HBIO 301 CHAPTER 16 EXAM QUESTIONS AND
ANSWERS WITH COMPLETE SOLUTIONS GRADED A++
LATEST UPDATE
What are the 5 special senses?
1. Gustation - taste
2. Olfaction - smell
3. Vision
4. Equilibrium
5. Hearing
Why are special senses different from general somatic senses?
Special senses have distinct special sensory receptors rather than being widely
distributed throughout the body
Where are the olfactory organs located?
Olfactory epithelium (nasal cavity)
What are the layers of the olfactory organs?
1. olfactory epithelium
2. lamina propria
What types of cells make up the olfactory epithelium?
olfactory receptor neurons - chemoreceptors
Highly modified bipolar neurons
,How do olfactory receptor neurons work?
Detect dissolved chemicals interacting with odorant-binding proteins
How many odorant binding proteins does a human have and how many smells
can we distinguish between? How many primary smells?
900 odorant binding proteins
2,000 - 4,000 odors
50 primary smells
How often are olfactory receptor neurons replaced?
~ every 60 days
What are lamina propria made of?
Areolar connective tissue
What do lamina propria contain?
Olfactory glands that secrete mucus
What must happen in order to smell something?
Odor must be dissolved in the mucus secreted by olfactory glands
How can we smell more odors than we have odorant-binding proteins?
Population encoding
Combinations of different receptors working together
Single odorant molecule binds to more than one receptor
What type of adaptation has taken place when we are no longer keenly aware of a
strong odor after being exposed to it for some time?
Central adaptation
Ensures you quickly lose awareness of a new smell but retain sensitivity to others
, How does central adaptation work?
CNS adapts to the stimulus
The senses keep sending the information but the brain does not respond
What is unique about olfaction compared to other special senses in terms of
neural transduction pathway to cerebral cortex? What effect does this have?
ONLY type of sensory info that reaches the cerebral cortex without first synapsing in the
THALAMUS
No sensory dampening
Which special senses transmit information to the hypothalamus and limbic
system?
Olfaction
Gustation
What does it mean that olfaction and gustation transmit information to the
hypothalamus and limbic system?
Emotional, behavioral, and memory responses to odors (olfaction) and taste (gustation)
What type of reflexes are stimulated by olfaction since it is connected to the
hypothalamus and limbic system?
salivation, digestive secretion, sneezing, and coughing
What special senses have stem cells for continual replacement?
Olfaction (smell)
Gustation (taste)
What cells replace gustation cells? How often are they replaced?
ANSWERS WITH COMPLETE SOLUTIONS GRADED A++
LATEST UPDATE
What are the 5 special senses?
1. Gustation - taste
2. Olfaction - smell
3. Vision
4. Equilibrium
5. Hearing
Why are special senses different from general somatic senses?
Special senses have distinct special sensory receptors rather than being widely
distributed throughout the body
Where are the olfactory organs located?
Olfactory epithelium (nasal cavity)
What are the layers of the olfactory organs?
1. olfactory epithelium
2. lamina propria
What types of cells make up the olfactory epithelium?
olfactory receptor neurons - chemoreceptors
Highly modified bipolar neurons
,How do olfactory receptor neurons work?
Detect dissolved chemicals interacting with odorant-binding proteins
How many odorant binding proteins does a human have and how many smells
can we distinguish between? How many primary smells?
900 odorant binding proteins
2,000 - 4,000 odors
50 primary smells
How often are olfactory receptor neurons replaced?
~ every 60 days
What are lamina propria made of?
Areolar connective tissue
What do lamina propria contain?
Olfactory glands that secrete mucus
What must happen in order to smell something?
Odor must be dissolved in the mucus secreted by olfactory glands
How can we smell more odors than we have odorant-binding proteins?
Population encoding
Combinations of different receptors working together
Single odorant molecule binds to more than one receptor
What type of adaptation has taken place when we are no longer keenly aware of a
strong odor after being exposed to it for some time?
Central adaptation
Ensures you quickly lose awareness of a new smell but retain sensitivity to others
, How does central adaptation work?
CNS adapts to the stimulus
The senses keep sending the information but the brain does not respond
What is unique about olfaction compared to other special senses in terms of
neural transduction pathway to cerebral cortex? What effect does this have?
ONLY type of sensory info that reaches the cerebral cortex without first synapsing in the
THALAMUS
No sensory dampening
Which special senses transmit information to the hypothalamus and limbic
system?
Olfaction
Gustation
What does it mean that olfaction and gustation transmit information to the
hypothalamus and limbic system?
Emotional, behavioral, and memory responses to odors (olfaction) and taste (gustation)
What type of reflexes are stimulated by olfaction since it is connected to the
hypothalamus and limbic system?
salivation, digestive secretion, sneezing, and coughing
What special senses have stem cells for continual replacement?
Olfaction (smell)
Gustation (taste)
What cells replace gustation cells? How often are they replaced?
