Neurotransmitters are degraded or taken describe the

6. Neurotransmitters are degraded or taken
 Describe the mode of action of excitatory and inhibitory
neurotransmitters.

Lesson 10: Organisms Sense Their Environment
o Compare and contrast the three categories of vertebrate sensory
receptors.
o Explain the 4 steps involved in conveying sensory information to the
CNS.
o Describe how stimulus-gated ion channels work.
o Explain the relationship between intensity of stimulus and frequency of
action potentials.
o Explain how mechanoreceptors are involved in hearing and balance.

 noxious substances and tissue damage
 free nerve endings
o Thermoreceptors
 temperature changes
 contain TRP ion channels responsive to hot and cold
 skin and hypothalamus
o Proprioceptors & Baroreceptors
 monitor the position and movement of the body
 muscle tension
 muscle spindles
 Golgi tendon organs
 Blood Pressure (Baroreceptors)
 carotid sinus
 aortic arch
o Sound Detection
 outer, middle, inner ear
 sound waves strike tympanic membrane which sends
vibrations to the bones of the middle ear
 oval window transfers sound to inner ear
o Transduction- The Cochlea
 spiral-shaped complex structure that is fluid filled
 sound waves are converted into pressure waves
 cochlear duct
 organ of corti
 pressure waves vibrate the basilar membrane
 sensory hair cells
 stereocilia embedded in tectorial membrane
o action potentials
o Motion receptors
 invertebrates have statocyst: detect gravity & motion
 vertebrates
 utricle: horizontal movement
 saccule: vertical movement
 semicircular canals: detect angular motion