Functions of Nervous System
(1) monitors the internal and external environments (2) integrates sensory information (3) coordinates voluntary and involuntary responses of many other organ systems
perform all of the communication, information processing, and control functions of the nervous system. Basic functional units of the nervous system.
supporting cells that separate and protect the neurons, provide a supportive framework for neural tissue. Acts as phagocytes and helps regulate the composition of the interstitial fluid.
long fiber that carries impulses away from the cell body of a neuron
branching extensions of neuron that receives messages from neighboring neurons
specialized site where the neuron communicates with another cell.
have more than two processes, but cannot be distinguished from dendrites.
two processes, separated by the cell body
single process, with the cell situated off to the side.
more than two processes, single axon and multiple dendrites. Most common!
deliver information from sensory receptors to the CNS.
carry information from the CNS to peripheral effectors in a peripheral tissue, organ or organ system.
Most numerous. Distribute sensory information and coordinate motor activity.
Central Nervous System (CNS)
-consists of the spinal cord and brain
-responsible for integrating, processing, and coordinating sensory data and motor commands.
Peripheral Nervous System (PNS)
-includes all of the neural tissue outside of the CNS.
-delivers sensory information to the CNS and carries motor commands to peripheral tissues and systems.
brings sensory TO the CNS from receptors in peripheral tissues and organs.
carries motor commands FROM the CNS to muscles, glands, and adipose tissue.
Somatic Nervous System
-controls skeletal muscle contractions
Autonomic Nervous System
-provides automatic regulation of smooth muscle, cardiac muscle, glandular secretions, and adipose tissue at the subconscious level.
assist in producing, circulating, and monitoring cerebrospinal fluid.
maintain blood brain barrier, provide structural support, regulate ion nutrient in dissolved gas concentrations, and forms scar tissue after injury.
myelinate CNS axons and provide structural framework.
remove cell debris, wastes, and pathogens by phagocytosis.
surround neuron cell bodies in ganglia, regulate oxygen, carbon dioxide, nutrient and neurotransmitter levels.
-surround all axons in PNS
-responsible for myelination of peripheral axons
-participate in repair process after injury
Chemically Gated Channels
-open or close when they bind specific chemicals
-most abundant on the dendrites and cell body of a neuron
Voltage Gated Channels
open or close in response to changes in the transmembrane potential
Mechanically Gated Channels
-open or close in response to physical distortion of the membrane surface
-important in sensory receptors that respond to touch, pressure, or vibration.