Chapter 7 Special senses Flashcards
What are the Five special senses?
- Smell
- Taste
- Sight
- Hearing
- Equilibrium (touch)
Which receptor senses light?
Photoreceptors
What receptor senses chemicals?
Chemoreceptors
What receptor senses pressure?
Mechanoreceptors
What are 1 2 and 3?
- free neuron dendrites (smell)
- Encapsulated dendrites (touch)
- Association with a non-neuronal sensory cell (taste, sound, sight)
What is the Olfactory bulb?
- It’s involved with the sense of smell, uses chemoreceptors.
- Type 1 receptors (free neuron endings)
How does the Olfactory Bulb work?
- Sensory neurons are organized in “olfactory bulb”
- Free dendrites are embedded in nasal tissue and have proteins that sense chemicals
- Action potentials can occur and are transmitted to brain via the “olfactory tract”, an afferent path.
What is Gustation?
- It has do with the sense of taste, uses chemoreceptors
- Type 3 receptors (non-neuronal cell association)
How does Gustation work?
- Our tongue is covered in papillae
- Taste buds are located on the sides of papillae
- A taste bud is defined as a grouping of specialized cells (taste cells) that bind to flavor molecules
What do Taste Bud cells do?
- Taste cells have proteins that can bind to flavor molecules in membrane
- Binding of chemical to taste cell can result in depolarization of the cell
- Taste cells are associated with neuron free endings at synapse
- Allows for the transmission of action potential
- Signal leaves taste bud on afferent nerve to brain (gustatory nerve)
What are qualities of sight?
- Light enters and is focused on the retina (nervous tissue of the eye)
- Retina consists of pigmented cells and neuronal-associated cells
- Pigmented cells help collect light
- Neuronal-associated cells include photoreceptors, bipolar, and ganglion cells
- Similar to type 3 receptor (non-neuronal cell association)
What are the three different types of cells?
- Photoreceptors
- Bipolar cells
- Ganglion cells
What do Photoreceptors, Bipolar Cellls, and Ganglion Cells do for the Retina?
- Photoreceptors absorb light
- Bipolar cells (neurons) are either excited or inhibited by photoreceptors
-
Ganglion cells “sum” bipolar activity
- Their axons form the optic nerve, which runs to the brain
- Summation occurs at ganglion cell to determine if action potential is initiated
What do Photoreceptors do and what are Rods and Cones?
- Photoreceptors use pigments to detect light
- Rods (rhodopsin)
- Dim light vision
- Black and white
- Cones (photopsin)
- Bright light vision
- Color
- Three types of photopsin (blue, green, and red)
A person is diagnosed with having dysfunctional retinal cones. What disease would this represent?
A. Blindness
B. Color blindness
C. Poor night vision
D. Far-sightedness
C. Color Blindness
What is the process of Retinal Implants?
- Electric chips embedded in retina and electrically attached to optic nerve
- Acts as photoreceptors to initiate communication to the brain
What does the Sense of Hearing?
- Uses mechanoreceptors
- The conversion of sound waves to action potentials
- Energy of sound waves is transmitted through air and liquid
- Type 3 receptor (non-neuronal cell association)
What are the three regions of the process of the sense of hearing and what are their functions or how do they work?
- Outer: transmits sounds waves to ear drum
- Middle: ear drum vibrates middle ear bones
- Inner: vibrations are transferred to fluid (think wave pool) and can trigger depolarization in specialized cells in “cochlea”
What is another name for the inner ear and what is it?
Three fluid filled tubes wrapped together like a snail shell
Middle is the cochlear duct
Cochlear duct
Location of Organ of Corti (converts sound to action potentials)
What does the Organ of Corti contain?
- Contains specialized mechanoreceptors hair cells
Respond to mechanical stimulation (bending)
Gated-channel proteins that opens in response to vibrations
What do the hair cells do to contribute to the Organ of Corti
- Hair cells are secured by the basilar membrane
- “Hairs” or stereocilia are embedded in tectorial membrane above
- Stereocilia bend when vibrations occur and depolarize cell
- Hair cells communicate with auditory neurons, which will use summation to initiate an action potential
