9 Recall and understanding

4 In the condition synovitis the synovial membrane secretes excess synovial fluid. How might this affect the function of a synovial joint?

- Excess synovial fluid fills the joint cavity - this decreases that range of motion

2 Could a fibrous joint perform its functions if it were a diarthrosis? Explain your reasoning.

- Fibrous joints provide stability between two bones - diarthrosis joints are freely moveable joints with little stability - this joint is most likely non-functional

3 Which class of synovial joint do you think would be the most stable? Which class would be the least stable? Explain your choices.

- Plane joints are the most stable as they have the least range of motion. - Ball and socket joints are the least stable joint as they have the greatest range of motion

Compare and contrast circumduction and rotation.

- Rotation is twisting of a bone around its own axis - circumduction movement of a bone in a circular motion, through multiple axes.

5 Your friend is on the basketball court when she is pushed over the leg of a fallen player and lands on the court on her bent knee. She tries to get up, but immediately realizes something is wrong. The trainer examines her knee and finds excessive motion with the posterior drawer test. What has happened? Explain the results of the posterior drawer test.

- injury to the posterior cruciate ligament - the posterior draw test is positive - the tibia is allowed to move too far backward, or posteriorly on the femur

1 How would the function of synovial joints be changed if they lacked joint cavities? Explain.

- joint cavities allow for an increase range of motion - Without joint cavity, bones are fibrous or cartilaginous and have a less range of motion. - Joint is not freely moveable

When the shoulder joint dislocates, it most commonly dislocates posteriorly, meaning that the joint capsule tears on the posterior side and the head of the humerus pushes partly out through the capsule. Why do you think the posterior capsule more commonly tears? (Hint: Consider the structure of the capsule and look at the ligaments of the shoulder joint.)

- the anterior portion of the capsule has the fewest supporting structures.

4 Which of the following describes a hinge joint correctly?

A. The convex articular surface of one bone fits into a concave articular surface of another bone.

True/False: Mark the following statements as true (T) or false (F). If the statement is false, correct it so it is a true statement. Bursae improve the fit between two bones in a synovial joint.

FALSE - articular discs....

True/False: Mark the following statements as true (T) or false (F). If the statement is false, correct it so it is a true statement. Articular discs provide a smooth, nearly frictionless surface for articulation.

False Articular cartilage provides

True/False: Mark the following statements as true (T) or false (F). If the statement is false, correct it so it is a true statement. Fluid-filled sacs called ligaments often lie between tendons and the joint capsule of a synovial joint.

False- Fluid filled sacs are bursa

True/False: Mark the following statements as true (T) or false (F). If the statement is false, correct it so it is a true statement. The articulating ends of the bones in a synovial joint are covered by articular cartilage.

TRUE

True/False: Mark the following statements as true (T) or false (F). If the statement is false, correct it so it is a true statement. The joint capsule of a synovial joint is lined with a synovial membrane.

TRUE

How do nonaxial, uniaxial, biaxial, and multiaxial synovial joints differ?

These are synovial joints. They differ in the number of axes motion of bones. Nonaxial do not move on an axis; uniaxial move around a single axis, biaxial is on two axis and multi axial is on multiple axes.

7 Which of the following correctly describes a pivot joint? a. The convex articular surface of one bone fits into a concave articular surface of another bone. b. One bone rotates around another bone. c. The flat articular surfaces of two bones glide past one another. d. The rounded,ball-like end of one bone fits into a concave depression of another bone.

b. One bone rotates around another bone.

3 Synovial joints are surrounded by a/an ______________________ and filled with ______________________. a articular disc; serous fluid b. joint capsule;synovial fluid c. articular cartilage; serous fluid d. articular disc; synovial fluid

b. joint capsule; synovial fluid

2 The main function of a fibrous joint is to a. allow motion to occur between two bones. b. provide stability between two bones. c. unite two bones with cartilage. d. allow some motion while still providing stability between two bones. e. unite two bones with a synovial cavity.

b. provide stability between two bones.

1. An amphiarthrosis is defined as a a. joint that allows no motion. b. joint that is freely moveable. c. joint with multiple axes of motion. d. joint that allows some motion.

d. joint that allows some motion.