Histology Guide

virtual histology laboratory

Chapter 4 - Muscle Tissue

Muscle cells (also known as muscle fibers) synthesize and maintain the contractile function of connective tissue. Three types of muscle are recognized based on their distinctive structural and functional features: skeletal, cardiac and smooth muscle.

Skeletal and cardiac appear straited because of the parallel arrangement of contractile filaments appear as an alternating series of transverse bands. Smooth muscle appears non-straited because of the less ordered array of contractile filaments.

Skeletal Muscle

Skeletal muscle is composed of large, multinucleated cells with the nuclei located at the periphery. The parallel arrangement of contractile filaments produces striations of alternating transverse bands. Light microscopy can resolve these bands.

MH 055a Skeletal Muscle

(longitudinal and cross section)

MH 055ahr Skeletal Muscle

(longitudinal section)

MHS 237 Skeletal Muscle

(longitudinal section)

MHS 262 Skeletal Muscle

(cross section)

Skeletal Muscle Fibers

MHS 238 Teased Muscle

Muscle Insertion

A muscle insertion is where muscle fibers connect to a tendon attached to a bone.

MH 030 Tendon

MH 023bx Fascia Lata

MH 029b Bone

Cardiac Muscle

Cardiac muscle is composed of branched, mononuclear cells (occasionally bi-nucleate) with the nuclei located in the center of the cell. The cells show the same striations as skeletal muscle.

MH 054 Cardiac Muscle

(longitudinal and cross sections)

MH 056 Muscle Types

(phosphotungstic acid)

Purkinje Fibers

Purkinje fibers are specialized cardiac muscle cells that convey electrical impulses that coordinate cardiac muscle contraction.

MH 058a Heart

(periodic acid-Schiff's stain)

MH 074 Heart

(phosphotungstic acid)

Smooth Muscle

Smooth muscle contains the same contractile proteins (actin and myosin) as skeletal and cardiac muscle, but the less ordered array of contractile filaments does not produce striations.

MH 053 Smooth Muscle

MH 024 Mesentery

MH 016x Small Intestine

MH 130a Gallbladder