Learning Objectives Sensory Systems Describe and explain the
Learning Objectives: Sensory Systems • Describe and explain the sequence of events in a receptor. • Describe and explain the function of various receptor types, along with animal examples. • Describe the reception of light by eyes. • Explain the structure and function of hearing in mammals.
What needs to happen in the cell phone for you to listen and watch the TV program? How stuff works
Sequence of events in a biological receptor Basic Function Reception Amplification Stimulus Receptor protein activated In accessory organs or in receptor Receptor ion channels opened or closed Transduction Depolarization or hyperpolarization Receptor potential (graded) Transmission Integration Neurotransmitter released from receptor cell(s) Sensory neuron Receptor = sensory neuron action potential(s) directly to CNS
Sensory transduction Reception Transmission Amplification Transduction
What series of events occur in moth during the depicted event?
Based on figs. 46. 2 and 46. 3
Transmitting information to the brain If all types of external stimuli are converted to electric signals in the form of action potentials, how can the brain interpret different stimuli as different?
Chemoreceptors General: transmit information on total solute concentration in a solution. Specific: respond to individual kinds of molecules, such as oxygen, carbon dioxide, glucose. Intermediate: respond to general categories of related chemicals (taste and smell).
Thermoreceptors Why do you think that there are separate hot and cold receptors?
Electromagnetic receptors
F. Nicklin
Science 2001
Fig. 46. 9
Mechanoreceptors and nocireceptors What would bending or stretching of plasma membrane will cause in cells? Based on fig. 46. 4 In vertebrate ear
Science 2001
Sound waves (Air) (Fluid) (membrane) Outer (membrane) Inner Based on fig. 46. 5
Are there transducers in the ear? Why?
Based on fig. 46. 7
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