Histology: Muscle and Nervous Tissue

1. Histology: Muscle and Nervous Tissue

2. Regenerating Muscle Tissue http://www.youtube.com/watch?v=Tng3Pjsa7-I

3. Muscle tissue is made of… • Myocytes-elongated cells • Also called muscle fibers • Each myocyte contains many myofibrils (organelle responsible for muscle contraction)

4. Many myocytes are mutlinucleated

5. Myocytes rarely undergo mitosis

6. Structure of Muscle Tissues • Blood vessels wrap around fibers • Fibers are attached to motor neurons • Covered with connective tissue • Can be striated or smooth

7. What does striated mean? • Appearing striped • These “stripes” are actually proteins (actin and myosin)

8. Types of Muscle Tissue • Striated Muscle • Cardiac Muscle • Smooth Muscle

9. Striated Muscle (skeletal muscle) • Involved in voluntary movement • Attached to vertebrate skeleton • Multinucleated • Striated

10. Smooth Muscle • Involuntary movement • Controlled by autonomic nervous system • Lines organs • Multinucleated • No striation

11. Cardiac Muscle • Located in heart • Responsible for moving blood and maintaining blood pressure (involuntary and automatic) • Some striation • Uninucleated • Cell separated by intercalated disc

12. Mad Cow Disease • To protect people against the human variant of mad cow disease, health experts say, it is crucial to keep central nervous system tissue of beef cattle out of the food supply. And that means controls and testing at slaughterhouses, where there is a risk that tissues will become mingled when animals are killed and processed. • NYTimes(August 08)

13. Neurons Dendrites receive messages Axons transmit messages

14. Neuroglia

15. Neurons never undergo mitosis. Neuroglia divide rarely.

16. Nervous Tissue • Combination of neurons and neuroglia • Neurons connected end to end = ganglions • Nerve=grossly visible • Found in central and peripheral nervous system • Function: Send and receive signals from internal and external stimuli