Joints TEST

Question 1

What is a joint?

Answer 1

A joint is a functional junction between bones

Question 2

What is arthrology?

Answer 2

Arthrology is the study of joints

Question 3

What are the three major types of joints (classified by the type of tissue binding the joint)?

Answer 3

1. Fibrous (fibrous connective tissues)
2. Cartilaginous (fibrocartilage connective tissue)
3. Synovial (synovial membrane, and epithelial tissue)

Question 4

Describe the characteristics of fibrous joints and give an example of this type of joint

Answer 4

Fibrous joints are immovable. They have a tiny bit of fibrous connective tissue between the bones they join. Examples of fibrous joints are the sutures of cranial bones.

Question 5

Describe the characteristics of cartilaginous joints and give an example of this type of joint

Answer 5

Cartilaginous joints have tough fibrocartilage connective tissue between the bones they join. They are able to move slightly. Examples of cartilaginous joints include the (1) intervertebral disc and (2) pubic symphysis

Question 6

Describe the characteristics of synovial joints and give an example of this type of joint.

Answer 6

Synovial joints are the most common type of joint in the body and have synovial membranes (an epithelial tissue) lining the joint and secreting synovial fluid. Synovial joints allow free movement. Examples of synovial are the (1) humerus articulating with the glenoid cavity of the scapula, an d(2) the femur articulating with the acetabulum of the hipbone or coxa.

Question 7

What is the basic structure of a typical synovial joint?

Answer 7

1. Have articular cartilage (hyaline cartilage) at the ends of the two articulating bones
2. Have synovial membranes that surround the joint and produce synovial fluid which fills the synovial cavity
3. Have a joint capsule made of heavy connective tissue which surrounds the entire joint to protect and stabilize it
4. Have bursae (outpockets of membranes) to help cushion the joint

Question 8

What are the functions of the synovial joint structures?

Answer 8

1. Articular cartilage is very smooth and reduces friction between the two articulating bones
2. Synovial membranes secrete synovial fluid to fill the synovial cavity and further reduce friction
3. Synovial fluid reduces friction, moistens the cartilage, and nourishes the cartilage (necessary because cartilage has no blood vessels). Normal synovial fluid has the consistency of raw egg white
4. Joint capsule provides stability and protection for the joint
5. Bursae help to cushion the joint

Question 9

What are two characteristics are used to classify synovial joints?

Answer 9

Shape and movement

Question 10

What are the four major types of synovial joints?

Answer 10

1. Hinge joint
2. Ball and socket joint
3. Pivot joint
4. Saddle joint

Question 11

Describe the characteristics and functions of hinge joints and give an example of this type of joint

Answer 11

1. Hinge Joint Characteristics: the convex surface of one bone fits into the concave surface of another bone; can move in only one phase
2. Functions: increases or decreases the angle formed by the joint
3. Examples: elbow and knee

Question 12

Describe the characteristics and functions of ball and socket joints and give an example of this type of joint.

Answer 12

1. Ball and Socket Joint
2. Characteristics: head of one bone fits into depression of another bone; provides the most movement of any joint
3. Functions: provides movement in all planes and provides rotational movement around a central axis
4. Examples: hip (femur in acetabulum of coxa); shoulder (humerus in glenoid cavity of scapula)

Question 13

Describe the characteristics and functions of pivot joints and give an examples of this type of joint.

Answer 13

Pivot Joints

Characteristics: one bone pivots on or around another bones

Functions: provides rotation around a central axis

Examples: head of radius rotating around ulna; atlas
rotating (pivoting) around the dens of the axis)

Question 14

Describe the characteristics and functions of saddle joints and give an example of this type of joint.

Answer 14

Saddle Joint

Characteristics: both bones have concave and convex surfaces (saddle-shaped); concave surface of one bone articulates with concave surface of another bone

Functions: provides movement in two planes

Examples: first metacarpal articulating with the trapezium (a carpal bone)

Question 15

What are the five types of joint movement? (If given an examples, be able to tell which of the types of joint movement is involved.)

Answer 15

Flexion

Extension

Adduction

Abduction

Circumduction

Question 16

Give the function and an example of flexion

Answer 16

Flexion functions to decrease an angle. An example is the biceps contracting and decreasing the angle of the elbow (hinge joint)

Question 17

Give the function and an example of extension

Answer 17

Extension functions to increase an angle. An example is the triceps contracting and increasing the angle of the elbow (hinge joint)

Question 18

Give the function and an example of adduction

Answer 18

Adduction functions to bring a limb toward the midline of the body. An example of the medial adductor muscle in the thigh contracting which functions to bring the thigh toward the midline of the body.

Question 19

Give the function and an example of abduction

Answer 19

Abduction functions to move a limb away from the midline of the body. An example is the deltoid muscle contracting to take the arm away from the midline

Question 20

Give the function and an example of circumduction

Answer 20

Circumduction functions to make a circular motion. An example is the arm moving in a circle

Question 21

How does dorsiflexion differ from plantar flexion?

Answer 21

Dorsiflexion involves tilting the foot upward at the ankle while plantar flexion involves titling the foot down and back at the ankle

Question 22

How does circumduction differ from rotation?

Answer 22

Circumduction involves making a circular movement while rotation involves rotation around a central axis

Question 23

What are four joint disorders discussed in class?

Answer 23

Osteoarthritis and rheumatoid arthritis

Bursitis

Gout

Sprains

Question 24

To what does the term arthritis refer?

Answer 24

Inflammation of the joints

Question 25

What causes osteoarthritis and what are its symptoms?

Answer 25

Osteoarthritis is the most common form of arthritis. It is initially triggered by a trauma (injury). This results in destruction of articular cartilage which causes bone to move against bone. Also, the synovial fluid has decreased viscosity. All this makes it more difficult for the bones associated with the joint to move properly. Symptoms are extreme pain and immobility

Question 26

What causes rheumatoid arthritis and what are its symptoms?

Answer 26

Rheumatoid arthritis starts with a disorder of the immune system which can be brought about by emotional stress. It results in inflammation of the synovial membrane. The membrane then secretes more synovial fluid, causing joints to swell. Symptoms are swelling, extreme pain, and immobility

Question 27

What causes bursitis and what are its symptoms?

Answer 27

Bursitis is inflammation of the bursae, or membrane sacs which cushion joints. It commonly occurs in hips, shoulders, and knees when they are overused. Symptoms are extreme pain. (an example is lots of walking can inflame the bursa between the calcaneus bone and the achilles tendon. Another example is tennis elbow cause by inflammation of bursa between the olecranon process of the radius and the skin.)

Question 28

What causes gout and what are its symptoms?

Answer 28

Gout is an accumulation of uric acid crystals in the joints, commonly the big toe. It occurs due to the inability of the body to break down purines, so diet plays a role in gout. Gout is also more prevalent in males. Symptoms are extreme pain and immobility. Fresh cherries and fresh pineapple are often eaten to relieve the symptoms of gout

Question 29

What causes sprains and what are their symptoms?

Answer 29

Sprains are caused when connective tissues around the joints (cartilage, ligaments, tendons) become overstretched or torn. It is often caused by twisting. Symptoms are swelling, extreme pain, and immobility

Question 30

Are disorders of the joints a relatively new occurrence?

Answer 30

No. Fossilized remains of a Tyrannosaurus rex showed signs of gout and a 500,000 year old skeleton with osteoarthritis has been found.