Unit 3 ReviewIncludes information from 3A, 3B, 3C

PHRENOLOGY: BUMPS IN YOUR HEAD

• Early 1800’s German physician Franz Gall invented a popular idea that bumps on our skull reveal mental ability and character traits.

• Britain had 29 Phrenological societies and some traveled to the US to give “skull readings”

Structure of Neurons

• What are Neurons and how do they transmit information?• NEURONS: are nerve cells, the basic building block of the nervous system.

• 3 Types:• Sensory Neurons: carry info from receptors to brain and spinal cord.

• Motor Neurons: carry info from brain and spinal cord to muscles and glands

• Interneurons: neurons within the brain who communicate internally with the other two.

• Action Potential: A brief electrical charge that travels along the Axon of a Neuron

Structure of Neurons

Structure of Neurons

Resting Potential Nothing is happening. The gates are closed and the positive

ions are on the outside with the negative ions on the inside of the cell.

• “Negative Ions inside the Neuron is Natural” Action Potential – (Neural Impulse)

a neural impulse; a brief electrical charge that travels down an axon

generated by the movement of positively charged atoms in and out of channels in the axon’s membrane

This process is due to stimulation from either heat, chemicals, pressure or light

The Neural Impulse

• Polarization• When the inside of the Neuron is negatively charged relative to the outside

(resting potential)

• Depolarization• When the electrical charge of a cell moves toward zero

Neural Impulse

• Refractory Period• The time it takes for the positive ions to be pumped out.

Threshold the level of stimulation required to trigger a neural impulse

All or None Law : Neurons either fire or don’t. there is no half way. Like a gun, car, or toilet.

Excitatory signals : “Step on the Gas”

Inhibitory Signals: hit the “Brakes”

Transmission Between Neurons

• Synaptic vesicles• Sacs in terminal button that release chemicals into synaptic space

• Neurotransmitters• Chemicals released by synaptic vesicles

• Receptor sites• Location on receptor neuron for specific neurotransmitter

• Reuptake• Neurotransmitters in the synapse are reabsorbed

into the sending neurons through the process of reuptake

Synapse

Synapse [SIN-aps] a junction between the axon tip of the sending neuron and the dendrite or

cell body of the receiving neuron. This tiny gap is called the synaptic gap or cleft.

Agonists

Antagonists

Neural Communication

The Nervous System

The Nervous System

• Nervous System: The bodies speedy, electrochemical communication network.

• Central Nervous System (CNS): the brain and spinal cord• Peripheral Nervous System (PNS): the sensory and motor neurons

that connect the body to the CNS

Peripheral Nervous System

• Somatic Nervous System: Controls Voluntary Actions. (I volunteer “Somah” community is a better place. )

• Autonomic Nervous System: Controls our glands and muscles of internal organs.. “My love, you Autonomically make my heart beat”

• Sympathetic Nervous System: arouses and expands energy. When I feel sympathy for someone, my heart beats for them.

• Parasympathetic Nervous System: Conserves energy and calms the body. ”I’m so calm I feel paralyzed.”

Endocrine System

• Endocrine System: the body’s “Slow” communication system. • Hormones: Chemical messengers that travel through the body and

brain and affect our behavior. • Adrenal Glands: secrete hormones that arouse the body in times of

stress. • Pituitary Glands: Regulates growth and controls the other endocrine

glands.

The Endocrine System

Endocrine System the body’s “slow”

chemical communication system

a set of glands that secrete hormones into the bloodstream

Tools of Discovery: How do we study the brain?

Early Methods

• Observation: Clinical Observations of patients revealed some brain-mind connections.

• For example: Damage To• one side of brain caused paralysis

on opposite side of body. • back of brain disrupts vision.• left front of brain causes speech

difficulties.

Modern Methods

• Modern methods record the brains electrical, metabolic, and magnetic signals using various techniques.

• Brain Lesion• EEG• CT Scan• PET Scan• MRI• fMRI

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Brain Stem

The Medulla [muh-DUL-uh] is the base of the

brainstem that controls heartbeat and breathing.

Pons: is involved in motor control and sensory analysis... for example, information from the ear first enters the brain in the pons. It has parts that

are important for the level of consciousness and for sleep.

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Brain Stem

Pons and inside that the (Reticular Formation) is a nerve network in the brainstem that plays an important role in controlling arousal.

•It is involved in motor control and sensory analysis... for example, information from the ear first enters the brain in the pons. It has parts that are important for the level of consciousness and for sleep.

The Reticular Formation controls:•Attention •Cardiac Reflexes •Motor Functions •Regulates Awareness •Relays Nerve Signals to the Cerebral Cortex •Sleep

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Brain Stem

The Thalamus [THAL-uh-muss] is the brain’s

sensory switchboard, located on top of the brainstem. It directs

messages to the sensory areas in the cortex and transmits replies to the

cerebellum and medulla.

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The “little brain” attached to the rear of the brainstem. It

helps coordinate voluntary

movements and balance.

Cerebellum

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The Limbic System is a doughnut-shaped

system of neural structures at the

border of the brainstem and

cerebrum, associated with emotions such as fear, aggression and drives for food and sex. It includes the

hippocampus, amygdala, and hypothalamus.

The Limbic System

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Amygdala

The Amygdala [ah-MIG-dah-la] consists of two almond-shaped neural clusters linked to the emotions of fear and

anger.

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Hypothalamus

The Hypothalamus lies below (hypo) the

thalamus. It directs several maintenance activities like eating,

drinking, body temperature, and control

of emotions. It helps govern the endocrine

system via the pituitary gland.

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The Cerebral CortexThe intricate fabric of interconnected neural cells

that covers the cerebral hemispheres. It is the body’s ultimate control and information processing

center.

The Cerebral Cortex

Frontal Lobes involved in speaking and muscle movements and in making

plans and judgments Parietal Lobes

include the sensory cortex Occipital Lobes

include the visual areas, which receive visual information from the opposite visual field

Temporal Lobes include the auditory areas

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The Cerebral Cortex

Aphasia impairment of language, usually caused by left hemisphere

damage either to Broca’s area (impairing speaking) or to Wernicke’s area (impairing understanding)

Broca’s Area an area of the left frontal lobe that directs the muscle

movements involved in speech Wernicke’s Area

an area of the left temporal lobe involved in language comprehension and expression

zombie brains

Split Brain

• Corpus Callosum• the large band of neural fibers connecting

the two brain hemispheres and carrying messages between them.

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• Split Brain• a condition resulting from surgery that

isolates the brain’s two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them.

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Genes: Our Codes for Life

•Chromosome•DNA (deoxyribonucleic acid)•Genes

• Active (expressed) vs. inactive

•Genome

Twin and Adoption StudiesIdentical Versus Fraternal Twins

• Identical twins•Fraternal twins

Twin and Adoption StudiesIdentical Versus Fraternal Twins

Heritability

•Heritability = the proportion of variation among individuals that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and environments studied.

• “difference among people”

Natural Selection and Adaptation

•Evolutionary psychology• Natural selection

• Mutation• Adaptation• Fitness

Evolutionary Success Helps Explain Similarities

•Behaviors that contribute to survival are found throughout cultures

• Ex : Our attraction to fatty and sweet foods• Ex : Differing attitudes about sex between men and women

Critiquing the Evolutionary Perspective

•Backward theorizing – Hindsight Bias•Impact of social influence