Lesson 6: Articulations

Question 1

From least movement to most movement order the following – amphiarthrosis, synarthrosis, diarthrosis.

Answer 1

Synarthrosis (cant move), Amphiarthrosis (very limited movement), Diarthroses (synovial joints only). Remember…SAD

Question 2

What joint is amphiarthrotic?

Answer 2

Most cartilaginous joints are amphiarthrosis e.g. intervertebral discs, pubic symphysis

Question 3

All fibrous joint are what?

Answer 3

All fibrous joints are connected by fibers and are either synarthrotic or amphiarthrotic.

Question 4

All synovial joints are what?

Answer 4

All synovial joints are diarthrotic

Question 5

Name two uniaxial joints

Answer 5

A hinge and pivot joint are uniaxial – e.g. knee and elbow

Question 6

What are three proprioceptors found in our muscles and joints?

Answer 6

1. Muscle spindles (in the muscles) 2. Golgi tendon organs 3. Pacinian corpuscles (found in tendons)

Question 7

What are bursae and what role do they have within a joint?

Answer 7

Bursa are found around some synovial joints, and are fluid filled sacs that reduce the friction between tendons and other structures around the joint.

Question 8

Name the type of synovial joint and the movement allowed for the Knee.

Answer 8

Hinge – flexion and extension.

Question 9

Name the type of synovial joint and the movement allowed for the Elbow.

Answer 9

Hinge – flexion and extension

Question 10

Name the type of synovial joint and the movement allowed for the Glenohumeral.

Answer 10

Ball and socket – flexion, extension, abduction, adduction, circumduction, rotation.

Question 11

Name the type of synovial joint and the movement allowed for the Intertarsal joints.

Answer 11

Gliding or planar – all directions though only within the plane of the articulating bones i.e. sliding.

Question 12

Name the type of synovial joint and the movement allowed for the Radioulnar joint (proximal or distal).

Answer 12

Pivot – rotates.

Question 13

Name the type of synovial joint and the movement allowed for the Carpometacarpal joint of the thumb.

Answer 13

Saddle – flexion, extension, abduction, adduction, circumduction.

Question 14

Name the type of synovial joint and the movement allowed for the TMJ.

Answer 14

Plane and hinge.

Question 15

Name the type of synovial joint and the movement allowed for the Interphalangeal joints.

Answer 15

Hinge joints – flexion and extension.

Question 16

Explain the following diagram and how it relates to muscle force:

Answer 16

The brain sends down action potentials to a muscle that result in fibers contracting. The faster the action potential is sent, the more force is produced by those fibers. Once there is complete tetanus, a faster firing frequency will not result in a larger force.

Question 17

How can we increase force production in a muscle?

Answer 17

We can send down faster action potentials (ie summation) or we can recruit more fibers (ie recruitment). For maximum force the brain sends down the biggest fastest signal it can. For a very small force it will send down a tiny signal, very slowly. So you get very few fibers firing in incomplete tetanus.