Transcript The Brain and Nervous System

The Brain and
Nervous System
Neuron = Nerve Cell
 Nerve cells pass
messages along to
others.
 All or none
principle of nerve
cells.
 What we feel is
dependent on the
amount of
neurons that fire.
Neuron Communication
 Neuron “firing” is
the release of
neurotransmitters.
 Neurotransmitters
are chemical
messengers - those
chemicals can
influence mental
abilities and
emotion.
Nervous System
 Nervous system has three
types of neurons:
 Sensory neurons - send info
from tissues and organs
toward CNS
 Motor neurons - how the
CNS sends instructions out
to body tissues.
 Interneurons - processes
internal commincation in
the CNS
So how do we feel?
Nervous System
 Brain and spinal cord
form the Central
Nervous System.
 Peripheral Nervous
System connects the
CNS with body sense
receptors, muscles,
and glands.
Somatic and Autonomic Nervous System
 Make up the PNS
 Somatic NS allows
voluntary control of
muscles.
 Autonomic NS controls
glands and organs.
 Sympathetic NS arouses a person.
 Parasympathetic NS conserves energy and
calms.
The Brain
 Big mass of gray
tissue…that
ultimately defines
who we are.
 Brain control
unconscious
functions, and also
contains our
thoughts.
Reading the Brain
 Now we can record
brainwaves through
EEG.
 PET scans show areas of
brain activity.
 MRI and fMRI show the
brain and blood flow.
Brainstem
 Oldest part of the brain includes the spinal cord.
 Medulla - controls
breathing and heartbeat.
 Pons - helps coordination
in movement.
 Reticular Formation is
about filtering nerve
messages to parts of the
brain, also has to do with
arousal.
 Thalamus - like a sensory
switchboard.
Cerebellum
 Coordinates
voluntary
movement.
 No conscious
effort.
Influencing emotions and motives
 Hippocampus processes memory.
 Amygdala influence fear and
aggression.
 Hypothalamus influences motives
for hunger, thirst, sex
- releases hormones
by controlling the
pituitary gland.
Mice and Hypothalamus
 Hypothalamus controls
pituitary gland which
controls hormones - so
HT takes orders from
other parts of the brain
that influence our
motives.
 This includes release of
pleasure hormones, rats
that could stimulate
their HT electrically
would do so 7000 times
an hour.
Cerebral Cortex
 Covers the
cerebral lobes, is
the control/info
processing part of
our brain.
 Our conscious
mind.
Motor Cortex
 Part of our cerebral
cortex that controls
movement.
 Right hemisphere
controls left side of
body and vice versa.
 Sensory Cortex is
similar, it reports
senses around your
body.
Neural Prosthetics
Frontal Lobe
 Frontal lobe has to do with
decision making, thinking,
personality.
 Phineas Gage was a
railroad working in 1848
that had a spike go through
his brain. He could think
and had memories, but his
personality was total
different.
Hemispheres of
the Brain
 Corpus Callosum - wide
band of axon fibers
connects the hemispheres.
 Left and Right
Hemispheres have largely
different functions:
 affect movement on different
sides of the body
 Language - left, spatial
thinking - right
Split Brain
 Purpose of the corpus
callosum is to send
information to the
other hemisphere severed patients have
difficulty.
 Patients brain
hemispheres will
interpret events
differently, and not
communicate.