Muscular System

Question 1

muscular system

Answer 1

responsible for all types of body movement

providing support, stabilizing joints, and generating heat for the body

Question 2

muscle fibers

Answer 2

specialized muscle cell

contract to facilitate body movement

Question 3

Cardiac muscle

Answer 3

striated, short, and branched

one nucleus, are branched, and are rectangular.

contraction involuntary

found in walls inside heart

Question 4

Skeletal muscle

Answer 4

striated, long, and cylindrical

many nuclei in a skeletal muscle cell

attached to bones in skeletal system

muscle contracts voluntarily

Question 5

Smooth muscle

Answer 5

consists of non-striated muscle cells that are spindle-shaped

one nucleus

found in the walls of internal organs like the bladder and stomach

involuntary

Question 6

endomysium (tissue, skeletal muscle)

Answer 6

encases individual skeletal muscle fibers

Question 7

perimysium (tissue, skeletal muscle)

Answer 7

connective tissue that bundles muscle fibers together

Question 8

fascicle

Answer 8

Bundles of skeletal muscle fibers

Question 9

epimysium (tissue, skeletal muscle)

Answer 9

connective tissue that binds Each fascicle together

Question 10

sarcolemma

Answer 10

cell membrane that surrounds a skeletal muscle fiber

Question 11

sarcoplasm

Answer 11

cytoplasm of the skeletal muscle fiber

Question 12

myofibrils

Answer 12

One muscle fiber is filled with several long, cylindrical proteins

the contractile units of the fiber

Question 13

sarcomere

Answer 13

smallest contractile unit in a myofibril

Question 14

myofilaments

Answer 14

proteins that make up a myofibril

Question 15

myosin (myofilaments)

Answer 15

protein molecules that make up thick band myofilaments

Question 16

actin (myofilaments)

Answer 16

protein molecules that link together to form thin bands

Question 17

M line

Answer 17

center of sacromere

Question 18

A-band

Answer 18

Thick and thin filaments

Question 19

I-band

Answer 19

Thin filaments only

Question 20

Z-line

Answer 20

Actin filament attachment site

Question 21

H-band

Answer 21

Thick filaments only

Question 22

Slide filament theory

Answer 22

explains muscle contraction. According to this theory, actin filaments slide past myosin filaments, pulling the actin filaments closer to the center of the sarcomere, or M line

Question 23

crossbridges

Answer 23

attachments of actin and myosin

Question 24

sarcoplasmic reticulum

Answer 24

surrounds myofibrils

Question 25

ATP process

Answer 25

With the help of energy in the form of ATP

• myosin heads are energized to attach to binding sites in actin and form a crossbridge.
• After energy in the myosin head is released, the myosin pulls actin myofilaments closer to the M line.
• This head can only form another crossbridge when another molecule of ATP attaches to the head, reenergizing it.

Calcium also plays an important role in determining when contraction happens.

Question 26

Ligaments

Answer 26

bones to bones

Question 27

joint

Answer 27

formed where ligaments connect bones

Question 28

Immovable

Answer 28

fibrous joints, these consist of bones held together by connective tissues

bones are in very close contact

Exp: immovable joint is the intersection of cranial bones in the skull

Question 29

Partly movable

Answer 29

cartilaginous joints, these consist of bones held together by cartilage

joints allow some degree of movement

movable joints include the vertebral discs in the spine

Question 30

Synovial

Answer 30

allow the largest freedom of movement because the bones are separated by a joint cavity

Exp: synovial joints are the hip and shoulder

Question 31

Tendons

Answer 31

attach muscle to bone

consist of tough connective tissue that is found on either side of the joint where two bones are connected

work with skeletal muscles to move bones

Question 32

flexor

Answer 32

muscle that causes a joint to bend

Question 33

extension muscle

Answer 33

muscle that contracts and causes a joint to straighten