Transcript The Nervous System and the Control of Movement

The Nervous System and
the Control of Movement
“He’s Got what you might
call a control problem. The
guy has a million dollar
arm, but only a ten cent
brain.”
 --From Bull Durham
(1988)
Nervous System
We have now seen how muscle
contraction/movement occurs and how the body
creates energy to sustain movement. But what
initiates the movement?
The Nervous system is the body’s system which
is responsible for gathering information, storing
it, and responding to it. Its main objective is
gather internal and external information,
analyze that information and initiate certain
responses to satisfy certain needs.
Pass it on…..
2 teams, everyone holds hands
Last person of each team holds a stop
watch
When I say “GO” I will send out a signal
to each team, it will travel around the
circle and once it reaches the last person
you must stop the stop watch
Switch up the last person of each team
Spinal cord
The Components of the
Nervous System
Central Nervous System (CNS)
Peripheral Nervous System (PNS)
Overview….
(A) Central Nervous System
Composed of two
parts:
The Brain
The Spinal Cord
Parts of the skull
Brain
Frontal lobe: higher order
thought, and initiation of
movement
Parietal lobe:
somatosensation (pain,
temperature, and touch
sensation from the body)
Temporal lobe: processes
auditory, olfactory (smell),
and gustatory (taste)
information
Occipital lobe: processes
visual information
Cerebellum: refines and
coordinates movement
The Brain…
Cerebrum
Cerebellum
Brain Stem
Diencephalon
Limbic System
Reticular activating
system
Spinal Cord
Spinal Cord
Dorsal View
Cerebrum…Largest part of the
brain!
 Contains nerve centres
that control sensory
motor activities as well as
intelligence
 Divided down the middle
into two halves (Cerebral
Hemispheres)
 Each hemisphere is
divided into four lobes
named after the cranial
bones which protect that
area of the brain
Cerebellum…The Second
largest part of the brain!
Lies behind and
below the cerebrum
Main function is to
co-ordinate muscle
movement and
control balance
The Brain Stem
Located below the
cerebrum and in front
of the cerebellum
Links the cerebrum
with the spinal cord
Responsible for
autonomic functions,
posture, muscle tone,
and eye movement
The Diencephalon
 Consists of the Thalamus
and the Hypothalamus
 Located b/w the
cerebrum and the brain
stem
 Thalamus relays sensory
info
 Hypothalamus controls
things such as body
temperature, appetite,
emotions and other
autonomic functions
Other components
The Limbic system is responsible for
regulating emotions, and hunger
The reticular activating system is
responsible for sending sensory
information to the appropriate centres for
interpretation. Also it is crucial for
maintaining consciousness.
Spinal Cord
 Second major component of the
CNS
 Main pathway for information
connecting the brain and the
peripheral nervous system
 Runs through the vertebral
column
 Spinal nerves branch off of the
spinal cord, b/w vertebra,
allowing nerves to travel to
tissues and organs
 Cervical nerves are named
according to where they branch
away from the vertebrae. Eg. C6--deltoid, L3,4---quads
When Things go wrong!
(B) Peripheral Nervous
System
 The PNS consists of those parts of the nervous system
that lie outside of the Brain and spinal cord
 Massive road network carrying information to and from
the CNS
 Consists of 12 pairs of cranial nerves that emerge from
the brain, and 31 pairs of spinal nerves that leave the
spinal cord at various parts of the body
 Each pair of nerves contain one motor nerve (efferent
nerves) and one sensory nerve (afferent nerves).
 Afferent---CNS
 Efferent---muscles/organs
Overview revisited….
Peripheral Nervous System
 Autonomic Nervous System
 Involuntary contraction of
cardiac muscle and smooth
muscle cells
-sympathetic system prepares
body for emergencies, and
turns things on. Release of
adrenaline
-parasympathetic system
brings the body back to
normal after being stimulated
by the sympathetic system
 Somatic Nervous System
 Involves the awareness of our
environment and the
subsequent muscular activity
to cope with that situation.
 Involves afferent nerves
sending information to the
CNS, and efferent nerves
sending a stimulus to muscles.
 E.g. Page 97 in text…..shows
how this system works
together with the autonomic
system
Sensory and Motor Neurons
Questions
Draw a mind map/concept map of the Nervous
system. Include a brief description of each
component
Outline the reflex arc. What is it? and what are
the five parts?
What are proprioceptors?
Compare and contrast GTO and Muscle Spindles
What is the stretch reflex?
What is reciprocal inhibition?
What is the crossed extensor reflex?