Unit 7- Nervous System Structures and Functions
Synapse
A junction where information is transmitted from one neuron to the next.
Motor input
A response to stimuli which activates muscles or glands.
PNS divisions
Autonomic nervous system (ANS) Somatic nerves
Nervous system is divided into
Central Nervous System (CNS) and Peripheral Nervous System (PNS)
Neurotransmitter
Chemical released by axon Crosses gap to stimulate dendrite of second neuron
autonomic nervous system (ANS)
Control of involuntary or unconscious bodily functions
nervous system functions
Coordinates all activities of the body
synaptic cleft
Gap between neurons Electrical impulse cannot cross
Sensory afferent neurons
Nerve cells that carry impulses towards the central nervous system
somatic nerves
Nerves that serve the skin and skeletal muscles and are mainly involved with the conscious and voluntary activities of the body.
parasympathetic nervous system
Serves as counterbalance for sympathetic nerves Causes heart rate to slow down, lowers blood pressure, and stimulates digestion
Sympathetic branch of ANS
Stimulates body in times of stress and crisis Increases heart rate, dilates airways, increases blood pressure, inhibits digestion, and stimulates production of adrenaline "fight or flight response"
ANS divided into 2 branches
Sympathetic branch Parasympathetic branch
Sensory input
To gather information occurring inside/outside the body
Parts of a Neuron
What are the different parts of a neuron?
Neurons
a nerve cell; the basic building block of the nervous system
CNS (central nervous system) consists of
brain and spinal cord
Neurons have 3 parts
cell body, dendrites, axon
PNS (peripheral nervous system) consists of
cranial nerves and spinal nerves
Neurons can conduct
electrical impulses
Nervous system has 2 types of cells
neurons and glial cells
Motor efferent neurons
neurons that take information from the brain to the rest of the body
neuroglial cells
provide physical support, insulation, and nutrients for neurons