Biology of Psychology Notes Chapter 3 PDF

Maya Picinich Chapter 3 Psychology Notes The Biological Bases of Behavior In the \"Neural Impulse: Using Energy to Send Information\" section, just know what an action potential is - you don\'t need to know the rest of it Right Brain/Left Brain: Cerebral Specialization Chapter Introduction: -...

Maya Picinich Chapter 3 Psychology Notes The Biological Bases of Behavior In the \"Neural Impulse: Using Energy to Send Information\" section, just know what an action potential is - you don\'t need to know the rest of it Right Brain/Left Brain: Cerebral Specialization Chapter Introduction: - S.M. is not afraid of anything, exposed her to fear stimuli yet she stayed calm - It turns out she developed a rare disease that destroyed a small structure called the **amygdala** - Located in both the right and left halves of her brain - Important and crucial control center of fear - Hard for her to detect when she is in danger 3.1: Communication in the Nervous system - When watching a moving a stimulus strikes your eye - Your brain interprets the light stimulus, and signals are flashing to other parts of your body - Behavior depends on rapid information processing - Information travels from your eye to your brain, brain to muscles of your arm and hand, and palms back to brain - Nervous system is complex communication network where signals are received, integrated and transmitted - Handles information Nervous Tissue: The Basic Hardware - Living tissue composed of cells - Cells fall into two major categories: glia and neurons - **Neurons: individual cells in the nervous system that receive, integrate and transmit information** - Basic links that permit communication within the nervous system - Communicate with each other - Some receive signals from outside the nervous system or carry messages from the nervous system to the muscles that move the body - **Soma: (also known as cell body) contains the cell nucleus and much of the chemical machinery common to most cells** - Greek for body - **Dendrites: parts of a neuron that are specialized to receive information** - **Axon fiber: impulses are transmitted** - **Terminal buttons: release chemical messengers that carry signals to other neurons** - **Dendrites send information to the cell body then it travels along the axon** - **Axon: a long, thin fiber that transmits signals away from the soma to other neurons or muscles or glands** - Axons are wrapped in cells with a high concentration of white, fatty substance called myelin - Myelin sheath: insulating material that encases some axon - Helps speed up the transmission of signals that move along the axons - Also stabilizes axon structure and patterns of connectivity in neural networks - Loss of muscle control seen with disease **multiple sclerosis** is due to degeneration of myelin sheets - Some axons have segments that have the sheaths and some don't - Axons end in a cluster of terminal buttons - **Terminal buttons: small knobs that secrete chemicals called neurotransmitters** - Chemicals that transmit information from one neuron to another - Where neurons interconnect are called synapses - **Synapse: a junction where information is transmitted from one neuron to another** - **Information is received at dendrites, passed through soma and along axon, and is transmitted to the dendrites of other cells at meeting points called synapses** **Glia:** - Glia: cells found throughout the nervous system that provide various type of support for neurons - Much smaller than neurons - Equal number of neurons and glial cells - Functions: supply nourishment to neurons, remove neurons waste, provide insulation around axons - Myelin sheaths: derived from special types of glial cells - Some type of glia can detect neural impulses and send signals to other glial cells - Some can feed signals back to neurons - 2 viewpoints of glial: modulate the signaling of neurons - Glial cells shield synapses from "chatter" of surrounding neuronal activity - Glial cells play a role in a variety of major disorders - Dysfunction in glial cells can contribute to the development of schizophrenic disorder or depression. - Glial cells are a key factor in experience of chronic pain, key parts of the body's stress response and the development of epilepsy **The Neural Impulse: Using Energy to send Information** - Voltage of neuron remains constant then the cell is quiet - Neuron is stimulated, channels in its cell membrane open, briefly allowing positively charged sodium ions to rush in - Action potential: a very brief shift in a neuron's electrical charge that travels along an axon - After the firing of action potential, the channels in the cell membrane close up **The Synapse: Where Neurons meet** - Synapses depend on chemical messengers - Synaptic cleft: a microscopic gap between the terminal button of one neuron and the cell membrane of another neuron - Must cross this gap to communicate - **Presynaptic neuron: sends a signal across the gap** - **Postsynaptic neuron: receives the signal** - Neural impulse reaches an axon's terminal button and triggers the release of chemical messengers called neurotransmitters - Specific neurotransmitters can only bind to receptor sites that its molecular structure will fit into like a key and lock - Arrival of an action potential at an axon's terminal buttons triggers the release of neurotransmitters - Most chemicals are stored in small sacks known as synaptic vesicles - Released when a vesicle fuses with the membrane of the presynaptic cells and its contents spill into the synaptic cleft - Receptor sites: tuned to recognize and respond to some neurotransmitters but not others **Receiving Signals: Postsynaptic Potentials** - **Postsynaptic potential: a voltage changes at a receptor site on a postsynaptic cell membrane** - Do not follow the all-or none law as action potentials do - They vary in size, and they increase or decrease the probability of a neural impulse in the receiving cell in a proportion to the amount of voltage change - 2 messages can be sent - Excitatory and inhibitory - excitatory- positive voltage shift that increases the likelihood that the postsynaptic neuron will fire action potentials - inhibitory psp- negative voltage shift that decreases the likelihood that the postsynaptic neuron will fire action potentials - last only a fraction of a second - after the neurotransmitters drift away from the receptor sites or are inactivated by enzymes - some are resorbed - reuptake- a process in which neurotransmitters are sponged up from the synaptic cleft by the presynaptic membrane - allows synapses to recycle materials **Integrating Signals: A Balancing Act** - Neurons are linked in dense networks - receive signals from others - must integrate excitatory and inhibitory signals arriving at many synapses before it decides to fire a neural impulse - linked in chains, pathways, circuits, and networks - The link is fluid - elimination of old plays a bigger role than creation of new synapses - usually more synapses then needed are formed - synaptic pruning- the elimination of old or less-active synapses - sculpting of neural pathways also involves the production of new myelin and the generation of new myelin sheaths - may contribute to learning **Neurotransmitters and Behavior** - specific neurotransmitters function at specific synapses - cant bind to just any site - lock and key Acetylcholine (Ach)-released by motor neurons controlling skeletal muscles -contributes to regulation of attention, arousal, memory -could be stimulated by nicotine \--Alzheimer's - made connection that cells communicate - found in nervous system - motor neurons and voluntary muscles Monoamines: - dopamine, norepinephrine, serotonin Dopamine (DA) -contributes to control of voluntary movement -cocaine and amphetamines elevate activity at DA synapses Dopamine circuits in medial forebrain bundle characterized as reward pathway \--Parkinsonism -movement -memory -pain perception -attention -learning -arousal Norepinephrine -contributes to modulation of mood and arousal -cocaine and amphetamines elevate activity and NE synapses -depressive Serotonin -Involved in regulation of sleep and wakefulness, eating, aggression -Prozac and similar antidepressant drugs affect serotonin circuits -Depressive, anorexia Gaba: -serves as a widely distributed inhibitory transmitter -contributes to regulation of anxiety -anxiety -amino acids -inhibitory effects Endorphins: - internally produced chemicals that resemble opiates in structure and effects - Organization of the Nervous System: - Myth: people only use 10 percent of their brain - 86 billion neurons in the brain - Damage in tiny areas have severe effects **The Peripheral Nervous System:\ ** - Peripheral nervous system-made up of all those nerves that lie outside the brain and spinal cord - Nerves-bundles of neuron fibers that are routed together in the peripheral nervous system - Sub divided into somatic and autonomic The Somatic Nervous System: - Made up of nerves that connect to voluntary skeletal muscles and sensory receptors - Cables that carry information from receptors in the skin, muscles, and joints to the central nervous system - Afferent nerve fibers-axons that carry information inward to the central nervous system from the periphery of the body - Efferent nerve fibers-axons that carry information outward from the central to the periphery The Autonomic nervous system: - Made up of nerves that connect to the heart, blood vessels, smooth muscles and glands - Controls automatic involuntary, visceral functions like heart rate, digestion and perspiration - Fight or flight response - Divided into sympathetic and parasympathetic - Sympathize - the branch of the autonomic nervous system hat mobilizes the body's resources for emergencies - Paratympanic- branch of the autonomic nervous system that generally conserves bodily resources The Central nervous system: - Lies within the skull and spinal column - Brain and spinal cord - Cerebrospinal fluid-nourishes the brain and provides cushion - Blood-brain barrier- semipermeable membrane that stops some chemicals, including drugs, from leaving the bloodstream to enter the brain The Spinal Cord: - Connects the brain to the rest of the body - Runs from base of the brain to the waist The Brain: - 3 pounds Looking Inside the Brain: Research Methods - Lesioning- destroying a piece of the brain - Electrical simulation of the brain-sending a weak electric current into the brain structure to simulate it - CT- computerized tomography - Computer-enhanced X-ray of brain structure - Horizontal slice - MRI-magnetic resonance imaging - Magnet fields, radio waves, and computerized enhancement to map out brain structure - Three-dimensional images - PET-positron emission tomography - Radioactive markers to map chemical activity - Color-coded map - fMRI-functional magnetic resonance imaging - several new variations on MRI tech that monitor blood flow and oxygen to show high activity - Three major regions of the brain - Hindbrain - Midbrain - Forebrain - Found in relation to the brainstem - Connects the cerebrum of the brain to the spinal cord and cerebellum Parts of brain: Cerebrum- sensing, thinking, learning, emotion, consciousness, and voluntary movement Amygdala- emotion and aggression Hypothalamus- regulating basic biological needs: hunger, thirst, temp control Pituitary gland- master gland that regulates other endocrine glans Hippocampus-learning and memory Pons-sleep and arousal Medulla-regulating largely unconscious functions like breath and circulation Spinal cord-transmitting information between brain and rest of body Reticular formation- group of fibers that carry stimulation related to sleep and arousal through brainstem Cerebellum-structure that coordinates fine muscle movement Hindbrain: - Includes the cerebellum, medulla and the pons - Medulla- largely unconscious yet essential functions like breathing, muscle tone and circulation - Pons- bridge of fibers that connect brainstem with cerebellum - Several clusters of cell bodies involved with sleep and arousal - Cerebellum-large and deeply folded structure adjacent to back surface of brainstem - Coordination and helps with balance - Disruption can disrupt motor skills - Recall of emotions??? - 80 percent neurons 10 percent volume Midbrain: - Brainstem that lies between hindbrain and forebrain - Contains an area that helps with sensory processes, vision - Dopamine-releasing neurons - Voluntary movements - Hindbrain-midbrain - Reticular formation-contributes to the modulation of muscle reflexes, breathing, and pain perception - Regulation of sleep and wakefulness Forebrain: - Largest and most complex region of the brain - Includes thalamus, hypothalamus, limbic system and cerebrum - Wrinkled surface of the cerebrum is the cerebral cortex and it looks like a cauliflower The Thalamus: - Structure in the forebrain through which all sensory information must pass to get to the cerebral cortex - Has a number of cell bodies - Integrates information from different senses Hypothalamus: - Structure found near the base of the forebrain that is involved in the regulation of basic biological needs - Lies underneath thalamus - Varius clusters of cells - Communicates and exerts influence with every major subdivision of central nervous system - Four f's-fighting, fleeing-feelings and mating Lymbic system - Loosely connected network of structures located roughly along the border between the cerebral cortex and deeper subcortical areas - Hippocampus - Amygdala - "pleasure centers" - Appear where the medical forebrain bundle passes through the hypothalamus Cerebrum: - Largest and most complex part of the brain - Learning remembering, thinking - Cerebral cortex- convoluted outer layer of the cerebrum - Folded and bent - Divided into two halves - Cerebral hemispheres-right and left - Separated in the center of the brain by a fissure - Descends to a thick band of fibers called the corpus callosum - Major structure that connects the two cerebral hemispheres - Divided into 4 loves Occipital lobe- back of the head, includes cortical area, visual signals are sent Parietal lobe- registers sense of touch Temporal-Auditory and processing Frontal lobe-largest lobe, movement, muscle contraptions Plasticity of the brain: - Flexible - Aspects of experience can sculpt brain structure - Neurogenesis-formation of new neurons - Can be formed in olfactory bulb and hippocampus - Deante gyrus Split brain research: - Cut to reduce severity of seizures - Hemisphere connection is to opposite sides The Endocrine System - Endocrine system-consists of glands that secrete chemicals into the bloodstream to help control bodily functioning - Hormones- chemical substances released by endocrine glands - Pulsatile-several times per day but only last a few minutes - Most of the endocrine system is controlled by the nervous system through the hypothalamus - Pituitary gland-releases a great variety of hormones that fan out within the body stimulating actions in other endocrine glands - Nervous system and endocrine system helps with fight or flight - Hypothalamus sends signals along two pathways - Oxytocin-hormone that is released by pituitary gland and regulates reproductive behavior - May foster empathy and trust Genetics: - Chromosomes: threadlike strands of DNA molecules that carry genetic information - Every cell contains 46 chromosomes - Operate in 23 pairs - Each coming from each parent - Genes-DNA segments that serve as the key units in hereditary transmission - Polygenic-influenced by more than one pair of genes Detecting Hereditary Influence: - Family studies- researches asses hereditary influence by examining blood relatives to see how much they resemble on another on a specific trait - Twin studies-researches asses hereditary influence by comparing the resemblance of identical twins and fraternal twins with respect to a trait - Identical-one egg splits - Fraternal-two eggs are fertilized - Adoption studies- asses hereditary influence by examining the resemblance between adopted children and both their biological and their adoptive parents - Genetic mapping-process of determining the location and chemical sequence of specific genes on specific chromosomes - Epigenetics-the study of heritable changes in gene expression that do not involve modifications to the DNA sequence - Natural selection-heritable characteristics that provide a survival or reproductive advantage are more likely than alternative characteristics to be based on to be subsequence generation and thus be "selected" over time - Adaptation: inherited characteristic that increases in a population because it helped solve a problem of survival or reproduction during the time it emerged Critical period- a limited time span in the development of an organism when it is optimal for certain capacities to emerge because the organism is especially responsible to certain experiences Right brain- musical material Left brain-verbal material Extrapolation-effect is estimated by extending beyond some known values or conditions