Ap Psych unit 1 biological bases

genotype

comprises all of the possible combinations of genes.

The phenotype

is the observable result

monozygotic twins

since they develop from one fertilized egg

Heritability

the degree of variance among individuals that can be attributed to genetic variations.

Pituitary gland

regulates growth, breast milk production, childbirth, bonding, and communicates to other glands to release hormones

Nervous System

a complex network of cells, tissues, and organs that work together to control and coordinate all bodily functions

(Master control unit)

Consit of spinal cord and brain

Peripheral nervous system

body’s link to the outside world

Consist of Autonomic Nervous System and somatic Nervous System

Autonomic nervous system

Regulates involuntary bodily processes, such as heart rate

-respiration

-digestion

-pupil concentration

-operates automatically without conscious decision

• Contains sympathetic and parasympathetic nervous system

Sympathetic nervous system

Mobilizes bodily resources in response to threat by speeding up heartrate and respiration and drawing stored energy from bodily reserves

Parasympathetic nervous system

Replenishes bodily resources by promoting digestion and slowing down other bodily processes

somatic nervous system

sensory information from sensory organs to the central nervous system and relays motor commands to muscle; controls voluntary movements

Cell Body (soma)

Center of neuron

Contains the nucleus and produces energy for the neuron

Nucleus

Center of cell body

-Contains the genetic information of the neuron in the form of DNA

Dendrites

Branches extending from the cell body

Receive chemical messages via neurotransmitters from other neurons and transports them to the cell body of the neuron

Axon

A long tube-like extension attached to the cell body

• Sends the electrical message (ACTION POTENTIAL) away

  from the cell body of the neuron

Myelin Sheath

insulating layer of fat cells surrounding the axon of some neurons

• Fatty substance produced by glial cells that provides

  insulation and increases the SPEED of the electrical

  message (action potential)

  * Deterioration of the myelin sheath leads to the loss of

  muscle control associated with the neurological disease

  multiple sclerosis (MS)

Terminal Buttons (Terminal Buds / Axon Terminal)

Small knoblike structures at the end of the axon

• Contains neurotransmitters in vesicles (sacs) to be released across the synapse.

Synaptic Vesicles

Tiny sacs located in the terminal buttons

• Responsible for storing and releasing neurotransmitters

Synapse

(Synaptic Cleft/Gap)

Extremely narrow space between

the terminal button of the sending

neuron and the receptor site of the

receiving dendrite

• location of neurotransmission

  No physical contact between neurons

Receptor Sites

Ends of the dendrites on the

postsynaptic neuron

• Areas on the dendrite that receive neurotransmitters to

  initiate cell firing

Sensory Neurons (also known as Afferent Neurons)

take input received through sensory receptors throughout

the body, such as in the skin, eyes, nose, ears, and tongue, and pass it on toward the brain and spinal cord to

initiate a response

Motor Neurons (also known as Efferent Neurons)

transmit signals from the brain to our muscles and other

organs.

interneurons

relay neurons, or connectors, allowing for information to pass between neurons.

Neural Impulse

relay neurons, or connectors, allowing for information to pass between neurons.

Resting Potential

(Polarization)

While the neuron is waiting for a message, the fluid-filled interior of the axon has a negative charge and the fluid exterior has a positive charge

● Charged particles or ions are located on the inside (Potassium - K+) and outside (Sodium - Na+) of the axon membrane.

Threshold

When the neuron is stimulated by pressure, heat, light, or chemical messages, the electrical charge inside the exon can reach a tipping point (slightly more positive than the resting potential)

All-or-None Principle

Once threshold has been reached, the neuron fires completely, regardless of how strong the stimulus was

Action Potential

(Depolarization)

Occurs during the action potential when the interior of the axon changes to a less negative charge. The firing process of the neuron begins when the axon allows certain ions through its semi-permeable membrane, making the interior of the axon become less negative.

● Sodium (Na+) ions move to the inside of the ion

● Potassium (K+) ions move to the outside of the ion

Repolarization

During this period the sodium-potassium pump returns the ions to their original positions on the inside and outside of the axon, reestablishing the resting potential

Refractory Period

While repolarization is occurring, the neuron cannot fire because it is resetting itself to its original resting potential state

Excitatory Neurotransmitters

are chemicals that when released from the terminal buttons excite connecting neurons and cause them to fire

Inhibitory Neurotransmitters

are chemicals that when released from the terminal buttons inhibit (prevent) the next neurons from firing.

Dopamine

Pleasure, reward, voluntary movement, learning, and attention

• Certain dopamine pathways are involved in drug addiction.

Acetylcholine (AcH)

Memory and movement

Serotonin

Mood, appetite, and sleep

Norepinephrine

Mood and sleep

Glutamate

Memory and learning, Major excitatory, neurotransmitter

GABA

Relaxation and sleep

Major inhibitory

neurotransmitter

Endorphins

Inhibits pain signals

Reuptake

neurotransmitters are reabsorbed by the presynaptic neuron

Agonists

drugs that work by either blocking reuptake or mimicking the natural neurotransmitters by fitting into receptor sites on the postsynaptic neuron

Antagonists

drugs that work by occupying receptor sites on the postsynaptic neuron and block the impact of

neurotransmitters

Individuals with schizophrenia have too much dopamine, and antipsychotic medications act as dopamine to block the receptor sites and prevent cell excitement

Brainstem

• Automatic survival functions

• Sends and receives information

Cerebellum

● Balance and coordination

● Fine motor movements

● Procedural memory

Medulla

● Survival functions (heartbeat,

breathing, and digestion)

● Reflexes (sneezing, coughing,

vomiting, and swallowing)

Reticular Formation

● Arousal to stimuli

● Sleep

● Attentiveness

● Filters incoming stimuli and relays

important information to the

thalamus

Basal Ganglia

● Smooth voluntary body movements

Thalamus

● Filters and relays sensory

information except for smell to the

appropriate parts of the cerebral

cortex

Limbic System

● Learning

● Memory

● Emotion

● Basic drives

Hippocampus

● Explicit memory formation

● Learning

Amygdala

Emotions (especially fear and

aggression)

Hypothalamus

● Maintenance functions (eating,

drinking, body temperature, and

sex)

● Controls the autonomic nervous

system

● Controls the endocrine system by

influencing the pituitary gland

Suprachiasmatic Nucleus (SCN)

● Regulation of circadian rhythm

● Regulation of sleep cycle

Corpus Callosum

Relays information between the two hemispheres

The ___________ are where the perception of temperature on the skin occurs

Parental lobes

cerebrum

the largest and most developed area of the brain, the cerebrum, refers to most of the brain except for the brainstem and cerebellum and is comprised of two separate layers.

• Internal layer made up of axons of neurons and glial cells (white matter)

Cerebral cortex

The one-fourth-inch thick wrinkled outer layer is called the _____ and is made up of the cell bodies of neurons called gray matter

association area.

Any portion of the cerebral cortex that is not devoted to motor or sensory functions

gyri

the ridges along the surface of the cortex

sulci

valleys on the surface

fissures

deep or pronounced grooves on the cerebral cortex in each hemisphere

frontal lobes

Front apart of brain

parietal lobes

behind frontal lobe

Temporal lobe

located above the ears

Occipital lobes

back of the cortex

Prefrontal Cortex

Part of frontal Lobe

● Controls conscious thoughts and actions

● Working memory

● Short-term and long-term planning

Broca’s Area

Part of Frontal Lobe

● Controls the facial muscle movements required for speech

production

Primary Motor Cortex

Part of the Frontal Lobe

● Controls voluntary movement

● Left motor cortex controls movement on the right side of the body

● Right motor cortex controls movement on the left side of the body

Primary Somatosensory Cortex

Parietal Lobes

● Sensory input is received for touch and body position

● Left sensory cortex controls sensation for the right side of the body

● Right sensory cortex controls sensation for the left side of the body

Primary Visual Cortex

Occipital Lobes

● Information from the left visual field goes to the right side of each eye

and is interpreted by the right visual cortex

● Information from the right visual field goes to the left side of each eye

and is interpreted by the left visual cortex

Primary Auditory Cortex

Temporal Lobe

● Processes most auditory information from the opposite ear

Wernicke’s Area

Temporal Lobe

● Responsible for language comprehension

● Creates meaningful statements

Lesions

● Involves the removal of a portion of an organism’s brain; often on animals

Removing the lateral portion of the hypothalamus in a rat will cause it to stop eating but removing the ventromedial portion will cause it to overeat

● Researchers observe behavioral changes to determine the function of specific areas of the brain; has helped scientists localize brain region responsibilities

● Often used on humans to remove and stop the spread of brain tumors

Direct Stimulation

● Opposite of lesioning

● Researchers electrically stimulate the brain; often on animals

● Stimulating the amygdala of mice will result in an aggressive reaction

● The use of electrical stimulation has helped surgeons understand the potential results of

removing specific areas of the brain during tumor removal

Brain Imaging

● Enable psychologists to look inside the human brain to identify either the structure or function of various brain parts

● See chart below and on the next page

EEG

Electroencephalogram

measures electrical activity of the neurons below the electrodes placed on the scalp. The EEG is often used to show brain wave patterns of electrical activity during sleep stages and seizures.

Purpose = Function

Advantages

● Noninvasive

● Abnormal patterns indicate neurological disorders

Disadvantages

● Difficult to determine which specific brain

areas are producing the electrical activity

fMRI

The functional magnetic resonance imaging technique uses magnetic fields to produce images of the brain and tracks real-time brain activity by measuring blood flow carrying oxygen to active brain tissue.

Advantages

● No exposure to radioactive materials like

during a PET scan, allowing researchers to

conduct multiple scans on the same individual

● Ability to pinpoint and track mental processes

that occur over seconds as opposed to

minutes, such as thinking about an object

Disadvantages

● Cannot be used on an individual with a

metallic implant including a pacemaker or

surgical pin

● Although no harmful consequences have been

identified, the long-term impact of exposure

to powerful magnets is unknown

Neuroplasticity

The brain's ability to reorganize itself by forming new neural connections throughout life, allows the neurons (nerve cells) in the brain to compensate for injury and disease and to adjust their activities in response to new situations or to changes in their environment.

Conscious Awareness

All the ideas in your immediate awareness, such as your thoughts, feelings, senses

Non conscious

Biological functions occurring without your awareness, such as respiration and digestion

Preconscious

Items we can access from long-term memory; stored information about yourself or your environment that you are not currently aware or thinking of but can easily call to mind when asked

Subconscious

Hidden memories that influence behavior despite no clear memory of them; information you have been exposed to be cannot recall; mere exposure effect (also known as the familiarity principle) - if you have a memory of a dog barking loudly and charging at you at age three, you may not recall your terror/fear, but you are still not likely to buy a product advertised with a barking dog

Unconscious

From the psychoanalytic perspective (Sigmund Freud), hidden memories that influence behavior but can never be known to the conscious mind; Freud characterized these as conflicts between competing parts of our personalities (the id, superego, and ego) that influence our attitudes and actions

Psychoactive drugs

a chemical substance that alters a perceptions and moods.

Tolerance

the diminishing effect of a drug after repeated use that requires the user to take larger and larger does before experiencing the drug’s effect.

Withdrawal

the discomfort and distress that follow the discontinued use of a drug

Physical dependence

a physiological need for a drug, marked by unpleasant withdrawal symptoms when the drug is no longer taken

Psychological dependence

a psychological need to use a drug, such as to relieve negative emotions

Addiction

compulsive drug craving and use, despite adverse consequences.

Biological Rhythms

the periodic physiological fluctuations our bodies go through.

Annual cycles

cycles that occur in our bodies on a yearly basis, such as SAD (Seasonal Affective Disorder – becoming depressed during the winter), or birds flying south for the winter and bears hibernating.

28-day cycles

cycles that occur every month. Ex. a woman’s menstrual cycle.

Circadian rhythm

the biological clock; regular bodily rhythms that occur on a 24-hour cycle, such as body temperature or wakefulness.

Suprachiasmatic nucleus (SCN)

a pair of grain-of-rice –sized cell clusters in the hypothalamus that helps in waking up a person when it is activated by light-sensitive retinal proteins. It works with the pineal gland.

Melatonin

a sleep-inducing hormone. The SCN causes the brain’s pineal gland to decrease its production of melatonin in the morning or to increase it in the evening

Adenosine

a neurotransmitter that causes drowsiness and the slowing of nerve cells. Caffeine is an antagonist that blocks the transmission of adenosine keeping us awake.

Sleep

a periodic, natural loss of consciousness. Throughout the night, the body experiences many sleep cycles, each one lasting

around 90 minutes. Each cycle has 4 stages (N1, N2, N3, and, REM)

Beta waves

waves of someone who is wide awake