NERVOUS SYSTEM Session 5 Flashcards
What receptors are involved in sensory transduction and what are they responsible for ?
- Exteroceptors : detect stimuli from outside the body
- Interoceptors : receive stimuli from inside the body
what are the different categories of sensory receptors and what do each of them respond to ?
- Chemoreceptors : responds to chemical substances ( taste , smell and blood pH )
- Photoreceptors : responds to light
- Mechanoreceptors : responds to mechanical forces ( hearing , balance , touch , blood pressure )
- Thermoreceptors ; responds to changes in temperature
What is sensory adaptation ?
- This is when there is a decrease in response to a stimulus over time.
For example, when you smell an odor at first and later. arent aware that its even there
What are the two major components of somatic senses and what are they associated with ?
- One for detection of mechanical stimuli and another for painful stimuli and temperature.
- They are associated with the skin , muscles , joints and viscera
For somatic senses, what are the different categories of receptors ?
- Proprioceptors
- Cutaneous Receptors
- Pain receptors
What are proprioceptors involved in ?
- They are mechanoreceptors that are involved in body perception as well as reflex actions that maintain muscle tone , equilibrium and posture.
What are cutaneous receptors involved in ?
- They make skin sensitive to touch , pressure , temperature and pain.
What are pain receptors responsible for ?
- When tissues are damaged by toxins or mechanical , thermal or electrical stimuli they release chemicals called prostaglandins which bind to nociceptors ( free nerve endings )
What is the meaning of Referred Pain ?
- This is when the stimulation of nociceptors in internal organs is felt as pain elsewhere.
Where are the taste buds located ?
- Primarily located around papillae but are also present on the hard palate , the pharynx and the epiglottis
What are the five main types of taste receptors ?
- Sweet, sour , salty , bitter and umami (savoury)
How does the brain receive taste information ?
- The taste buds have supporting cells and taste cells with microvilli , so when molecules bind to receptor proteins on the microvilli , nerve signals are sent to the gustatory ( taste ) cortex in the parietal lobe.
What in the nasal cavity helps with taste ?
- Olfactory cells that area found in the olfactory epithelia