Chapter 12 - Nervous Tissue

Brain and spinal cord

All nervous tissue except the brain and spinal cord

Bundle of hundreds to thousands of axons of individual neurons plus associated connective tissue and blood vessels; each one follows a defined path and serves a specific area of the body

Small masses of nervous tissue located outside the brain and spinal cord; they contain mainly neuron cell bodies.

Carries signals from various receptors to the CNS, Somatic (from skin, muscles, bones, joints), Visceral (viscera from abdomen and thorax)

Signals from CNS to glands and muscles, Somatic (to skeletal muscles), Visceral or Autonomic (to glands, cardiac muscle, smooth muscle), divided into Sympathetic and Parasympathetic

(Tends to prepare for action)

(Calming or slowing effect)

All cells are excitable but nerve cells have developed this to the highest level

Produce and conduct electrical signals

Neurotransmitters carry signal across synapse.

Specialized to detect stimuli, a variety of types, and transmit it to the CNS, begin in virtually every organ end in CNS

Contained entirely in the CNS, communicate between neurons, carry out integrative functions, account for 90% of neurons

Send signals to muscle and glands

(soma, perikaryon); Contains the nucleus, cytoplasm and the typical cellular organelles, prominent RER