Psychology
• Individual cells in the nervous system that
receive, integrate, and transmit
information.
• The adult human brain
weighs about 3 pounds
(1,300-1,400 g).
• The human brain has
about 100 billion
neurons.
• Neurons multiply at a rate 250,000
neurons/minute during early pregnancy.
• Day 40 Brain waves are recordable!
• Dendrites= the
branching extensions
of a neuron that
receives info. and
conduct impulses
toward the cell body
(into the neuron).
• Nucleus: part of the
neuron that contains
chromosomes (genetic
material).
• Cell body a.k.a Soma=
part of a cell which
contains the nucleus
and other parts that
keep the cell healthy.
• Myelin Sheath= Fatty
substance that
surrounds MOST
axons. Speeds up
conduction velocity of
action potentials.
• Loss of myelin is one of
the main causes of
Multiple Sclerosis.
• Node of Ranvier: Gaps
in the myelination of
axons.
• Axon= a neuron’s
extending fiber, which
conducts impulses
away from the cell
body and transmits to
other neurons, muscle
or gland cells.
• Axon terminals (a.k.a
Synaptic terminal, and
terminal buttons)=
endpoint of a neuron
where
neurotransmitters
(discussed soon) are
stored.
Neurons have the ability to change---to make
new connections or to strengthen old
ones.
Examples: learning
Violin player gains expertise, the motor area
linked to the fingers of the left hand
becomes larger (Juliano, 1998).
• The network of nerve cells for communicating
and processing information from within and
outside the body
• Consists of the brain and spinal cord.
• Can be compared to a computer…processing
center
• Regulates EVERYTHING in your body.
• Enables you to think, plan, and create.
Regulate life processes.
• A series of 22 fused bones protect the brain.
• The adult human brain weighs about 3
pounds.
• The brain devotes huge amounts of neural
circuitry to the hands, lips, feet and tongue.
• Your brain uses about 12 watts of power—a
fraction of the energy of a household lightbulb.
• A column of nerves nearly as thick as your thumb.
• Extension of the brain.
• Cord is a neural pathway that transmits info. b/w
the brain and the peripheral nervous system.
• Receives incoming info. From your sense organs.
• Carries outgoing commands from the brain to
muscles, glands, and organs.
• There are about 13,500,000 neurons in the human
spinal cord.
• A reflex controlled at the level of the spinal
cord, a reflex that bypasses the brain.
• Examples: jerk your knee when it is tapped,
pull your hand away from a burning surface,
or blink when a gust of wind sent particles of
debris hurtling toward your eyeballs.
• The nervous system that connects the spinal
cord and brain with the sensory organs,
muscles, and glands.
• Transmits messages b/w your central nervous
system and your sensory organs and muscles.
• It helps your muscles to contract in response
to an INTENTIONAL command.
• A.K.A. Skeletal nervous system
• Controls internal bodily processes as
heartbeat, respiration, digestion, blood
vessels and glands.
• Automatically
• You can control SOME of these functions, ex.
Intentionally breathing more rapidly or
slowly.
• Divided into two divisions: Sympathetic
Nervous System and the Parasympathetic
Nervous System
• Speeds up bodily processes and draws energy
from stored reserves.
• Accelerates your heart rate and breathing
• Provides more fuel/energy for the body by
releasing glucose
• Strong emotions, such as anxiety, fear, or
anger.
• +Accelerator in a car
• Regulates bodily processes, such as digestion.
• Converts food into glucose
• Conserve energy by SLOWING DOWN bodily
processes such as heart rate, breathing, etc.
• Engaged when you are relaxing or digesting a
meal.
• +breaks in a car