Chapter 38: The Nervous System - The Sensory System Flashcards
(27 cards)
1) ____ step process to get sensory information to the CNS
1) Four
Steps for information traveling to CNS
1) Stimulation (sensory information)
2) Transduction (converted to potential)
3) Transmission (carried to CNS)
4) Interpretation (perception)
Types of sensory systems depend on the 1) ___________
Classification of receptors based on 2) ___________
1) types of stimuli
2) location
- Exoteroreceptor
- Proprireceptors
Types of receptors
Mechanoreceptors Thermoreceptors Photoreceptors Chemoreceptors Nociceprtors
Location of receptors
Exoteroceptors: Sense organs (vision, hearing, smell, taste) that are also responsible for touch, pressure, pain, temperature.
Interoceptors: Viscera and blood vessels
Proprioceptors: Similar to interoreceptors. Occur in skeletal muscle, tendons, joints, ligaments, CT wraps, which monitor the degree of stretch of the organs they occupy.
Receptors can be 1) ________ or they can 2) ________
1) afferent neurons, meaning they take signals toward CNS
2) regulate afferent neurons if they are not neurons themselves (i.e. sensory receptor cell)
Chemoreception
TASTE & SMELL
- These are not limited to mouth and nose sensations (fish taste via skin, flies taste via feet)
- Human taste -
* Taste buds are collections of taste receptors. Buds are located on visible papillae.
Taste
"Gustation"
Papilla = circuvallate (back of tongue), foliate (side of tongue), and fungiform.
*****Papilla-----> Taste pore
-------> taste bud
Receptors: Sweet, sour, salty, umami!1) _______ and 2) ________ act DIRECTLY on ion channels
1) Salty
2) Sour
1) ________, 2) _________, and 3) _________ act INDIRECTLY on ion channels via 4) ___________
1) Sweet
2) Bitter
3) Umami
4) G proteins (protein-coupled receptors)
Smell -
“Olfaction”
- Stimulus enters nasal epithelium where it becomes a solution (mucus)
- Genes coding for olfactory receptors = 1000
**Humans have 400 of these
genes. 600 are
pseudogenes
**Each receptor only
expresses ONE (OR)
molecule!
- What we perceive as a smell is actually a COMBINATION of responses from some subset of the 400 (OR) receptor molecules. “Profiles!!”
***** Receptor cell (cilia) —->
Olfactory nerve
1) _______ sensory information has a relatively 2) _______ route to higher brain centers, so it is very powerful!
1) Odor
2) Unfiltered
Gravity and movement: sensation and transduction occur in 1) _________
1) inner ear
Gravity and movement
Vestibular apparatus - provides the brain with information about the body’s position in space, and it is used to maintain balance and equilibrium.
Transduction in the vestibular apparatus occurs via 1) _______ movement within the structure, which deforms the 2) _________.. Direction of movement will either 3) _________ or 4) ________ the membrane.
1) fluid
2) hair cells
3) depolarize
4) hyperpolarize
Vestibular apparatus
Fluid filled structure that provide brain with information regarding the body’s position.
- Utricle : horizontal acceleration, with respect to GRAVITY
- Saccule : vertical acceleration, with respect to GRAVITY
- Semi-circular canals : angular (rotation) acceleration
The ear
Outer ear
- Pinna -----> Auditory canal
Middle ear
-
Inner ear
- Cochlea
- Semicircular canals (rotation)
- Vestibule
- Utricle (horizontal
acceleration)
- Saccule (vertical
acceleration)
Eustachian tubePathway of sound
Outer ear —–> tympanic membrane ——> middle ear bones (Malleus, incus, and sales) ——> oval window ——> fluid in inner ear (cochlea = continuous)
Inner ear: Cochlea = 1) ______ fluid filled chambers
1) Three
- Vestibular canal (continuous)
- Cochlear duct
- Tympanic canal
Flexibility along the basilar membrane in the organ of Corti (which includes the basilar membrane, hair cells, and the tectorial membrane) varies along its length. Because of this, the position along the membrane which the hair cells are deformed varies with the frequency of sound.
Frequency of sound = 1) _________
1) Pitch
HIGH = 20,000 Hz, short waves (stimulate cochlea near beginning of structure) MEDIUM = 2,000 Hz, medium waves LOW = 500 Hz, long waves (stimulate structure further down its length)
Visions 5 basic structures
1) Iris
2) Lens
3) Retina
4) Fovea
5) Optic nerve
Receptors of the eye are 1) _______, and there are 2) _______ types.
1) Photoreceptors
2) two
- Rods (low light, black/white)
- Cones (illumination, color)
Region of the retina with most accurate vision is the 1) ______
1) Fovea
- Mostly cones, which are responsible for detailed vision.
- Very few rods
Rods & cones - Pigments respond to light by changing 1) ________ _____
1) Isometric form - CIS to TRANS!
a) Synaptic terminal
b) Inner segments
c) Connecting cilium = modified ciliated cells!!!
d) Outer segments (contain
PIGMENT DISKS)
- Photopigment of rods = rhodopsin
- Photopigments of cones (3) are photopsins (red, blue, and green)/
