Interaction of heredity and the environment:

• Evolutionary psychology- Humans develop certain behaviors that contribute to the survival of the next generation. Assessing how biology is intertwined with psychology.

• Nature v Nurture- The debate on whether humans are the way they are based off of either genetics and heredity or our environment/culture/how we were raised/anything that influences us on the day to day. For this debate you are either on one side or the other, not a little in each side.

  • Observing twins with nature v nurture- Monozygotic meaning identical twins from a single fertilized egg, and dizygotic meaning fraternal twins with two fertilized eggs. Identical twins share exactly the same DNA but often have different personality characteristics

• Heritability- Extent to how appearance and traits are accounted for by genes. Heritability is applied to groups and not the individual.

  • Genetics becoming more similar between two groups means heritability is lower

  • Genetics becoming more dissimilar between two groups means heritability is higher

  • Environment becomes more similar between two groups means heritability is higher

  • Environment becomes more dissimilar between two groups means heritability is lower

The Nervous system

• The nervous system is the vast connections of the communication in the humans body connected all through neurons. This system is divided into two parts;

  • Central nervous system (CNS): The brain and the spinal cord which is the main control center.

  • Peripheral nervous system (PNS): Nerve networks that connect the rest of the body to the spinal cord and the brain.

• Somatic nervous system: Specific nerves that transmit signals from the brain to skeletal muscles for voluntary movement.

• Neurotransmitters: carry messages from one neuron to the next.

• Soma: Cell body of the neuron the keep the cell together. Referred to as the ‘life support’.

• Dendrites: Receiver of messages on the neuron, located on the soma. Referred to as the antenna.

• Axon: Long part of the neuron that sends the signal down from the dendrites, through the cell body, to the axon terminal.

• Axon terminal: Tips at the end of the axon that will send the signal from the neuron to either other neurons or to muscles.

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• Synapse: It is the contact point between an axon terminal and a connecting neurons.

• Neural transmission: The process when information travels through the neuron.

• The way signals and information is send is through chemicals, aka electrochemically.

• Synaptic vesicles: part of the end of the axon terminal where neurotransmitters are released and go into the synapse.

• Synaptic clef/gap: the exact point in between the axon terminal and the dendrite. The gap is a millionth of an inch wide.

• Pre-synaptic is the sending cell. Defining trait is the neurotransmitters.

• Post-synaptic is the receiving cell. Defining trait is the receptor cites.

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• Glial cells: Cells that provide physical structure for neurons to grow on as well as nutrients and they clean up dead neurons. Glial cells are 90% of our brain.

• Sensory neurons (Afferent neurons): Carry information from nerves through out the body and send it to the spinal cord/brain to relay the sensation.

• Motor neurons (Efferent neurons): Carry information from the brain/spinal cord to part of the body for movement.

• Interneurons: Neurons in the spinal cord that communicate between sensory inputs and motor outputs. They are the ‘translator’ between sensory information and motor information.

• Reflex arc: Sensory input —> Spinal cord —> processes information —> interneurons recprocate —> motor action

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• Autonomic nervous system: Controls unconscious actions such as breathing, blinking, etc.

• Sympathetic nervous system: Controls your fight or flight response along with alertness.

• Parasympathetic nervous system: Controls resting response, digestion, and relaxing function.

The endocrine system/ the brain structure

• Hormones are chemical messengers that are released from endocrine glands and into the blood stream which control body functions. Different than neurotransmitters.

• Pituitary gland is a pea sized structure in the brain that regulates stress, growth, reproduction, and part of pregnancy. This gland is controlled by the hypothalamus.

  • Brain —> Pituitary gland —> other glands —> hormones —>

• Pineal gland in the back of the brain secretes melatonin which regulates sleep.

• Thyroid gland is in the lower neck which regulates metabolism, growth, and appetite.

  • Damage to this gland results in bad sleep, concentration, fatigue, depression, dry skin, and a sensitive to cold, joint and muscle pain.

• Adrenal glands on top of both kidneys are involved with stress response.

• Gonads are sex glands that regulate estrogen in women and testosterone in men.

• Astonishing hypothesis: Everything you ever experience is a result of chemical interactions. “You are nothing but a pack of neurons”

About and types of neurotransmitters

• Oxytocin regulates social interactions and sexual reproduction responses by increasing the production of oxytocin when hugging, kissing, etc.

• Acetylcholine (ACh) is involved with thoughts, learning, memory, and in the activation of muscles.

• Serotonin is involved with mood. Connected with happiness, regulating emotions, and sleep. It is an inhibitor for anxiety and depression.

• Dopamine involved with the feeling of reward, pleasure, and satisfaction. Associated with addiction as people feel the need for the reward feeling coming from addiction. To much natural dopamine results in schizophrenia.

• Norepinephrine is your fight or flight response that is associated with danger, attention, and contracts blood vessels in order to increase blood flow.

• Gaba calms the body down by calming the central nervous system, increasing sleepiness, decreases anxiety/alertness/muscle tension. Not enough gaba leads to anxiety, seizures, tremors, and insomnia.

• Glutamate functions involve the memory, thinking, long term memory, and learning. Too much leads to overstimulation of the brain causing migraines up to epileptic seizures.

• Endorphins causes the euphoria feeling. Relieves stress and pain and created the feeling of pleasure.

• Excitatory neurotransmitters: Excite connections causing them to fire.

• Inhibitory neurotransmitters: Prevent neurons from firing.

• Drugs:

  • Psychoactive drugs: Chemicals that change a state of consciousness.

    • Neurotransmitters and psychoactive drugs act the same way.

  • Agonist drugs unlock receptors.

  • Antagonist drugs lock receptors.

  • Stimulants: Increase activity in the CNS making the neurons fire more making the body more active.

    • Ex: Caffeine, Cocaine.

  • Depressants: Slow down the active of the CNS making neurons fire less. Causes the body to reduce tension, affect judgement/concentration along with motor activity.

    • Ex: Alcohol, opioids, and sedative drugs.

Structures of the brain

• The brain is composed of two hemispheres. The left side controls the right side of the body and the right side controls the left side of the body.

  • Left side: Controls language, speech, handwriting, calculations, sense of time. Anything with analysis.

  • Right side: Controls perception, visualization, spatial perception, recognition of patterns, faces, emotion, melodies, and expression. The left side functions are more wide spread and include more creativity.

• Corpus collsum: It is a bundle of nerves that connect the two hemispheres so signals can travel back and forth.

• Cerebral cortex (grey matter): Most outer layer and is folded on top of itself many times so it has more surface area to have greater neural firing. Better firing leads to a higher level of thinking, thoughts, language, and ability to reason.

• Limbic system: Also known as the midbrain it is a section of the brain located under the cerebral cortex.

  • Hypothalamus: Controls hunger, thirst, emotions, body temperature regulation, and our circadian rhythm.

  • Hippocampus: It organizes and structures our memories along with being able to connect certain senses with memories.

  • Amygdala: Controls our fight or flight response.

  • Thalamus: Processes and transmits movement/sensory information.

  • Pons: Connects the brain and spinal cord along with controlling unconscious movement like breathing.

  • Visual/auditory cortex: Revives and process visual/auditory information.

  • Medulla: Controls processes like heartbeat, breathing, and blood pressure.

• Lobes: Sections of the brain with specific functions.

  • Frontal lobe: Reasoning, motor skills, high cognition, and expressive language.

    • Prefrontal cortex: Complex cognitive behavior, personality expression, decision making, and social behavior.

    • Broca’s area: Motor functions like speech production and language comprehension.

  • Parietal lobe: Process sensory signals, pressure, temperature, and pain.

    • Somatosensory cortex: Receives and processes information from the entire body.

  • Occipital lobe: Visual processing center. The right section is for the left eye and the left section is for the right eye.

  • Temporal lobe: Hearing processing center and for meaningful speech.

Brain scanning

• X-ray:

• Electroencephalograph (EEG):

• Computer Tomography (CT or CT Scan):

• Magnetic Resonance Imaging (MRI):

• Magnetic Cephalography:

• Functional MRI (fMRI):

• Position Emission Tomography (PET Scan):