Chapter 10: The Nervous System
Medical professionals:
1. Neurologists: specialize in disorders of the nervous system
2. Neurosurgeons: perform surgical procedures on the NS
3. Psychiatrist: diagnose and treat mental disorders
4. Anesthesiologists: administer anesthetics and are responsible for pain
management
5. Psychologists: concerned with the behavior of the human mind
6. Licensed professional counselors: treat people with mental, behavioral,
and emotional problems/disorders
7. Neuropsychologists: evaluate patient’s memory, language, and
cognitive functions and develop appropriate treatment plans
8. EEG Technicians: operate specialized equipment that measures the
electrical activity of the brain, peripheral nervous system, and spinal
cord
Structure of the NS:
How all communication is done through your body
Two major subdivisions:
1. Central Nervous System
a. Brain and spinal cord
2. Peripheral Nervous System
a. All neurons and nerves outside the CNS
b. 12 pairs of cranial nerves originating from the brain and 31
pairs of spinal nerves originating from the spinal cord
The PNS is further divided into:
o Sensory division: sensory nerves (afferent nerves) carry
messages toward the spinal cord and brain from sense organs
o Motor division: motor nerves (efferent nerves) carry messages
away from the brain and spinal cord to muscles and organs
The visceral motor division is called the autonomic nervous system
(ANS): carries signals to glands, cardiac and smooth muscles; operates
at a subconscious level outside of voluntary control
o Sympathetic division: arouses body for action by increasing
the heart and respiratory rate to create a better oxygen supply
to the brain and muscles
o Parasympathetic division: calms body and slows heart and
respiratory rates but stimulates digestion
, The somatic motor division carries signals to the skeletal muscles
and is within your voluntary control
Functions of Nervous System
1. Sensory input:
a. Goes to brain from receptors all over the body
b. We are conscious of external stimuli that we receive from our
body as it interacts with our environment
c. Inside the body internal stimuli i.e. oxygen amounts, CO2 in the
blood, and other homeostatic variables like temperature are
continually processed at a subconscious level
2. Motor output:
a. Stimulates skeletal muscles to contract allowing movement
b. NS controls sweat, saliva, and digestive enzymes production
3. Evaluation and integration:
a. Happen in brain and spinal cord to process sensory input, initiate
a response, and store the even in memory
4. Homeostasis:
a. Takes in internal sensory input and responds to it
b. Example: the NS responds by stimulating the heart to deliver the
correct volume of blood to ensure oxygenation and removal of
waste products from cells
5. Mental activity:
a. It happens in brain to cause thinking, feeling, understanding,
responding, and remembering
Cells of NS
Neurons
o Receive stimuli
o Transmit impulses to other neurons or organ receptors
o Consists of a cell body, axons, & dendrites
o Dendrites: branched extensions of the neuron’s cell body; direct
impulses toward the cell body
o Axons: carry the impulses away from the cell body; covered in a
myelin sheath
Bundles of axons are white and create the white matter of the brain
Neuron cell bodies, dendrites, and synapses appear gray and create
gray matter
Medical professionals:
1. Neurologists: specialize in disorders of the nervous system
2. Neurosurgeons: perform surgical procedures on the NS
3. Psychiatrist: diagnose and treat mental disorders
4. Anesthesiologists: administer anesthetics and are responsible for pain
management
5. Psychologists: concerned with the behavior of the human mind
6. Licensed professional counselors: treat people with mental, behavioral,
and emotional problems/disorders
7. Neuropsychologists: evaluate patient’s memory, language, and
cognitive functions and develop appropriate treatment plans
8. EEG Technicians: operate specialized equipment that measures the
electrical activity of the brain, peripheral nervous system, and spinal
cord
Structure of the NS:
How all communication is done through your body
Two major subdivisions:
1. Central Nervous System
a. Brain and spinal cord
2. Peripheral Nervous System
a. All neurons and nerves outside the CNS
b. 12 pairs of cranial nerves originating from the brain and 31
pairs of spinal nerves originating from the spinal cord
The PNS is further divided into:
o Sensory division: sensory nerves (afferent nerves) carry
messages toward the spinal cord and brain from sense organs
o Motor division: motor nerves (efferent nerves) carry messages
away from the brain and spinal cord to muscles and organs
The visceral motor division is called the autonomic nervous system
(ANS): carries signals to glands, cardiac and smooth muscles; operates
at a subconscious level outside of voluntary control
o Sympathetic division: arouses body for action by increasing
the heart and respiratory rate to create a better oxygen supply
to the brain and muscles
o Parasympathetic division: calms body and slows heart and
respiratory rates but stimulates digestion
, The somatic motor division carries signals to the skeletal muscles
and is within your voluntary control
Functions of Nervous System
1. Sensory input:
a. Goes to brain from receptors all over the body
b. We are conscious of external stimuli that we receive from our
body as it interacts with our environment
c. Inside the body internal stimuli i.e. oxygen amounts, CO2 in the
blood, and other homeostatic variables like temperature are
continually processed at a subconscious level
2. Motor output:
a. Stimulates skeletal muscles to contract allowing movement
b. NS controls sweat, saliva, and digestive enzymes production
3. Evaluation and integration:
a. Happen in brain and spinal cord to process sensory input, initiate
a response, and store the even in memory
4. Homeostasis:
a. Takes in internal sensory input and responds to it
b. Example: the NS responds by stimulating the heart to deliver the
correct volume of blood to ensure oxygenation and removal of
waste products from cells
5. Mental activity:
a. It happens in brain to cause thinking, feeling, understanding,
responding, and remembering
Cells of NS
Neurons
o Receive stimuli
o Transmit impulses to other neurons or organ receptors
o Consists of a cell body, axons, & dendrites
o Dendrites: branched extensions of the neuron’s cell body; direct
impulses toward the cell body
o Axons: carry the impulses away from the cell body; covered in a
myelin sheath
Bundles of axons are white and create the white matter of the brain
Neuron cell bodies, dendrites, and synapses appear gray and create
gray matter
