The Senses Flashcards
Special sense have receptors …..
-strategically placed in unique organs for hearing and balance,olfaction(smell), gustation(taste), and visual system
Sensory receptors are formed by…. And there function is…
terminals of afferent neurons or by specialized cells that synapse with afferent neurons
-to gather information about the external and internal environment
Sensory receptors respond to stimuli such as… by changing their…. To …..which results in a ….
-respond to stimuli such as light, heat, chemicals, mechanical stress, by changing their conductance to ions such as sodium, potassium, calcium which results in a change in membrane potential
Define sensory transduction
-conversion of stimulus to a change in membrane potential
What types of sensory receptors are formed by dendrites of an afferent neuron
-temperature and pain receptors
What types of sensory receptors are formed by a cell that synapses with an afferent neuron
-mechanoreceptors, photoreceptors and chemoreceptors
What are the 2 main types of sensory receptors?
-receptor is afferent neuron
-receptor regulates afferent neuron
What are the 5 basic types of sensory receptors
-mechanoreceptor: detect changes in body position, pressure, acceleration(auditory receptors of the ear)
-photoreceptors: detect light and are located in the eye
-chemoreceptors: detect specific molecules or conditions such as acidity(taste buds)
-thermoreceptors: temperature
-nocireceptors: detect tissue damage or noxious chemicals. Their activity leads to pain
Touch and pressure receptors in human skin can be
-free neuronal endings or encapsulated neuronal endings of sensory neurons
What does the meissne’s copuscle in the skin sense?
-touch
What does the pacinian corpuscle in the skin sense?
-pressure
Define propioception
-the sense of the relative position of the neighboring parts of the body
Propioceptive sense is composed of
-information from sensory neurons located in the inner ear (motion and orientation)
-and in the stretch receptors located in the muscles and the joint supporting ligaments(stance)
Propioceptors detect stimuli used by the
-CNS to monitor and maintain body and limb positions
-mechanoreceptors in muscles,tendons, joints detect changes in pressure/tension of body parts
Where are stretch receptors found
-in muscle and tendons (in tendons its called golgi tendon organs= nerve fiber with collagen strands that connect the muscle to the tendon; GTO detects muscle tension
Stretch receptors in the muscle:
-detect position and movement in the limbs by detecting how much and how fast a muscle is stretched
Balance involves
The vestibular system of the inner ear
The vestibular apparatus is comprised of… and perceives
-3 semicircular canals and 2 fluid filled chambers; utricle and saccule
-the position and motion of the head using mechanoreceptors
Semicircular canals in the ear detect..
-rotation motion
The ampulla of the semicircular canal
-detects rotational movement of the head body
The utricle and saccule in the ear give information about
-head position (up/down)
-changes in the rate of linear motion of the body
Summarize the concept of balance
-Gelatinous mass moves in response to gravity or movement, bending hair cells and initiating action potentials
-patterns of stimulation are translated by brain into specific information about head position of acceleration
Hearing relies on…
-sensory hair cells in the ear that respond to the vibrations of sound waves
Define sound waves
-Exist as variations of pressure in a medium such as air
- are created by the vibration of an object which cause the air surrounding it to vibrate
-the vibrating air then causes the human eardrum to vibrate, which the brain interprets as sound
Vibrations produce…. Volume or loudness is function of …… Pitch is function of
-sound waves
-function of wave amplitude
-function of wave frequency
The eardrum is also called the
-tympanic membrane
The eustachian tube leads to
-the throat
-when we swallow the tube opens, air flows in or out of the ear to equalize pressure
The Basilar membrane….
-forms part of the floor of the cochlear duct
-anchors the sensory hari cells in the organ of corti
-vibrates in response to the vibrations transmitted through the inner ear
Organ of corti
-region of the inner ear that contains sensory hair cells that detect the sound vibrations transmitted to the inner ear
-is the sensory organ of hearing which is distributed along the partition separating fluid chambers in the coiled tapered tube of the cochlea
-is the sensory epithelium, a cellular layer on the basilar membrane
In the ear, Hair cells arranged in rows of inner hair cells…. And outer hair cells…
-responsible for hearing
-regulate tension of basilar membrane
In the ear, as sterocilia bend, they open
-K+ gates (mechanically gated ion channel)
Bending steriocilia in one direction…. Bending in the opposite direction…
-depolarizes the cell and stimulates neurotransmitter release
-repolarizes the cell and stops release
Hair cells in the organ of Corti are “turned” to certain sound frequencies by way of their location in the cochlea due to the…. In the basilar membrane
-degree of stiffness
Basilar membrane is …. Near the oval window and … at the outer end of cochlear duct
-narrow and stiff
-wider
High pitched sounds vibrate the basilar membrane at its…
-narrow, stiff beginning end
What does the cornea do?
-transparent, admits and refracts light, covers the iris, pupil and anterior chamber