Nervous system

Parts of the nervous system:

• Central nervous system - a bilateral, essentially symmetrical structure with distinct parts. Receives sensory information from the skin through bundles of long nerve fibers, called axons, and transforms it into coordinated motor commands that are relayed to the muscles for action through other bundles of nerves
  • Spinal cord - contains the machinery needed for simple reflex behaviors.
  • Brain stem - conveys sensory information to higher regions of the brain and motor commands from those regions downward to the spinal cord. Also regulates attention.
  • Brain:
    • Hypothalamus
    • Thalamus
    • Cerebellum
    • Cerebral Hemispheres/ Cerebral Cortex - concerned with higher mental functions: perception, action, language, and planning
      • Basal ganglia - help regulate motor performance
      • Hippocampus - involved with aspects of memory storage
      • Amygdala - coordinates autonomic and endocrine responses in the context of emotional states

The biology of nerve cells:

• The neuron doctrine - the neuron is the fundamental building block and elementary signaling unit of the brain.
• The ionic-hypothesis - focuses on the transmission of information within the nerve cell. It describes the mechanisms whereby individual nerve cells generate electrical signals, called action potentials, that can propagate over a considerable distance within a given nerve cell.

The chemical theory of synaptic transmission - focuses on the transmission of information between nerve cells. It describes how one nerve cell communicates with another by releasing a chemical signal called a neurotransmitter. The second cell recognizes the signal and responds by means of a specific molecule in its surface membrane called a receptor.