Lab 4 Muscular Tissue & Nervous Tissue (1) Skeletal muscle (No.9) Cardiac muscle (No.10, heart) Smooth muscle (No. 1, small intestine) Neuron (No.11, spinal cord) (Drawing) Note: Next Lab Quiz 1: From beginning to Nervous tissue Jun Zhou（周俊）, Ph.D & M.D School of Medicine, Zhejiang University 20131016

Skeletal muscle Connective tissue coverings (responsible for force transduction): Epimysium: surround the entire muscle Perimysium: surround a muscle bundle Endomysium: surround individual muscle cells Muscle tissue is responsible for movement of the body and its parts and for changes in the size of internal organs. This tissue is characterized by aggregates of specialized, elongated cells arranged in parallel array, whose primary role is contraction. The general organization of skeletal muscle and its relation to the surrounding connective tissue. Note the organization of the endomysium that surrounds individual muscle cells (fibers), the perimysium that surrounds a muscle bundle, and the epimysium that surrounds the entire muscle.

Skeletal muscle: HE X100

Skeletal muscle: HE X100

Skeletal muscle:HEX400 Perimysium Endomysium Muscle fiber Peripherally situated nuclei myofibrils Skeletal muscle:HEX400

Skeletal muscle: HEX400 Long cylindrical cell Multinucleate Dark bands-A Light bands-I At higher magnification, cross-striations of the muscle fibers are readily seen. The nuclei of skeletal muscle fibers are located in the cytoplasm immediately beneath the plasma membrane. Skeletal muscle: HEX400

Cardiac muscle Endocardium Myocardium Epicardium

endocardium Purkinge fibers myocardium

Cardiac muscle:HEX100 Intercalated discs Cross striation Elongated and centrally situated nuclei The arrows point to the intercalated disks. The disks repsent specialized cell-to-cell attachments of the cardiac muscles cells.Also note the apparent branching of the muscle fibers. Cardiac muscle:HEX100

Cardiac muscle:HEX400

Cardiac muscle:HEX400 (cross section) Cap Cardiac muscle:HEX400 (cross section)

Smooth muscle Adventitia Muscular layer Submucosa Mucosa Small intestine: HEX40

Smooth muscle:HEX400 Elongated spindle-shaped cell Centrally situated nucleus No cross striation Cells are elongate and have tapering ends.Note that the nuclei in the longitudinal sectioned muscle cells appear elongate and also exhibit tapering ends, thus matching the shape of the cell. Also note that the longitudinally sectioned muscle cells are not easily delineated from one another, which is on account of the way they lie over one another within the thickness of the section. Smooth muscle:HEX400

Smooth muscle:HEX100 A few cells with nuclei CT betw. fibers In contrast, the nuclei in the cross-sectioned muscle cells are circular in profile.Also, some of the cross-sectioned cells appear to lack a nucleus,a refection that the section passed through one of the ends of the cells. Smooth muscle:HEX100

Nerve tissue: neuron+neuroglia Neuron: gray matter (CNS), ganglia (PNS) Posterior horn The spinal cord is organized into an outer part, the white matter, and an inner part, the gray matter that contains nerve cell bodies and associated nerve fibers. Anterior horn

Motor neuron: HE×400 Multipolar neuron Axon Axon hillock Dendrite Nissl body Motor neuron: HE×400

Motor neuron: HE ×400

The end