Term
An indicator of sensory acuity of an area
Two-point Threshold
2 Examples of Tonic Receptors
Nociceptors and proprioceptors
What's the suspensory ligament that encircles the lens and holds it in position?
Ciliary zonule
NT released from photoreceptors has excitatory or an inhibitory effect on bipolar cells?
Inhibitory (hyperpolarizing)
Receptor organ of hearing
Spiral organ of Corti
Which photoreceptor is the more numerous and sensitive one?
Rods
2 Examples of Phasic Receptors
Certain touch and pressure receptors, thermoreceptors, and olfactory receptors
Pupil constricts in bright light - under which control - parasympathetic or sympathetic?
Parasympathetic
With light, is cGMP high or low?
Low
Fluid (pressure) waves passing through cochlear duct generate a shearing force
between the ____ membrane and the ____ membrane
basilar, tectorial
Joint receptors, golgi tendons, muscle spindles are examples of what kind of receptors?
Proprioceptors
Example of receptor that has Encapsulated Nerve Endings
Muscle spindles
When parasympathetic input increases,
what happens to ciliary muscles & ciliary zonule & lens?
Ciliary muscles contract - Ciliary zonule loosens - Lens bulges
Rods contain three types of which cation channels:
Cyclic nucleotide-gated (CNG) channels (allow influx of Na+ and Ca2+)
K+ leak channels
Voltage-gated Ca2+ channels (regulate exocytosis of NT)
Stereocilia connects to what kind of channels?
Mechanically-gated cation channels
Ability of the eye to change its focus from distant to near objects (and vice versa)
Accommodation
2 examples of receptors that have Free nerve endings
Nociceptors & thermoreceptors
When sympathetic input increases,
what happens to ciliary muscles & ciliary zonule & lens?
Ciliary muscles relax - Ciliary zonule tightens - Lens flattens
Explain bleaching reaction
With light, retinal (the pigment) changes shape - breaks away from opsin - loss of color and function - opsin is alone & bleached
Where in the ear do u find Na+ rich fluid & where K+ rich fluid? (be specific)
Na - Bony labyrinth w perilymph
K - Membranous labyrinth w endolymph
Where are cutaneous sensations perceived?
Primary somatosensory cortex in parietal lobe
Name receptors that detect wetness
Humans do not have specific sensory receptors for wetness.
Thermal Receptors: Detect the cooling effect caused by water evaporation or contact with cool liquids.
Mechanoreceptors: Sense changes in texture, slip, stickiness, and light pressure on the skin.
Contextual Inference: The brain combines these signals with prior experiences to create the "illusion" or perception of wetness, which is why it can be tricked (e.g., feeling wet when touching a cold metal surface)
Myopic vs Hyperopic eye. Where r the focal points for each? Eyeball long or short?
Myopic - focal point in front of retina, eyeball too long
Hyperopic - focal point behind the retina, eyeball too short
cGMP - high. NT r released.
Is it in the dark or light?
Darkness
Tip links of stereocilia tighten or loosen to lead to depolarization?
Tighten, openning mechanically gated ion channels