Spinal Control of Movement

Question 1

What is the Motor System?

Answer 1

the motor system consists of all our muscles and neurons that control them

Question 2

Who is Charles Sherrington?

Answer 2

(1) discovered that behavior requires coordinated action of various combinations of muscles
(2) observed in cats and dogs rhythmic movement in legs after spinal cord had been severed

Question 3

What is motor control?

Answer 3

(1) the spinal cord’s command and control of coordinated muscle
(2) the brain’s command and control of motor programs in the spinal cord

Question 4

What is the peripheral somatic motor system?

Answer 4

joints, skeletal muscles, and spinal motor neurons and interneurons

Question 5

What are the two types of muscle?

Answer 5

Smooth and striated

Question 6

What is smooth muscle?

Answer 6

• lines the digestive tract, arteries, and related structures
• innervated by nerve fibers from ANS
• plays a role in peristalsis
• control of blood pressure and blood flow

Question 7

What are the two types of striated muscle?

Answer 7

Cardiac and skeletal

Question 8

What is the function of a cardiac muscle?

Answer 8

• the heart muscle which contracts rhythmically, even in the absence of innervation
• innervation of the heart comes from the ANS
• functions to accelerate or slow down heart rate

Question 9

What is the function of a skeletal muscle ?

Answer 9

• skeletal muscles constitute the bulk of muscle mass in the body
• functions to move bones around joints
• moves eyes within head
• to inhale and exhale
• control facial expression
• produce speech
• enclosed in connective tissue sheath that, at the ends of muscle, forms tendons
• innervated from single axon branch from the CNS

Question 10

What are muscle fibers?

Answer 10

cardiac, smooth, and skeletal muscles, within each muscle there are hundreds
-the cells of skeletal muscle, and each fiber is innervated by a single axon branch from the CNS

Question 11

What are these muscles and parts of the nervous system called?

Answer 11

the Somatic Motor System

Question 12

Describe the Elbow Joint

Answer 12

• the joint is formed where the humerus (the upper arm bone) is bound by fibrous ligaments to the radius and ulna (the bones of the lower arm)
• the joint functions like a HINGE on a pocket KNIFE

Question 13

What is flexion?

Answer 13

movement in the direction that closes the knife

Question 14

What is extension?

Answer 14

movement in the direction that opens the knife

Question 15

What are the muscles that cause flexion?

Answer 15

1. the brachialis (tendons insert into the humerus at one end and the ulna at the other)
2. the biceps brachii
3. the coracobrachialis

Question 16

What are the muscles called that cause flexion?

Answer 16

Flexors

Question 17

What are flexors called when they work together?

Answer 17

Synergists

Question 18

What are the two synergistic muscles that cause extension?

Answer 18

1. Triceps brachii

2. Anconeus

Question 19

What are the triceps brachii and anconeus called?

Answer 19

Extensors

Question 20

Because flexors and extensors pull on the joint in different directions, what are they called?

Answer 20

Antagonists

Question 21

What does relaxing the antagonists do?

Answer 21

allows movement to be faster and more efficient because the muscles are not working against one another

Question 22

What are axial muscles?

Answer 22

muscles responsible for movement of the trunk

Question 23

What are proximal (girdle) muscles)

Answer 23

muscles that move the shoulder, elbow, pelvis, and knee

Question 24

What are distal muscles?

Answer 24

muscles that move the hands, feet, and digits (fingers and toes)

Question 25

What does the axial musculature do?

Answer 25

maintains posture

Question 26

What does the proximal musculature do?

Answer 26

locomotion

Question 27

What does the distal musculature do?

Answer 27

particularly of the hands, specialized for manipulation of objets