Unit 1 - Biological Bases of Behavior (p1)

Nature

The genetic or biological factors that influence behavior and development

Nurture

Environmental variables that impact who we are, how we are raised + experiences

Biological Psychology

Stresses importance of genetics + biological influences

Heredity

Sum of all biological processes by which particular characteristics are transmitted

Genes

Segments of DNA molecules are the functional units of heredity

Epigenetics

Study of heritable changes in gene expression

Monozygotic

Identical twins

Dizygotic

50% genes shared 

Evolutionary Psychology

Study how natural selection favored behavior that contributed to survival

Natural Selection

Heritable characteristics that provide a reproductive advantage

Nervous System

Body’s communication network that consists of all nerve cells → allows organisms to sense, organize, + react 

Peripheral Nervous System

Sensory motor neurons that connect the CNS to rest of the body - includes automatic, sympathetic, and parasympathetic nervous systems

Central Nervous System

Brain + spinal cord → communicates with body’s sensory receptors, muscles, + glands

Autonomic Nervous System

Autopilot → controls involuntary bodily functions

part of the PNS

Somatic Nervous System

Voluntary motor controls → transmit signals from brain to muscles

part of the PNS

Sympathetic Nervous System

Protecting + registering threat → fight, flight, freeze

Parasympathetic Nervous System

Conserves energy + restores body to calm → rest + digest

Neuron

Nerve cells that transmit info throughout the body

Sensory Neurons

Carry info from nerves to CNS

Motor Neurons

From brain + spinal cord to ret of the body

Interneurons

Neurons within the CNS that communicate internally + intervene btwn sensory inputs + motor outputs

Reflex Arc

Signal is sent from sensory organ to spinal cord which processes info instead of brain

Action Potential

A neural impulse; a brief electrical charge that travels down an axon

Glial Cells 

Support cells in the nervous system

Neural Transmission

Neurons communicate with each other

Threshold

The level of stimulation required to trigger a neural impulse

Depolarization

A decrease in the electrical charge across a cell membrane

Refectory Period 

A period immediately following stimulation during which a nerve or muscle is unresponsive 

Resting Potential

The state of the neuron when not fiting a neural impulse

Reuptake

The absorption by a presynaptic nerve ending of a neurotransmitter that it has secreted

The Endocrine System

Interconnected w/ the nervous system, it is the second communication system → secretes hormones

Hormones

Can be chemically identical to some neurotransmitters

Adrenal Glands

On top of kidneys → secrete hormones like adrenaline

Pituitary Gland

Controlled by the hypothalamus → releases hormones that help with growth + influences other glands

Oxytocin

Love, connection, pregnancy

Adrenaline

Fight, flight, freeze

Leptin

Regulating hunger → fullness

Ghrelin

Appetite

Acetylcholine

Movement/muscle action, thought, learning, memory - excitatory 

dementia + Alzheimer’s, paralysis, severe muscle spasms

Serotonin

Feelings of well-being, sleep cycle - inhibitory (frug treatments for depression)

Depression, anxiety, obsessive compulsive disorders, hallucinations

Dopamine

Pleasure, reward, motivation - inhibitory

Depression, muscular rigidity, anxiety, ADHD

Norepinephrine

Response to danger + attention - excitatory

depression + mental disorders, anxiety

GABA

Calms motor controls + vision - inhibitory

anxiety disorders, seizures, tremors, overly relaxed, sleeping + eating disorders 

Glutamate

Normal brain operations, thinking, long-term memory, learning - Excitatory

overstimulate the brain, seizures, migraines

Endorphins

Relieve pain, stress, gives feelings of pleasure - Inhibitory

experiencing pain, body doesn’t give adequate warnings about pain

Genetic Predisposition

The likelihood of developing certain traits of disorders based on genetics

Eugenics

A controversial and unethical movement aimed at improving the genetic composition of humans through selective breeding

The Brainstem

Oldest + innermost region

Medulla

Controls the heartbeat + breathing - part of brainstem

Injured: death

Pons

Helps regulate sleep cycle + breathing - part of brainstem

Injured: difficulty regulating sleep or interpreting sensory info

Reticular Activating System

Regulates a little bit of everything → nerve network - part of brainstem

Injured: coma + sleep issues

The Thalamus

Sensory switchboard for every sense except smell, sends signals to cerebral cortex - part of limbic system

If injured: hypersensitivity, chronic pain, vision loss

The Cerebellum

Coordinates voluntary movements like posture, balance, and coordination (alcohol) - hindbrain

Injured: problems with walking + balance

The Limbic System

Involved in emotion, motivation, and memory

Hippocampus

Processes memory - part of limbic system

If injured: unable to learn or convert info into long-term memory

The Amygdala

Processes emotions + influence aggression + fear - part of limbic system

Injured: show little emotion

The Hypothalamus

Regulates hunger, body temp, thirst, and other homeostatic systems - part of limbic system

Injured: unable to tell when they are hungry or thirsty, overweight + excessive sleeping

Corpus Callosum

Bundle of nerve fibers that connects the 2 hemispheres

Injured: split brain → hemis can’t communicate

The Cerebral Cortex

The outer layer of the brain → thinking 

Frontal Lobe

Decision making, problem solving, controlling behavior, and speaking - cerebral cortex

Injured: personality changes + inability to reason

Prefrontal Cortex

Part of the frontal lobes involved in planning complex behaviors and expression

Motor Cortex

Controls voluntary movements - frontal lobe

Injured: paralyzed

Parietal Lobe

Receives sensory input for touch + body position - cerebral cortex

Injured: difficulty recognize an object by touch

Occipital Lobes

Receive info from visual fields - cerebral cortex

Injured: blindness, blind spots

Temporal Lobes

Auditory areas (hearing + memory) - cerebral cortex

Injured: difficult to understand language + process

Association Areas

Link sensory inputs 

Brain’s Plasicity 

Ability for the brain to modify itself after types of damage

Split Brain

2 hemispheres of the brain can’t communicate anymore

Left Brain

Controls right side of body, language, reasoning

Right Brain

Controls left side, facial recognition 

The Midbrain

Relay system → vision + hearing + feeling pain - in brainstem

Injured: movement disorders

Broca’s Area

Essential in speech production → command center for speaking - frontal lobe

Injured: difficulty generating fluent speech while keeping comprehension abilities intact 

Wernicke’s Area

Comprehension of speech - temporal lobe

Injured: can produce speech that sounds normal but doesn’t make sense 

Somatosensory Cortex

Detects sensory info - parietal lobe

Injured: numbness/difficulty feeling pain