Yt lesson

• What is the primary function of the nervous system?

  To coordinate and regulate feedback mechanisms
• What are the two main divisions of the nervous system?

  Central and peripheral nervous systems
• What does the central nervous system consist of?

  Brain and spinal cord
• What is the role of the peripheral nervous system?

  It involves all nerves outside the brain and spinal cord
• What connects the brain to the rest of the body?

  The spinal cord
• What are the major parts of the central nervous system?

  Brain and spinal cord
• How long is the spinal cord?

  40 to 50 centimeters
• What is the function of the spinal cord?

  Transmits impulses to and from the brain
• What are involuntary movements controlled by?

  The spinal cord and reflexes
• What does the peripheral nervous system carry?

  Impulses from sensory to motor nerves
• What does the somatic nervous system regulate?

  Activities under conscious control
• What does the autonomic nervous system control?

  Internal organs and involuntary functions
• What are the two subdivisions of the autonomic nervous system?

  Sympathetic and parasympathetic nervous systems
• What is the sympathetic nervous system known for?

  Fight-or-flight response during stress
• What does the parasympathetic nervous system do?

  Slows down heart rate and increases digestion
• What is the basic unit of the nervous system?

  Neuron or nerve cell
• What are the components of a neuron?

  Cell body, dendrites, axon, myelin sheath
• What produces the myelin sheath?

  Schwann cell
• What is the function of dendrites?

  Receive impulses and carry them to the cell body
• What do nodes of Ranvier allow?

  Fast electrical impulse generation along the axon
• What are the three classifications of neurons?

  Sensory, motor, and associative neurons
• What do sensory neurons do?

  Carry impulses from sense organs to the brain
• What is the role of motor neurons?

  Carry impulses from the brain to muscles
• What do associative neurons do?

  Analyze and interpret data in the CNS
• What types of receptors are involved in the nervous system?

  Photoreceptors, mechanoreceptors, olfactory receptors
• How does a stimulus lead to a response?

  Sensory neuron carries message to CNS
• What is homeostasis?

  Balance of internal body conditions
• What does homeostasis regulate?

  Body temperature, fluids, salts, gases
• What are the components of the control system in the body?

  Sensors, control center, communicating system
• What do sensors do in the body?

  Gather information about internal and external conditions
• What are the communicating systems of the body?

  Nervous system and endocrine system
• What is the role of the control center in the body?

  Examine information and compare to normal values
• What happens if information received is outside normal range?

  Brain sends messages to correct the condition
• What is the negative feedback mechanism?

  Reduces or minimizes changes in the body
• What does the positive feedback mechanism do?

  Increases the rate of processes in the body
• When is positive feedback important?

  When rapid change is necessary
• What can happen when the body is not in homeostasis?

  Organ failure or diseases may occur
• What is anxiety?

  Uncomfortable feeling of fear or uneasiness
• What is panic disorder?

  Repeated episodes of sudden fear
• What is depression?

  State of being sad and loss of interest