Joints Flashcards
What are the three types of joints (based on composition)?
Fibrous joints
Cartilaginous joints
Synovial joints
What is the difference between a synchondrosis and symphysis?
Synchondrosis: hyaline cartilage union, exists temporarily between the epiphysis and diaphysis of juvenile long bones and skull. Permanently between the skull and hyoid apparatus.
Symphysis: fibrocartilage union (mandible, pelvis, between vertebrae)
What are the five parts of a synovial joint?
Synovial membrane - vascular connective tissue that lines the inner surface of joint capsules. Has synoviocytes that synthesize synovial fluid.
Joint capsule - thick, fibrous capsule that supports joint
Synovial fluid - egg-white consistency fluid that functions as lubricant and provides nutrition (contains hyaluronic acid and lubricin).
Articular cartilage - see definition below.
Joint cavity - fluid-filled space that separates articulating bones
What are the characteristics of articular cartilage?
Avascular and aneural (no blood vessels, no nerves)
Acts as a shock absorber and a bearing surface
Absorbs synovial fluid which diffuses through the cartilage matrix to provide it with nourishment
What are synoviocytes and what is their function?
A type of cell that exists within the synovial membrane and synthesizes synovial fluid.
What is flexion?
decreasing the angle between two bones.
What is extension?
increasing the angle between two bones.
What is adduction?
moving a part toward the median line
What is abduction?
moving a part away from the median line
What is circumduction?
movement in a cone-shape
What is pronation?
rotating the limb so the paw/foot faces down
What is supination?
rotating the limb so the paw/foot faces up
What are the three types of cartilage?
- Hyaline cartilage
- Elastic cartilage
- Fibrocartilage
What are the 3 types of muscle tissue and their characteristics?
Cardiac muscle: striated, musculature of the heart, branched fibers.
Skeletal muscle: striated, generally attached to bone, usually under voluntary control, non-branched fibers
Smooth muscle: not striated, found in the walls of viscera (gut, vessels, glands, etc.)
What is the difference between the origin and insertion of a muscle?
Origin: least movable end
Insertion: most movable end
What is myofiber?
muscle fibers that are made up of elongated, multinucleate cells
What are Myofibrils?
bundles of protein filaments that cause contraction
What is the sarcoplasm?
the cytoplasm of striated muscle cells; contains mitochondria to provide energy for contraction
What is the epimysium?
loose or dense connective tissue surrounding an entire muscle
What is the perimysium?
loose connective tissue defining muscle fascicles
What is the endomysium?
small amounts of loose connective tissue surrounding individual muscle fibers
What are sarcomeres?
repetitive unit of myofibrils that are thick and thin filaments
What is a bursa?
tiny, slippery sac of fluid/synovial pocket that provides a cushion and reduces friction between the tendons, ligaments, muscles, and bony prominences.
What are the features of cardiac muscle?
- Striated, branching fibers
- Central nuclei
- Myofibers are separated by intercalated discs
What are the basic features of arteries?
White, thick, relatively rigid walls
Conveys oxygenated blood to all organs
What are the basic features of veins?
Transports deoxygenated blood to the heart
Thinner walls, appear blue when filled with clotted blood
Have valves that ensure unidirectional flow and prevent reflux of blood when circulation stagnates
What are the basic features of capillaries?
Smallest of the body’s vessels
Allows transfer of water, gasses, solutes, etc.
