The Nervous System and the Control of Movement. The Nervous System The nervous system is the body's...
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Transcript of The Nervous System and the Control of Movement. The Nervous System The nervous system is the body's...
The Nervous System and the Control of Movement
The Nervous System The nervous system is the body's way of
gathering information, storing it, and responding to it
Main role is to assemble information about conditions external and internal to the body Analyze this information Initiate responses that may be necessary to satisfy
certain needs
Two Components of the Nervous System
Brain + spinal cord = central nervous system (CNS)
Peripheral nervous system (PNS) = responsible for other things i.e. Heart Digestive system Muscular control All voluntary and involuntary neuromuscular
controls
The Brain Control centre or “computer” of the body Incapable of performing physical tasks,
therefore it sends commands to other parts of the body to perform them
6 main parts: cerebrum, cerebellum, brain stem, diencephalon, limbic system, reticular activating system
Cerebrum Largest part of the brain Contains nerve centres that control sensory and
motor activities Can be divided into two halves or
“hemispheres” Each hemisphere is divided into 4 lobes (named
after the bone that they lie over Frontal lobe, temporal lobe, parietal lobe, occipital
lobe
Cerebellum Second largest region Lies behind and
below the cerebrum Main function is to
coordinate muscle movement and control balance
Brain Stem Below cerebrum and
in front of cerebellum Links the cerebrum
with the spinal cord Houses brain centres
responsible for autonomic functions, postural control, muscle tone, and eye movement
Diencephalon Consists of thalamus
and hypothalamus Thalamus relays most
sensory stimuli to the cerebral cortex Controls awareness of
pain, screening of incoming signals, focusing attention
Hypothalamus controls body temperature, appetite, emotions and various automatic functions
Limbic System Composed of a
collection of structures within the cerebral hemispheres that regulate basic drives i.e. Hunger, aggression, emotional drives
Screens information going to the cerebral cortex
Reticular Activating System
Network of neurons Fans out through the
cerebral cortex Directs information to
appropriate centres for interpretation
Crucial for maintaining consciousness
Vertebral Column and the Spinal Cord
Main pathway for information connecting the brain and peripheral nervous system
Spinal cord runs through the vertebrae Starts from the the base of the brain stem and
travels down to the second lumbar vertebra Spinal nerves carry sensory information towards
the CNS and motor commands away from the CNS
Peripheral Nervous System
Consists of the parts of the nervous system that lie outside the CNS (everything but the brain and spinal cord)
Carries information in and out of the CNS Motor Nerves – aka efferent nerves carry
information from the CNS to the body's organs Sensory Nerves – aka afferent nerves carry
information from sensory receptors to the CNS
Autonomic Nervous System
Subsystem of the PNS Controls involuntary actions (i.e. Heart beat) Comprised of two branches which act as
opposing systems Sympathetic system Parasympathetic system
Sympathetic System Causes localized bodily adjustments to occur
(i.e. Sweating) Prepares bodies for emergencies
This involves release of adrenaline, increased heart rate, widening of blood vessels, and “fight or flight” responses
Parasympathetic System
Helps to return the body to normal after it has been altered by the sympathetic system
i.e. Sympathetic system will increase heart rate, parasympathetic system will decrease heart rate to bring it back to its resting state.
Somatic Nervous System
Another subsystem of the PNS Responsible for our awareness of the external
environment Contains both afferent and efferent nerve fibres Through this system, the PNS receives and
processes information from receptors in the skin, voluntary muscles, tendons, and joints
Gives us the sensations of touch, pain, heat, cold, balance, body position, and muscle action
Cont... Handles the muscles in our extremities Allows us to move