Psychology: The Brain and Nervous System

Central Nervous System

  • The brain and spinal cord make up the central nervous system.

Spinal Cord

  • The spinal cord is the long bundle of nerve fibers that carry messages responsible for transmitting information to and from the body to the brain.
  • It is crucial for life-saving reflexes.

Endocrine System

Glands and Hormones

  • Hormones are chemicals released into the bloodstream by the endocrine glands.
  • The pituitary gland controls all other endocrine glands.
  • Melatonin: A hormone released by the pituitary gland that reduces body temperature and prepares the body for sleep.
  • Gonads: Are the sex glands that secrete hormones regulating several developmental processes, sexual behavior, and reproduction.
  • Adrenal Glands: Located at the top of the kidneys, they secrete hormones that regulate salt intake, control stress reactions, and provide a secondary source of sex hormones that affect the sexual changes occurring during adolescence.

Technology & Brain Imaging

Imaging Techniques

  • CT Scan: A brain imaging method that uses computer-controlled X-rays.
  • Electroencephalograph (EEG): Used to measure brain waves.

Brain Structure and Functions

Different Parts of the Brain

  1. Medulla: A structure in the brainstem responsible for life-sustaining functions such as breathing and heart rate.
  2. Pons: A structure in the brainstem that plays a role in sleep, dreaming, left-right body coordination, and arousal.
  3. Reticular Formation: Responsible for the ability to selectively attend to certain kinds of information in one's surroundings and become alert to changes.
  4. Thalamus: Acts as a relay station for all incoming sensory information.
  5. Hypothalamus: Involved in eating, drinking, sexual behavior, sleeping, and temperature control.
  6. Hippocampus: Responsible for the formation of long-term memories.
    • Related to Alzheimer's Disease: Impairments in the hippocampus are linked to memory loss in Alzheimer's disease.
  7. Amygdala: Responsible for fear responses and the memory of fear.
  8. Corpus Callosum: A thick band of neurons that connects the right and left cerebral hemispheres.
  9. Broca's Area: Located in the frontal lobe, dedicated to the production of fluent speech.
    • If someone has a split-brain operation, it is often due to severe epilepsy.

Neurons and the Nervous System

Structure of Neurons

  • Dendrites: Receive messages from other neurons.
  • Cell Body (Soma): Responsible for maintaining the life of the neuron.
  • Axon: Sends messages away from the neuron.
  • Axon Terminals: Transmit messages to other neurons.
  • Myelin: A protective coating for the axon, made up of fatty acids, which increases speed and efficiency of signal transmission.
  • Nodes of Ranvier: Gaps between segments of the myelin sheath.

Action Potential

  • The action potential refers to the electrical charge inside the neuron being positive in comparison to the electrical charge outside the neuron.

Summary of Key Concepts for Testing

  1. Central nervous system comprises the brain and spinal cord.
  2. Spinal cord serves as a long bundle of neurons that carry messages fast to/from the brain and is responsible for lifesaving reflexes.
  3. Hormones are chemicals released into the bloodstream by endocrine glands.
  4. The pituitary gland oversees all other endocrine glands.
  5. Melatonin lowers body temperature and prepares for sleep.
  6. Gonads regulate sexual development and behavior.
  7. Adrenal glands control stress reactions and influence sexual changes during adolescence.
  8. CT scans provide detailed brain imaging via X-rays.
  9. EEG measures brain activity via brain waves.
  10. Medulla manages vital functions, while the pons aids in sleep and coordination.
  11. Reticular formation helps with attention and alertness to changes.
  12. Thalamus relays sensory information.
  13. Hypothalamus regulates thirst, hunger, and temperature.
  14. Hippocampus is essential for long-term memory formation and is affected in Alzheimer's disease.
  15. Amygdala is essential for fear-related responses.
  16. Corpus Callosum connects both hemispheres.
  17. Broca's Area is critical for speech production.