Uniquely designed to receive and transmit electrical and chemical signals throughout the body.
Nervous (or neural) tissue
Nervous tissue is found in the
Brain, spinal cord, and peripheral nerves
Nervous tissue is composed primarily of two general cell types:
- Neuroglial Cells (support the neurons)
Longest cells in the body and may reach up to a yard in length.
Neurons are composed of three primary parts:
- Perikaryon (stroma) – cell body
- Dendrites – short cytoplasm extension
- Axon – long single extension of cytoplasm.
Function of dendrite
receive impulses from the other cells
Function of axon
conducts impulses away from the cell body.
Found in greater numbers in neural tissue. They do not transmit impulses but rather serve to support.
Specialized types of neuroglial cells function to
- Isolate the conductive membranes
- provide a supportive framework that helps to bind the components to neuronal tissue together
- phagocytize debris
- help supply nutrients to neurons by connecting them to blood vessels
Which systems maintain homeostasis.
endocrine and nervous system
Nervous system has three basic functions:
- sensory functions (externally),
- integrating functions (within the spinal cord),
- motor functions (externally).
Nervous system consist of two parts:
- Central Nervous System: Brain, Spinal Cord
- Peripheral Nervous System: Cranial Nerves, Spinal Nerves, Autonomic Nerves, Sympathetic Division, Parasympathetic Division
The cell body (soma or perikaryon) is large and contains:
- the nucleus of the cell.
- majority of the cell organelles that synthesize the materials needed by the neuron (neurone), particularly energy (mitochondria) and neurotransmitters (synthesized by the ribosomes and rough endoplasmic reticulum).
Some of the areas containing large amounts of Rough ER and ribosomes stain darkly and these areas are referred to as
The Nissl bodies give the grey coloration to the areas of the spinal cord that contain the cell bodies of the neurons, the so-called