Transcript Receptors and Senses

Receptors and Senses
Amelia Hoyt
Relationship Between Receptors &
Senses
The senses are a result of receptors
-they are used to identify changes in the
environment
-detecting/processing sensory information and
generating motor responses is the
physiological basis for all animal behavior
Pathways
Four basic functions:
1 sensory reception
2 transduction
3 transmission
4 perception
-the ultimate effect of the wide range of
sensory receptors is to open/close ion
channels
1) Sensory Reception
receptor:
-a sensory cell or organ
-a subcellular structure that interacts directly with stimuli
types of receptors:
-mechanoreceptors
-chemoreceptors
-electromagnetic receptors
-thermoreceptors
-pain receptors
2) Transduction
-sensory transduction: conversion of a physical
or chemical stimulus to a change in the
membrane potential of a sensory receptor
-receptor potential: change in the membrane
potential itself
3) Transmission
-for many receptors, transducing the energy in
a stimulus into a receptor potential initiates
transmission of action potentials to the
Central Nervous System
4) Perception
-color, smell, sound, taste, touch
-constructions formed in the brain: do not
exist outside of it
Sensory Systems
-hearing
-sight
-taste and smell
Hearing
-result of mechanoreceptors
-related to perception of body equilibrium
(balance)
-mechanoreceptor cells produce receptor
potentials when settling particles or moving
fluid causes deflection of cell-surface
structures
Sight
-ability of animals to detect light and other
electromagnetic radiation
-underlying mechanism for capturing light is
the same despite the use of a diverse set of
organs
-all contain photoreceptors: cells that
contain light-absorbing pigment molecules
-genes for vision present among diverse
groups
Taste and Smell
-gustation: taste
-olfaction: smell
-both depend on chemoreceptors that detect
specific chemicals in the environment
-for terrestrial animals, taste=detection of
tastants and smell=detection of odorants
-no distinction between taste and smell in
aquatic animals
Senses in Cnidarians
-Cnidarians lack image-forming eyes
-rely on chemoreceptors to recognize the
smell and taste of prey
-rely on mechanoreceptors to recognize the
pressure and vibration of prey
Senses in the Annelida
(polychaetes)
-receptors detect light, chemicals, pressure
-have ciliated structures believed to be
chemoreceptors
-have eyes, which can form compound images
-some species have statocysts
Senses in the Arthropoda (insects)
-modified cuticles into a diverse number of
receptors
-setae
-pressure sensors
-antennae
-compound eyes and ocelli
-some species have statocysts
Senses in Mammalia (humans)
-hearing & equilibrium closely related
-five types of tastants: sweet, sour, salty,
bitter, umami
-vision is well-processed to form images in
color and eyes have the ability to focus by
changing the shape of the lens
-individual taste cells contain receptors that
only recognize one specific tastant
Hearing Disorders
Otosclerosis:
-unknown causes, but likely a genetic link
-result of an abnormal sponge-like bone growing in the
middle ear, preventing it from vibrating in response to
sound waves
-symptoms: progressively worse hearing, better hearing in
noisy rather than quiet environments, sometimes
tinnitus (ringing)
-diagnosis: audiometry/audiology, or temporal bone CT
-Treatment: hearing aid, fluoride, calcium, or vitamin D,
surgery (stapedectomy or stapedotomy)
Age-related hearing loss
-cause: the tiny hairs in the ear becoming
damaged or dying; result of accumulation of
factors
-symptoms: certain sounds seeming overly
loud, difficulty hearing in noisy areas, highpitched sound distinction difficulty, voices
seeming slurred, tinnitus
-diagnosis: audiometry/audiology
-treatment: hearing aids, alternate means of
communication, surgery (cochlear implant)
Vision Disorders
-myopia: "nearsighted" result of too long
eyeball length or too steep cornea
-symptoms: poor ability to see at a distance
-diagnosis: vision test
-treatment: glasses, contacts, refractive
surgery
-hyperopia: "farsighted"; result of too short
eyeball or too flat cornea, hereditary
condition
-symptoms: difficulty seeing objects up close
-diagnosis: vision test
-treatment: glasses, contacts, refractive
surgery
Taste and Smell Disorders
-Anosmia: loss of smell, wide range of causes
including infection, deformed nasal bones,
tumors, malnutrition, surgery, certain nasal
sprays, etc.
-symptoms: loss of smell
-diagnosis: inability to detect odors for an
extended period of time
-treatment: has to be for underlying causes;
no treatment for the condition itself
-Aguesia: loss of or impaired ability to taste;
may be general, partial, or specific to some
tastants; potentially caused by: loss of smell,
infection, nerve damage, etc.
-symptoms/diagnosis: loss of taste to some or
all tastants, sometimes loss of smell
-treatment: must be geared towards
underlying cause
Conclusion
Benefits of having a sensory system:
-detection of danger
-detection of prey
-greater awareness of surroundings
-sexual selection
Bibliography
Hinde, R.T., (1998). "The Cnidaria and Ctenophora". In Anderson, D.T.,. Invertebrate Zoology. Oxford University Press. pp. 28–57. ISBN 0195513681.
Ruppert, E.E., Fox, R.S., and Barnes, R.D. (2004). Invertebrate Zoology (7 ed.). Brooks / Cole. pp. 111–124.ISBN 0030259827.
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Völkel, R., Eisner, M., and Weible, K. J. (June 2003), "Miniaturized imaging systems"(PDF), Microelectronic Engineering 67–68: 461–472,
doi:10.1016/S0167-9317(03)00102-3
"Age-related hearing loss: MedlinePlus Medical Encyclopedia." National Library of Medicine - National Institutes of Health. N.p., n.d. Web. 25 Mar.
2012. <http://www.nlm.nih.gov/medlineplus/ency/article/001045.htm>.
"Ageusia - RightDiagnosis.com." Right Diagnosis. N.p., n.d. Web. 25 Mar. 2012. <http://www.rightdiagnosis.com/medical/ageusia.htm>.
"Anosmia - Inability to perceive odors · Ear, Nose, Throat, and Dental problems articles | Body & Health Conditions center | SteadyHealth.com." Info
Center | SteadyHealth.com. N.p., n.d. Web. 25 Mar. 2012. <http://ic.steadyhealth.com/anosmia_inability_to_perceive_odors.html>.
"Hyperopia - Farsighted Vision problems ." LASIK |Laser Eye Surgery| Lasik Doctors |The Lasik Surgery Directory. N.p., n.d. Web. 25 Mar. 2012.
<http://www.the-lasik-directory.com/hyperopia.html>.
"Introduction to Animals, Sponges, Cnidarians." Bio Lectures: Animal Diversity: Lower Invertebrates/Sponges. N.p., n.d. Web. 25 Mar. 2012.
<faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20lectures/Animal%20Diversity/Lower%20Invertebrates/sponges.
htm>.
"Mechanisms for Prey Identification in Cnidarians ." College of Charleston. N.p., n.d. Web. 25 Mar. 2012.
<podolskyr.people.cofc.edu/biol337/reports/report%201-2.pdf>.
"Myopia - Difficulty Seeing From a Distance - Nearsighted Vision Correction with LASIK procedures."LASIK |Laser Eye Surgery| Lasik Doctors |The
Lasik Surgery Directory. N.p., n.d. Web. 25 Mar. 2012. <http://www.the-lasik-directory.com/myopia.html>.
"Otosclerosis: MedlinePlus Medical Encyclopedia." National Library of Medicine - National Institutes of Health. N.p., n.d. Web. 25 Mar. 2012.
<http://www.nlm.nih.gov/medlineplus/ency/article/001036.htm>.
Reece, Jane B.. Campbell Biology. 9. ed., Global ed. Harlow: Pearson Education, 2011. Print.
"What tells anemones to kill their enemies? - Free Online Library." Free News, Magazines, Newspapers, Journals, Reference Articles and Classic Books
- Free Online Library. The Free Library by Farlex, n.d. Web. 25 Mar. 2012.
<http://www.thefreelibrary.com/What+tells+anemones+to+kill+their+enemies%3f-a07502159>.