The Nervous System Flashcards
what is the role of the nervous system?
to transmit information rapidly
What are the 3 main steps in the the nervous system pathway?
- detection of stimulus
- Processing in brain
- response in other part of body
What are the physical components/parts of the first step: detection of stimulus
- sensory receptors
- afferent/sensory neurons
What are the components of the second step: Integration?
central nervous system
(brain & spinal cord interneurons)
what are the components of the third step: motor outpur?
- efferent/motor neurons
- effector cells (muslce cells or glands)
what’s in the central nervous system?
- brain
- spinal cord
what’s in the peripheral nervous system?
- afferent (sensory) neurons
- efferent (motor) neurons
- ALL neurons outside of CNS are PNS
what are the two divisions of the peripheral nervous system?
the sensory (afferent) division and the motor (efferent) division
What are the two sensing environments of the sensory (afferent) division?
the external and internal environment
What are the two parts of the motor (efferent) division?
autonomic nervous system and the somatic nervous system
What are the two divisions of the autonomic nervous system?
parasympathethic division and sympathetic division
what senses sense the external environment?
somatic and special sense
what senses sense the internal environment?
visceral senses
what do somatic senses detect - examples?
skin, muscle, joints
what do special senses detect - examples?
vision, hearing, smell, taste, equilibrium (balance)
what do visceral senses detect - examples?
- fullness of stomach
- blood pressure
- blood volume
- oxygen levels
where do exteroreceptors detect stimuli?
outside the body
where do interoreceptors detect stimuli?
within the body
what is an effector cell?
a cell that carries out the body’s response to a stimulus
what is motor output
the conduction of signals from integration centers to effector cells
what does the stomatic nervous system do?
responds to external and internal stimuli by sending signals to skeletal muscles (VOLUNTARY)
what does the autonomic nervous system do?
responds to stimuli by sending signals to smooth muscle, cardiac muscle and organs of the body
what does the sympathetic nervous system do?
- prepares the body for stress ( increase heart rate, rate of gas exchange, glucose metabolism)
- inhibits digestive and excretory systems
what does the parasympathetic nervous system do?
- restores body to normal balance - calming
- stimulates digestive and excretory systems (salivary glands, stomach, intestine, pancreas, bladder)
- decreases heart rate, and rate of gas exchange in lungs
what affects the sympathetic nervous system?
epinephrine / norepinephrine
what affects the parasympathetic nervous system?
acetylcholine
what is a nerve?
a group of neurons bundled together
what is a neuron
a nerve cell - the structural and functional unit of the nervous system
what is an excitable cell?
a cell capable of producing large, rapid electrical signals - a change in membrane protential
what are examples of excitable cells?
neurons & muscle cells