muscular system overview

Question 1

general functions of muscle tissue

Answer 1

movement, stability (joint stabilization + posture), control of openings and passages, heat production, hormone secretion (stimulate synthesis of glucose), glycemic control (stores glucose)

Question 2

major functions of muscle tissue

Answer 2

excitability (sensitvity to stimulus)
elasticity (stretch and recoil)
extensibility (ability to stretch)
contractibility (ability to shorten)
conductivity

Question 3

skeletal muscle general location and characteristics

Answer 3

–> located where tendons connect to bone
–> striated, multinucleated on sides of cell, long unbranched fibers, voluntary action

Question 4

smooth muscle general location and characteristics

Answer 4

–> located in walls of hollow organs (bladder, stomach, airways)
–> not striated, single nucleus, small spindle shaped fibers, involuntary action

Question 5

cardiac muscle general location and characteristics

Answer 5

–> located in heart
–> striated, single nucleus, branched fibers (intercalated discs), involuntary action

Question 6

function of skeletal muscle

Answer 6

contraction of muscles that allow for movement of body

Question 7

function of cardiac muscle

Answer 7

contraction of heart

Question 8

function of smooth muscle

Answer 8

contraction of muscles that helps with digestion and breathing

Question 9

organization of skeletal muscle (cell to whole muscle)

Answer 9

sacromeres –> myofibrils –> muscle fiber –> facile –> whole muscle

Question 10

sacromeres

Answer 10

functional unit of muscle

Question 11

myofibrils

Answer 11

made of sarcomeres gives striated appearance

Question 12

muscle fiber

Answer 12

individual cell that contains organelles (mitochondria), striated appearance

Question 13

whole muscle

Answer 13

includes blood vessels and nerves to distribute nutrients to muscles

Question 14

connective tissue layers that surround each skeletal muscle fiber

Answer 14

myofibrils –> endomysium (areolar CT)
muscle fiber –> perimysium (dense irregular CT)
facile –> epimysium (dense irregular CT)

Question 15

sarcolemma

Answer 15

cell membrane that surrounds muscle fibers

Question 16

transverse tubules

Answer 16

infoldings of the sarcolemma that runs between terminal cisterns (triads)
–> allow for nerve stimulation

Question 17

sarcoplasmic reticulum

Answer 17

specialized smooth ER that weaves around each myofibril
–> stores calcium

Question 18

thick (myosin) filament

Answer 18

consists of myosin molecules with heads protruding at opposite ends of filament

Question 19

thin (actin) filament

Answer 19

two strands of actin twisted into a helix and two regulatory proteins

Question 20

troponin

Answer 20

helps position tropomyosin and binds calcium ions
–> when it binds it exposes binding site for myosin to attach

Question 21

tropomyosin

Answer 21

stabilizes actin and blocks myosin binding sites to prevent constant contraction

Question 22

components of sarcomere

Answer 22

a-band, i-band, h-zone, z-disc, m-line

Question 23

a- band

Answer 23

overlap of actin and myosin which remains the same size during contraction (6:1)

Question 24

i-band

Answer 24

ACTIN ONLY
–> small during contraction

Question 25

h-zone

Answer 25

MYOSIN ONLY
–> disappears completely during contraction

Question 26

z-disc

Answer 26

one length of sarcomere from one z disc to another
–> get closer during contraction

Question 27

m-line

Answer 27

center point where everything is pulled towards