Nervous tissue

Neuron tissue 

• Found in the brain, spinal cord, nerves and is characterized by the ability to conduct electrical signals called action potentials. 
• Contain neurons and glia. 
• Neurons are the conducting cells of the tissue. 
• Composed of the cell bdy, dendrites and an axon. 
• Cell body contains the nucleus and the site of the cell functions. 
• Dendrites and axons consits of projections of cytoplasm surrounded by memnrane. 
• Receive action potentials. 
• Axon conducts action potentials away from cell body. 
• Much larger than dendrites, constant diamter along their entire length. 

Neuron groups 

• Multipolar neurons have multiple dendrites and a single axon. 
• Bipolar neurons have a single dendrite and an axon. 
• Peseudopunipolar neurons have a single, short process that extends from the cell body and then divides into two branches, extend to the periphery and to the central nervous system. 
• Two branches function as a single axon, there are dendritelike receptors on the peripheral branch. 

Glia

• Support cells of the brain, spinal cord and peripheral nerves. 
• Nourish, protect, insulates neurons. 

Overview of the autonomic nervous system 

• Maintains homeostatis of the body by regulating involuntary activities, including heart rate, breathing rate, body temperature, digestive process. 
• Motor divisons of the nervous system control the effectors of the body. 
• Contains somatic motor system and the ATS. 
• Somatic system regulates the activities of skeletal muscle and the ANS regulates the activity of the other effectors. 
• ANS is subdivided into the sympathetic divisions, and the enteric nervous system. 
• Enteric nervous system consists of nervous tissue of the digestive tract. 
• Sympathetic and parasympathetic dividions regulates the activity of effectors throughout the body, but each divison influences the tissue under diffrent conditions. 
• Sympathetic division referred to as flight or fight divison because it has more influences on effectors under conditions of increased physical activity. 
• Parasympathetic divison has more influences under conditions of rest and is oftern referred to the rest and digest division. 

Contrasting the somatic and autonomic neurons 

• Peripheral nervous system is composed of sensory and motor neurons. 
• Carry action potentials from the many sensory receptors of the body to the central nervous system. 
• Motor neurons carry action potentials from the CNS to the effectors of the body. 
• Motor neurons that innervate skeletal muscle are called somatic motor neurons, they are part of the…