Download The Nervous System

The Nervous System
The Brain
Function of the Nervous System
1. Regulates behavior
2. Maintains homeostasis;
3. Regulates the other organ systems
4. Controls sensory and motor functions
Central Nervous System
Vs.
Peripheral Nervous System
Central Nervous System
Brain
Spinal Cord
Peripheral Nervous System
Sensory neurons - running from stimulus receptors that
inform the CNS of the stimuli
Motor neurons - running from the CNS to the muscles
and glands - called effectors - that take action.
Major Parts of the Brain
Cerebrum – controls conscious activities,
intelligence, memory, language, skeletal muscle
movements, and senses
Cerebellum – controls balance, posture and
coordination
Brainstem - Medulla oblongata, pons and
midbrain – controls involuntary activities such
as breathing and heart rate.
Cerebrum
The brain is the only part of the body
that does not have pain receptors.
Parts and Function of a Nerve Cell
Cell Body (soma) - contains nucleus
Dendrites - branch-like extensions that
receive impulses and carry them to the cell
body
Axon - extension of the neuron – carries
impulses away from the cell body and
towards other neurons
AxonTerminals - connects to muscle, gland or
another neuron, releases a chemical
message (neurotransmitter)
Neuron
Diseases of the Nervous System
Cerebral Palsy – caused by abnormalities in parts of the brain
that control muscle movements. The early signs of cerebral
palsy usually appear before a child reaches 3 years of
age. Most common symptoms are a lack of muscle
coordination when performing voluntary movements (ataxia);
stiff or tight muscles and exaggerated reflexes (spasticity);
walking with one foot or leg dragging; walking on the toes, a
crouched gait, or a “scissored” gait; and muscle tone that is
either too stiff or too floppy. Cerebral palsy can’t be cured, but
treatment will often improve a child's capabilities.
Epilepsy – Epilepsy is a brain disorder in which clusters
of nerve cells, or neurons, in the brain sometimes
signal abnormally. In epilepsy, the normal pattern of
neuronal activity becomes disturbed, causing strange
sensations, emotions, and behavior or sometimes
convulsions, muscle spasms, and loss of
consciousness. Epilepsy is a disorder with many
possible causes. Can be treated with various types of
medication.
Parkinson’s Disease – affects nerve cells, or neurons, in a part
of the brain that controls muscle movement. Neurons that make
a chemical called dopamine die or do not work properly.
Dopamine normally sends signals that help coordinate your
movements. No one knows what damages these cells.
Symptoms of Parkinson's disease may include; Trembling of
hands, arms, legs, jaw and face, stiffness of the arms, legs
and trunk, slowness of movement, poor balance and
coordination. As symptoms get worse, people with the disease
may have trouble walking, talking or doing simple tasks. They
may also have problems such as depression, sleep problems or
trouble chewing, swallowing or speaking.