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Reflex Arc- unconscious motor output due to sensory input
Sensory (afferent)neuron---->Spinal cord----> Motor (efferent) neuron----> effector (ex: muscle or gland)
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2 point threshold (acuity for sensation)
- minimum distance at which 2 points are perceived as being the same or separate
- Ex: palm, back of forearm, back of upper arm, calf, top of foot
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Referred pain-
- pain that is perceived as coming from a source other than its true origin.
- why?-the nerves from the perceived source and the true origin- enter the spinal cord at the same level and the information is misinterpreted by the brain.
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Accomodation
the ability of the eye to focus the images of objects at different distances from the lens.
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Nystagmus
Involuntary oscillations of the eye
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Pupillary reflex
parasympathetic nervous system(bright lights-->constrict pupil), Sympathetic-->dialation of the pupil
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Afferent neurons are
sensory--> towards CNS
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Efferent neurons are
motor--> away from CNS
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How many synapse are crossed in a single reflex arc during a muscle stretch reflex?
1 synapse
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The ventral root of spinal nerves contain____ neurons, whereas the dorsal root contains____ neurons.
- Ventral= Motor
- Dorsal= Sensory
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Describe the sequence of events that occurs from the time the patellar tendon is stretched to the time the leg is extended ( knee-jerk reflex)
Patellar tendon is tapped---> stimulates sensory neuron---> A.P. spinal cord---> A.P. motor neuron---> A.P. muscles quads---> leg/knee extends
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Describe the pathway for hearing from external stimulus to neural stimulation; include all relevant terminology
Sound waves (stimulus)---> Pinna (auricle)---> External auditory canal---> Tympanic membrane---> Mallus---> Incus---> Stapes---> Oval window---> Cochlea---> Spiral organ of corti---> Basilar membrane (vibrated by perilymph)---> Sensory hair cells move---> Stimulate the tectorial membrane---> Cause A.P. down Cranial Nerve 8 (Vestibularcochlear Nerve)---> To medulla---> Thalamus---> Auditory cortex (temporal lobe)
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The organ of equilibrium is called the
Vestibular apparatus
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The structures sensitive to angular acceleration in three planes are the
semicircular canals
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The structure sensitive to linear acceleration are the ____and_____. Together, they are called the____organs
Utricle(horizontal), Saccule (verticle)= Otolith organs
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The fluid within the organs of equilibrium is known as
endolymph
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An illusion of movement or spinning is called
vertigo
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The sense of equilibrium is transmitted by the__ (its number) cranial nerve, also known as the____ (its name) nerve.
VIII, Vestibularcochlear
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Describe how the senses equilibrium from externl stimulus to neural stimulation; include all relevant terminolgy
- Start spinning left---> Endolymph lags behind bending cupula to the (R); as the spinning continues the cupula straightens up; when the spinning stops thte endolymph continue in the same direction as the spin (L) bending the cupula to the (L).
- After a period of time returns to "rest". The bending of the cupula stimulates the sensory hair cells causing A.P. down Cranial nerve VIII
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Vestibular Nystagmus
- As the spin begins (to the left) the eyes look to the Right; as the spin continues to the Left the eyes look to the Right
- When the spin stops they oscillate to the Left and then "jerk" back to midline
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