Muscles And Joints Lecture

Question 1

A motor unit consists of

Answer 1

Motor neuron and ALL muscle cells innervated by it

Question 2

Concentric contraction: muscle ______, _____ movement

Answer 2

Concentric contraction: muscle SHORTENS, CAUSES movement

Question 3

Isometric contraction: muscle _____, ____ movement, often _____ _____

Answer 3

Isometric contraction: muscle LENGTH REMAINS CONSTANT, PREVENTS movement, often RESISTING GRAVITY

Question 4

Eccentric contraction: muscle _______, _____ movement, often ____ ______.

Answer 4

Eccentric contraction: muscle LENGTHENS, CONTROLS movement, often RESISTS GRAVITY.

-Gross muscle lengthens as gradually fewer cells contract

Question 5

Fixed end of muscle= _____ and moveable end of muscle= _______. _____ moves toward _____

Answer 5

Fixed end of muscle= ORIGIN and moveable end of muscle= INSERTION. INSERTION moves toward ORIGIN

Question 6

Upper and lower fibers of trapezius cause _____ ____ of scapula. The middle fibers cause ______.

Answer 6

Upper and lower fibers of trapezius cause UPWARD ROTATION of scapula. The middle fibers cause RETRACTION.

Question 7

____ angle formed between vector and axis is the most effective for a particular movement.

Answer 7

PERPENDICULAR angle formed between vector and axis is the most effective for a particular movement.