Nervous System

• What are the components of the sensory system?

  Vision, Taste, Hearing, Touch, Smell, Balance
• What organs are associated with the sensory system?

  Ears, eyes, taste buds, olfactory epithelium
• What connects sensory receptors to the nervous system?

  Afferent neurons
• What does the somatic nervous system control?

  Voluntary movements
• What type of neurons are involved in the somatic nervous system?

  Efferent neurons
• Where are the cell bodies of somatic nervous system neurons located?

  Brain stem
• What does the autonomic nervous system control?

  Involuntary functions
• What are the two divisions of the autonomic nervous system?

  Sympathetic and Parasympathetic
• What is the primary function of the sympathetic nervous system?

  Fight or flight response
• How does the sympathetic nervous system affect heart rate?

  Increases heart rate and force of contraction
• What happens to pupils during a sympathetic response?

  Pupils dilate
• How does the sympathetic nervous system affect digestion?

  Slows down digestion
• What is the role of the parasympathetic nervous system?

  Rest and digest
• How does the parasympathetic nervous system affect heart rate?

  Decreases heart rate and blood pressure
• What does the enteric nervous system regulate?

  Digestion
• How is the enteric nervous system characterized?

  Largely independent of CNS
• What are sensory receptors?

  Specialized cells detecting environmental changes
• What do sensory receptors convert energy into?

  Start of nerve impulse
• What are steady-state receptors?

  Generate impulses while state remains constant
• What are changing-state receptors?

  Respond to variation in stimulus intensity
• What are the types of sensory receptors?

  Exteroceptive, Interoceptive, Proprioceptive
• What are mechanoreceptors?

  Receptors responding to mechanical pressure
• What happens when pressure is applied to mechanoreceptors?

  Connective tissue deforms
• What opens stretch-sensitive sodium channels in mechanoreceptors?

  Pressure applied to skin
• What does the generator potential create in mechanoreceptors?

  Action potential
• What are photoreceptors?

  Receptors sensitive to light
• What are the two types of photoreceptors?

  Rods and Cones
• What do cone cells detect?

  Colour images
• What is the function of rods?

  Sensitive to low light intensity
• What connects photoreceptor cells to ganglion cells?

  Bipolar cells
• What do ganglion cells do?

  Transmit nerve impulses to optic nerve
• What does rhodopsin allow?

  Vision in poor light
• What happens to rhodopsin in light?

  Absorbs light and splits
• What causes a generator potential in rod cells?

  Change in permeability to Na+
• What is the structure of neurons?

  Cell body, dendrites, axon, axon terminal
• What is the function of dendrites?

  Receive signals from axons
• What is the role of the axon?

  Transmit electrical signals away from cell body
• What is the function of the axon terminal?

  Connects to other nerve or effector cells
• What are glial cells?

  Support and nourish neurons
• What do astrocytes do?

  Maintain blood-brain barrier