Brain Structure and Function If the human brain

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)

Parts of the Brain THALAMUS Relays messages amygdala hippocampus pituitary CEREBELLUM Coordination and balance BRAINSTEM Heart rate and breathing

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 almondshaped 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

The lobes of the cerebral hemispheres Planning, decision making speech Sensory Auditory Vision

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 LEFT RIGHT 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

Brain Plasticity

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 13 th, 1848 • Phineas 25 years old • Rutland & Burlington Railroad, Cavendish, VT • Paving the way for new RR tracks • “Tamping Iron” – 1. 25 in x 3 ft

Phineas Gage • 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=c 6 k. RP 41 ygr. I

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. © 2014, 2011, 2008 by Pearson Education, Inc. All rights

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. © 2014, 2011, 2008 by Pearson Education, Inc. All rights

The Anatomy of a Neuron © 2014, 2011, 2008 by Pearson Education, Inc. All rights

Transmission of Neural Impulses © 2014, 2011, 2008 by Pearson Education, Inc. All rights

Neurotransmitter Functions and Relationships © 2014, 2011, 2008 by Pearson Education, Inc. All rights

Neural Transmission • The Brain's Inner Workings - Part 1 Structure and Function • http: //www. youtube. com/watch? v=C 13 OVRgu. Q r. Q&feature=relmfu • The Brain's Inner Workings - Part 2 – Cognition • http: //www. youtube. com/watch? v=1 Nix. App. WW ec&NR=1&feature=endscreen • Neurons and how they work • http: //www. youtube. com/watch? v=FR 4 S 1 Bqd. F G 4&feature=related

Steps in Neural Transmission Class Challenge Goal: 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=i. E 3 M g. MFf. I 6 U

Introductory Psychology Concepts The Brain - Major Structures and Their Function Amygdala Cerebrum Hippocampus Thalamus Corpus callosum Hypothalamus Pituitary gland Pons Cerebellum Medulla Brain stem Reticular formation Spinal cord