Term
| Sensory receptors are formed by what? |
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Definition
| Dendrites of afferent neurons or by specialized cells that synapse with afferent neurons. |
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Term
| What is the function of sensory receptors? |
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Definition
| To gather information about the external and internal environment. |
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Term
| How do sensory receptors respond to stimuli (such as light, heat, chemicals, and mechanical stress)? |
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Definition
| By changing their conductance to ions (such as sodium, potassium, or calcium.) |
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Term
| What does the sensory receptor's response to stimuli result in? |
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Definition
| A change in membrane potential which causes the brain to process signals into sensory sensations. |
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Term
| What is sensory transduction? |
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Definition
| The conversion of a stimulus to a change in membrane potential. |
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Term
| What are the 5 basic types of sensory receptor? |
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Definition
| Mechanoreceptors, Photoreceptors, Chemoreceptors, Thermoreceptors, Nociceptors. |
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Term
| What kind of receptors detect tissue damage or noxious chemicals and lead to pain? |
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Definition
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Term
| How does sensory perception work? |
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Definition
| Information is routed from sensory receptors to particular brain regions that identify a specific stimulus as a sensation. |
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Term
| What does the Meissener's corpuscle sense? |
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Definition
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Term
| What does the pacinian corpuscle sense? |
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Definition
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Term
| What are some examples of touch and pressure receptors in human skin? |
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Definition
1)Free nerve endings (dendrites).
2) Encapsulated nerve endings of sensory neurons. |
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Term
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Definition
| Mechanoreceptors that detect stimuli used by the CNS to monitor and maintain body and limb position. |
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Term
| What happens when hairs are moved? |
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Definition
| Sensory hair cells generate action potentials in afferent neurons. |
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Term
| What do mechanoreceptors in muscles, tendons, and joints detect? |
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Definition
| Changes in pressure/tension of body parts. |
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Term
| What is the Vestibular Apparatus? |
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Definition
| A mechanoreceptor found in the inner ear consisting of 3 semicircular canals and 2 fluid filled chambers: the utricle and saccule. It perceives the position and motion of the head. |
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Term
| The Utricle and Saccule are... |
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Definition
| Oriented 30 degrees to each other. They control information about head position (up/down) and changes in the rate of linear motion of the body. |
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Term
| What organs contain sensory hair cells with stereocilia? |
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Definition
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Term
| What are otoliths and where are they found? |
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Definition
| Calcium carbonate crystals found wihin the membrane of hair cells. When this membrane moves, the hair cells are bent and the neurotransmitter releases action potential, causing the brain to perceive movement. |
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Term
| What are proprioceptors and what do they do? |
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Definition
Stretch receptors found in muscles and tendons (called Golgi tendon organs in tendons -- branching dendrites.)
They detect position and movement in the limbs by detecting how much and how fast a muscle is stretched. |
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Term
| What do stretch (proprioceptors) detect? |
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Definition
| The position and movement in the limbs by detecting how much and how fast a muscle is stretched. |
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Term
| What do the stretch receptors allow muscles to do? |
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Definition
| Provide a constant force under a constant load and adjust to changes in the load (Coffee Cup). |
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Term
| What does the sense of Hearing rely on? |
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Definition
| Sensory hair cells (mechanoreceptors) in organs (the ear) that respond to the vibrations of sound waves. |
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Term
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Definition
| Variations of pressure in a medium such as air. They are created by the vibration of an object, which causes the air surrounding it to vibrate. The ear drum picks up the vibrations and the brain interprets them as sound.Bas |
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Term
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Definition
| Forms part of the floor of the cochlear duct. Anchors the sensory hair cells in the Organ of Corti. It vibrates in response to the vibrations transmitted through the inner ear. |
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Term
| What is the Organ of Corti? |
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Definition
| An organ located in the cochlear duct that contains sensory hair cells that detect the sound vibrations transmitted to the inner ear. |
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Term
| How does the thickness of the basilar membrane affect vibrations? |
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Definition
| It's narrow near the oval window and wider at the end of the cochlear duct. High pitched sounds vibrate the basilar membrane at its narrow end and low pitched sounds vibrate the basilar membrane near the outer end. |
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Term
| What are the sounds that we hear? |
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Definition
1) Combinations of vibrations at different frequencies and intensities occuring simultaneously with different degrees of force along the basilar membrane of the cochlea.
2) Specific action potentials generated in specific neurons are transmitted to auditory centers in the brain, integrated, and result in our perception of a specific sound. |
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Term
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Definition
| Transparent structure in the eye that admits light. |
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Term
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Definition
| The part of the eye located behind the cornea that controls the diameter of the pupil and regulates the amount of light that strikes the lens. |
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Term
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Definition
| The part of the eye that focuses images on the retina. |
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Term
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Definition
| It lines the back of the eye and contains photoreceptors and neurons that integrate information detected by the photoreceptors. |
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Term
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Definition
| When you're looking at things that are near or far. Far = relaxed ciliary muscles, flat lens. Near is opposite. |
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Term
| Photoreceptors of the eye do what? |
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Definition
| Contain pigment molecules that absorb energy of light. They generate changes in membrane potential. |
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Term
| What are Retinal Photoreceptors? |
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Definition
| Light-absorbing pigments in all animals. |
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Term
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Definition
| Specialized for the detection of low-intensity light. |
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Term
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Definition
| Specialized for detecting light of different wavelengths (colors). |
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Term
| What do photopigment molecules do? |
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Definition
| They absorb light in photoreceptor cells. They consist of retinal combined with an opsin protein. There are 3 photopigments (photopsins) and photopigments are found in the discs. |
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Term
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Definition
| Retinal+Opsin photopigment found in rods, is a G-prtein coupled receptor. |
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Term
| What are the three segments of a Cone? |
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Definition
1) Outer segment (houses discs that contain light-absorbing photopigment).
2) Inner segment (houses a cell's metabolic machinery).
3) Synaptic terminal (stores and releases neurotransmitters). |
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Term
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Definition
| Retinal+Opsin photopigment found in rods, is a G-prtein coupled receptor. |
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Term
| What is the direct pathway of vision? |
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Definition
| Photoreceptors -> Bipolar Cells -> Ganglion cells. |
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Term
| What are Horizontal cells? |
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Definition
| (retina) Cells that receive information from the photoreceptors and transmit it to surrounding bipolar neurons. |
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Term
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Definition
| Cells that receive their inputs from the bipolar cells and activate the ganglion neurons that are in their vicinity. |
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Term
| What happens in a Receptor Field? |
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Definition
| Ganglion cells receive signals from a specific group of photoreceptor cells (or the receptive field for that ganglion cell). |
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Term
| How many photoreceptor cells are there and how many ganglion cells are there? |
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Definition
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Term
| What kind of receptive fields result in sharper images? |
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Definition
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Term
| What are the two types of bipolar cells? |
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Definition
| On center and Off center. |
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Term
| Off center and On center bipolar cells react the same when... |
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Definition
| There is no light on both the center and the surround or there is light on the center and the surround. |
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Term
| When do On center ganglion cells fire rapidly? |
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Definition
| When light is on the center only. |
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Term
| When do off center cells fire rapidly? |
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Definition
| When Light is on the surround only. |
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Term
| _____polarisation causes the ganglion cell to fire. ____polarisation inhibits the cell. |
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Definition
| Depolarisation causes the cell to fire; Hyperpolarisation inhibits the cell. |
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Term
| How many types of cones do humans have? |
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Definition
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Term
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Definition
| A photopigment found in cone cells that consists of retinal and specific opsins. |
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Term
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Definition
| They absorb light of overlapping wavelength ranges and Give rise to the perception of a particular color in the brain. |
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Term
| How does the processed signal travel to the visual cortex? |
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Definition
| It is sent via the optic nerve and through the lateral geniculate nuclei. |
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Term
| What do chemoreceptors form in vertebrates? |
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Definition
| Parts of receptor organs for taste (gustation) and smell (olfaction). |
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Term
| What do chemoreceptors respond to? |
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Definition
| the presence of specific molecules in the environment. |
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Term
| What do taste receptors do? |
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Definition
| They detect molecules from food or other objects that come into direct contact with the receptor. They are primarily used to identify food. |
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Term
| What on the tongue contains the taste buds? |
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Definition
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Term
| What do Olfactory Receptors do? |
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Definition
| They detect molecules from distant sources and are used for Food identification, Detection of predators and prey, Identification of family and group members, Location of trails and territories, and Communication. |
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Term
| What can also connect to the limbic system because signals from it can elicit and emotional/viseral response? |
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Definition
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Term
| How does smell contribute to taste? |
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Definition
| Vaporized molecules from foods are transmitted from the throat to the olfactory receptors in the nasal cavities. If the sense of smell is lessened, then taste perception is diminished. |
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Term
| Thermoreceptors consist of... |
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Definition
Free nerve endings
1) At the body surface
2) In the body interior (in limited numbers).
They detect changes in body temperature (like a snake's Pit organs). |
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Term
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Definition
| They detect stimuli that can damage body tissue. They are located on the body surface and the interior; Information from receptors is integrated in the brain into the sensation of pain. |
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Term
| What are the two Axons that transmit pain? |
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Definition
1) Glutamate Releasing: sharp, localized pain
2)Substance P: Dull, aching pain (not well localized). |
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Term
| What happens in a pain suppressing system? |
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Definition
| When released, endorphins bind to receptors on substance P releasing neurons and decrease amount of substance P released. |
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