Brain Anatomy - Short Course: Neurons and Subcortical Structures



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Two Types of Cells Make Up Brain: Neurons and Glial Cells

  • Neurons - don't regenerate themselves on a regular basis like other cells; communicate with other neurons and form networks by means of electrical and chemical signals. They have dendrites and a single axon, which is usually covered by myelin. Dendrites receive information from other cells. The axon sends information to other cells. Neurons communicate electrochemically by passing messages at the synapse (connection) between axons and dendrites.
  • Glial Cells - don't participate directly in electrical signaling like neurons but they help. Important in development of the fetal brain; help remove debris of dead cells after a brain injury; act as a sponge to mop up potentially toxic chemicals and help form/maintain the blood-brain barrier.

Central Nervous System Parts:

  • Spinal Cord - extension of the brain; carries messages between brain and body; carries out some reflex actions independent of the brain (ex. knee jerk)
  • Brainstem - located at base of brain; three parts - midbrain, pons, medulla oblongata. Purpose is survival; controls autonomic functions that aren't under our conscious control but necessary for survival.
  • Cerebellum - located at the back of the brain; key to balance, maintenance of body posture, and coordination of muscle function.
  • Thalamus and Hypthalmus - two walnut sized structures in the core of the brain; regulate perception and the body's vital functions. Thalamus is a relay station that directs the flow of information between the sense organs and the cortex. Hypothalamus works with the pituitary gland to control functions needed for maintaining the normal state of the body.
  • Amygdala - two almond shaped structures deep in the center of the brain; alarm system for the brain; involved in the fight-or-flight response
  • Hippocampus - holds short term memory and eventually sends that memory to the cortex where it is stored long-term.