unit 1

biological bases of behavior

nature (genes)

all of the genes and hereditary factors that influence who we are- from our physical appearance to our personality characteristics

nuture (environment)

refers to all the environmental variables that impact who we are

-early childhood experiences

-how we were raised

-social relationships

-our surrounding culture

biological psychology

studies the impacts of biological influences and genetics on development through technology and various study techniques

-twin studies

-family studies

-adoption studies

heredity

Sum of all biological processes by which particular characteristics are transmitted from parents to their offspring

Genes “Little Instructions”

Segments of DNA molecules are the functional units of hereditary, make up the body’s blueprint

Epigenetics

Study of changes in gene expression(inactive vs active) due to non genetic causes

Evidence shows that our environment can alter how our genes are expressed

Sensitive Periods

A particular time in life in which some behaviors or physical characteristics should be expressed

monozygotic twins “identical”

result from a single fertilized egg that splits in two (genetically identical)

dizygotic twins “fraternal”

develop from two zygotes and share 50% of their DNA

heritability

the extent to which differences in the appearance of a trait across several people can be accounted for by differences in their genes

-heritability estimates are usually generated by twin studies

natural selection

the process by which organisms with traits better suited to their environment are more likely to survive and reproduce, passing on those advantageous traits to future generations

the nervous system

the body’s internal communication network, consisting of a complex system of nerves, neurons, and specialized cells

central nervous system

Consist of brain and spinal cord
-Coordinates the actions and interactions of the brain and spinal cord. 
-Body’s main control center

peripheral nervous system

Consist of all the nerves outside of the brain and spinal cord.
-Acts as sensory communication network to and from the rest of the body.

motor pathway

signals from brain to muscles/glands

sensory pathway

Signals from sensory receptors to the brain.

Somatic Nervous System

division of the PNS responsible for controlling voluntary movements of muscles and relaying sensory information from the body to the CNS

Sensory Neurons “Afferent Neurons”

Carry information from the nerves to the CNS
(Sensory-Afferent)

Motor Neurons “Efferent Neurons”

Carry information from the brain and spinal cord to muscle fibers throughout the body
(Motor-Efferent)

interneurons (relay)

neurons within the brain and spinal chord that communicate internally and intervene between the sensory inputs and motor outputs

reflex arc

the simple neural pathway involved in a reflex, where sensory neurons transmit information to the spinal chord, which immediately activates motor neurons to produce a rapid, automatic response

autonomic nervous system

division of the PNS which regulates involuntary and unconscious actions without conscious control, such as glands, cardiac muscles, and internal organs

sympathetic nervous system

branch of the autonomic system that mobilizes the body’s resources during stress or emergencies, preparing the body for “fight or flight” responses (heartbeat, blood pressure, sweating, etc.)

parasympathetic nervous system

the brach that calms the body by reducing heart rate and arousal while conserving energy, promoting routine maintenance activities, and increasing digestion; often described as “rest-and-digest”

neuron “nerve cell”

specialized nervous system cells which act as electrochemical messengers

glial cells

surround and insulate neurons, providing nutrients, and strengthening neural signal speed

dentrites “antenna”

branch-like entrances that receive electrical messages from other cells

soma “life support”

maintains the health and function of the cell and nucleus

axon “talker”

fiber that extends from the cell body to the terminal endings, shoots message to its destination

myelin sheath

layer surrounding axon which protects from damage, insulates signals, and speeds up messages

-produced and maintained by surrounding glial cells

axon terminals

neural endings which connect to other cells through terminal buttons/synaptic knobs

synapse “contact point”

gap between terminal buttons of one neuron and receptor sites of another

synaptic vesicles

store neurotransmitter chemicals that are released at the synapse and reabsorbed

synaptic cleft or gap

less than a millionth of an inch wide

receptor sites

locks on the dendrites which receive neurotransmitter signals and process them

neurotransmission-electrochemical

process by which electrical activity in stimulated cells allow for chemical signals to be sent between multiple neurons

resting period

period of rest where cell is negatively charged inside (contains mostly Potassium (K) ions) and positively charged outside (contains mostly Sodium (Na+) ions)

selectively permeable membrane

promotes homeostasis in cell and allows for clear resting and action potentials by blocking certain ions or molecules from the cell, while allowing others in

-the membrane is located on the axon

step 1: charge begins

dendrite receptor sites receive a chemical signal from other cells

step 2: threshold is reached

incoming signals cause enough stimulation to fire

-if stimulation is not strong enough, your neuron doesn’t fire

all-or-none principal

a neuron fires completely or not at all; every action potential is the same strength

step 3: depolarization

sodium ions (Na+) rush into the neuron’s axon membrane, making the inside more positive and causing electrical charge

step 4: action potential

electrical impulses from depolarization spread down each section of the axon as a chain reaction of sodium channels opening, to the axon terminals

step 5: re uptake

after chemicals deliver their message at the synapse, they are reabsorbed into the vesicles by the sending neuron for reuse

step 6: refractory period

reset period of inactivity, positive ions are flushed back out

multiple sclerosis

autoimmune disease resulting from the immune system damaging the myelin sheaths of neurons in the nervous system

myasthenia gravis

disease in which the immune system blocks or destroys receptor sites for acetylcholine, decreasing the nerve signals muscles receive

neurotransmitters

chemicals that carry specific commands from one neuron to another

excitatory neurtransmitters

increase the likelihood of connecting neurons firing/reaching action potential

inhibitory neurotransmitters

relay their message but prevent the next neurons from firing

acetylcholine “movement and memory”

EXCITATORY principle neurotransmitter involved in muscle movement, learning, and memory

Surplus: severe muscle spasms

Deficit: dementia, alzheimer’s, myasthenia gravis, lack of muscle control

serotonin “mood”

INHIBITORY connected to feelings of emotional well being and happiness, keep you wakeful

Surplus: hallucinations

Deficit: depression, some anxiety disorders, OCD

dopamine “reward”

INHIBITORY pleasure chemical associated with reward, learning, motivation, attention, addiction, and movement

Surplus: schizophrenia

Deficit: depression, parkinson’s disease, memory problems, ADHD, anxiety

norepinephrine “fight or flight”

EXCITATORY increases sympathetic NS, alertness, arousal, response to danger

Surplus: anxiety

Deficit: depression

GABA “calming”

INHIBITORY sleepiness, calm states, and slowing of the NS

Surplus: over relaxation/sedation, impaired reaction time

Deficit: anxiety disorders, insomnia, seizures

glutamate “memory”

EXCITATORY involved with thinking, long-term memory, and learning

Surplus: overstimulation, mood swings, migraines, epileptic seizures

Deficit: lack of concentration, mental exhaustion

endorphine “euphoria”

INHIBITORY relieves pain and stress, gives feelings of elation and euphoria especially after exercise

Surplus: inadequate brain signals, artificial highs

Deficit: more pain felt

Substance P “pain”

EXCITATORY helps transmit pain and inflammation signals through the CNS

Surplus: increase in nausea, stress response, less control of emotional behavior

Deficit: negative impacts of learning and memory

endocrine system

a system of glands that secrete chemical messengers called hormones into your bloodstream, which travel to target organs to regulate body functions

hormones “chemical messengers”

-slower to take effect than neurotransmitters, but longer lasting

-some are chemically identical to neurotransmitters

pituitary gland “master gland”

pea-sized brain structure controlled by the hypothalamus which regulates stress, growth, and reproduction, and controls other glands in the body

thyroid gland+parathyroid

lower neck, secretes a hormone called thyroxin that regulates metabolism, growth, blood calcium levels and appetite.

pineal gland

near back of the brain, tracks day/night light cycle to secrete sleep hormones called melatonin, which regulates sleep and body rythmns

adrenal glands

two glands on top of each kidney involved in stress response by releasing cortisol and epinephrine, which aid in sympathetic activity (increase heart rate, BP, blood sugar, etc.)

gonads

reproductive glands, which release focus mainly on estrogen for women and testosterone for men

oxytocin

powerful hormone which regulates attachment (especially motherly attachment), social interaction, bonding, and reproduction, released in the hypothalamus

epinephrine “adrenaline”

hormone produced in high stress “fight or flight” situations, gives a physical boost and heightened awareness

cortisol

body’s hormonal mechanism to cope with long-term stress, released to regulate your metabolism, motivation, and blood-sugar

pancreas

releases insulin and glucagon, which regulate the level of glucose (blood sugar) in the blood

thymus

releases hormone Thymosin which regulates production of the immune system’s response to possible disease and infection

hemispheres

the brain has two hemispheres, the left controls the right side of our body, and the right controls the left side of our body

corpus callosum

bundle of nerve fibers that connects the two hemispheres, messages move from one side of the brain to the other

left hemisphere

specializes in language, calculation, handwriting, speech, sense of time and rythymn, and any kind of thought requiring analysis

right hemisphere

specializes in more widespread processing, including visual perception, visualization, recognition of patterns, faces, emotions, melodies, and expression of emotion

cerebral cortex “gray matter”

the outer layer of the brain and largest section, which is lateralized

the frontal lobe

associated with reasoning, motor skills, higher level cognition, and expressive language

prefrontal cortex

used in planning complex, higher-order cognitive behavior, personality expression, decision making, and moderating social/self-control behaviors

motor cortex

receives information from various lobes and utilizes this information to carry out body movements

broca’s area

located in the lower portion of the left frontal lobe, controls motor functions involved with speech production and grammatical planning

parietal lobes

contains the centers for processing sensory signals such as touch, pressure, temperature, vibration, and pain

somatasensory cotex

receives and processes body-position and tactile sensations for each body part

occipital lobes

contains the visual centers of the brain

-primary visual cortex: allows us to see by connection to our optic nerve (from eyes)

visual association cortex

allows us to recognize lines, angles, shapes, shadows, and movement

temporal lobe

areas of the cortex located just behind the temples containing the neurons responsible for the sense of hearing and meaningful speech (and recognition, especially of the face-right lobe)

wernicke’s area

located in the temporal lobe on the left side of the brain and is responsible for the comprehension of speech

brainstem

key component in the CNS at the base of the brain, and most primitive section of the brain

medulla oblongata “medulla”

controls life sustaining, vital autonomic functions such as heart rate, breathing, and blood pressure

pons

role in several autonomic functions such as stimulating breathing and controlling sleep cycles

cerebellum

helps control bodily muscles in unison for fluid voluntary movement, maintaining posture, and balance

the reticular formation

network of nervous system nerves that carry messages between and through parts of the brain stem, including pain intensity signals, control signals, and filtering out unnecessary stimuli in our environment

thalamus

the “relay station” or “router” off the brain, which processes and transmits motor and sensory information (for vision, hearing, tasting, and touch) to the cerebral cortex NOT SMELL

limbic system

network of structures responsible for instinctive traits, basic drives, and primal emotions located beneath/with-in the cerebral cortex

hypothalamus

maintains homeostasis: controlling thirst, hunger, emotion, body temp, circadian rhythms; also hormones by controlling the pituitary gland’s functioning

hippocampus

critical role in the formation, organization, and storage of new memories, as well as connecting them with certain sensations and emotions

amygdala

primarily involved in processing emotions like fear and aggression, and becomes active as a survival response during stressful or threatening situations (fight or flight)

neuroscience

brain science which seeks to understand the brain

case studies

Phineas Gage- proof that prefrontal is responsible for personality and cognitive skills

lesioning studies

research method which areas of the brain are removed/disabled to determine their specific functions

prefrontal lobotomy

operation that removes/disconnects prefrontal cortex to control abnormal behavior

hemispherectomy

surgery in which a hemisphere in the brain is removed

-treat epilepsy