Muscle tissue types - Department of Animal Science

Muscle tissue types• Skeletal– Striated– Elongated cells– Multinucleated cells– Voluntary• Cardiac (Heart)– Striated– Branched cells– 1-3 central nuclei– Involuntary• Smooth– Nonstriated– Single central nucleus– InvoluntarySkeletal MuscleCardiac MuscleSmooth Muscle

Light Micrograph of Skeletal Muscle

Electron Micrograph of Skeletal MuscleFrom: http://www.siumed.edu/~dking2/ssb/EM007b.htm

Light Micrograph of Cardiac MuscleFrom Dr. Gwen Childs, Department of Anatomy and Neurobiology, University ofArkansas for Medical Sciences, taken from Cytochemistry.net, athttp://www.cytochemistry.net/microanatomy/muscle/striated_cardiac_muscle.htm

Cardiac Muscle StructureLight micrograph of mammalian cardiac muscle,showing individual cells and centrally located nuclei

Electron Micrograph of Cardiac MuscleFrom U.C. Davis Medical Histology Website

Smooth Muscle• H&E Stained muscularisexterna = muscle layerof intestine• Spindle-shaped, mononucleatedcells– 5-10 μm in diameter– 30-200 μm long• Centrally-located nucleiFrom the Boston UniversityHistology Learning System, at:http://www.bu.edu/histology/m/index.htm

EM of Smooth MuscleFrom the Boston University Histology Learning System, at:http://www.bu.edu/histology/m/index.htm

Structure of arteries vs. veins

• ContinuousTypes of capillaries– Endothelial cell layeris continuous– In most tissues,e.g., brain, muscle• Fenestrated– Holes or filtration pores inendothelial layer– In tissues that do rapidabsorption or filtration, e.g.kidney, small intestine,endocrine glands