lab 4

Question 1

motor unit recruitment

Answer 1

an increace in the strength or force of the muscle contraction caused by an increase in the number of active motor units

Question 2

skeletal muscle

Answer 2

excitable tissue in that an action potential is generated along the plasma membrane of muscle cells

Question 3

neuromuscular junction

Answer 3

specialized synapse where motor neurons release neurotransmitters

Question 4

in vertebrates

Answer 4

motor neurons always excite muscle fibres

Question 5

skeletal muscle contraction under

Answer 5

voluntary control by the CNS

Question 6

movement of limbs accomplished by

Answer 6

coordinating the contraction and relaxation of antagonistic muscle groups

Question 7

tendons

Answer 7

used to attach muscles to bones

Question 8

electromyogram

Answer 8

recording of muscle activity

Question 9

electromyogram accomplished by

Answer 9

placing recording electrode on skin overlying muscle group

Question 10

electromyogram provides

Answer 10

important information about regulation and control of limb movement

Question 11

muscle spindles

Answer 11

mechanosensory receptors responsible for providing information about the length or rate of change of the length of a muscle

Question 12

muscle spindles stretched when

Answer 12

external force stretches muscle

Question 13

muscle spindles involve

Answer 13

large diameter sensory axons, contain small number of synapses in circuit

Question 14

when motor neurons are stimulated

Answer 14

they trigger contraction of the same muscle group

Question 15

calf muscle group composed of

Answer 15

gastrocnemius

Question 16

achilles tendon

Answer 16

located above heel and connect gastrocnemius muscle to tarsal bone of foot

Question 17

planar flexion

Answer 17

downward movement of foot

Question 18

dorsiflexion

Answer 18

upward movement of foot

Question 19

strength of striated muscle contraction depends on

Answer 19

amount of electrical activity in muscle

Question 20

vertebrate skeletal muscle

Answer 20

made up of groups of muscle fibres that are innervated by motor neurons