Laboratory Exercise 6: Muscle Tissue, Neuromuscular Junction, and Axial Muscles

Vocabulary flashcards covering skeletal muscle tissue histology, microscopic fiber structures, neuromuscular junction components, and axial musculature concepts from Laboratory Exercise 6.

Neuromuscular Junction (NMJ)

The connection between the nervous system and a skeletal muscle fiber, which begins approximately where the axon of the motor neuron widens.

Triad

A muscle fiber structure composed of one transverse (T) tubule and two terminal cisterna on either side.

Sarcomere

The structural unit of skeletal muscle visible in cross section with dark and light bands (striations), spanning from Z-line to Z-line.

Neurolemmocyte

A glial cell of the peripheral nervous system (PNS), also known as a Schwann cell, that forms the myelin sheath around a motor neuron axon.

Motor End Plate

A specialized, modified region of the sarcolemma that forms part of the neuromuscular junction.

M Line

The dark black line running through the center of the dark A-bands of a sarcomere.

Z Line (or Disc)

The dark black line passing through the light I-bands that delineates the boundaries of a sarcomere.

A-Bands

The dark bands visible within the striations of a sarcomere.

I-Bands

The light bands visible within the striations of a sarcomere.

Sarcolemma

The muscle cell plasma membrane.

Sarcoplasm

The cytoplasm of a muscle cell.

Axial Skeletal Muscles

Muscles that have both attachments on parts of the axial skeleton; they support and move the head and spinal column, support and protect abdominal and pelvic organs, and move the face and jaw.

Endomysium

The innermost connective tissue sheath surrounding a muscle cell, labeled as fascia on muscle model A.

Skeletal Muscle Neuromuscular Junction Histology

A microscopic view of striated skeletal muscle fibers showing branching motor neuron axons terminating at synaptic knobs and motor end plates.

Skeletal Muscle Fiber Model A

An anatomical model demonstrating a muscle cell with a neuromuscular junction, showing structures such as the sarcolemma, sarcoplasm, myofibrils, motor end plate, axon terminal, and Schwann cell.

Skeletal Muscle Fiber Model B

An anatomical model showing a cross section of a muscle cell with internal structures including the sarcoplasmic reticulum, terminal cisterna, transverse tubules forming triads, and a neuromuscular junction with synaptic vesicles and a synaptic cleft.