types of muscles: smooth, skeletal, and cardiac.
smooth muscle
These were described in Module 2. The majority of the internal organs, such as the digestive organs, lungs, urinary tract, and blood vessels are made up of smooth muscle.
controlled involuntarily by the nervous system.
cardiac muscle
The heart is made of cardiac muscle.
controlled involuntarily by the nervous system.
Skeletal muscles
Skeletal muscles produce movement
Skeletal muscle is controlled voluntarily
Joints
Joints are where two or more bones connect. Skeletal muscles attach to bones around the joints and contract to produce movement. A skeletal muscle has three parts: the body, an origin, and an insertion.
origin
Joints and muscle
The origin is where the muscle starts, and it is attached to a fixed bone.
insertion
Joints and muscle
The insertion is where the muscle attaches to the bone that it moves.
body
Joints and muscle
The body of the muscle is between these two points and is where the contraction occurs. A muscle contraction occurs when the muscle cells shorten and thicken. This pulls the bone where the muscle has inserted, generating movement at the joint.
fibrous joints
Some joints do not provide any movement; these are called fibrous joints. This type of joint is found between the bones of the skull.
cartilaginous joint
A cartilaginous joint provides slight movement. These joints are found between the vertebrae of the spine.
synovial joint
A synovial joint allows free movement in a variety of directions due to synovial fluid found in the joint, which provides lubrication. Examples of these joints are found in the hips, knees, shoulders, elbows, wrists, and ankles.
Flexion
Terms for the movements that can occur at synovial joints
Bending a limb
Elbow and knee
Extension
Terms for the movements that can occur at synovial joints
Straightening a flexed limb
Elbow and knee
Circumduction
Terms for the movements that can occur at synovial joints
Moving a body part in a circular motion
Shoulder and hip
Abduction
Terms for the movements that can occur at synovial joints
Moving a body part away from the middle
Shoulder and hip
Adduction
Terms for the movements that can occur at synovial joints
Moving a body part toward the middle
Shoulder and hip
Tip: To help remember the difference between abduction and adduction, remember that ADDuction “adds” to the body by bringing that body part closer to the midline.
Protraction
Terms for the movements that can occur at synovial joints
Moving a body part forward
Jaw
Retraction
Terms for the movements that can occur at synovial joints
Moving a body part backward
Jaw
Rotation
Terms for the movements that can occur at synovial joints
Moving a body part around a central axis
C1 Vertebrae
Dorsiflexion
Terms for the movements that can occur at synovial joints
Bending a body part backward
Wrist and ankle
Pronation
Terms for the movements that can occur at synovial joints
Turning the palm downward
Wrist
Supination
Terms for the movements that can occur at synovial joints
Turning the palm upward
Wrist
Eversion
Terms for the movements that can occur at synovial joints
Turning the sole outward
Ankle
Inversion
Terms for the movements that can occur at synovial joints
Turning the sole inward
Ankle
