Transcript Contemporary psychology Biological foundations of psychology

Contemporary psychology
Biological foundations of
psychology
Ottilia Boross
McDaniel College Budapest
2008
The nervous system
The Central Nervous System
The brain
glial cells
neurons
The building blocks of the nervous system
Neurons
Transmit
neural impulses
messages to
other neurons,
glands and muscles
and vice versa
Three types of neurons
Sensory:
Carry messages from sense receptors toward
the central nervous system
Motor:
Carry messages away from central nervous
system toward the muscles and glands.
Inter-:
Relay messages from one set of neurons to
another.
Neurons from different
part of the body
hippocampus
cortex
Nerve:
bundle of
elongated axons
cerebellum
Nucleus
group of cell bodies of neurons
in the brain and the spinal cord
N
g
u
c
l
e
u
s
:
See: nucleus accumbens
(reward, laughter, pleasure, addiction and fear).
Ganglion:
group of cell bodies of neurons
outside the brain and the spinal cord
see: retina
(vision)
Glial cells
support neurons
provide them with nutritiants
clean up waste
Multiple sclerosis
Structure of the Neuron
Dendrites
Branched fibers that extend outward from the
main cell body and carry information into neuron.
Cell Body
The part of a cell (including neurons) containing
the nucleus - which includes the chromosomes.
Axon
Conducts information from the cell body to the
axon terminals in the form of an electric charge.
Myelin sheath
A fatty insulation coating some types of neural
axons, which speeds conduction of neural impulses.
Axon Terminals
Bulb-like structures at the end of the axon, which contain
neurotransmitters
Action potential
a "spike" of
+ and - ionic discharge
that travels along the
axon (electric impulse)
„All or none”
Action
potential
opens up
the
synaptic
vesicles
Synapse (chemical)
lock-and-key action
Neurotransmitters
• chemicals transmitting information
through the synaptic gap
• bind to the receptors of the
receiving (postsynaptic) neuron
uptake
degradation
reuptake
uptake
degradation
excitatory - inhibitory
Clostridium botulinum
How
botox
works
Alzheimer’s disease
(low level of acetylcholine)
Ronald Reagan
Parkinson’s disease
• Muhammad Ali
Michael J. Fox
(low level of
dopamine)
connects the brain
with the peripheral
nervous system
comprised of cell
bodies and axons
that carry messages
Afferent: toward the
brain (sensory function)
Efferent: away from the
brain (motor function)
The spinal cord
The brain
1.3 - 1.4 kg
1 trillion nerve cells (neurons)
trillions of "support cells" - glia
Functional organization of the
human brain
Brain
Hindbrain
Midbrain
forebrain
Hindbrain
Brainstem
Cerebellum
Hindbrain
Brainstem (primitive portion of brain)
Pons
- dreaming
- sleep regulation
Medulla
-
breathing
heart rate
upright position
nerve tracks cross over
Reticular activating system
- arousal system within the brainstem
Reticular formation
activates the cortex
maintains muscle tone
of"antigravity muscles“
regulates
breathing
heartbeat
sense of pain
arousal
mechanism
coordinates
• movement
• motor learning
• motor planning
Midbrain
connects the
brainstem to
the forebrain
controls sensory processes
brain activity
Forebrain
thalamus
hypothalamus
limbic system
pituitary gland
cerebral cortex
Relay station
between sense
receptors and
the brain
Controls sleep,
wakefulness
Regulates
homeostasis
eating
drinking
hormons
sexual behavior
emotion
stress
The limbic system
Long-term memory
The limbic system
Emotions (fear),
memory
Pituitary gland
Two hemispheres
• Not identical, not symmetrical
• Left brain – dominant (speach center)
• Broca’s area – speach production
• Wernicke’s area – speach understanding
• Corpus callosum – thick bundle of nerves that
interconnects the hemispheres
Split brain
Surgery for epilepsy : cut the corpus callosum
Sperry (1968) & Gazzaniga (1970)
Cerebral Cortex
The Peripheral Nervous System
Autonomic:
controls
self-regulated action of
internal organs and glands
Somatic:
controls
voluntary movements of
skeletal muscles
Sympathetic (arousing)
acts as a unit, simultaneously excites the
different organs of the body
“Fight or Flight”
Parasympathetic (calming)
affects one organ at a time
The
Endocrine
System
“slow” chemical
communication
system
a set of glands
secrete hormones
into the
bloodstream
EEG - electroencephalograph
• the measurement of the
brain’s electrical activity,
recorded from electrodes
placed on the scalp.
Computerized axial tomography, CAT
• threedimensonal
image of the
brain from a
large series
of twodimensional
X-ray images
PET Scanning - positron emission
tomography
• Measuring the brain's blood flow and
metabolic activity.
radioactively labeled
sugar (tracer) is
injected to the blood
MRI - magnetic resonance
imaging
• A powerful magnet realigns the protons of
the body's hydrogen atoms so that they all
spin along the same axis ....
•... normally, the nuclei
of the body's atoms
spin on axes aligned in
all different
directions.
Human Genome
30.000-35.000 genes in the nucleus of
every human cell
DNA
Two strands, twisted
together in a double helix
The links between the
strands are called bases
The sequence of the basepairs is unic to any
individual
DNA
• Each DNA molecule carries many genes
• Genes: the basic phisical and functional
units of heredity. The DNA segments
(specific sequence of bases) carry this
genetic information.
• 99.9 % of our DNA is identical to
everyone else’s
Chromosomes:
• Tightly twisted and coiled
threads of DNA
(deoxyribonucleic acid) +
protein molecules
• Each chromosome contains a
single, long piece (strand) of
DNA
• Chromosome: 0.004 mm
• DNA: 4 cm (10.000 times
longer)
23 pairs
of
chromosomes
Sex chromosomes
Twinstudies
Identical twins
nature or nurture?