Unit 1.1-1.4 Psychology

Evolutionary Perspective

study of how psychological traits and behaviors have evolved over time to enhance survival and reproductive success

Natural Selection

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

Nature vs. Nurture

genetics vs. environment

Nature (Genes)

the inherent biological and genetic factors that influence an individual's psychological development, traits, behaviors, and cognitive abilities

Nurture (Environment)

environmental influences and experiences that shape an individual's psychological development, behaviors, and cognitive processes

Twin Studies

Examines similarities and differences between identical (monozygotic) and fraternal (dizygotic) twins to assess the relative influence of genetics and environment on traits and behaviors

Adoption Studies

Investigates similarities between adopted children and their biological and adoptive families to assess the impact of genetics versus environment on various traits and behaviors

Family Studies

Analyzes similarities and differences among family members, including parents and siblings, to understand the interplay of genetics and environment in shaping traits and behaviors within a family unit

Heredity

the transmission of genetic information from biological parents to offspring.

Genetic Predisposition

the inherited likelihood of developing specific traits or conditions due to genetic factors from biological parents

Genome

the complete instructions for making an organism

Eugenics

the belief in improving the genetic quality of a human population by controlling reproduction to increase desirable traits and decrease undesirable ones

nervous system

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

Central Nervous System

• consists of the brain and spinal cord

• serves as the command center of the body, responsible for processing information, coordinating responses, and regulating bodily functions

What does the spinal cord serve as?

a vital pathway for transmitting sensory info from the body to the brain and motor commands from the brain to the body

Peripheral Nervous System

• consists of all the nerves and ganglia outside the brain and spinal cord

• serves as a communication network, transmitting sensory information from the body to the CNS

Autonomic Nervous System (4)

• division of the peripheral nervous system

• regulates involuntary bodily functions

• operates automatically, without conscious control

• consists of two main branches: the sympathetic nervous system and the parasympathetic nervous system

Sympathetic Nervous System

• responsible for activating the body's "fight or flight" response in times of stress or danger

• increases heart rate, dilates airways, and redirects blood flow to essential organs, preparing the body to respond to perceived threats

Parasympathetic Nervous System

• responsible for promoting relaxation and restoring the body to a calm state after experiencing stress or danger

• slows heart rate, constricts airways, and enhances digestion, allowing the body to conserve energy and recover from stressors

Somatic Nervous System

• division of the peripheral nervous system

• responsible for controlling voluntary movements and relaying sensory information from the body to the CNS

Endocrine System

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

Neurons

• specialized cell that serves as the building block of the nervous system, transmitting electrical and chemical signals throughout the body

• it consists of three main parts: the cell body (soma), dendrites, and axon

cell body (soma)

he central part of the neuron that contains the nucleus

axon

• a long, slender projection of the neuron that carries electrical impulses away from the cell body toward other neurons

• covered by a myelin sheath, which helps speed up the transmission of signals

dendrites

branch-like extensions of the neuron that receive signals from other neurons or sensory receptors

Neurotransmitters

chemical messengers that cross the synaptic gaps between neurons

Where are neurotransmitters stored?

vessicles

8 main neurotransmitters

• acetylcholine

• serotonin

• glutamate

• endorphins

• dopamine

• norepinephrine

• GABA

• Histamine

Acetylcholine

enables muscle action, learning, and memory

Serotonin

Affects mood, hunger, sleep, and arousal

• Low levels increases the risk of depression

Glutamate

A major excitatory neurotransmitter; involved in memory

Endorphins

"morphine within"--natural, opiatelike neurotransmitters linked to pain control and to pleasure (can inhibit pain)

Dopamine

influences movement, learning, attention, and emotion

• responsible for feelings of reward and pleasure

Norepinephrine

helps control alertness and arousal; undersupply can depress mood

GABA

a major inhibitory neurotransmitter

Histamine

released by cells in response to injury and in allergic and inflammatory reactions, causing contraction of smooth muscle and dilation of capillaries

Glial Cells

• the "support cells" of the nervous system

• provide structural support, insulation, and nourishment to neurons

• play essential roles in maintaining brain health and supporting neuronal function

Motor Neurons

nerve cells that transmit signals from the CNS to muscles, glands, and organs, initiating and controlling voluntary and involuntary movements

Sensory Neurons

• specialized nerve cells that transmit sensory information from sensory receptors, such as those in the skin, muscles, and organs, to the CNS

• detect various stimuli, including touch, temperature, and environmental changes, and convert these stimuli into electrical signals that can be processed by the brain

Interneurons

nerve cells that serve as connectors within the CNS, relaying signals between sensory neurons and motor neurons

Reflex Arc

neural pathway that controls reflex actions, allowing for rapid, automatic responses to sensory stimuli without conscious thought (primitive reflexes)

Explain hand touching stove

Sensory neurons detect stimuli and send signals to the spinal cord. Interneurons relay this information to motor neurons, which trigger reflexive muscle or gland responses, such as withdrawing a hand from a hot surface.

The Homunculus Mapper

A map of your body surface on your brain's cortex that is not proportional to actual space

Neural Transmission

the process by which neurons communicate with each other through electrical and chemical signals

Depolarization

phase of action potential where the inside of the neuron becomes less negative compared to the outside due to the influx of positively charged ions, such as sodium ions, through ion channels in the cell membrane

Threshold

the level of stimulation required to trigger an action potential in a neuron (minimum amount of stimulation necessary to produce a response)

Action Potential

brief electrical impulse that travels along the axon of a neuron

All-or-Nothing Principle

states that once a neuron reaches its threshold of excitation, it will fire an action potential at full strength

• if the stimulus is strong enough to trigger an action potential, the neuron will respond with a full-strength impulse

Refractory Period

brief period following an action potential during which a neuron is unable to generate another action potential

Why does the refractory period occur?

the neuron's sodium channels are temporarily inactivated and the cell membrane returns to its resting state

Resting Potential

the stable, negative electrical charge that exists across the cell membrane of a neuron when it is not actively transmitting signals

How is resting potential maintained?

by the unequal distribution of ions, with more sodium ions outside the cell and more potassium ions inside

Reuptake

process in which neurotransmitters that have been released into the synapse are reabsorbed by the presynaptic neuron from which they were originally released

Multiple Sclerosis "MS"

chronic autoimmune disease that affects the central nervous system, including the brain and spinal cord

When does MS occur?

when the immune system mistakenly attacks the protective myelin sheath, a fatty substance that surrounds and insulates nerve fibers, causing inflammation and damage

Myasthenia Gravis

chronic autoimmune disorder that affects the neuromuscular junction, where nerve impulses are transmitted to muscles

When does Myasthenia Gravis occur?

when the immune system produces antibodies that block or destroy the receptors for acetylcholine, a neurotransmitter that stimulates muscle contraction

Psychoactive Drugs (3)

• substances that alter brain function, leading to changes in perception, mood, consciousness, cognition, or behavior

• act on the central nervous system

• can be categorized into stimulants, depressants, hallucinogens, and opioids

Agonists

Substances that bind to neurotransmitter receptors and mimic their effects OR blocking reuptake, increasing the effectiveness of neurotransmission/enhancing neural activity

Selective Serotonin Reuptake Inhibitors (SSRIs)

such as Prozac, a drug used to treat depression, function as agonists by delaying the reuptake of serotonin, making it more available.

Antianxiety medications (i.e., Xanax)

fit into receptor sites for GABA and excite the cell

Antagonists

Substances that bind to neurotransmitter receptors without activating them, blocking the effects of neurotransmitters and decreasing the effectiveness of neurotransmission

Schizophrenia meds

block the dopamine receptors

Curare

blocks the action of ACh

Botulinumtoxin (Botox)

blocks release of ACh

Reuptake Inhibitors

Medications that block the reabsorption of neurotransmitters by the sending neuron, thereby increasing the concentration of neurotransmitters in the synaptic cleft and enhancing neurotransmission

Stimulants

Drugs that increase neural activity and arousal, leading to heightened alertness, attention, and energy levels

Caffeine

• a natural stimulant found in coffee, tea, and some sodas

• acts on the central nervous system, increasing alertness and reducing fatigue by blocking the neurotransmitter adenosine

Cocaine

• powerful stimulant derived from the coca plant

• increases neural activity, leading to euphoria, increased energy, and alertness

• works by blocking the reuptake of dopamine, serotonin, and norepinephrine.

Depressants

• drugs that slow down neural activity and bodily functions

• induce relaxation, sedation, and can lower inhibitions

Alcohol

• depressant drug that slows down neural activity in the central nervous system