Muscle Tissues Histology

Franklin College A & P 210 Muscle Tissue Histology

Muscle Tissue Exerts Force specialized for

converting ATP into mechanical energy of motion

Movement functions as

Locomotion, internal movements, and communication

Stability functions as

Maintain posture, stabilize joints, and produces force against gravity

Control functions as

Openings/passageways (sphincters) and glycemic control

Heat Protection controls as

Shivering, goosebumps, 30% of body heat is produced by skeletal muscles

Excitability

Able to respond to stimuli by changing membrane potential (voltage)

Conductivity

Able to host waves of electrical excitation that travel along fibers

Contractility

Shorten when stimulated

Extensibility

Able to be stretched

Elasticity

Able to return to original resting length after being stretched

Muscles need blood supply to survive

The arteries bring in the blood, the veins drain the blood and bring the blood back into the heart which then goes into the lungs and back into the body for use

Muscles need nerve supply to move

Nerves innervate muscle cells to provide electrical stimulation, and without this stimulation, the cells undergo atrophy

Skeletal Muscle

Associated with bones; voluntary, multinucleated, striated

Cardiac Muscle

Found in the heart; involuntary, mononucleated, striated with intercalated disks

Smooth Muscle

Found in blood vessels and many organs; involuntary, mononucleated, not striated

Myofibers

Another word for skeletal muscle cells, also called muscle fibers

Myofibers are innervated by

Somatic motor neurons and feature specialized organelles and fatigue relatively quickly

Cardiomyocytes

Cardiac muscle cells that are shorter and less fibrous than myofibers; innervated by automatic nerve fibers and highly resistant to fatigue

Smooth Muscle Cells

Fusiform shape rather than long and fibrous with slower, longer contractions that are less quick to fatigue; innervated by automatic nerve fibers; line hollow organs and involved in control and internal movements