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PSYC_NOTE-C3

By Juanita Mcdonald,2014-07-03 08:24
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PSYC_NOTE-C3

    PSYCHOLOGY 100

    Chapter 3:

    Biological Psychology: Bridging the Levels of Analysis

Outline:

    ; Nerve Cells

    ; Brain-Behavior Network

    ; The Endocrine System

    ; The Brain in Action

    Biological Psychologists/Neuroscientists: Researchers who study the relationship between the nervous system and behavior. Bridging the gap between the nervous system and our behavior allows us to span multiple levels of analysis.

Nerve Cells

    ; Neurons are brain cells that specialize in communication

    ; There are around 100 billion neurons, with around 160 billion connections between them

    ; Oddly shaped compared to other cells in the body, they have a number of specific features

Neuronal Components

    ; Cell body (soma): Center of neuron; builds new cell components

    ; Dendrites: Branch like extension that receive information from other neurons

    ; Axons: “Tails” of the neuron that spread out from the cell body and transmit information

    Glial Cells

    ; Cells in the nervous system that:

    Play a role in the formation of myelin and the blood brain barrier

    Respond to injury

    Remove debris

    Enhance learning and memory

    ; Plentiful in the brain (1:1 ratio with neurons)

    ; Astrocytes most abundant: Increase reliability of neuronal transmission ; Ogliodendrocytes: Promote new connections and produce the myelin sheath

    around axons

    Multiple Sclerosis: Myelin sheaths are eaten away. Messages become

    scrambled.

    Electrifying Thought

    ; Neurons respond to neurotransmitters by generating electrical activity ; When there are not neurotransmitters acting on a neuron, it is at the resting

    potential

    ; When there is enough of a charge inside the neuron (threshold), an action

    potential will occur

    Action Potentials

    ; Abrupt waves of electric discharge triggered by a change in charge inside the

    axon

    ; This is the neuron “firing,” an all-or-none response

    ; Originates near cell body and travel down the axon to the axon terminal, triggering

    neurotransmitter release

    ; Neurons can fire 100 to 1,000 times per second

    ; In between firings, there is a very brief absolute refractory period

    ; The longer the axon, the more limited their maximal firing rate is

    Neurotransmission

    ; This process is halted by reuptake, when NTs go back into the axon terminal

    ; Neurotransmitters vary in their messenges: some excite and others inhibit the

    nervous system

    ; Each neurotransmitter has a specific role and function in brain and body function

; Monoamines only contain one amino acid

    Norepinephrine and serotonin influence arousla and response to stimuli

    Dopamine plays role in response to rewarding experiences ; Neuropeptides are specialized functioning (like endorphins for pain relief) ; Anandamides binds to same receptors at THC, influences eating, motivation,

    memory, and sleep

Psychoactive Drugs

    ; Psychoactive drugs target the production or inhibition of certain neurotransmitters

    and impact mood, arousal, or behavior

    ; Opiates mimic endorphins and increase activity (agonists), while selective

    serotonin reuptake (SSR) blocks reuptake of serotonin

    ; Agonists decrease activity, like dopamine blockers for schizophrenia

Neural Plasticity and Learning

    ; Neurons from rats reared in standard or enriched conditions.

    ; Increase in branching and extension of dendrites in the enriched condition.

; During learning, long-term potentiation occurs and makes synapses perform

    better

    ; Once we reach adulthood, our plasticity decreases sharply: can recover only

    partially from brain injury and illness

The Brain-Behavior Network

    ; Sensory information comes intoand decisions come out ofthe central

    nervous system (CNS)

    ; The nerves outside the CNS are called the peripheral nervous system (PNS)

Cerebral Cortex

    ; The forebrain is the most developed area of the human brain, giving us our

    advanced intellectual abilities

    ; Consists of two cerebral hemispheres connected by the corpus callosum which

    allows communication between them

Components of Forebrain

    ; Majority of the forebrain is composed of the cerebral cortex

    ; Can be divided into four lobes, each associated with a different function

Frontal Lobes额叶?大脑前庭

    ; Assist in motor function, language, memory

    ; Oversee and organize most other brain

    functions (executive functioning)

    ; The body is mapped onto the motor cortex

    ; The prefrontal cortex is responsible for thinking,

    planning, and language

    ; Contributes to mood, personality and

    self-awareness

    >> Phineas Gage

Parietal Lobe顶叶?顶骨叶

    ; Specialized for touch and perception

    ; Contains the somatosensory cortex, which is sensitive to pressure, pain, and

    temperature

    ; Communicates information to the motor cortex every time we reach, grasp, or

    move our eyes

Temporal Lobe颞叶

    ; Lower part of the cerebral cortex, it plays a role in hearing, understanding

    language, and storing autobiographical memories

    ; Contains the auditory cortex and Wernickes area, responsible for speech

    comprehension

Occipital Lobe枕叶

    ; Lies at the rear of the brain and is specialized for vision

    s primary ; When sensory information enters the brain, it first goes to that sense

    sensory cortex, then to the association cortex

Selected Areas of the Cerebral Cortex

The Basal Ganglia

    ; Structures in the forebrain that help to control movement

    ; Damage contributes to Parkinsons disease

    ; Allow us to perform movements to obtain rewards and reinforcement

Parkinsons Disease

    - Tomography scan shows major loss of dopamine neurons, which naturally contain a dark

    pigment.

    - Ventricles, shown in blue in the middle of the brain, are abnormally large due to the death

    of surrounding brain tissue.

Limbic System

    ; The emotional center of the brain that also has a role in smell, motivation, and

    memory

    ; Thalamus丘脑 relays information from the sense organs to primary sensory cortex

    ; Hypothalamus下丘脑 regulates and controls internal bodily states; controls the

    pituitary gland

    ; Amygdala扁桃腺 plays key roles in fear, excitement, and arousal

    ; Hippocampus海马体 plays a role in spatial memory; damage causes inability to

    form new memories

Brain Stem

    ; Connects the cerebral cortex and spinal cord

    ; Performs some basic bodily functions

    ; Serves as a relay station between the cortex and rest of nervous system ; Midbrain contributes to movement, tracking of visual stimuli, and reflexes

    triggered by sound

    ; Reticular Activating System connects the forebrain and cerebral cortex and

    plays key role in arousal

Hindbrain

    ; Cerebellum plays a predominant role in our sense of balance and enables us to

    coordinate movement and learn motor skills

    ; Pons connects cortex to cerebellum and triggers dreams ; Medulla regulates breathing, heartbeat, and other vital functions

Spinal Cord

    ; The thick bundle of nerves that conveys signals between the brain and the body ; Sensory nerves carry information from body to the brain,

     motor nerves carry information from brain to the rest of the body ; Also contains interneurons, which allow reflexes to happen

Peripheral Nervous System

    ; Somatic nervous system conveys information between the CNS and the body,

    controlling and coordinating voluntary movement

    ; Autonomic nervous system controls the involuntary actions of our internal

    organs and glands; has two divisions

    ; Sympathetic division is engaged during a crisis or after actions requiring fight or

    flight

    ; Parasympathetic division controls rest and digestion

    ; When one is activated, the other is inactive

The Endocrine System

    ; Endocrine System: System of glands and hormones that controls secretion of

    blood-borne chemical messengers

    ; Hormones: Chemicals in the bloodstream that influence particular organs and

    glands

    ; Also helps regulate emotions

Hormones

    Pituitary gland: Master gland that, under the control of the hypothalamus, directs the other glands of the body

    Releases hormones that influence growth, blood pressure, and other functions

    Oxytocin: reproductive functions (childbirth), role in maternal (milk) & romantic love

    Adrenal gland: Tissue located on top of the kidneys that releases:

    Adrenaline: boosts/restricts energy production in muscle cells

    Cortisol: Regulates blood pressure and cardiovascular function, body

    s use of proteins, carbohydrates, and fats.

    Sexual reproductive glands:

     Testes in males

     Ovaries in females

    Sexual hormones:

     Testosterone ? Estrogen

Mapping the Mind: The Brain in Action

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