Bio Review Notes - Psych

Consent

  • Always get consent when in doubt to avoid distress.

Nervous System

  • The nervous system has two main parts:

    • Central Nervous System (CNS)

    • Peripheral Nervous System

Central Nervous System (CNS)

  • Made up of the brain and spinal cord.

  • Consists mainly of interneurons.

  • Controls the endocrine system.

Interneurons

  • The majority of neurons are interneurons.

  • Connect the brain to the rest of the body.

Endocrine System

  • Involves glands like the pituitary.

  • Related to the hypothalamus, which controls functions like hunger.

Peripheral Nervous System

  • Everything outside the CNS.

Somatic Nervous System

  • Governs voluntary motor movement.

  • Sensory afferent, Motor efferent (SAME).

    • Sensory: Sensation to the brain.

    • Motor: Information from the brain to the muscles.

Autonomic Nervous System

  • Involuntary responses (heart rate, digestion, sexual response, etc.).

  • Broken down into:

    • Sympathetic Nervous System

      • Fight, flight, or freeze responses.

      • Also includes tend and befriend response (caring response to stress).

      • Taxing on the body's energy.

      • Physiological, emotional, and psychological response to arousal.

    • Parasympathetic Nervous System

      • Calming; rest and digest.

Neurons

  • Two types of brain cells: neurons and glial cells.

Neurons

  • Sending Neuron: Presynaptic.

  • Receiving Neuron: Postsynaptic.

  • Synapse: Connection between neurons.

    • Sending and receiving occurs at every synapse.

Dendrites

  • Detect information.

  • Receive information.

Neural Signals

  • Excitatory: Fire, fire, fire.

  • Inhibitory: Don't fire, don't fire, don't fire (slows down firing).

Axon

  • Announcing part of the neuron.

  • Covered by the myelin sheath.

Myelin Sheath

  • Multiple Sclerosis (MS) is a central nervous system disorder involving degradation of the myelin sheath.

  • Myasthenia Gravis (MG) is a somatic nervous system disorder that impacts motor function, but is not related to myelin sheath degradation.

    • Both MS and MG result in loss of motor functioning, but for different reasons.

Axon Terminal

  • End of the axon where neurotransmitters are released.

  • Also called the terminal button or terminal knob.

Neurotransmitters

  • Leave the axon terminal and bind to receptor sites.

  • Specific neurotransmitters bind to specific receptor sites (e.g., serotonin to serotonin receptors).

  • Reuptake: Neurotransmitters are sucked back into the presynaptic neuron.

Key Neurotransmitters (SNAGP)

  • Serotonin

  • Norepinephrine

  • Acetylcholine (ACh)

  • Glutamate

  • GABA

  • Endorphins

  • Dopamine

  • Substance P

Neurotransmitter Imbalances

  • Too much Dopamine: Schizophrenia.

  • Too little Dopamine: Parkinson's disease, Depression.

  • ACh deficiency: Alzheimer's disease.

  • Endorphins: Natural opiates; pain relief (severity varies).

Agonists and Antagonists

  • Agonist: Increases the effect of a neurotransmitter (e.g., alcohol as a GABA agonist).

  • Antagonist: Decreases the effect of a neurotransmitter

Brain Lobes

Frontal Lobe

  • Reasoning.

  • Motor cortex.

  • Broca's area: Physical speech production.

    • Damage: Broca's aphasia.

Parietal Lobe

  • Sensory cortex.

  • Contralateral control: Opposite side control.

  • Representation is proportional to sensory/motor control needed.

Contralateral Control

  • The right side of the brain controls the left side of the body, and vice versa.

Temporal Lobe

  • Wernicke's area: Language comprehension.

    • Damage: Wernicke's aphasia (can speak, but it doesn't make sense).

Occipital Lobe

  • Visual cortex.

  • Damage: Neural blindness (various types of visual distortions).

Corpus Callosum

  • Connects the two hemispheres of the brain.

  • Split-brain studies show that severing the corpus callosum can prevent patients from verbally identifying what they see in one visual field because the language processing (typically in the left hemisphere) cannot access the information.

Limbic System

  • Subcortical structure involved in memory and emotion (Hippo HAT).

Hippo HAT

  • Hippocampus: Long-term memory formation.

    • Converts short-term memory to long-term memory.

    • Most active during REM sleep.

    • Depressed by drugs and alcohol.

  • Hypothalamus: Master of the endocrine system.

    • Four Fs: fight, flight, food, fornication.

    • Regulates homeostasis (body temperature, etc.).

  • Amygdala: Emotion (especially anger).

    • Puts emotional time stamps on memories (flashbulb memories).

    • Damage can lead to decreased or increased fear, sex drive, and aggression.

    • Involved in classical conditioning.

  • Thalamus: Sensory processing (except smell) and consciousness.

    • Damage can lead to a coma.

Hindbrain

  • Cerebellum: Coordination and nonverbal learning.

    • Implicit/procedural/nondeclarative memory.

  • Reticular Formation: Sleep-wake cycle.

  • Medulla: Heart rate, breathing.

    • Damage can be fatal or require a respirator.