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Joints Ch. 8
Chapter 8 Q & A
Question | Answer |
---|---|
What are joints? | Articulations where 2 bones meet |
What functions do joints serve? | Some joints are completely immovable, some allow limited movement, most permit considerable movement |
What are the classifications of joints? | Fibrous (synarthroses), cartilaginous (amphiarthroses), and synovial (diarthroses) |
What are fibrous joints? | They result when collagen fibers from one bone penetrates the adjacent bone, anchoring the bones in place |
What are cartilaginous joints? | 2 bones joined by cartilage that are slightly movable |
What are synovial joints? | The most numerous and veersatile of all the body's joints; freely movable; 6 types of synovial joints |
What is the synovial joint with the widest range of motion? | Ball-and-socket joint such as the hip and shoulder |
What are the 6 types of synovial joints? | Pivot, hinge, gliding, ball-and-socket, saddle, and condyloid. |
What is a pivot joint? | A projection from one bone articulates with a ring-shaped socket of another bone, allowing the bones to rotate |
Where is a pivot joint located? | The dens of the axis articulating with the atlas and radioulnar joint |
What is a hinge joint? | Convex surface of one bone fits into a concave depression of another allowing only back-and-forth movement |
Where is a hinge joint located? | Elbow, knee, and interphalangeal joints |
What is a gliding joint? | 2 relatively flat bone surfaces slide over one another; least mobile of all the synovial joints |
Where is a gliding joint located? | Tarsals, carpals, and articular processes of the vertebrae |
What is a ball-and-socket joint? | A ball-shaped head of one bone fits into a cup-like socket of another offering the widest range of motion |
Where is a ball-and-socket joint located? | Shoulder and hip |
What is a saddle joint? | Concave in one direction and convex in the other, allows back-and-forth and side-to-side movement, although the side-to-side motion is limited |
What is a condyloid joint? | An oval convex surface of one bone fits into a similarly shaped depression of another, allowing flexion and extension as well as side-to-side movement |
Where is a saddle joint located? | Found only in the thumbs |
Where is a condyloid joint located? | Distal end of the radius articulating with the carpals and the joints at the base of the fingers |
What are the 7 ranges of movement? | Flexion and extension, abduction and adduction, circumduction, rotation, supination and pronation, inversion and eversion, protraction and retraction |
What is flexion? | Bending a joint so as to DECREASE the angle of the joint |
What is extension? | Straightening a joint so as to INCREASE the angle between the bones |
What is dorsiflexion? | Moving the toes UPWARD |
What is plantar flexion? | Moving the toes DOWNWARD |
What is internal rotation? | When a bone spins TOWARD the body's midline |
What is external rotation? | When a bone spins AWAY FROM the body's midline |
What is supination? | Movement that turns the palm UPWARD |
What is pronation? | Movement that turns the palm DOWNWARD |
What is hyperextension? | Extreme extension of a joint beyond its normally straight position |
What is the difference between abduction and adduction? | Abduction is movement of a body part AWAY from the midline of the body. Adduction is the movement of a body part TOWARD the midline of the body |
What is circumduction? | The distal end of an appendage moves in a circle |
What is the difference between inversion and eversion? | Inversion is a foot movement that turns the sole medially, TOWARD the other foot. Eversion is a foot movement that turns the sole laterally, AWAY FROM the other foot |
What is the differnce between protraction and retraction? | Protraction moves a part FORWARD. Retraction moves a part BACKWARD |
What are the major anatomical features of the shoulder? | The shoulder is a ball-and-socket joint supported by 5 principal ligaments and 4 bursae. |
What are the major anatomical features of the elbow? | The elbow is a hinge joint consisting of 2 articulations. A single joint capsule encases both. |
What are the major anatomical features of the hip? | The hip is a ball-and-socket joint, but more stable that the shoulder because the hip socket is much deeper |
What are the major anatomical features of the knee? | The knee is the largest and most complex joint in the body. It contains 13 bursae2 collateral ligaments, PCL, ACL, and 2 meniscus |
How do most shoulder dislocations occur? | Result of a downward driving force. The shoulder is the most likely joint to be dislocated and children are especially prone |
How do most knee injuries occur? | The knee is injured more often than the hip. It is especially susceptible to blows or sudden stops or turns. The most common athletic injury. The meniscus and ACL are most frequently injured. Surgery is often necessary; healls slowly or not at all |
What is significant about joint replacement? | Most commonly on the hip and knee; more than 300,000 in the U.S. each year; most often due to osteoarthritis |
What is osteoarthritis? | "Wear-and-tear" arthritis; common effect of aging; affects 85% of people over 70; affects the hips, intervertebral joints, and fingers |
What is rheumatoid arthritis? | Autoimmune disease; antibodies attack the synovial membrane; degeneration of the articular cartilage and thickening of the synovial membrane; pain and joint deformity; fatigue, fever, anemia; no cure |