B.1.3.1 Muscle Tissues (1)

What are the three types of muscles?

skeletal, cardiac and smooth

What are skeletal muscles?

tendons that mostly attach to bone

What is the main function of the skeletal muscle?

to move the skeleton

What are skeletal muscles under?

voluntary control

Skeletal muscle appearance

striated

What are cardiac muscles under?

involuntary control (contract unconciously)

Cardiac muscle appearance

striated

what are some smooth muscle tissues with an example?

lines the walls of blood vessels and hollow organs

What do smooth muscles exert on tendons?

forces which pull on bones

What does this result in?

joint movement

What are smooth muscles under?

involuntary movement

Properties of muscle tissue

contractility, extensibility, elasticity, atrophy, hypertrophy

Contractility

nerve signal for the muscle to contract and create force

How do muscles work?

in pairs

What happens when one muscle contracts?

the other muscle lengthens

Extensibility

muscles can stretch beyond their normal length

Elasticity

muscles can return to their original lengths after being stretches

Atrophy

when body tissue becomes smaller or loses mass

Hypertrophy

when body tissue grows larger in size

Skeletal muscle

.

Epimysium

a thick, protective layer that surrounds the entire muscle

What does the epimysium help protect?

the muscle

What does the epimysium help transfer force to?

the tendons when the muscle contracts

Perimysium

a layer that divides the muscle into bundles called fasicles

What does the perimysium provide?

support

What does the perimysium allow to reach the muscles?

blood vessels and nerves

Endomysium

a thin layer of tissue that surrounds each individual muscle fiber

What does the endomysium help with the exchange of?

nutrients and waste between the muscle fibers and the blood

What is a muscle fiber

long cells with multiple nuclei, filled with structures that allow the muscle to contract and produce movement

Myofibril

rod-shaped structures inside muscle fibers

What is myofibril responsible for?

for muscle contractions

What is myofibril made of?

repeating units called sacromere

Sacromere

smallest unit in a muscle that contracts

What is a sarcomere made up of?

two types of filaments (actin and myosin)

Actin

thin filaments that serve as the 'tracks' for myosin

Myosin

thick filament with heads that attach to actin

What does myosin help with by pulling on actin?

helps with the muscle contraction process