Transcript Biology and Psychology - Austin Community College

Biology and Psychology
Examine the effects of our
physiological states on our thinking
and behavior.
Biology and Psychology
Internet Listening & Viewing:
Radio Lab (www.wnyc.org)
Season One: “Who Am I?” & “Emergence”
Season Three: “Sleep”
Youtube: “Pinky & the Brain” (seriously!)
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Learning Objectives:
Evolutionary Psychology
Neurons, Neurotransmitters
The Nervous Systems
Brain, including the Cerebral Cortex
Endocrine System
Evolutionary Psychology
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“The Struggle For Existence”
Intention versus Instinct
Adaptation and Natural Selection connected with
behavior and mental processes.
Charles Darwin: Heredity, Genes, & Chromosomes
Monozygotic Twins (MZ) 1 zygote = identical twins
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Dizygotic Twins (DZ) 2 zygotes = fraternal twins
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Nature (heredity) and Nurture (environment)
Science and Religion
Neurons
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A single nerve cell.
“building blocks of the nervous system”
Born with 100+ billion (brain)
transmit hundreds of messages /second
Neural impulse
electrochemical discharge
Neurons: 2 Types
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Sensory (Afferent)
from
sensory receptors to
brain/spinal cord
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Motor (Efferent)
from
brain/spinal cord to
muscles/glands
SENSORY (Afferent) NEURONS
NEUROTRANSMITTERS
SYNAPSE
(junction)
PRE-SYNAPTIC
POST-SYNAPTIC
CELL BODY
(SOMA)
AXON
Axon Hillock
DENDRITES
Axon Terminals
MOTOR (Efferent) NEURON
Synapse
(junction)
NEUROTRANSMITTERS
PRE-SYNAPTIC
DENDRITES
POST-SYNAPTIC
Axon
Hillock
Myelin
Sheath
AXON
CELL BODY
(SOMA)
Nodes
of
Ranvier
AXON TERMINALS
Neurons: Important Parts
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Cell Body (Soma) (stores energy)
Axon (transmits impulses)
up
to 3’ long
the bigger, the more vulnerable
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Dendrites (receives messages)
“ears”,
rootlike structures
Neurons: Important Parts
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Myelin Sheath (fat-like casing)
Axon Hillock (amplifier, relay)
Axon Terminal
connects axon to new dendrite
Synapse (junction)
Neurons: Important Parts
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Glial Cells
support,
guide and help repair
the neuron
produce myelin
nourish & insulate neuron
direct growth, remove waste
How Neurons “Fire”
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2 States: Resting & Action
“nervous
irritability” - electrical
stimulation
excitatory or inhibitory
abnormal firing
Neural Communication
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Messages enter through the dendrites and
travel along the axon.
Sent from axon terminals to muscles,
glands, and other neurons.
Neurotransmitters are released in Synaptic
Cleft and taken up by next dendrite.
Neurotransmitters
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Chemical substances involved in the
transmission of neural impulses.
Change electrical charges into chemical
signals.
Made from amino acids.
Each sends many messages.
Acetylcholine (Ach)
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Voluntary movements (muscle), learning,
memory, & sleep.
PNS: activates muscles, slows ParaSymp
Brain: breathing, attention, arousal,
motivation
Botox, Food Poisoning, Perspiration, Strokes
Noradrenaline
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Derived from Dopamine.
Brainstem, heartbeat, arousal (alertness),
eating, mood disorders.
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much - Schizophrenia,
 Too little - Depression.
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Role in smoking & hunger.
Dopamine
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“Euphoria” (amine group)
Voluntary movements, learning,
memory, attention.
little - Parkinson’s (L-Dopa)
 Too much - Schizophrenia,
Dopamine Hypothesis – New
research indicates the role of
Glutamate may more important.
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Endorphins
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Endogenous Morphines “pleasure”
Pain messages in the brain.
Hot
peppers (capsaicin)
Runner’s High
Role in physical trauma.
Serotonin
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Emotional arousal (anxiety [esp. OCD] &
mood disorders)
Sleep, appetite, impulse and aggressive
behaviors.
All hallucinogens simulate Serotonin.
Serotonin
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Depression Treatments (too little)
“SSRI” Paxil, Zoloft, Prozac: Increase the
availability (effects) of Serotonin.
“MAOI” (monoamine oxydase Inhibitors)
Inhibit the effects of Serotonin.
Effects of Ecstacy and Cocaine.
The Nervous System
2 main divisions:
Peripheral: software
Central: hardware/cpu
Peripheral Nervous System
Consists of sensory and motor neurons
that transmit messages to and from CNS.
 Without it, we’d be isolated from the world.
2 Main Divisions:
 Somatic (sensory) connects CNS with
sensory receptors, skeletal muscles, &
surface of the body.
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Autonomic
Autonomic Nervous System
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Regulates glands, muscles of internal
organs, and activities including:
 Heartbeat,
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respiration, dilation, & digestion.
Has two branches:
“Accelerator” / “Fight or Flight”
 Parasympathetic: “Brake” - deep breaths
 Sympathetic:
Central Nervous System
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Spinal Cord
“information superhighway”
Column of nerves within spine.
All messages travel through this
structure.
Brain
Brain
2 Hemispheres connected by corpus callosum, and
contains no nerve endings.
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Weighs approx. 3 lbs., 85% water
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Uses approx. 20% of body’s energy
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Development continues to age 20
Historical views: Ancient Greeks & Chinese,
Egyptians Middle Kingdom
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Brain
3 Parts:
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Hindbrain (oldest) Vital bodily functioning
Midbrain
coordinating
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sensory functioning
Forebrain (newest) largest.
houses Cerebral Cortex
Hindbrain
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Where spinal cord meets brain
3 Structures:
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Medulla
Pons
Cerebellum (“little brain”)
BRAIN STRUCTURES
MIDBRAIN & HINDBRAIN
corpus callosum
MIDBRAIN
Consciousness
Plays a role in vision & audition, coordinates
basic movements with sensory information,
vital to attention sleep & arousal.
1.Tegmentum motor movement
HINDBRAIN
Vital bodily functioning
“reptilian brain”-these structures are
equal the entire reptile’s brain.
2. Tectum visual/auditory cells
Governs whole body movements in response to
light & sound.
1. Cerebellum (little brain)-maintains balance/
coordination motor movement, impacts sensory info,
virtually unchanged throughout evolution.
Birds/Lower animals these structures are their
visual & auditory brains.
2. Reticular Formation (netlike) finger shaped,
important in control of arousal, sleep & wake cycles
for alertness.
3. Pons (bulge, “bridge”) helps control eye & facial expressions,
attention, respiration, sleeping & dreaming, alertness.
4. Medulla (continuation of spine) regulates heartbeat,
digestion, blood pressure, respiration.
Midbrain
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Coordinates basic movements with
sensory information.
Houses Reticular Activation System
(RAS) - aids in control of arousal,
sleep and wake cycles for alertness.
 Alcohol
lowers activity of RAS.
Forebrain
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Thalamus, Hypothalamus,
Limbic System, Basal Ganglia,
& Cerebrum.
Cerebral Cortex “Brain”
 thought
& language
 2 hemispheres, 4 lobes
1. Thalamus
(“chamber/inner room”, egg shaped).
“Communication center for the senses”,
Brain’s sensory switchboard, relays sensory
information to cerebral cortex, aids in perception.
2. Hypothalamus
(also part of the Endocrine system / Controls
Endocrine & ANS)
Hunger, thirst, sexual behavior, caring for
offspring, aggression, some motivation &
emotion.
The 4 “F’s”:
Feeding, Fleeing, Fighting, & Fornication
3. Basal Ganglia
postural movements, limb coordination.
BRAIN STRUCTURES
FOREBRAIN
corpus callosum
5. Cerebrum “crowning glory of the brain”
Only in humans is it such a large part of
the brain. Cognitive abilities of thinking
and language, connected by the corpus
callosum, houses the cerebral cortex.
4. Limbic System (emotional/smell brain)
A system of checks and balances.
Memory, motivation & emotion
[laughter, love, rage, lust & fear].
Located on the inner edge of cerebrum.
LIMBIC SYSTEM STRUCTURES:
a. Hippocampus (“seahorse”) memory
b. Amygdala (“almond”) fear, aggression, learning & memory
c. Olfactory Bulb — olfaction
CEREBRAL CORTEX
OVERVIEW
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Total surface area is approximately 324 sq. inches. (full page of a newspaper)
1/8” thick covering of the cerebrum (tangles of a xons and dendrites)
There are four lobes (covers both hemispheres)
Cortex = bark (tree)
FRONTAL
TEMPORAL
PARIETAL
OCCIPITAL
CEREBRAL CORTEX
FRONTAL LOBE
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Reasoning
planning
parts of speech
movement (motor cortex)
Humans have very large frontal
lobes.
PARIETAL LOBE
 Some language
 perception
Central Fissure
[touch, pressure, pain]
Prefrontal Cortex
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Problem solving
complex thought
Creation of expectation
emotions
OCCIPITAL LOBE
 Vision
Visual Cortex
Broca’s Area
[Part of the Frontal lobe]
[Left hemisphere only]
 Speech production & articulation Lateral Fissure
TEMPORAL LOBE
 Audition
 Detection of simple visual
stimuli
 Reading music
Wernicke’s Area
[Part of the Temporal lobe]
[Left hemisphere only]
 Language comprehension
Pheromones
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1959 “Carrier of excitement”
Odors, sweat
Humans not really sensitive, but
animals are.
Vomeronasal
organ (VNO)
Wellesley Effect (M. McClintock)
Aphasia
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Impaired ability to comprehend or express
oneself through language.
 Broca’s Aphasia
(left hemisphere)
 Wernicke’s Aphasia (left hemisphere)
Endocrine System
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Behavioral Effects, ductless glands
feedback circle (steady states)
regulated by hypothalamus
hormones (slow)
 secreted
into bloodstream
 horman (Greek) “to stimulate, excite”
Endocrine Structures
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Hypothalamus
 “master
of the master gland”
 influences Pituitary gland only
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Pituitary Gland
 central
to the body’s functioning
 regulates other glands via hormones
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Thyroid Gland
 body’s
accelerator
 effects metabolism (weight)
Endocrine Structures
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Pineal gland
 melatonin:
sleep-wake cycle
 Pancreas: blood / sugar level
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Adrenal Glands
 involved
in stress, fear, & anxiety
 regulated by Pituitary Gland
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Testes & Ovaries
 menstrual
cycle