PSYC 001 - Test 2: Biology + Stress & Health

Neural Communication

How neurons talk to each other across the synapse

Neurotransmitters

Chemical messengers that are released from the axon terminal to the synapse, travels across the gap, and binds to the receptor sites on receiving neurons.

Nervous System

Central nervous system, peripheral nervous system, sympathetic/parasympathetic divisions.

Brain Structures

Limbic system, cortex, lobes, plasticity

Biological Model of Psychology

Every thought, emotion, and behavior has a biological correlation in the brain. 20% of U.S. adults experience mental health conditions in a year. They are now understood as brain-based disorders.

Biological Psychology

Scientific study of links between biological and psychological processes. No thought, feeling, or behavior doesn’t have a corresponding biological event in the brain and body.

Neurons

specialized nerve cell that receives, processes, and transmits information throughout the nervous system. Communicates electrically (within cell) and chemically (between cells).

Sensory/Afferent

Carries information TO the brain from senses.

Motor/Efferent

Carries information FROM the brain to muscles and glands.

Interneurons

Connects neurons together. Most plentiful type.

Parts of The Neurons

Dendrites (finger-like projections that receive signals from other neurons and pass to the cell body)

Soma (processes incoming signals, decides whether to fire action potential based on threshold)

Axon (long projection that carries action potential away from the cell body towards the next neuron)

Myelin Sheath (coating around axon that speeds signal transmissions)

Axon Terminals (end station)

Synapse (space between two neurons; neurotransmitters cross this gap, carrying the signal foreward)

Action Potential

When excitatory signals exceed inhibitory threshold, a neuron fires electrical charge down the axon.

Resting Potential

Neuron is at rest, charged and ready.

Refractory Period

Brief reset before the neuron fires again.

Excitatory Neurotransmitter

Increases the likelihood that the next neuron will fire (ex: glutamate)

Inhibitory Neurotransmitter

Decreases the likelihood tat the next neuron will fire (ex: GABA)

Lock & Key Model

Each neurotransmitter has a specific shape that fits certain receptor sites. The receptor can only be activated by the right neurotransmitter (or a drug that mimics its shape).

Agonist

Increases/enhances the effect of a NT. (mimics NT, blocks reuptake, increases NT production)

Reuptake

The process where a neuron absorbs a neurotransmitter back into itself after it finishes sending a chemical message across a synapse.

Antagonist

Decreases/blocks effect of a NT. (blocks receptor sites, speeds reuptake, decreases NT production)

Key Neurotransmitters

Acetylcholine (Enables muscle action, learning, and memory. Connected to alzheimers)

Dopamine (Influences movement, learning, attention, and emotions. Connected to schizophrenia and parkinsons)

Serotonin (Affects mood, hunger, sleep, arousal. Connected to depression.)

Norepinephrine (Controls alertness and arousal. Connected to depressed moods)

GABA (Inhibitory NT, controls anxiety. Connected to seizures, insomnia, and tremors)

Glutamate (Excitatory NT, helps with memory, learning, and brain development. Connected to overstimulation, migraines, seizures.)

Endorphins (Influences perception of pain and pleasure. Connected to opiod usage)

Significance of Alcohol + Brain

Disrupts 4 NT systems simultaneously. Has a wide range of effects on mood, memory, coordination, and judgement. GABA agonist, glutamate antagonist, dopamine agonist, acetylcholine antagonist

Neurotransmitters & Mental Health Disorders

Depression (low serotonin, norepinephrine, dopamine. meds: SSRIs, SNRIs, NDRIs)

Anxiety (low GABA, high norepinephrine. meds: GABA agonists, beta-blockers)

ADHD (low dopamine, norepinephrine (pfc). meds: stimulants, atomoxetine)

Schizophrenia (high dopamine (limbic), low glutamate (pfc). meds: antipsychotics)

PTSD (high norepinephrine, low serotonin, cortisol dysregulation. meds: prazosine)

Addiction (dopamine dysregulation. meds: naltrexone, bupropion)

Central Nervous System

Brain, spinal cord, receives all data and makes calls.

Peripheral Nervous System

Somatic (connects CNS to voluntary muscles, controls consciousness)

Autonomic (controls involuntary internal organs. heart, breathing, digestion)

Sympathetic (activates by stressors, real or perceived)

Parasympathetic (activated when the threat is removed. deep breaths, meditation, safe social connections activate this)

Endocrine System

Set of glands that send hormones through the body via the bloodstream, hormones travel through the body and triggers response in target organs. This system is slower and longer-lasting.

Pituitary Gland

“Master gland.” Controls other glands.

Hypothalamus

Links the nervous and endocrine system together

Adrenal Glands

Produces adrenaline and cortisol (stress). Cortisol imbalance is linked to depression, PTSD, anxiety, and burnout.

Thyroid

Regulates metabolism and body temperature. Imbalance mimics depression (hypo) and anxiety (hyper).

Sex Hormones

Affects mood disorders, postpartum depression, and PMS.

Stress

Unpleasant emotional state resulted from perception of danger.

Stressor

Source of stress.

Acute Stress Vs. Chronic Stress

Acute stress is short term, chronic stress is long-term.

Cognitive Appraisal Models

Helps us predict when a stimulus/event is likely to be a stressor. We make rapid initial assessments to determine harmless positive/negative stimuli.

Hassles

Insignificant sources of stress.

Sympathetic-Adrenal-Medullary Pathway (SAM)

Acute stress. Activates SNS, which activates adrenal medulla, etc.

Hypothalamus-Pituitary-Adrenal System (HPA)

Chronic stress. The hypothalamus is altered when a stressful situation is identified. Chronic stress releases CRF, which releases ACTH, which activates the adrenal cortex, etc.

Cortisol

Affects almost every organ and tissue in the body. Regulates body stress system, helps control use of fats/proteins/carbohydrates, suppresses inflammation, regulates blood pressure and sugar, and controls sleep-wake cycle. Always should be at homeostasis, too much or too little is dangerous.

Stress Responses + Women

Women more likely to tend & befriend stressors (oxytocin).

Stress Responses + Socioeconomic Status

Those with lower SES experience worse health. Those with lower SES have more exposure to toxins.

Stress + Immune System

The immune system doesn’t do well with long-term stressors (autoimmune diseases). Stress suppresses lymphocytes (white blood cells in the immune system)

Chronic Stress + Personality Types

Type A people are more vulnerable to heart diseases than Type B.

Overall Wellbeing + Chronic Stress

Mood, sleep, hunger, and appetite are closely intertwined and are affected by chronic stress. Health isn’t just the absence of disease, but the ability to respond to daily challenges.

Ways to Manage Stress

Sense of Control (Try to eliminate stress where you can

Coping Strategies (aerobics, mindfulness, social support)

Problem-Focused Coping

Addressing issues head-on by finding solutions.

Emotion-Focused Coping

Targets negative emotions from the situation. Can be positive (relaxing with friends) and negative (binge eating).

Relationship-focused coping

Designed to maintain social relationships. Can be positive and negative.

Brainstem

Connects the brain to the spinal cord. Controls essential life functions.

Parts of The Brainstem

Pons (sleep, dreams, wake, arousal)

Medulla (breathing, heart rate, swallowing, damage is immediately life-threatening)

Reticular Activating System (RAS) (consciousness and arousal)

Cerebellum

Balance and coordination, fine-motor skills, timing of movements, procedural learning (learning to ride bike)

Limbic System

A set of interconnected structures that are critical for survival. Emotional and memory experiences

Hypothalamus + Limbic System

Homeostasis, controls the pituitary gland. Master regulator

Amygdala

Detects threats, triggers fear response. Heightened amygdala results in anxiety, lower amygdala results in psychopathic presentation.

Hippocampus

Forms NEW long-term memories, and involved in spatial navigation. Stress damages this over time.

Left Hemisphere

Controls right side of body. Involved in language, reading, math, logic, and analysis

Right Hemisphere

Controls left side of body. Involved in nonverbal communication, visual-space perception, music/art, emotions, and pattern recognition)

Frontal Lobe

Executive functions, decision-making, impulsivity, emotional regulation, motor cortex, and speech (Broca’s area)

Temporal Lobe

Hearing, language comprehension (Wernicke’s area), smell, facial recognition, and memory (hippocampus)

Parietal Lobe

Touch, taste, temperature, spatial processing, body awareness, and sensory integration

Occipital Lobe

Prime visual processing, located at the back of the brain.

Neuroplasticity

The brains ability to reorganize itself by forming new neural connections throughout life

Neurogenesis

The creation of new neurons

CT Scan

Structural, detects tumors, bleeds, strokes, doesn’t show brain activity

MRI

Structural, detailed brain anatomy, detects subtle lesions, tumors, and MS

fMRI

Functional, used for research on cognition, emotions, decisions, and used for clinical decisions

PET Scan

Functional, detects early alzheimers, and maps dopamine receptors in addiction

EEG

Functional, epilepsy, sleep disorders, and consciousness research