AnaPhy - Muscular System

The muscular system

Muscles are responsible for all types of body movement – they contract or shorten and are the machine of the body

Skeletal muscle, Cardiac muscle, Smooth muscle

Three basic muscle types are found in the body

Elongated

muscles are?

muscle cell

muscle fiber

Microfilaments

Contraction of muscles is due to the movement of

Muscle

Prefix myo refers to?

Muscle

Prefix mys

sarco

flesh

tendons to bones

most skeletal muscle are attached by?

multinucleate

cells are

Striated

have visible banding

Voluntary

subject to conscious control

connective tissue

Cells are surrounded and bundled by?

Endomysium

around single muscle fiber

Perimysium

around a fascicle (bundle) of fibers

Epimysium

covers the entire skeletal muscle

Fascia

on the outside of the epimysium

Epimysium

it blends into a connective tissue attachment

tendon

cord-like structure

Aponeuroses

sheet-like structure

smooth muscle

has no striations

spindle

shaped cells

smooth muscle

has single nucleus

Involuntary

no conscious control

Smooth muscle

Found mainly in the walls of hollow organs

smooth muscle

Slow, sustained and tireless

Cardiac muscle

has striations

Cardiac muscle

Usually has a single nucleus

Cardiac muscle

Joined to another muscle cell at an intercalated disc

Cardiac muscle

It is involuntary

Smooth muscle

voluntary

Cardiac Muscle

Found only in the heart

Cardiac Muscle

in a steady pace

Functions of muscle

Produce movement ∙ Maintain posture ∙ Stabilize joints ∙ Generate heat

Nuclei

are just beneath the sarcolemma

Sarcolemma

specialized plasma membrane

Sarcoplasmic reticulum

specialized smooth endoplasmic reticulum

Myofibril

Bundles of myofilaments

Myofibrils

are aligned to give distrinct bands

I band

Light band

A band

Dark band

Sarcomere

Contractile unit of a muscle fiber

Thick Filaments

myosin filaments

Microscopic Anatomy of Skeletal Muscle

Organization of the sarcomere

Thick filaments

Composed of the protein myosin

Has ATPase enzymes

Thin Filaments

Actin Filaments

Thin filaments

composed of protein actin

True

TRUE OR FALSE - Myosin filaments have heads (extensions, or cross bridges)

True

TRUE OR FALSE - Myosin and actin overlap somewhat

Myosin Head

has ATP & actin binding site

Irritability

the ability to receive and respond to a stimulus

Contractility

ability to shorten when an adequate stimulus is received

Motor Neuron

Skeletal muscles must be stimulated by a nerve to contract

Motor Unit

∙One neuron

∙Muscle cells stimulated by that neuron

Neuromuscular junctions

association site of nerve and muscle

Synaptic cleft

gap between nerve and muscle

Neurotransmitter

chemical released by nerve upon arrival of nerve impulse

acetylcholine

The neurotransmitter for skeletal muscle is