Name: _________________________________________
Guided Notes: Nervous System
Nervous system
 One of the two main communication systems in the body
 Coordinates all the activities of the body carrying messages from one cell to the next
 Enables the body to respond and adapt to changes that occur inside and outside the body
 Basic structural unit is the NEURON or nerve cell
Each neuron consists of:
 The _____________________________________________body.
 _____________________________________________.
 The _____________________________________________.
Neurons
 Cell body consists of nucleus
 Dendrites consist of nerve fibers that carry impulses toward the cell body
 Axon is a single nerve fiber that carries impulses away from the cell body
 _____________________________________________sheath covers the axon (fat
covering) that insulates and maintains the axon
 Nodes of Ranvier are areas where no myelin is present
 The axon of one neuron lies next to the dendrites of another neuron
 The spaces between them are called synapses
 Impulses coming from one axon “jump” the synapse to get to the dendrite of another neuron
which carry it in the right direction
 Special chemicals, neurotransmitters, found at the end of each neuron allow impulses to pass
from one neuron to another so impulses can follow many different routes
Nerve fibers
 Nerves are a combination of many nerve fibers found in the brain and spinal cord
 3 types:
 _____________________________________________– sensory nerves
 Nerves carry messages from body to the brain and spinal cord
 _____________________________________________– motor nerves
 carries messages from the brain and spinal cord to the body
 _____________________________________________- interneurons
 Carries impulses from the sensory neuron to the motor neuron
Central nervous system
 _____________________________________________
 _____________________________________________
Peripheral nervous system
 _____________________________________________
 Autonomic nervous system
 Controls involuntary body functions
Autonomic nervous system
 Includes peripheral nerves and ganglia (group of cell bodies outside the CNS that
carry impulses to involuntary muscles and glands)
Central nervous system
 BRAIN – mass of nerve tissue protected by membranes and skull
 Cerebrum
 Largest and highest section
 Has convolutions (folds) that separates the lobes
 4 lobes:
 _____________________________________________
 _____________________________________________
 _____________________________________________
 _____________________________________________

Frontal lobe
 Links all components of behaviors
 _____________________________________________control
 Injury here may cause lose of function on one side of the body
 _____________________________________________may become halted or disorganized
 _____________________________________________changes can occur
 Social rules are disregarded
 Sustained attention and “insight” are affected
Temporal lobe
 Perceives and recognizes _____________________________________________material
 Most commonly injured
 Causes misunderstandings in what is said
 Emotional changes such as unexplained panic or tearfulness can occur
 _____________________________________________temporal lobe involved in production of
speech, naming and verbal memory
 _____________________________________________temporal lobe involves musical ability,
foreign language, visual memory and comprehension of the environment
Parietal lobe
 Construction of _____________________________________________
 Recall of long term memories may be mixed up in time and sequencing
 Easily lost or confused about left/right
 Difficulty recognizing and naming what they see
 May affect ability to read, write or perform calculations
 _____________________________________________sensation and voluntary movement is
affected
 Injury to front part of the lobe may cause loss of body sensation
Occipital lobe
 _____________________________________________usually results in blindness to part or all
of the visual field
 People may experience “blind spots” or “holes”
 May misperceive pictures they see
 Recognition of colors may be distorted
 Cerebellum
 Below cerebrum
 Responsible for
 _____________________________________________,
 _____________________________________________
 _____________________________________________
 Diencephalon
 Section between the cerebrum and midbrain
 Contains 2 structures
 _____________________________________________– acts as a relay center
and directs sensory impulses to the cerebrum
 _____________________________________________– regulates and control
the autonomic nervous system, temperature, appetite, water balance, sleep,
etc. Also involved in emotions such as fear, anger, pleasure, pain and affection
 Midbrain
 Below the cerebrum and top of the brain stem
 Responsible for conducting impulses between brain parts and certain
_____________________________________________reflexes
 Pons
 Below the midbrain and in the brain stem
 _____________________________________________for conducting messages to
other parts of the brain, chewing, tasting, saliva production and assists with breathing
 Medulla oblongata
 Lowest part of the brain stem
 Connects with the spinal cord and is responsible for
________________________________________________________________________
 Spinal cord
 Continues down from the medulla oblongata
 _____________________________________________at the first or second lumbar
vertebrae
 Surrounded and protected by _____________________________________________
 Responsible for many _____________________________________________actions
and carrying afferent and efferent nerves
 Meninges
 3 membranes that cover and protect the brain and spinal cord
 _____________________________________________mater – outer layer
 _____________________________________________membrane – middle,
delicate layer
 _____________________________________________mater – attached to the
brain and contains blood vessels that nourish the nerve tissue
 The brain has 4 _____________________________________________ (hollow spaces that
connect with each other and the space under the arachnoid membrane)
 Filled with fluid called cerebrospinal fluid
 Circulates continuously
 Serves as _____________________________________________to protect brain and
spinal cord
 Carries _____________________________________________to parts of the CNS and
helps _____________________________________________waste products
Peripheral Nervous System
 Consists of the _____________________________________________and
_____________________________________________nervous systems
Somatic nervous system
 12 pairs of cranial nerves
 31 pairs of spinal nerves
 Spinal nerves carry messages to and from the spinal cord and are mixed nerves (both
afferent and efferent)
Autonomic Nervous System
 Branch of peripheral nervous system
 Maintains balance in the _____________________________________________functions of the
body and allows the body to react in times of emergency
 2 divisions:
 _____________________________________________
 _____________________________________________
 Work together to maintain homeostasis
 In times of emergency the sympathetic nervous system prepares the body to act
 Increased _____________________________________________
 Increased _____________________________________________
 Increased _____________________________________________
 Decreased _____________________________________________
 After the emergency, the parasympathetic nervous system counteracts actions of the
sympathetic nervous system
 Decreased _____________________________________________
 Decreased _____________________________________________.
Diseases/disorders
 Traumatic disorders – caused by injury:
 Concussion. _____________________________________________
 Brain contusion. _____________________________________________
 Congenital disorders – present at birth:
 Spina bifida.
_____________________________________________
 Hydrocephalus. _____________________________________________
 Cerebral palsy. _____________________________________________
 Cerebrovascular accident (CVA).
_____________________________________________
 Encephalitis. _____________________________________________
 Epilepsy. _____________________________________________
 Meningitis. _____________________________________________
 Multiple sclerosis (MS) _____________________________________________
 Neuralgia. _____________________________________________
 Paralysis. _____________________________________________
 Parkinson’s disease. _____________________________________________
 Dementia. _____________________________________________
 Alzheimer’s disease. _____________________________________________