Muscle Tissue (microscopic anatomy)

muscle fiber (cell)

an elongated multinucleated cell with a striated appearance

endomysium

connective tissue that surrounds a muscle fiber

fasicle

bundle of muscle fibers

perimysium

Connective tissue surrounding a fascicle

muscle organ

muscle cells, plus connective tissue wrappings, blood vessels, and nerve fibers

epimysium

surrounds entire muscle

tendon

Connects muscle to bone

nuclei of muscle fiber

multinucleated

sarcolemma of muscle fiber

plasma membrane of a muscle fiber

endomysium of muscle fiber

Connective tissue surrounding a muscle fiber (outermost layer)

sarcoplasmic reticulum of muscle fiber

specialized endoplasmic reticulum of muscle cells

mitochondria of muscle fiber

packed into spaces between myofibrils

myofilaments

The contractile proteins, actin and myosin, of muscle cells

transverse t tubules

Tubules that extend across the sarcoplasm and allow electrical impulses to travel deep into the cell

sarcomere

contractile unit of a muscle fiber

myofibril

tightly packed filament bundles found within skeletal muscle fibers

Z discs

Dark protein (connectin) where thin filaments attach

i bands

light bands

a bands

dark bands

m line

middle of sarcomere

neuromuscular junction

point of contact between a motor neuron and a skeletal muscle cell

motor end plate

the flattened end of a motor neuron that transmits neural impulses to a muscle

motor neuron

a neuron that sends an impulse to a muscle or gland, causing the muscle or gland to react

intercalated disc

part of the sarcolemma that connects cardiac tissue, and contains gap junctions and desmosomes

H zone of sarcomere

contains thick filaments of myosin only

dense bodies in smooth muscle

proteins that anchor filaments to sarcolemma at regular intervals