Psych Test 2 🧠

Hereditary

• genetic

• doesn’t change, the nature part of nature v. nurture

• research regarding how genes affect behavior are often done with twins due to identical genetic code

Behavior Genetics

• study relative power and limits of how nature and nurture influence behavior

• study twins (twin study)

  • identical monozygotic: same genome

  • fraternal dizygotic: different genome

Epigenetics

• how environment affects genome

Eugenics

• want to “improve genetic quality” of people

Central Nervous System

• soma is in the brain or spinal cord

Peripheral Nervous System

• soma is outside of the brain or spinal cord

• Somatic nervous system

  • voluntary movement

• Autonomic nervous system

  • involuntary functions

  • Parasympathetic nervous system

    • calms/slows down

  • Sympathetic nervous system

    • arouses

Neurons

• receives signals through dendrites and sends them through axons

• axons are encased in myelin sheath → causes faster transmission of signal

  • Schwann Cells

    • make up myelin sheath

• combined signal exceeds minimum threshold → neuron fires

• all or nothing process

Glial cells

• provide myelin and support, nourish and protect neurons

• non-neuronal cells

• not involved in neurotransmissions

Synapse

• area between the dendrite and axon

Types of Neurons

• sensory

  • body → brain

• motor

  • brain → body

• interneuron

  • only in CNS

  • connects sensory and motor neurons

Cell Body (Soma)

• where organelles are stored

Dendrites

• Branches from cell body

• Receives signals

Axons

• long extension of neuron

• sends signals away from soma

• covered by myelin sheath

  • multiple sclerosis: deteriorating myelin sheath

• saltatory conduction

  • action potential “jumps” → faster signaling

• Axon Terminal

  • end of axon

Reflex

• automatic protective response to stimulus

Threshold

• level of stimulation required to trigger a neural response

Resting Potential

• neurons aren’t firing but are able to

• inside of axon charge: -70 mV

  • channels closed

• threshold reached → channels open → depolarizes

Depolarization

• Na+ gates open → Na+ goes inside axon

• charge inside axon goes from -70 mV → (roughly) 40 mV

Repolarization

• K+ leaves axon → axon charge goes back to -70 mV

Hyperpolarization

• time neuron takes to go back to homeostasis after firing

Action Potential

• movement of positive ions along axon

• causes release of neurotransmitters

Reuptake

• intakes excess neurotransmitters

Neurotransmitters

• chemicals released from sending neuron

• travel across synapse and bind to receptor sites of other neurons

• influence receiving neuron

Excitatory Neurotransmitters

• trigger actions

• depolarizes

Inhibitory Neurotransmitters

• depress actions

• hyperpolarizes

Dopamine

• major excitatory neurotransmitters

• motivates to repeat behaviors

• schizophrenia: too much dopamine

• parkinson’s: too little dopamine

Serotonin

• mood booster

• happiness chemical basically

• not enough → depression

Opioids

• class of drugs

• cause excess stimulation of dopamine

• agonist of endorphins

• slows down heart rate → not enough O₂ to brain → death

  • narcan

    • reverse effect of opioid overdose

Split-Brain Patients

• cut corpus callosum

• hemisphere specialization

• last resort for severe seizures

Electroencephalogram (EEG)

• electrodes on scalp

• measure electroactivity/waves of brain neurons

• detect abnormalities in brain’s electrical activity

• diagnose brain disorders

• only shows function

Functional MRI (fMRI)

• application of MRI

• detects blood flow and brain areas

• shows brain structure and function

Pineal Gland

• releases melatonin at night

Hypothalamus

• releases hormones that affect the pituitary gland

Pituitary Gland

• master gland

• secrete hormones

Agonist

• mimics action of neurotransmitter

Antagonist

• block neurotransmitter

Stimulant

• excite neural activity

• ex: cocaine

Depressant

• slow neural activity

• ex: alcohol

Hallucinogen

• distort perception of reality

• ex: LSD