Neurophysiology: Exam III

Name: ______________________________ Exam III (100 points) Multiple-choice (3 pts each) 1) True or False? In the somatosensory system, stretch receptors are only found on the dendrites of mechanoreceptors receptors that signal touch information. A) True B) False 2) Which of the following has both a small receptive field and is fast adapting? A) Pacinian corpuscle B) Ruffini’s ending C) Meissner’s crpuscle D) Merkel’s disc 3) Which of the following is true about 2-point discrimination? A) It is the ability to discriminate if a single stimulus is deep pressure or light touch. B) Large receptive fields allow for greater 2-point discrimination than do small receptive fields. C) The back has the best 2-point discrimination due to it having very sparse receptive fields. D) It is easiest on the lips and fingertips due to small dense receptive fields. E) None of the above is true. 4) Which of the following is a true statement? A) The fastest sensory neurons can conduct an action potential at 120 m/sec. B) The fastest sensory information from the skin is conducted by Aβ (beta) neurons. C) Nocioceptive information is sent by both Aδ (delta) and C fibers. D) All of the above are true. E) Non of the above is true. 5) Which of the following is a true statement? A) There are 10 spinal nerves that emerge from the sacral portion of the spinal cord. B) A spinal nerve in your sacral region contains both sensory and motor neurons. C) There are 12 lumbar dermatomes. D) All of the above are true. E) None of the above is true. 6) Which of the following is a true statement? A) Lateral inhibition is when touch information inhibits nocioceptive information. B) More of the primary somatosensory cortex is devoted to the lips that the elbow. C) The cell bodies for motor neurons are located in the dorsal root ganglia. D) Sensory information entering the spinal cord never makes direct connections with motor neurons. E) A pacinian corpuscle adapts to constant stimulation very slowly. 8) Which of the following statements is true? A) Some nocioceptors are polymodal (eg. respond to both scalding heat and noxious chemicals). B) Nocioceptive information is relayed by both myelinated and non-myelinated neurons. C) Nocioceptors relay information about tissue damage. D) All of the above are true. E) None of the above is true. 9) What of the following is true about secondary hyperalgesia? A) It is when you feel pain without having tissue damage. B) It is when there is no pain even when tissue damage is occurring. C) It is when a noicioceptor releases substance-P making making others more sensitive. D) It is caused by histamine binding to blood vessels. E) It is when bradykinin binds to a nocioceptor. 10) Which of the following statements is true? A) A single neuron can send temperature information or nocioceptive information to the brain. B) Temperature information is only carried by non-myelinated neurons. C) Neurons carrying temperature information follow the same pathway as touch information. D) All of the above are true. E) None of the above is true. 12) Which of the following is a true statement? A) Touch information from your toe travels to your brain via the medial lemniscus pathway. B) A neuron in your toe sending touch information extends all the way up to your medulla. C) Touch information from your face doesn’t travel to your brain via the medial lemniscus pathway. D) All of the above are true. E) None of the above is true. 14) Which of the following is a true statement? A) All of the muscle cells in a single motor unit are of the same type. B) Motor neurons “know” which muscle cell type to connect with due to chemicals from the muscle cell. C) A large motor unit has more motor neurons than a small motor unit. D) All of the above are true. E) None of the above is true. 24) Which of the following is a true statement? A) High frequency sounds cause movement in the “floppy” part of the basilar membrane. B) The tectorial membrane is a rigid structure that hair cells are pushed against. C) When a hair cell stereocilia is bent, channels are opened and K+ leaves the cell. D) All of the above are true. E) None of the above is true. 25) Which of the following is a true statement? A) The outer ear consists of the pinna, tympanic membrane and ossicles. B) The ossicles act as levers to amplify the movement of membranes caused by sound waves. C) The tympanic membrane is smaller in area than the oval window. D) All of the above are true. E) None of the above is true. 26) The attenuation reflex … A) is caused by the contracting of two small muscles attached to ossicles. B) amplifies sound from loud noises. C) dampens high frequency sounds better than low frequency sounds. D) All of the above. E) None of the above is true. 27) True or False? Typically light must first pass through ganglion and bipolar cells before hitting photoreceptors. A) True B) False 31) (4 pts) Given that light pattern A. causes a ganglion cell to fire best, order the following light patterns (from best to worst) in terms of their ability to stimulate the same ganglion cell. A 1) ______ 2) ______ 3) ______ 4) ______ A. (fires best lit like this) B C. D E 5) ______ 33) (5 pts) Emily is born with no pinna on the sides of her head. How will this effect the way she localizes where sound comes from? 27) (3 pts) Why can’t you read Braille with your back? 28) (3 pts) If you pinch yourself hard, why is there a sharp pain followed by a dull aching pain? 29) (4 pts) What would happen if you lost all of your myelinated sensory neurons in your foot? 31) (4 pts) If Fritz had damage to his spinal cord at the level of the belly-button, but only the left side was destroyed, how would this effect movement and sensation in both his right and left leg?