#3 Brain Unit (Clarke AP Psychology)

Afferent

Sensory neurons that convey information about senses from skin receptors and internal organs

Efferent

Motor neurons that tells muslces to relax or contract

Inter

____neurons communicate information between motor and sensory neurons

Dendrites

Part of neuron that receives messages

Branching tubular process that have receptor sites for receiving information

Soma

Part of the neuron that processes nutrients and provides energy for the neuron

Axon

Part of the neurons that carries and sends messages

Long, single conducting fiber of neuron that extends from the cell body

Myelin Sheath

Fatty covering around the axon of some neurons that speeds neural impulses

Axon Terminals

Located at the end of the axon, it sends messages across the synapse

Multiple Sclerosis

Immune system attacks the myelin sheath and disrupts communication between your brain and the rest of your body.

Outcome: No cure and in severe cases you lose the ability to walk

Glial Cells

Function: that support, nourish, and protect neurons

Think of neurons as the "queen bee" and _______ ________ as the "worker bees"

All or None Principle

A neural impulse will either occur or not, there is no in between

Action Potential

The nerve impulse activated in a neuron that travels down the axon and causes neurotransmitters to be released into a synapse.

Depolarization

Process where the negative ions rush outside the axon and the positive ions rush into the axon causing the neuron to fire

Resting Potential

While the neuron is in a stable, negatively charged, inactive state and is ready to fire.

Refractory Period

The period of rest during which a new nerve impulse cannot be activated

Synapse or Synaptic Cleft

Region or tiny space between two neurons

The space is between the axon terminal of one neuron and the dendrite of another

Excitatory Messages

increases the likelihood of a transmission because the pre-synaptic neuron tells the post-synaptic neuron to activate

Inhibitory Messages

Decreases the likelihood of a transmission because the pre-synaptic neuron tells the post-synaptic neuron not to activate

Reuptake

When the pre-synaptic neuron reabsorbs the excess neurotransmitters that were NOT absorbed by the post-synaptic neuron.

Neurotransmitters

Chemicals in the brain that determine many of our behaviors

Major ones include acetylcholine, dopamine, serotonin, Endorphin, noradrenalin

Acetylcholine

Neurotransmitter involved with memory and muscle movement

Too little: Alzheimer's Disease

Dopamine

Neurotransmitter that affects alertness, movement, and pleasant experiences

Related to Parkinson's disease- deficiency and Schizophrenia-excess.

Endorphins

Neurotransmitter that relieves pain and may induce feelings of pleasure/euphoria

similar to opiate pain medications such as morphine, Oxycontin, codeine, etc.

GABA

Major inhibitory neurotransmitter that slows down brain activity.

Lack of it leads to anxiety, seizures, tremors, and insomnia

Glutamate

Major excitatory neurotransmitter that stimulates/increases brain activity.

Too much leads to migraines or seizures

Norepinephrine

Neurotransmitter that influences alertness and physiological arousal.

Too little: depression-(physical symptoms-lethargy/low energy)

Serotonin

Neurotransmitter related to emotional state/mood, sleep.

too little: depression-(emotional symptoms)

Agonist

Binds to a receptor and either blocks reuptake of a neurotransmitter from the synapse or triggers the release of neurotransmitters into the synapse.

Antagonist

Binds to a receptor and then blocks the release of neurotransmitter into the synapse.

Central Nervous System

-The portion of the nervous system that includes the brain and the spinal cord

Peripheral Nervous System

Portion of the nervous system outside the brain and spinal cord

-Includes all of the sensory and motor neurons

Somatic Nervous System

-Part of peripheral nervous system (PNS) that includes motor nerves that stimulate skeletal (voluntary) muscle

-Enables you to move your head and neck, arms, hands, legs, abd feet purposefully

Autonomic Nervous System

Subdivision of peripheral nervous system (PNS) that is for involuntary behaviors and includes the sympathetic and parasympathetic nervous system

Parasympathetic Nervous System

-Part of autonomic nervous system whose stimulation calms the body following sympathetic stimulation

-Restores digestive processes (salivation , peristalsis, and enzyme secretion); restores pupils to normal size

Sympathetic Nervous System

-Part of the autonomic nervous system whose stimulation results in responses that help the body deal with stressful events

-Speeds heart rate, raises blood pressure, quickens breathing, releases glucose, and dilates pupils

Endocrine System

The body's "slow" chemical communication system;

A set of glands that secrete hormones into the bloodstream

Hormones

Chemical messengers that travel throughout the bloodstream and affect the brain

move slower but have longer lasting effects

Hypothalamus

-Controls several metabolic functions: body temperature, sexual behavior, hunger, thirst, and controls the endocrine system

Pineal Gland

Regulate sleep/wake cycles

Medulla

-controls blood pressure, heartbeat and breathing

Cerebellum

-"Little brain" located behind the medulla

-Control voluntary movements, coordination, and balance in behaviors that are very fast (for example, running or sprinting).

Reticular Formation

-Controls general body arousal, consciousness and physiological arousal

-If it malfunctions, we will fall into a deep coma

-also known as the RAS

Thalamus

-Located in top of the brain stem

-Processes all sensory information except smell and routes it to different parts of the brain for interpretation

Amygdala

-Part of limbic system in the brain

-Influences emotions such as aggression, fear, and self-protective bahaviors

-Processes emotional memories

Hippocampus

-Part of limbic system in the brain

-Enables formation and retrieval of long-term memories

Cerebral Cortex

Location: The thin outer layer of the brain (approx. 2 mm) and is made up of billion of nerve cells

Function: acts of main control center and information processing center used for creating memories, associations, and new movement

Somatosensory Cortex

-thin vertical strip of the cerebral cortex that receives incoming touch sensations from the rest of our body

Motor cortex

-Thin vertical strip at the back of the frontal lobe

-this part of the cerebral cortex sends signals to our muscles controlling our voluntary movements

Association Areas

Location: Areas of the cerebral cortex that are not involved in motor or sensory functions (75%+ of cerebral cortex)

Function: Combine information from all areas of the brain to produce higher mental functions (learning, remembering, thinking, and speaking)

Examples: Answering a Telephone combines: Temporal lobes (hear), Occipital lobes (see location of phone), Motor cortex (grab the phone), frontal lobe (engage in conversation), etc.

Corpus Callosum

Connect the two brain hemispheres and helps them communicate with each other

Broca's Area

-located in the left hemisphere and is responsible for controlling the muscles involved in producing speech

Wernicke's Area

-Located in the left hemisphere and interprets both written and spoken speech

Right Brain

-Receives sensory messages and controls then, motor function of the left half of the body

Left Brain

-Receives sensory messages and controls the motor function of the right of the body

-Hemisphere linked to speech and language processing

Split Brain Patients

People whose corpus callosum has been surgically severed

Frontal Lobes

-The brain lobe that interprets and controls emotional behavior, decision making and carrying out plans

-Also includes the the motor cortex

Parietal Lobes

-The brain lobe that is primarily for processing sensory information including touch, temperature, and pain from body parts

-Also includes the somatosensory cortex

Temporal Lobes

-The brain lobe that is primarily for learing, understanding language and understanding music

Occipitial Lobes

-The brain lobe that is primarily for visual information

Nature

Identical twin studies found that ___________ influences the following human behaviors: extraversion (social behaviors) and neuroticism (anxiety)

Nurture

Adoptive studies found that ___________ influences the following human behaviors: Attitudes, Values, Manners, Faith, and Politics

Twin Studies

Compares identical v fraternal ____ to determine the effects of nature or genetic influences.

Adoption studies

Studies this group of children to understand the impact of nurture or environmental influences.

Neuroplasticity

The brains ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience

Examples: Violin player develops a larger motor area linked to his left finger

EEG

PROCESS: Hook up electrodes to the scalp and pens then record the electronic signals

POSITIVES: Identifies brain wave activity and tells us individuals different states (Asleep, Awake, Anaesthetized)

NEGATIVES: Cannot show us the structures (anatomy) and identify individual functions

CAT scan (computerized axial tomography)

PROCESS: Put subject into a donut shaped x-ray machine

POSITIVES: Detects brain damage and detects blood flow on the surface

NEGATIVES: Cannot view interior structures

PET scan (positron emission tomography)

PROCESS: Inject patient with radioactive glucose (glucose is the brain's fuel)

POSITIVES: Able to show exactly which part of the brain is active and looks at slices or deep structures

NEGATIVE: You have to drink a substance

MRI (magnetic resonance imaging)

PROCESS: Giant magnet and scans head and magnet realigns the brain's hydrogen atoms, on the same axis

Machine takes a picture of the energy released by atoms when they return to their original spot

POSITIVES: Very clear, detailed pictures of specific brain areas and No need for tracer substance

fMRI (functional magnetic resonance imaging)

Combination of PET scan and MRI: Reveals blood flow to different parts/structures of the brain as well as anatomical irregularities.

Angular gyrus

Transforms visual representations of language into an auditory code for Wernicke's area to interpret.

Broca's aphasia

Inability to produce normal speech

Wernicke’s aphasia

inability to comprehend speech/language

Angular gyrus aphasia

Inability of angular gyrus to transform written language into auditory code

Contra-laterilzation

Each hemisphere of the brain controls motor movement and processes sensory information for the opposite side of the body.

Hemispheric lateralization (split-brain theory)

Theory that the left hemisphere is the center of human language; it is the linear/logical side of the brain and primarily responsible for reading, speaking, and reasoning. The right hemisphere of the brain is the home of spatial perception and nonverbal concept.