nervous system

• nervous system - coordinates all activities of the body

  • also enables the body to respond and adapt to changes both inside and out
• sensory neuron

  • nerve cell that carries impulses from a sense receptor to the brain or spinal chord
• Relay neuron - nerve cell that connects sensory and motor neurons
• Motor neuron - transmits impulses from the brain or spinal chord to a muscle or gland
• Axon - long fiber tbat carries the nerve impulses
• Nerve - a bundle of axons
• Synapse - the connection between adjacent neurons
• Neurotransmitter - chemical secreted into the gap between neurons at a synapse
• Reflex - a rapid automatic response to a stimulus
• Myelin sheath - covering or fatty material that speeds up the passage of nerve impulses
• Axon terminal - structure at the end of an axon that produces neurotransmitters to transmit the nerve impulse across the synapse
• Nerve impulse - the high speed signals that pass along the axons of nerve cells
• Dendrite - the branching filaments that conduct nerve impulses towards the cell
• Sense receptor - the sense organ or cell that receive stimuli from within and outside the body
• Response - the reaction to a stimulus by a muscle or gland
• Cell body - the part of the nerve cell containing the nucleus
• The two divisions of the nervous system are: central and peripheral
• CNS:

  • brain
  • Spinal chord
• PNS

  could be:

  • Somatic (voluntary)
  • Autonomic (involuntary)
• 6 MAIN SECTIONS OF THE BRAIN:

  • cerebrum
  • Cerebellum
  • Diencephalon
  • Midbrain
  • Pons
  • Medulla oblongata
• Cerebrum - contrals voluntary movement, intelligence, and memory

  • Divided into right and left hemispheres
• Frontal lobe - for reasoning and thought
• Parietal lobe - integrates sensory information
• Temporal lobe - processes the auditory information from the ears
• Occipital lobe - processing visual information from the eyes
• Cerebellum - in charge of muscle coordination, balance, posture, and muscle tone
• Thalamus - directs sensory impulses to the cerebrum
• Hypothalamus - controls and regulates temperature, appetite, water balance, sleep, and blood vessel constriction and dilation
• Midbrain - located below the cerebrum and responsible for eye and auditory reflexes
• Pons - responsible for certian reflex actions
• Medulla Oblongata - connects to the spinal chord

  - regulates heart and blood vessel function, digestion, respiration, swallowing, coughing, sneezing, blood
• Spinal chord - is the link between the brain and the nerves in the rest of the body
• 4 REGIONS OF THE SPINAL CHORD:

  • cervical
  • Thoracic
  • Lumbar
  • Spinal nerves
• Afferent - carries information from the BODY to the BRAIN
• Efferent - carries information from the BRAIN to the BODY
• Somatic system - responsible for nearly all voluntary muscle

  movements

  • Processes information from external stimuli
• Afferent neurons - take information from the nerves to the CNS
• Efferent neurons - take information from the CNS to the muscle fobers throughout the body
• 2 DIVISIONS OF AUTONOMIC NERVOUS SYSTEM:

  • Sympathetic
  • Parasympathetic
• Sympathetic nervous system - not normal state of body, is triggered during emergencies