Download Nervous System Period 7 - Mercer Island School District

Nervous System
Taylor, Kyra, Ryan, and Brennan
Function of Central and Peripheral Systems
● integrating sensory information and
responding accordingly
● The spinal cord serves as a conduit for
signals between the brain and the rest of the
body
● cells that detect information like smell and
vision, exclusively motor cells, like the
eyeballs and hearing
● connect the central nervous system to the
organs, limbs, and skin to allow for complex
movements and behaviors
Cell type
Neurons: transmit nerve pulses (signals)
Glial cells, multiple types
Satellite cells: physical support for neurons in peripheral system
Oligodendroglia: provides myelin (insulation) for neurons
Microglia: digest parts of dead neurons
Astrocytes: regulate the external chemical environment
Maintaining Homeostasis
The nervous system maintains
homeostasis by sending electrochemical
signals throughout the body,
coordinating and executing both the
voluntary and involuntary processes that
maintain homeostasis
Working with Other Systems
Skeletal system: calcium from your bones helps the
nervous system function
Digestive system: ends messages to the muscles for
eating and elimination of waste food
Cardiovascular system: regulates the heart rate using
baroreceptors
Alzheimer’s
Brain disease that causes a slow decline
in memory, thinking, and reasoning
skills.
Caused by genetic, lifestyle, and
environmental factors that affect the
brain over time.
Attacks the brain’s nerve cells, or
neurons, resulting in memory loss,
thinking and language skills, and
behavioral changes.
Parkinson’s
Most experience one or more of the four
most common motor symptoms.
Many of the symptoms are due to a loss of
neurons that produce a chemical in your
brain called dopamine.
Dopamine sends signals to the part of your
brain that controls movement. If neurons
that produce dopamine are lost, it can
affect the way that the body moves.
Central Nervous System
Consists of the brain and spinal cord
Brain is the major functional unit and is composed of the
brainstem, cerebellum and the cerebrum
Brainstem contains tracts from the spinal cord to the brain
Cerebellum handles sensory stimuli, motor information and
balance
Cerebrum handles emotion, memory perception and motor
functions
Spinal cord relays info to the brain through tracts in the
brainstem
Peripheral Nervous System
Divided into the somatic, sensory and
autonomic nervous systems
Somatic nervous system is voluntary and
transmits signals from the brain to end organs
(ex: muscles)
Sensory nervous system transmits signals from
senses to the CNS
Autonomic nervous system is mostly
involuntary and influences involuntary functions
(ex: digestive system)
Nerve Pulses
A nerve impulse is an electrical signal that travels along an axon. When the nerve is activated,
there is a sudden change in the voltage across the wall of the axon, caused by the movement
of ions in and out of the neuron
The speed of nerve impulses varies enormously in different types of neuron. The fastest travel
at about 250 mph
Neurons that need to transmit electrical signals quickly are sheathed by a fatty substance
called myelin
Nerve impulses are a way of coding information.
Receptor Types
Channel- Linked receptors: are cell membrane bound
receptors. They act through synaptic signaling on
electrically excitable cells
Enzyme-linked receptors: is a transmembrane receptor,
where the binding of an extracellular ligand causes
enzymatic activity on the intracellular side.
Intracellular receptors: are receptors located inside the
cell rather than on its cell membrane. Classic hormones
that use intracellular receptors include thyroid and steroid
hormones.
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