Week 1 (BBB, CNS, PNS, ANS)

Start on page 16

Blood Brain Barrier

What is the Blood Brain Barrier (BBB)?

The BBB is the method which chemicals are blocked from entering the blood vessels that are going to the brain.

When viruses the cells the call the immune system which then both the virus and the cell are destroyed. When its a skin or blood cell they regenerate but damaged neurons in vertebrates do not regenerate. The BBB minimizes the amount of chemicals moving in and out of the brain in order to minimize neuron cell death.

Endothelial

  • Cells that formed walls around capillaries of the brain

  • They keep both harmful and helpful chemical’s out of the bloodstream

  • Astrocytes provide nutrients to these endothelial

Vertebrate Nervous System

The nervous system encompasses the brain and all the nerves of the body.

Central Nervous System (CNS)

  • Brain and Spinal Cord

    • Spinal Cord communicates with all the sense organs and muscles of the body except for the head.

    • Has two Segments — Sensory and Motor nerves

      • Sensory nerves carrying sensory information to the brain

      • Motor nerves carrying commands from the brain to the muscles

Peripheral Nervous System (PNS)

  • The PNS can further be separated into two systems Somatic nervous system and Autonomic nervous system

    • Somatic controls voluntary muscles and brings sensory information to the CNS'

    • Autonomic controls involuntary muscles and manages responses to stress and relaxation

      • Sympathetic and parasympathetic systems

Autonomous Nervous System

  • Contains neurons that receive and send information to internal organs (heart, lungs, etc.)

  • The sympathetic and the parasympathetic systems work together to balanced the bodies reaction to stressed and relaxed states

  • The system control’s the bodies flight, fight, feeding, and sex

    • Sympathetic system is for emergencies like fight or flight

    • Parasympathetic system is for a relaxed state controlling things like rest and digestion.

Page 25 for diagram of how the systems fit together