Chapter 3 \"Biology and Behavior\" Psychology Notes PDF

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introduction to psych lecture notes in order...

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Chapter 3: Biology and Behaviour Module 2A The Neurons and the Neurotransmitters Watch “How the Brain Works Part 1”

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The Neurons: Billions of Brain Cells

What is a Neuron? •

Specialized cell.

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Conducts impulses throughout nervous system.

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Cell Body. Dendrites. Axon.

What are its 3 parts?

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3 types of Neurons Afferent (sensory) neurons relay messages from the sense organs and receptors - eyes, ears, nose, mouth, and skin- to the brain or spinal cord. Efferent (motor) neurons convey signals from the brain and spinal cord to the glands and muscles, enabling us to move. Interneurons thousands of times more numerous than sensory or motor neurons, carry information between neurons in the brain and between neurons in the spinal cord. 3 Parts of the Neuron

1. Cell Body • •

Contains the nucleus. Carries out metabolic functions.

2. Dendrites • Branch-like extensions of a neuron. • Receive signals from other neurons muscles, glands, sense organs 3. Axon • • •

Slender, tail-like extension of neuron. Transmits signals. See pg 60 image to understand this

Myelin Sheath • White, fatty coating wrapped around some axons. • Acts as insulation and enables impulses to travel much faster. • Degeneration of myelin ---- multiple sclerosis (jerky, uncoordinated movements) Glial Cells •

Help make brain more efficient by  Holding neurons together.  Removing waste products, e.g.: dead neurons.  Making myelin coating for axons.  Performing other manufacturing, nourishing, and clean-up tasks.

The Synapse

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Junction where axon of sending neuron communicates with receiving neuron across synaptic cleft.

Neurotransmitter •

Chemical produced by the body (75 of them) released into synaptic cleft from axon terminal of sending neuron. • •

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Crosses synapse and binds to appropriate receptors on dendrites or cell body of receiving neuron. Influences cell to fire/not fire.

Neural Impulse Begins Thought and Action

Resting Potential • Neuron is at rest (not firing).

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Inside of neuron has slight negative electrical charge compared to outside.

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Referred to as neuron’s resting potential.

Action Potential • When a neuron is stimulated. •

Positively charged particles flow into cell.

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Makes inside suddenly positive compared to outside of cell. This sudden reversal is called action potential. See image pg 62

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Neurotransmitters: Chemical Messengers

Receptors • •

Sites on dendrite or cell body of neuron. Interacts with specific neurotransmitters.

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Neurotransmitter molecules taken from synaptic cleft back into axon terminal.

Reuptake Terminates excitatory or inhibitory effect on receiving neuron.

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See image pg 63 Neurotransmitters (Chemicals) What do they do? ACETYLCHOLINE • Excitatory or inhibitory effects. • Excites skeletal muscle fibres. • Inhibits heart muscle fibres. • Excites neurons involved in learning new information. THE MONOAMINES Dopamine •

Excites learning, attention, movement, and reinforcement.

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Inhibits learning, attention, movement, and reinforcement.

Norepinephrine • Affects eating habits, alertness, and wakefulness. Epinephrine • Affects metabolism of glucose. Serotonin • •

Inhibitory. Role in mood, sleep, impulsivity, aggression, appetite.

AMINO ACIDS Glutamate (glutamic acid) • Primary excitatory neurotransmitter in brain. GABA (gamma-aminobutyric acid) • Main inhibitory neurotransmitter in brain. • Widely distributed throughout CNS. • Facilitates control of anxiety in humans. Connected to PTSD Endorphins • Opiate-like substances.

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Relief from pain or stress of vigorous exercise.

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Produce feelings of pleasure and well-being.

This is where you get a runners high To increase understanding Watch episode 3 Biological Psychology part 2 In the Real World: Neurotransmitters What’s in it for me? Your Brain on Drugs

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Module 2B

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The Central Nervous System To assist understanding this unit Watch episode 3 biological psychology Basics: How the Brain Works part 2

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Nervous System

Nervous System has two parts: Central Nervous System (CNS) • Brain. • Spinal cord, an extension of brain. Peripheral Nervous System Connects CNS to all other parts of body.

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See images on pg 66 • •

Divisions of the Human Nervous System The Brainstem 3 parts

Brainstem •

Begins at site where spinal cord enlarges as it enters skull.

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Controls automatic functions. Heartbeat, breathing, blood pressure, coughing, swallowing.

1.Medulla

2. Reticular Formation • Regulates arousal and attention. • Screens messages entering brain. • Remember selective attention? 3.Pons

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Major Structures of the Human Brain The Cerebellum

Cerebellum • • • • •

Plays role in movement, sleep, dreaming.

Means “little cerebrum.” Contains two hemispheres. Executes smooth, skilled body movements. Regulates muscle tone and posture.

Thalamus and Hypothalamus

Thalamus •

Located above brainstem.

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Relay station for information flowing into and out of higher brain centres.

– All sensory information flows through here to the correct area for processing Hypothalamus • Regulates hunger, thirst, sexual behaviour, emotional behaviours. body temperature, and our biological clock. •

Limbic System

Limbic System • Includes amygdala and hippocampus. • Collectively involved in emotion, memory, motivation. Amygdala •

Emotion, responses to aversive stimuli. Anxiety/PTSD

Hippocampus • Formation of long-term memories. Mapping. Module 2C The Cerebral Hemispheres Pg 69-74 Self study!! You can do it!! Complete the “Remember it” Box on page 74 to test your understanding! Module 2D Specialization of the Cerebral Hemispheres

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Cerebral Hemispheres

Lateralization • Specialization of cerebral hemisphere. Left Hemisphere • Controls right side of body. • Coordinates complex movements. • Controls production of speech, written language, reading, math logic. Right Hemisphere • Controls left side of body. • Specialized for visual-spatial perception, music, drawing following images. • Recognizes faces, patterns, voices •

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Specialized for understanding nonverbal behaviour .split brain

The Split Brain

Split-Brain Operation • Performed in severe causes of epilepsy. •

Corpus callosum cut, separating cerebral hemispheres.

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Usually lessens severity and frequency of grand mal seizures. Complete My psych lab hemispheric specialization experiment which brain dominance are you?? Module 2E

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The Brain across the Lifespan The Brain Across the Lifespan Brain grows in spurts. Spurts in childhood and adolescence correlated with major advances in physical and intellectual skills. Brain both gains and loses synapses throughout life.

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Brain weight begins to decline around age 30.

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Brain Damage Hippocampus can regenerate neurons. Damaged neurons can sprout new dendrites. Damaged neurons can re-establish connections with other neurons. Can assume some functions of lost brain cells.

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Axons can regenerate and grow. Plasticity= brain’s ability to reorganize and compensate for brain damage. Plasticity Module 2F Discovering the Brain’s Mysteries Pgs 79 &80 self study Module 2G

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The Peripheral Nervous System Peripheral Nervous System (PNS) • Nerves connecting CNS to body. • Autonomic NS. • Somatic NS. Somatic and Autonomic Nervous Systems

Somatic Nervous System • All sensory nerves transmitting information from sense receptors to CNS. • All motor nerves relaying messages from CNS to skeletal muscles. Under conscious control. Autonomic Nervous System • Transmits messages between CNS and glands, cardiac muscle, smooth muscles. Operates automatically • • The Human Nervous System Autonomic Nervous System, ctd

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Sympathetic Nervous System Triggered in response to threatening stimuli Prepares body for fight or flight Physiological changes provide extra strength, endurance and speed in order to maximize emergency response fight or flight fight

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Physical Effects Increased heart rate – pounding heart Muscle tension – trembling Rapid, shallow breathing Sweating Dry mouth Dizziness

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7. Goose bumps 8. Insensitivity to pain 9. Dilated pupils 10. Jumpy, easily startled Perceptual Effects Loss of peripheral vision – tunnel vision Hearing distortions – loud sounds seem quieter Time distortions – usually slows down Dissociation – events seem unreal, dreamlike or like you’re looking at yourself from outside 5. Visual clarity – see detail well • 1. 2. 3. 4.

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Cognitive Effects Loss of creative thinking Mental inflexibility Jump to conclusions Memory gaps and distortions Automatic pilot – little conscious thought Intrusive distracting thoughts not related to situation

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Parasympathetic Nervous System Returns body to calm, relaxed state Promotes recuperation Triggered by eating, deep muscle relaxation, meditation, yoga, controlled breathing parasympathetic Module 2H The Endocrine System Self Study this unit!! You can do it!...