Podcast
Questions and Answers
Which of the following is the initial response when an odorant binds to a G-protein-coupled receptor in the olfactory epithelium?
Which of the following is the initial response when an odorant binds to a G-protein-coupled receptor in the olfactory epithelium?
Which of the following statements accurately describes the olfactory pathway?
Which of the following statements accurately describes the olfactory pathway?
What is the role of the olfactory glands in the olfactory organs?
What is the role of the olfactory glands in the olfactory organs?
Why do dogs have a superior sense of smell compared to humans?
Why do dogs have a superior sense of smell compared to humans?
Signup and view all the answers
What is the primary function of gustation?
What is the primary function of gustation?
Signup and view all the answers
Where are gustatory epithelial cells (taste receptors) located?
Where are gustatory epithelial cells (taste receptors) located?
Signup and view all the answers
Why is the sense of smell particularly vulnerable to age-related decline?
Why is the sense of smell particularly vulnerable to age-related decline?
Signup and view all the answers
Study Notes
Special Senses: Olfaction (Smell)
- Olfaction is the sense of smell, involving olfactory receptors responding to airborne chemicals.
- Olfactory organs are located in the nasal cavities.
- These organs comprise two layers: olfactory epithelium and lamina propria
- Olfactory epithelium contains olfactory sensory neurons, which detect chemicals.
- These neurons are highly modified nerve cells that detect chemicals dissolved as they interact with odorant-binding proteins.
- Supporting cells and basal epithelial cells (stem cells) are also present in the epithelium.
- The lamina propria contains areolar tissue, blood vessels and nerves and olfactory glands that create mucus.
- Olfactory epithelium contains olfactory sensory neurons, which detect chemicals.
- Olfactory reception starts with an odorant binding to a G-protein-coupled receptor. This creates a generator potential (depolarization).
- Afferent fibers leave the olfactory epithelium, collect into bundles (20 or more) and penetrate the cribriform plate of the ethmoid bone.
- The bundles reach the olfactory bulbs of the cerebrum where the first synapse occurs.
- Axons leaving the olfactory bulb travel along olfactory tracts to the olfactory cortex, hypothalamus and limbic system. Olfactory information reaches the cerebral cortex without first being relayed by the thalamus, unlike other senses.
- Humans can distinguish thousands of chemicals.
- Dogs have significantly more olfactory receptor surface area than humans, resulting in a much better sense of smell (72 times greater).
- Olfactory receptors are replaced frequently. Still, the total number of neurons decline with age.
Special Senses: Gustation (Taste)
- Gustation provides information about food and liquids.
- Gustatory receptors (taste receptors) are found within taste buds.
- Taste buds are distributed across the superior tongue surface and the pharynx/larynx.
- Taste buds are associated with epithelial projections (lingual papillae).
- Types of lingual papillae:
- Filiform: lack taste buds.
- Fungiform: contain about 5 taste buds.
- Vallate (circumvallate): contain up to 100 taste buds.
- Foliate: have taste buds.
- Taste buds contain basal epithelial cells (stem cells).
- Gustatory receptors are gustatory epithelial cells.
- They extend microvilli through taste pores.
- They are replaced roughly every 10 days.
- They are innervated by cranial nerves (specifically the solitary nucleus of the medulla oblongata).
- Information travels through the thalamus and to the gustatory cortex of the insula.
- Four primary taste sensations: sweet, sour, salty, and bitter.
- Additional sensations: umami (savory, glutamate) and water.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your knowledge on the sense of smell and the anatomy of olfaction. This quiz covers the olfactory receptor structures, their functions, and how odor detection occurs. Dive deep into the fascinating world of olfactory sensory neurons and their role in the olfactory system.
