PSYCH UNIT 2

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* part of a neuron that contains nucleus
* cells life support center

Cell Body

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* neuron's often bushy, branching extensions that receive / integrate messages, conducting impulses towards the cell body

Dendrites

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* neuron extension that passes messages through its branches to other neurons or to muscles or glands

Axon

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* fatty tissue layer segmentally encasing axons of some neurons
* enables faster transmission as neural impulses move from one node to the next

Myelin Sheath

- myelin sheath degenerates causing communication to muscles to slow w/ eventual loss of muscle control

Multiple Sclerosis

- cells that play a role in learning, thinking, and memory
- provide nutrients, insulate myelin, guide neural connections, participate in info transmission / memory
- complex brains have more glial cells

Glial Cells

- another name for Glial Cells

Glue Cells

- neural impulse
- brief electrical charge, that travels down an axon

Action Potential

- transmit information by firing action potentials when stimulated

How do neurons transmit information?

- axons exterior is mostly positively charged Na+ ions
- interior has negative charge w/ both negatively charged protein ions and positively charged K+ ions

Resting Potential

- axon membrane allow's passage of some molecules / ions and inhibits passage of others

Selectively Permeable

- loss of inside/outside charge difference

Depolarization

- Resting
- more K+ ions inside & Cl- / Na+ ions outside
- (+) out, (-) in

Name/Describe Stage 1 of AP

- Depolarization
- Na+ voltage gated channels open
- Na+ ions rush IN cell

Name/Describe Stage 2 of AP

- Repolarization
- Na+ VG channels close & K+ VG channels open
- K+ ions rush OUT cell; (charge reversed)

Name/Describe Stage 3 of AP

- Hyperpolarization
- Na+/K+ pump restores original charge by pumping ions back into original spot

Name/Describe Stage 4 of AP

- neuron's gas pedal
- increase likelihood neuron will fire an action potential

Excitatory Signals

- neuron's brake
- decrease likelihood neuron will fire an action potential

Inhibitory Signals

- level of stimulation required to trigger a neural impulse
- if excitatory signal passes; AP fired down axon

Threshold

- in neural processing, a brief resting pause that occurs after a neuron has fired
- subsequent action potentials can't occur until axon returns to resting state

Refractory Period

- neuron's reaction of either firing (w/ full strength response) or not firing at all
- strength of stimulus does not affect speed/strength of action potential

All or None Response

- junction between axon tip of sending neuron and dendrite / cell body of the receiving neuron
- tiny gap at this junction

Synapse

- tiny gap at synapse
- neurons send neurotransmitters across space

Synaptic Gap/Cleft

- chemical messengers that cross synapse gaps between neurons
- when released by sending neuron, neurotransmitters travel across synapse & bind to receptor sites on receiving neuron

Neurotransmitter

- ions flow in either exciting or inhibiting the receiving neuron's readiness to fire an action potential

What happens when a neurotransmitter binds to a receptor site?

- a neurotransmitter's reabsorption by sending neuron

Reuptake

- reuptake
- neurotransmitters drift away
- neurotransmitters broken down by enzymes

What happens to excess neurotransmitters after a neuron reacts?

- drug that elevates mood / eases pain

Morphine

- "morphine within"
- natural opiate-like neurotransmitter linked to pain control and to pleasure
- produced in response to pain / vigorous exercise

Endorphins

- enable muscle action, learning, and memory
- malfunction is linked w/ Alzheimer's disease

Acetylcholine (ACh)

- influences movement, learning, attention, emotion
- oversupply linked w/ schizophrenia
- undersupply linked w/ parkinson's symptoms

Dopamine

- affects mood, hunger, sleep, arousal
- undersupply linked w/ depression

Serotonin

- helps control alertness and arousal
- undersupply can depress mood

Norepinephrine

- major inhibitory neurotransmitter
- undersupply linked w/ seizures, tremors, insomnia

GABA (Gamma Aminobutyric Acid)

- excitatory neurotransmitter involved in memory
- oversupply can overstimulate brain & cause migraine/seizures

Glutamate

- neurotransmitters that influence perception of pain/pleasure
- oversupply w/ opiate drugs can suppress body's natural endorphin supply

Endorphins

- artificial opiates / chemicals disrupts brain chemical balancing act
- can cause brain to stop producing natural opiates to balance, leaving the body in discomfort when the drug has left the body's system

How do drugs and other chemicals alter neurotransmission?

- molecule that increases a neurotransmitters action
- increase neurotransmitter production/release, block reuptake, etc.

Agonist

- molecule that inhibits or blocks a neurotransmitters action
- block transmitter release/production/receptor sites

Antagonist

- body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems

Nervous Systems

- the brain and spinal cord
- the body's decision maker

Central Nervous System (CNS)

- sensory & motor neurons that connects the CNS to rest of body
- gathers information & transmits CNS decisions to body parts

Peripheral Nervous System (PNS)

- bundled axons that form neural cables connecting CNS w/ muscles, glands, & sense organs

Nerves

- PNS
- CNS

General Division of Nervous System

Autonomic NS (ANS)
- Sympathetic NS
- Parasympathetic NS

Somatic NS (SNS)
- Sensory Input
- Motory Output

Division of PNS

- neurons that carry incoming info from body's tissues & sensory receptors to the brain & spinal cord

Sensory (afferent) Neurons

- neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

Moton (efferent) Neurons

- neurons within the brain & spinal cord
- communicate internally & process information between the sensory inputs & motory outputs
- mostly responsible for complexity of brain

Interneurons

- division of PNS that controls body's skeletal muscles
- AKA skeletal NS
- enables voluntary/conscious control of skeleton

Somatic NS

- part of the PNS that controls glands/muscles of internal organs (i.e. heart)
- Sympathetic division arouses, Parasympathetic division calms
- operates automatically (involuntary)

Autonomic NS

- division of autonomic NS that arouses the body, mobilizing its energy by arousing / expending it
- make alert & action ready
- i.e. accelerate heart rate, raise blood sugar

Sympathetic NS

- division of autonomic NS that calms the body, conserving its energy
- i.e. decrease heart rate, decrease respiration

Parasympathetic NS

- steady internal state
- Parasympathetic NS & Sympathetic NS work together to keep body at this state

Homeostasis

- work groups that the brain's neurons cluster into

Neural Networks

- two way information highway connecting the PNS and the brain
- ascending neurons send up sensory info while descending neurons send back motor info

Spinal Cord

- simple, automatic response to sensory stimulus, such as knee jerk response

Reflex

- severed spinal cord severs the connection of information to / from the brain
- you lose all sensation & voluntary movement in body regions w/ sensory & motor connections to the spinal cord below point of injury
- feelings of pain / pleasure cannot be produced

How does damage to the spinal cord affect the nervous system?

- body's "slow" chemical communication system
- set of glands that secrete hormones into bloodstream

Endocrine System

- chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues / interest in sex, food, aggression

Hormones

- some hormones have identical function to neurotransmitters
- both NS/ES produce molecules that act on receptors elsewhere
- NS is much faster than ES though ES effects outlast NS

Compare/Contrast: NS & ES

- pair of endocrine glands that sit just above kidneys & secretes epinephrine & norepinephrine that help arouse body in times of stress

Adrenal Glands

- adrenaline
- feelings linger a while after emergency has passed

Epinephrine

- noradrenaline
- feelings linger a while after emergency has passed

Norepinephrine

- ES most influential gland
- under influence of hypothalamus, pituitary regulates growth & controls other endocrine glands

Pituitary Gland

- brain region controlling pituitary gland

Hypothalamus

- enables contractions associated w/ birthing, breast feeding, & orgasm
- promotes bonding, group cohesion, & trust
- those nasally given oxytocin = more likely to trust strangers w/ money or private info

Oxytocin

- stressful events neurons triggers hypothalamus to instruct pituitary to release hormones that then affect NS
- brain relies on chemical messengers sent by the endocrine system to transmit instructions around the body via the nervous system to key organs

How does the ES transmit information and interact with the nervous system?

- stress hormone that increases blood sugar
- released by adrenal glands

Cortisol

- responding to hypothalamus signals, the pituitary releases hormones that trigger other endocrine glands to secrete hormones
- in turn, influence brain & behavior

Why is the pituitary gland called the "master gland?"

- a naturally or experimentally caused destruction of brain tissue
- scientists can selectively do so to map brain & see which functions are affected

Lesion

- amplified recording of the waves of electrical activity sweeping across the brain's surface measured by electrodes placed on scalp
- researchers present stimulus repeatedly & computer filters out until only electrical wave evoked by stimulus remains

Electroencephalogram (EEG)

- brain imaging technique
- when people complete activities in special rooms that cancel out all other magnetic signals , neurons create electrical pulses that form magnetic fields
- measuring speed/strength is indicative of how tasks influence brain activity

Magnetoencephalography (MEG)

- brain receives temporarily radioactive glucose & tracking gamma rays as task is performed shows the most active brain areas
- shows brain activity

PET (positron emission tomography) Scan

- show brain anatomy
- magnetic fields momentarily align atoms of brain molecules, radio waves pulse disorients them, & then when returned to normal, the atoms emit signals that provide detailed pics of soft tissues (i.e. brain)

MRI (magnetic resonance imaging)

- technique for revealing blood flow, & therefore brain activity by comparing successive MRI scans
- fMRI scans show brain function as well as structure

fMRI (functional MRI)

- brain regions via which blood continues to flow when brain is unoccupied

Default Network

- strength to which activity between brain regions correlates
- helps scientists understand how well different brain regions work together

Functional Connectivity

- oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull
- responsible for automatic survival functions
- crossover point where nerves from left side of the brain are mostly linked to right side & vice versa

Brainstem

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* base of the brainstem
* controls heartbeat and breathing

Medulla

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* above medulla
* coordinates movement & control sleeps

Pons

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* brain's sensory control center
* directly messages sensory info to sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla
* receives all sensory information except smell & directs to higher brain regions that deal with it & create responses

Thalamus

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* nerve network that travels through brainstem into the thalamus & plays an important role in controlling arousal/alertness
* filters incoming stimulus as goes to thalamus & relays important info to other brain areas

Reticular Formation

- "little brain"
- processing sensory input, coordinating voluntary movement and balance, and enabling nonverbal learning & memory
- helps judge time, modulate emotions, & discriminate sounds/textures

Cerebellum

- 2 halves of the brain

Cerebral Hemispheres

- neural system (including amygdala, hypothalamus, & hippocampus) located below the cerebral hemispheres
- associated with emotions and drives

Limbic System

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* 2 lima bean sized neural clusters in the limbic system
* linked to emotion

Amygdala

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* neural structure lying below the thalamus
* directs several maintenance (eating, drinking, body temperature) by helping govern endocrine system via pituitary gland
* linked to emotion & reward
* help maintain homeostatic state of being

Hypothalamus

- limbic system reward center in front of the hypothalamus

Nucleus Accumbens

- neural center located in the limbic system
- helps process explicit, conscious memories of facts & events for storage
- age & injury decreases size/function

Hippocampus

- 2 cerebral hemispheres contributing 85% of brains weight

Cerebrum

- intimate fabric of interconnected neural cells covering the cerebral hemispheres
- body's ultimate control and information processing center
- size indicates capacity for learning/thinking

Cerebral Cortex

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* portion of the cerebral cortex lying just behind the forehead
* involved in speaking & muscle movements & in making plans / judgements

Frontal Lobes

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* portion of the cerebral cortex lying at the top of the head & towards the rear
* receives sensory input for touch and body position

Parietal Lobes

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* portion of the cerebral cortex lying at back of the head
* including areas that require information from the visual field

Occipital Lobes

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* portion of the cerebral cortex lying roughly above the ears
* includes the auditory areas, each receiving information primarily from opposite ear
* underside of right = recognizing/identifying faces

Temporal Lobes

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* area at the rear of the frontal lobes that controls voluntary movement

Motor Cortex

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* area at the front of the parietal lobes that registers & processes body touch and movement sensations
* the more sensitive a body region = the larger the somatosensory cortex devoted to it is

Somatosensory Cortex

- areas of the cerebral cortex that integrate sensory & motor information for other functions
- involved in higher neural functions, such as learning, remembering, thinking, and speaking

Association Areas

- an experience involving the apparent perception of something not present

Hallucination

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* forward part of frontal lobes that enables judgement, planning, & processing of new memories

Prefrontal cortex