2 - human body

• As complex as our psychological experiences are (thoughts, emotions, and behaviors), they all occur as organic, physiological processes in our brains and in the rest of our bodies.

  
• Neurons


  The basic building block of our nervous system

  
• Neurons are not only found in our brain, but in other parts of our bodies as well.
• If we only have neurons in our brain, then we will certainly be mere floating consciousness with no awareness of and connection to our bodies.
• Parts of neurons

  • Dendrites
  • Soma
  • Axon
  • Axon terminals
• Glial cells


  Cells that cover the axon and have important functions in our nervous system

  
• Nerves are bundles of axons in our body, and they are coated with myelin, a protective sheath made up of glial cells called Schwann cells.
• If a nerve is severed, the severed nerves can reconnect thanks to the myelin sheath.
• Action potential

  The movement of the electrochemical impulse in the neuron
• Neurotransmission

  1. Neurotransmitters are released into the synapse

  2. Neurotransmitters attach to receptor sites on the next neuron

  3. Neurotransmitters are broken down by enzymes or taken back into the axon terminal through reuptake
• Neurotransmitters


  Molecules that transmit signals from one neuron to another
• Neurotransmitters have complex functions and we must be careful about making oversimplified statements about how they work.
• Nervous system


  • Central nervous system (brain and spinal cord)
  • Peripheral nervous system (nerves and neurons outside the central nervous system)

  
• Peripheral nervous system


  • Somatic nervous system (controls voluntary movement and senses)
  • Autonomic nervous system (controls involuntary bodily functions)

  
• The autonomic nervous system is divided into the sympathetic nervous system (deals with stress) and the parasympathetic nervous system.
• Sensory pathway


  Carries information from the senses to the central nervous system (brain & spinal cord)

  
• Motor pathway


  Carries information from the central nervous system to the voluntary musculoskeletal parts of our bodies

  
• Autonomic Nervous System


  Parts of our nervous system responsible for automatic movement
• Parts of the Autonomic Nervous System

  • Sympathetic nervous system
  • Parasympathetic nervous system

  
• Sympathetic nervous system is more active


  When you feel nervous, your heart beats faster, your breath becomes heavier, your stomach feels cramped, and you feel like your whole body is ready to DO SOMETHING! ANYTHING!
• Parasympathetic nervous system


  Restores the body back to normal after a stressor, responsible for the daily normal functioning of our breathing, heartbeat, and other automatic physiological response
• Endocrine System


  Responsible for the production of hormones, works together with our brains to regulate sleep, behavior, and emotions
• Hormones influence us more slowly than neurotransmitters as they flow through the bloodstream
• Oxytocin


  Stimulates labor contractions, encourages mother-infant attachment, modulates stress and fear response
• The brain is the organ in our body that receives information from our senses, processes that information, and sends out commands

  
• Main parts of the brain

  • Forebrain
  • Midbrain
  • Hindbrain
• Hindbrain


  Lowest part of our brain, located near the base of our skull, maintains functions such as breathing and heartbeat, composed of the medulla, pons, reticular formation, and cerebellum
• Midbrain


  Located near the top of the hindbrain, contains the colliculi, tegmentum, and cerebral peduncles
• Substantia nigra


  Part of the midbrain, has many receptors for and produces the neurotransmitter dopamine, responsible for reward and movement, part of the basal ganglia
• Forebrain


  Includes the limbic system and the cortex
• Limbic system


  Responsible for emotions, motivation, memory, and learning, consists of the thalamus, hypothalamus, hippocampus, amygdala, and cingulate cortex

  
• Thalamus


  Relay station between the sensory information and the cortex, except for the sense of smell
• Hypothalamus


  Responsible for emotions, regulating sleep, hunger, thirst, and sexual activity, intimately connected to the autonomic nervous system and endocrine system
• Hippocampus


  Primarily responsible for storing long-term, episodic memories
• Amygdala


  Primarily involved in fear responses and memories related to fear
• Cingulate cortex


  Connected to our learning via the outcomes or consequences of actions or behaviors, associated with empathy and social behaviors
• Cortex


  Responsible for directing voluntary movements, language, problem-solving, decision-making, and consciousness, divided into two hemispheres connected by the corpus callosum

  
• Lobes of the cortex

  • Occipital lobes
  • Parietal lobes
  • Temporal lobes
  • Frontal lobe

  
• Occipital lobes


  Responsible for processing visual information
• Parietal lobes


  Contains the somatosensory cortex, which processes information from our sensations and body perceptions