THE NERVOUS SYSTEMThe Communication System
THE NERVOUS SYSTEM FUNCTIONFunction: to communicate
conditions within the body and the surrounding environment◦Stimulus – something that
causes a change or response in an organism
◦Response – any reaction or change in an organism that is caused by a stimulus.
THE NERVOUS SYSTEM FUNCTION
NEURON – NERVE CELLhttp://argosymedical.com/Nervous/samples/animations/Firing%20of%20Neurons/index.html
Dendrites – receive signals from other cellsCell Body – contains the nucleus and organelles of the neuronAxon – long, slender part of neuron that carries impulse from cell body to terminalsSchwann cells – produce the myelin sheathmyelin sheath – fatty substance – increase speed signal travels down axonAxon Terminals – end of neuron that releases neurotransmitters to signal other neurons
TYPES OF NEURONS
Sensory Neurons – run from sensory receptors (sight, smell, touch, taste, sound) to the CNSInterneurons – found exclusively in the spinal cord and brain (CNS) – communicate with other neuronsMotor Neurons – carry information from the CNS to muscles or glands that carry out a response
THE NERVOUS SYSTEM COMPOSITIONCentral Nervous System
◦Brain◦Spinal Cord
Peripheral Nervous System◦Connects the central nervous
system to the rest of the body through nerves
THE BRAIN Cerebrum:
◦ Frontal Lobe- associated with reasoning, planning, parts of speech, movement, emotions, and problem solving
◦ Parietal Lobe- associated with movement, orientation, recognition, perception of stimuli
◦ Occipital Lobe- associated with visual processing ◦ Temporal Lobe- associated with perception and
recognition of auditory stimuli, memory, and speech Cerebellum is associated with regulation and
coordination of movement, posture, and balance. Brain stem is responsible for basic vital life functions
such as breathing, heartbeat, and blood pressure.
THE BRAIN (DOMINANCE)
THE SPINAL CORDA bundle of nerves that passes
through the bones of the vertebraedown the back.
It sends sensations to the brain from the body, and returns motor commands to the various parts of the body.
Responsible for most reflexes
PERIPHERAL NERVOUS SYSTEMConnects the central nervous system to the rest of the body through nerves.
HOMEOSTASIS
The human body uses stimuli it receives from internal and external sources to make adjustments so that the body can maintain homeostasis (a constant internal environment).
NERVOUS SYSTEM SUMMARY
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