Exercise 10Exercise 10Muscle histology

Muscle TypesMuscle TypesSkeletal –

attached to bone by tendons is responsible for voluntary movements.

Cardiac- located in heart

Smooth- located in the walls of internal organs, blood vessels, and airways

Skeletal muscle fibersSkeletal muscle fibersConnective tissue

layers:Epimysium-

around the entire muscle

Perimysium surrounds bundle of muscle fibers (fascicle)

Endomysium-surrounds each muscle fiber

Skeletal muscle cont.Skeletal muscle cont.Striations in

appear because of alternating light and dark bands from the arrangement of the thick and thin protein filaments called myofibrils.

Skeletal muscleSkeletal muscle

Cardiac muscleCardiac muscleForms branching

networks.StriatedLinked together

by intercalated discs

Smooth MuscleSmooth MuscleWidest in middle

and tapered toward each end.

Single nucleus

Cell structure of skeletal Cell structure of skeletal musclemuscleActin- main

component of thin filaments.

Myosin- main component of thick filaments

Together these are called myofilaments which are packaged into parallel bundles called myofibrils.

Structure of a skeletal Structure of a skeletal muscle fibermuscle fiber

Structure of a skeletal Structure of a skeletal muscle fibermuscle fiber

Sarcolemma or cell membrane

T-tubules-continuous with the sarcolemma and travel into the cytoplasm

Sarcoplasmic reticulum-SER

Cisternae- saclike extensions of the SR

Neuromuscular JunctionsNeuromuscular JunctionsSynaptic

terminal- the expanded knob at the end of the nerve fiber

Motor end plate-the region of the sarcolemma associated with the neuromuscular junctions.

Synaptic cleft- narrow space between the cell membrane

The EndThe EndView the different types of

muscle under the microscope.Be able to ID the various terms

on models, pictures or on slides