JOINTS & MUSCLE

Question 1

Motor Unit Description

Answer 1

Smallest function unit of muscle;

Alpha motor neuron + ALL muscle cells innervated by it

Question 2

Muscle cells contract in this matter

Answer 2

“All or nothing” contraction

Question 3

Define types of muscle contraction

Answer 3

Concentric - muscle shortens
Isometric - muscle length remains constant
Eccentric - controlled muscle lengthening

Question 4

Types of Joints

Answer 4

Fibrous - immobile, limited movement joint (teeth)
Cartilaginous - more movable with cartilage (intervertebral disks)
Synovial - facilitates movement, reduces friction (GHJ ball&socket)

Question 5

Describe what occurs in osteoarthritis

Answer 5

Articular cartilage between bones degenerate leading to pain and limited movement

Question 6

Compare the insertion to the origin of a muscle

Answer 6

Insertion - the relative more mobile bone attachment of a muscle
Origin - relatively more stable bone attachment

Question 7

The best muscle for a particular action is oriented _______ between the joint axis and applied force allowing for maximal _________

Answer 7

90 Degrees;

Torque