Biology and Psychology

Examine the effects of our physiological states on our thinking

and behavior.

Internet Listening & Viewing:Radio Lab (www.wnyc.org)

Season One: “Who Am I?” & “Emergence” Season Three: “Sleep”

Youtube: “Pinky & the Brain” (seriously!) Learning Objectives:

Evolutionary Psychology Neurons, Neurotransmitters The Nervous Systems

Brain, including the Cerebral Cortex Endocrine System

Biology and Psychology

Evolutionary Psychology“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

Dizygotic Twins (DZ) 2 zygotes = fraternal twins

Nature (heredity) and Nurture (environment) Science and Religion

Neurons 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 Sensory (Afferent)

from sensory receptors to brain/spinal cord

Motor (Efferent) from brain/spinal cord to

muscles/glands

SENSORY (Afferent) NEURONS NEUROTRANSMITTERS

DENDRITES

CELL BODY (SOMA)

Axon Hillock

Axon Terminals

SYNAPSE (junction)

AXON

PRE-SYNAPTIC POST-SYNAPTIC

MOTOR (Efferent) NEURON

DENDRITES

CELL BODY (SOMA) Nodes

of Ranvier

AXON TERMINALS

Myelin Sheath

AXON

Synapse (junction) NEUROTRANSMITTERS

Axon Hillock

PRE-SYNAPTIC POST-SYNAPTIC

Neurons: Important Parts Cell Body (Soma) (stores energy) Axon (transmits impulses)

up to 3’ long the bigger, the more vulnerable

Dendrites (receives messages) “ears”, rootlike structures

Neurons: Important Parts Myelin Sheath (fat-like casing) Axon Hillock (amplifier, relay) Axon Terminal

connects axon to new dendrite Synapse (junction)

Neurons: Important Parts Glial Cells

support, guide and help repair the neuron

produce myelin nourish & insulate neuron direct growth, remove waste

How Neurons “Fire” 2 States: Resting & Action

“nervous irritability” - electrical stimulation

excitatory or inhibitory abnormal firing

Neural Communication 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 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) Voluntary movements (muscle), learning,

memory, & sleep. PNS: activates muscles, slows ParaSymp Brain: breathing, attention, arousal,

motivation Botox, Food Poisoning, Perspiration, Strokes

Noradrenaline Derived from Dopamine. Brainstem, heartbeat, arousal (alertness),

eating, mood disorders. Too much - Schizophrenia, Too little - Depression.

Role in smoking & hunger.

Dopamine “Euphoria” (amine group) Voluntary movements, learning,

memory, attention. Too little - Parkinson’s (L-Dopa) Too much - Schizophrenia,

Dopamine Hypothesis – New research indicates the role of Glutamate may more important.

Endorphins Endogenous Morphines “pleasure” Pain messages in the brain.

Hot peppers (capsaicin) Runner’s High Role in physical trauma.

Serotonin Emotional arousal (anxiety [esp. OCD] &

mood disorders) Sleep, appetite, impulse and aggressive

behaviors. All hallucinogens simulate Serotonin.

Serotonin 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 System2 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.

Autonomic

Autonomic Nervous System Regulates glands, muscles of internal

organs, and activities including: Heartbeat, respiration, dilation, & digestion.

Has two branches: Sympathetic: “Accelerator” / “Fight or Flight” Parasympathetic: “Brake” - deep breaths

Central Nervous System 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. Weighs approx. 3 lbs., 85% water Uses approx. 20% of body’s energy Development continues to age 20

Historical views: Ancient Greeks & Chinese,

Egyptians Middle Kingdom

Brain3 Parts:

Hindbrain (oldest) Vital bodily functioning

Midbrain coordinating sensory functioning

Forebrain (newest) largest. houses Cerebral Cortex

Hindbrain Where spinal cord meets brain 3 Structures:

Medulla Pons Cerebellum (“little brain”)

BRAIN STRUCTURES MIDBRAIN & HINDBRAIN

1. Cerebellum (little brain)-maintains balance/coordination motor movement, impacts sensory info, virtually unchanged throughout evolution.

2. Reticular Formation (netlike) finger shaped, important in control of arousal, sleep & wake cycles for alertness.

MIDBRAIN Consciousness

Plays a role in vision & audition, coordinates basic movements with sensory information, vital to attention sleep & arousal. 1.Tegmentum motor movement

2. Tectum visual/auditory cells Governs whole body movements in response to light & sound.

Birds/Lower animals these structures are their visual & auditory brains.

corpus callosum

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.

HINDBRAIN Vital bodily functioning

“reptilian brain”-these structures are equal the entire reptile’s brain.

Midbrain 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 Thalamus, Hypothalamus,

Limbic System, Basal Ganglia, & Cerebrum.

Cerebral Cortex “Brain” thought & language 2 hemispheres, 4 lobes

BRAIN STRUCTURES FOREBRAIN 1. Thalamus

(“chamber/inner room”, egg shaped). “Communication center for the senses”, Brain’s sensory switchboard, relays sensory information to cerebral cortex, aids in per-ception.

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.

3. Basal Ganglia postural movements, limb coordination.

a. Hippocampus (“seahorse”) memory b. Amygdala (“almond”) fear, aggression, learning & memory c. Olfactory BulbOlfactory Bulb — olfaction

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

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:

FRONTAL

CEREBRAL CORTEX OVERVIEW

PARIETAL

TEMPORAL OCCIPITAL

Total surface area is approximately 324 sq. inches. (full page of a newspaper) 1/8” thick covering of the cerebrum (tangles of axons and dendrites) There are four lobes (covers both hemispheres) Cortex = bark (tree)

CEREBRAL CORTEX FRONTAL LOBE

Reasoning planning parts of speech movement (motor cortex)

Humans have very large frontal lobes.

PARIETAL LOBE Some language perception [touch, pressure, pain]

TEMPORAL LOBE Audition

OCCIPITAL LOBE Vision

Central Fissure

Prefrontal Cortex Problem solving complex thought Creation of expectation emotions

Broca’s Area [Part of the Frontal lobe] [Left hemisphere only]

Speech production & articulation

Wernicke’s Area [Part of the Temporal lobe]

[Left hemisphere only] Language comprehension

Lateral Fissure

Visual Cortex Detection of simple visual

stimuli Reading music

Pheromones 1959 “Carrier of excitement” Odors, sweat Humans not really sensitive, but

animals are. Vomeronasal organ (VNO) Wellesley Effect (M. McClintock)

Aphasia Impaired ability to comprehend or express

oneself through language. Broca’s Aphasia (left hemisphere) Wernicke’s Aphasia (left hemisphere)

Endocrine System Behavioral Effects, ductless glands feedback circle (steady states) regulated by hypothalamus hormones (slow)

secreted into bloodstream horman (Greek) “to stimulate, excite”

Endocrine Structures Hypothalamus

“master of the master gland” influences Pituitary gland only

Pituitary Gland central to the body’s functioning regulates other glands via hormones

Thyroid Gland body’s accelerator effects metabolism (weight)

Endocrine Structures Pineal gland

melatonin: sleep-wake cycle Pancreas: blood / sugar level

Adrenal Glands involved in stress, fear, & anxiety regulated by Pituitary Gland

Testes & Ovaries menstrual cycle