4.2 Key Terms

Question 1

Afferent neurons

Answer 1

Nerve cells that carry impulses towards the central nervous system

Question 2

Cardiac muscle

Answer 2

Striated muscle fibers (cells) that form the wall of the heart; stimulated by the intrinsic conduction system and autonomic motor neurons

Question 3

Carpal tunnel syndrome

Answer 3

Condition caused by compression of the median nerve in the carpal tunnel and characterized especially by weakness, pain, and disturbance of sensation in the hands and fingers

Question 4

Contract

Answer 4

To shorten and thicken

Question 5

Efferent neurons

Answer 5

Nerve cells that conduct impulses away from the central nervous system

Question 6

Endomysium

Answer 6

Delicate connective tissue surrounding the individual muscular fibers within the smallest bundles

Question 7

Epismysium

Answer 7

External connective-tissue sheath of a muscle

Question 8

Fascicle

Answer 8

Small bundle or cluster, especially of nerve or muscle fibers

Question 9

Insertion

Answer 9

Attachment of a muscle tendon to a moveable bone or the opposite of the origin

Question 10

Muscle

Answer 10

Organ composed of one of the three types of muscular tissue (skeletal, cardiac, and smooth), specialized for contraction to produce voluntary and involuntary movements of parts of the body

Question 11

Myofibril

Answer 11

Threadlike structure, extending longitudinally through a muscle fiber (cell) consisting mainly of think filaments (myosin) and thin filaments (actin, troponin and tropomyosin)

Question 12

Myosin

Answer 12

Contractile protein that makes up the thick filaments of muscle fibers

Question 13

Nerve

Answer 13

Cordlike bundle of neuronal axons and/or dendrites and associated connective tissue coursing together outside the central nervous system

Question 14

Origin

Answer 14

Attachment of a muscle tendon to a stationary bone or the end opposite the insertion

Question 15

Perimysium

Answer 15

Connective- tissue sheath that surrounds a muscle and forms sheaths for the bundles of muscle fibers

Question 16

Plexus

Answer 16

Network of interlacing blood vessels or nerves

Question 17

Rigor mortis

Answer 17

Temporary regidity of muscles occurring after death

Question 18

Sarcomere

Answer 18

Any of the repeating structural units of striated muscle fibrils

Question 19

Skeletal muscle

Answer 19

Organ specialized for contraction, composed of striated muscle fibers (cells), supported by connective tissue, attached to bone by a tendon or aponeurosis, and stimulated by somatic motor neurons

Question 20

Sliding filament mechanism

Answer 20

The explanation of how thick and thin filaments slide relative to one another during striated muscle contraction to decrease Sarcomere length

Question 21

Smooth muscle

Answer 21

Tissue specialized for contraction, composed of smooth muscle fibers (cells), located in the walls of hollow internal organs, and innervated by the automatic motor neurons

Question 22

Striation

Answer 22

Any of the alternate dark and light cross bands of a myofribil of striated muscle

Question 23

Tropomyosin

Answer 23

Protein of muscle that forms a complex with troponin regulating the interaction of actin and myosin in muscular contraction

Question 24

Troponin

Answer 24

Protein of muscle that together with tropomyosin forms a regulatory protein complex controlling the action of actin and myosin and that when combined with calcium ions permits muscular contractions

Question 25

Actin

Answer 25

Contractile protein that's part of the thin filaments in muscle fibers