chapter 2. central nervous system (cns) brain and spinal cord (all nerves within our bones) p. 61 ...
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The Nervous System
Central Nervous System (CNS) Brain and Spinal Cord (all nerves
within our bones) p. 61 Peripheral Nervous System
(PNS) All other nerves in the body that
are not part of the Brain and Spinal Cord
Links the Central Nervous System to the rest of the body
The Peripheral Nervous System
2 parts of the Peripheral Nervous System Somatic – Controls voluntary movement
through the body’s skeletal muscles Autonomic – Controls the automatic
functions of our body (ex. heart). Mnemonic is autonomic and automatic.
The Autonomic Nervous System Sympathetic
Mobilizes our body to respond to stress
Fight or Flight Response – state of increased physiological arousal, helps the body cope with and survive threatening situations
Parasympathetic Slows our body down after
responding to stress
Sympathetic vs. Parasympathetic
Sympathetic - Arousal Pupil: Dilates Heart: Accelerates Stomach: Digestion Inhibited Perspiration: Increases
Sympathetic vs. Parasympathetic
Parasympathetic – Calming Pupil: Contracts Heart: Slows down Stomach: Digestion is stimulated Perspiration: Decreases
Types of Neurons
Sensory Neurons – aka Afferent Neurons
Interneurons- connect sensory/motor neurons.
Motor Neurons – aka Efferent Neurons
Sensory Neurons
Sensory Neurons – aka Afferent Neurons Take info from the senses to
the brain Ex. You touch a hot light bulb,
receptors in your skin carry information to your spinal cord. When pain information enters the spinal cord it is sent to the interneuron
Interneurons
Interneuron Neurons of the central nervous system Communicate between sensory inputs
and motor outputs Ex. Information taken to the spinal cord
is sent to motor neuron by the interneuron
Motor Neurons
Motor Neurons – aka Efferent Neurons Take info from the brain to the senses
(think exits the brain) Ex. Information is sent from the spinal
cord to the muscles in the hand, causing the hand to withdraw quickly▪ At this same time, the interneuron may also
send information to other parts of the brain, which in turn sends out other motor neurons causing you to move your facial muscles (look of pain) or vocal muscles (yell)
Reflex
Reflex – an unlearned or involuntary reaction to some stimulus. These are processed through the spinal chord