Muscular tissue is composed of specialized cells involved in contraction. Skeletal muscle makes up body muscles and represents around 40 percent of the body mass. Skeletal muscle is striated and the fusion of individual cells produces longer, mature cells that are multinucleate. These nuclei are found on the edges of the cells. Skeletal muscle can be consciously controlled and is called voluntary muscle. Label and color the striations of the skeletal muscle cells, the nuclei, and individual cells.

Cardiac muscle is also striated but the striations are not as obvious as in skeletal muscle. This muscle is found in the heart and is involuntary. It does not involve conscious control. Cardiac muscle typically has only one centrally located nucleus per cell, and the cells themselves are branched. They attach to other cells by intercalated discs, which allow communication between cells for the conduction of impulses during the cardiac cycle. Label and color these features on the illustration.

Smooth muscle is not striated and it is involuntary. The cells are slender and have one nucleus located in the center of the cell. It is widely distributed in the body, making up, among other things, part of the digestive system, reproductive system, and integumentary system. Smooth muscle is found in glands and other areas not under conscious control. Label and color the nucleus and cell of smooth muscle.

Nervous tissue consists of the neuron and associated glial cells. Neurons have numerous branched extensions called dendrites, a central nerve cell body (soma) that houses the nucleus, and a long extension called an axon. The glial cells, also known as neuroglia, have many functions. Some of these are supportive of the neuron and some may involve processing of neural information. Label and color the parts of the neuron and the glial cells.

Answer Key: a. Striations, b. Nuclei, c. Cell, d. Skeletal muscle, e. Intercalated disc, f. Cardiac muscle, g. Smooth muscle, h. Nervous tissue, i. Nerve cell body, j. Glial cells (Neuroglia), k. Dendrites, I. Nucleus, m. Axon

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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  • thomas
    Why are skeletal muscle nuclei usually found on the edges of cells?
    7 years ago

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