Muscle and nervous tissue are the two main types of excitable tissue in the body. Muscle tissue includes three main types - skeletal muscle which is striated and voluntarily controlled, smooth muscle which is involuntarily controlled and found in organs, and cardiac muscle which is only found in the heart and is involuntarily controlled. Neurons are the basic unit of the nervous system, are found in the brain, spinal cord and nerves, generate and conduct electrical impulses, and are responsible for functions like muscle contraction, sensation, emotion, memory and reasoning.
2. Muscle Tissue
• Long, slender cells
• Lots of blood vessels
• Cells can contract (shorten)
• Contractile proteins = actin & myosin, form
microfilaments in the cytoplasm
3. Skeletal Muscle
• Each cell has many nuclei
• Striated: Light and dark bands caused by
arrangement of contractile proteins
• Under voluntary control
4. Smooth Muscle
• Found in organs
• 1 nucleus/cell
• No striations
• Involuntary control
5. Cardiac Muscle
• Only in heart
• Striated
• Shorter cells than skeletal muscle
• 1 nucleus/cell
• Involuntary
6. Neurons
• Found in brain, spinal cord, and nerves
• Generate and conduct electrical impulses
• Stimulate muscle contraction, sense
environment, responsible for emotions,
memory, and reasoning
