U3

Question 1

muscles

Answer 1

elongated cells held together by connective tissue
- respond to stimuli by contracting

Question 2

skeletal muscle fibers are attached to

Answer 2

bone and some muscles to skin

Question 3

features of skeletal cells

Answer 3

long cylindrical cells with obvious striation
multi nucleic

Question 4

skeletal cells are regulated under _______ NS

Answer 4

somatic

Question 5

cardiac muscle line

Answer 5

walls of heart

Question 6

features of cardiac muscles

Answer 6

• branching chains of cells
• uninuecleic
• striations
• intercalated discs
• bundles of cardiomyocytes

Question 7

cardiac muscles are regulated by _______ NS

Answer 7

autonomic

Question 8

smooth muscles are found on

Answer 8

walls of organs

Question 9

features of smooth muscles

Answer 9

single fusiform
unineucleic
no striation

Question 10

smooth muscles are regulated by

Answer 10

autonomic NS

Question 11

myofibrils

Answer 11

long rod shaped organelles in muscle fibers each separated into sections called Z-discs

Question 12

sarcomere

Answer 12

region between z-discs

Question 13

thin protein filaments

Answer 13

made of actin
z-discs act as anchors for these

Question 14

myosin

Answer 14

thick filaments made of rod-shaped proteins and angular head (contraction of a muscle = swelling of the head)

Question 15

what happens to z-discs during contractions

Answer 15

they get closer as filaments slide past one another (H-zone disappears)

Question 16

striated appearance is result of thin and thick filaments _________

Answer 16

overlapping

Question 17

I-bands

Answer 17

consist of thin filament on either side of z-disc (light bands)

Question 18

A-bands

Answer 18

both thick and thin filaments overlap in the middle of sarcomere (dark bands)

Question 19

H-zone

Answer 19

centre of A-bands

Question 20

M-line

Answer 20

centre of H-zone

Question 21

skeletal muscles must be stimulated by a _________ _________ for contraction

Answer 21

motor neuron

Question 22

motor unit

Answer 22

1 motor neuron and all of the skeletal muscles it stimulates

Question 23

neuromuscular junction

Answer 23

point of contact between motor neuron and muscle fiber

Question 24

sarcolemma

Answer 24

membrane of muscle fibre

Question 25

skeletal muscle fibres contract only when stimulated by _____ released from ___________

Answer 25

Ach neuromuscular junction

Question 26

what are the steps in the sliding filament theory

Answer 26

- ca release after action potential moves into muscle fiber which triggers sliding of filaments resulting in contraction - allows for myosin filaments to bind to thin filaments exposing active cites on actin - app used to detach myosin from actin allowing cycle to continue