Brain Structure and Function. “If the human brain were so simple that we could understand it, we...

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Brain Structure and Function

“If the human brain were so simple that we could understand it, we would be so simple that we couldn’t”

-Emerson Pugh, The Biological Origin of Human Values (1977)

BRAINSTEM Heart rate and breathing

CEREBELLUM Coordination

and balance

Parts of the Brain

amygdala

pituitary

hippocampusTHALAMUS

Relays messages

The Brain• Brainstem

–responsible for automatic survival functions

• Medulla–controls heartbeat

and breathing

Reticular Formation

•Widespread connections •Arousal of the brain as a whole

•Reticular activating system (RAS)

•Maintains consciousness and alertness•Functions in sleep and arousal from sleep

The Cerebellum

–helps coordinate voluntary movement and balance

The Limbic System

• Hypothalamus, pituitary, amygdala, and hippocampus all deal with basic drives, emotions, and memory

• Hippocampus Memory processing

• Amygdala Aggression (fight) and fear (flight)

• Hypothalamus Hunger, thirst, body temperature, pleasure; regulates pituitary gland (hormones)

The Limbic System Hypothalamus

neural structure lying below (hypo) the thalamus; directs several maintenance activities eating drinking body temperature

helps govern the endocrine system via the pituitary gland

linked to emotion (show video)

The Limbic System

• Amygdala –two almond-

shaped neural clusters that are components of the limbic system and are linked to emotion and fear

The Brain• Thalamus

– the brain’s sensory switchboard, located on top of the brainstem

– it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

The Cerebral Cortex

• Cerebral Cortex –the body’s

ultimate control and information processing center

The lobes of the cerebral hemispheres

Planning, decision making speech

Sensory

AuditoryVision

The Cerebral Cortex

• Frontal Lobes– involved in speaking and

muscle movements and in making plans and judgments

– the “executive”

• Parietal Lobes

– include the sensory cortex

The Cerebral Cortex

• Occipital Lobes

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

• Temporal Lobes

– include the auditory areas, each of which receives auditory information primarily from the opposite ear

The Cerebral Cortex

• Frontal (Forehead to top) Motor Cortex

• Parietal (Top to rear) Sensory Cortex

• Occipital (Back) Visual Cortex

• Temporal (Above ears) Auditory Cortex

Brain Lateralization

Our Divided Brains

• Corpus collosum – large bundle of neural fibers (myelinated axons, or white matter) connecting the two hemispheres

Hemispheric Specialization

Symbolic thinking

(Language)

Detail

Literal meaning

Spatial perception

Overall picture

Context, metaphor

Contra-lateral division of labor

• Right hemisphere controls left side of body and visual field

• Left hemisphere controls right side of body and visual field

Split Brain Patients

• Epileptic patients had corpus callosum cut to reduce seizures in the brain

• Lives largely unaffected, seizures reduced• Affected abilities related to naming objects in

the left visual field• left and right brain differences in

learning.m4v• http://www.youtube.com/watch?

v=4Qi5_dANWYo•

Brain Plasticity

• The ability of the brain to reorganize neural pathways based on new experiences

• Persistent functional changes in the brain represent new knowledge

• Age dependent component

• Brain injuries

Environmental influences on neuroplasticity

Impoverished environment

Enriched environment

Phineas Gage

• September 13th, 1848

• Phineas 25 years old

• Rutland & Burlington Railroad, Cavendish, VT

• Paving the way for new RR tracks

• “Tamping Iron”– 1.25in x 3ft

• Accident– Quick Recovery

• Months later: “No longer Gage”– Before: capable, efficient, best foreman, well-balanced

mind– After: extravagant, anti-social, liar, grossly profane

• Stint with P.T Barnum• Died 12 years later• Watch Clip: http://www.youtube.com/watch?

v=c6kRP41ygrI

Phineas Gage

The Nervous System

• The nervous system is made up of neurons, nerve cells that transmit signals or “messages” throughout the body.

• Dendrites – The rootlike structures at the ends of neurons that receive messages from other neurons.

• Axon – The long, thin part of a neuron along which nerve impulses travel.

The Nervous System• Terminals – The small branching structures at the

tips of axons.• Neurotransmitters – Chemical substances that

transmit messages from one neuron to another.• Synapse – The junction between one neuron and

another across which neurotransmitters pass.• Receptor site – A part of a dendrite on a receiving

neuron that is structured to receive a neurotransmitter.

The Anatomy of a Neuron

Transmission of Neural Impulses

Neurotransmitter Functions and Relationships

Neural Transmission

• The Brain's Inner Workings - Part 1 - Structure and Function

• http://www.youtube.com/watch?v=C13OVRguQrQ&feature=relmfu

• The Brain's Inner Workings - Part 2 – Cognition

• http://www.youtube.com/watch?v=1NixAppWWec&NR=1&feature=endscreen

• Neurons and how they work• http://www.youtube.com/watch?

v=FR4S1BqdFG4&feature=related

Steps in Neural Transmission Class ChallengeGoal: gain a hands-on idea of how electrical information is passed along

an axon for neural transmission to occur.• 1 Facilitator and 12 students. • Facilitator- Assign the following roles to each student in

your group: electrical stimulus, dendrite, cell body, axon, myelin sheath (use four students for this one), positive ion, negative ion, terminal button, and neighboring neuron. (use the text to help you understand what each role does)

• Group – Students line up in the correct order of neural transmission.

• Facilitator – Orchestrate the group to ‘act out’ each of the steps and have each student act out their parts as you are going through the steps. Do this a couple of times until you think they have the hang of it. Next, allow the students to run through the steps by themselves. (Extra points for creativity)

Neural Transmission Act 1• electrical stimulus

• dendrite

• cell body

• axon

• myelin sheath (use four students for this one)

• positive ion

• negative ion

• terminal button

• neighboring neuron.

• The Brain – History Channel

• http://www.youtube.com/watch?v=iE3MgMFfI6U

Introductory Psychology Concepts

The Brain - Major Structures and Their Function

ThalamusCorpuscallosum

HypothalamusPituitary gland

PonsMedulla

Reticular formation Spinal cordBrain stem

Cerebellum

CerebrumAmygdala Hippocampus

Brain Structure and Function. “If the human brain were so simple that we could understand it, we...

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