Study Guides (248,403)
Canada (121,536)
Physiology (149)
PSL300H1 (104)
Quiz

Past Quiz Questions.doc

10 Pages
153 Views
Unlock Document

Department
Physiology
Course
PSL300H1
Professor
Michelle French
Semester
Fall

Description
Quiz 1 (Fall 2007, Summer 2008) 1. Why is an excess of KCl in the extracellular fluid of the body lethal? A. It creates a big positive charge in the extracelular fluid. B. The high concentration of K outside cell membranes greatly hyperpolarizes cell membranes. C. It blocks the activity of the Na ,K -dependent ATPase in cell membranes. + D. It reduces the diffusion of K out of cells into the extracellular fluid. E. It increases the concentration gradient of K across cell membranes. 2. How does an action potential 'travel' along an excitable membrane? A. It travels in saltatory fashion along unmyelinated axons. + B. It travels by the diffusion of Na ions through the cytoplasm. C. It does not go anywhere; it generates passively spreading depolarizing currents that trigger another action potential farther along the membrane. D. It travels by depolarizing glial cells (Schwann cells or oligodendrocytes). E. It serves as the source of currents that increase the resting charge on adjacent membrane. - 3. Opening a Cl ion channel in the post-synaptic membrane normally holds the membrane at resting levels, around -70 mV. What could be changed to - make a Cl current depolarize the membrane? A. Increase the normal concentration gradient for Cl across the membrane. - B. Increase the intracellular [Cl ] such that E is aClut -50 mV. C. Reduce the resting polarization of the membrane to about -60 mV. D. Block the Cl channels with a toxin or poison. - E. Use a different neurotransmitter than GABA to bind to the Cl ion channel. 4. An 'afterhyperpolarization' [complete the sentence] A. refers to inhibitory postsynaptic potentials. B. follows all action potentials. C. is necessary to generate a train of action potentials at the initial segment of an axon. D. refers to hyperpolarization of an axon terminal (presynaptic inhibition). E. is an increase in membrane polarity due to the opening of voltage-gated Cl channels. 5. Why is excitable membrane refractory immediately after an action potential? A. The afterhyperpolarization prevents excitation of the membrane. B. It takes many milliseconds to repolarize the membrane, especially if there are no + voltage-gated K channels present. C. Because of depolarization block. D. The 'Na pump' requires several milliseconds to restore the Na concentration gradient across the membrane. E. Na channels require time to restore their 'resting' configuration after the membrane potential repolarizes below threshold level. Quiz 2 (Fall 2007) Which statement is true about olfactory sensory neurons? (Answer: C) A. They each express many types of receptor protein. B. When an odorant molecule binds to a receptor, a cation channel is opened directly. C. They generate action potentials when sufficiently depolarized. D. The odorant-receptor bond activates a protein kinase to amplify the signal. E. In humans, there are about 1,000 different receptor proteins expressed. Which factor will decrease the activity of muscle spindle afferents? (Answer: A) A. contraction of extrafusal muscle fibers. B. passive stretch of the muscle. C. contraction of intrafusal muscle fibers. D. activation of gamma-motoneurons E. contraction of the antagonist muscle How does the 'gate control' mechanism of pain sensitivity operate? (Answer B) A. Due to extensive convergence on spinal neurons, nociceptor signals from one area are confused with pain inputs from another area. B. Low-threshold mechanoceptor afferents activate interneurons, in the substantia gelatinosa, that presynaptically inhibit nociceptor afferents. C. Pain-sensitive neurons in lamina I of the dorsal horn are inhibited by Merkel cell afferents. D. Within the dorsal horn, nociceptor inputs from one region are inhibited by nociceptor inputs from another region. E. ' Wide dynamic range' cells in the dorsal horn are inhibited by group C afferent input. The center-surround receptive field structure of retinal neurons? (Answer D) A. is used to detect the difference in stimulus wavelength composition between center and surround. B. is retained throughout the visual system. C. is constructed by amacrine cell connections between bipolar and ganglion cells D. is used to detect luminance gradients between the center and surround fields. E. is followed by short-wavelength cones to make connections to ganglion cells. Which statement is FALSE regarding object recognition in the visual system? (Answer D) A. Form analysis relies on the ventral visual pathway. B. Oriented cells and end-stopped cells in visual cortex contribute to construction of the outlines of objects. C. 'Face cells' and other object-selective cells congregate in the fusiform gyrus of the inferior temporal lobe. D. The cytochrome oxidase 'blobs' of V1 are critically important for recognition of the outlines of objects. E. Background structures (e.g. buildings) tend to be discriminated by neurons with receptive fields in the peripheral part of the retina. Quiz 2 (Summer 2008) Which statement is true about olfactory sensory neurons? A. They each express many types of olfactory receptor protein. B. Olfactory receptor proteins are ionotropic. C. Their action potential current is mediated by cAMP-gated cation channels. D. The odorant-receptor bond activates adenylyl cyclase. E. In humans, there are about 1,000 different olfactory receptor proteins expressed. Which factor will decrease the activity of muscle spindle afferents? (Answer: A) A. contraction of extrafusal muscle fibers. B. passive stretch of the muscle. C. contraction of intrafusal muscle fibers. D. activation of gamma-motoneurons E. contraction of the antagonist muscle How does the 'gate control' mechanism of pain sensitivity operate? A. Due to extensive convergence on spinal neurons, nociceptor signals from one area are confused with pain inputs from another area. B. Low-threshold mechanoceptor afferents activate interneurons, in the substantia gelatinosa, that postsynaptically inhibit nociceptive neurons. C. Activity in large-diameter mechanoreceptor afferents reduces neurotransmitter release from nociceptive afferents. D. Within the dorsal horn, nociceptor inputs from one region are inhibited by nociceptor inputs from another region. E. ' Wide dynamic range' cells in the dorsal horn are inhibited by group A afferent input. Which statement is FALSE regarding object recognition in the visual system? A. Form analysis relies on the ventral visual pathway. B. Neurons in the cytochrome oxidase 'blobs' of V1 construct the outlines of objects. C. 'Face cells' and other object-selective cells are found in the fusiform gyrus of the inferior temporal lobe. D. Oriented and end-stopped cells in visual cortex provide the basic elements for discrimination of object form. E. Background structures (e.g. buildings) tend to be discriminated by neurons with receptive fields in the peripheral part of the retina. Quiz 3 (Fall 2007) 1.What feature of the stretch and Golgi tendon reflexes enables them to cooperatively maintain posture at a given joint? A. One excites motoneurons and the other inhibits motoneurons. B. Both are activated by the same stimulus in a given muscle. C. Usually, they are both active simultaneously in the same muscle. D. They are both dependent on gamma motoneuron discharge. E. The response to a Golgi tendon reflex triggers a stretch reflex and vice versa. 2. Why does a Parkinson's patient move slowly (bradykinesia)? A. The discharge level of pallidal neurons is too low. B. Premotor centers are excessively inhibited. C. Too much dopamine is released within the striatum. D. Too much dopamine is released within the pallidum. E. The discharge level of subthalamic nucleus neurons is too low 3. How can a stroke which damages part of the corticospinal tract cause 'foot drop' during the swing phase of the step cycle? A. The spinal central pattern generators (CPGs) of the leg step cycle are dysfunctional. B. Postural pattern generators in the brainstem reticular formation are dysfunctional. C. Spinal CPGs do not program ankle flexion during the swing phase; human motor cortex adds it in. D. The Babinski sign is responsible for foot drop. E. Corticospinal tract losses result in hyperactive extensor thrust reflexes. 4. Feeding is regulated by the hypothalamus, especially the arcuate nucleus. What factor activates neuropeptide Y-containing neurons in the arcuate nucleus? A. circulating leptin B. a high plasma glucose concentration C. circulating insulin D. low levels of antidiuretic hormone in the plasma E. circulating ghrelin 5. The following measures to increase body temperature or reduce heat loss are labeled as sympathetic, parasympathetic, or neuroendocrine. Which one is NOT correct? A. sympathetic: cutaneous vasoconstriction B. parasympathetic: reduction in cardiac output C. sympathetic: piloerection D. parasympathetic: shivering E. neuroendocrine: reduction of antidiuretic hormone release in posterior pituitary Quiz 4 (Summer 2008) 1. At low levels of synaptic input to a motor nucleus in the spinal cord, the very first neurons to be 'recruited ' would probably be: A. large alpha motoneurons B. gamma motoneurons C. small alpha motoneurons D. Renshaw cells E. slow motor units 2. The pulling of actin filaments towards the center of sarcomeres during muscle contraction is directly powered by: A. hydrolysis of ATP to ADP + Pi and release of the high energy bond B. Ca2+ binding to troponin C. 'elastic' restoring forces in the myosin head or crossbridge D. creatine kinase E. hydrolysis of creatine phosphate 3. When adenylyl cyclase is activated, A. steroids are produced. B. cAMP is usually formed. C. protein kinases are metabolized. D. calcium ions are released from intracellular stores. E. adenosine is synthesized. 4. Identify the ONE INCORRECT statement. The endocrine system is able to coordinate the complicated functions of our bodies in part due to its own complexity. There are multiple: A. ligands for one receptor. B. signaling pathways activated by one hormone. C. tissues expressing the same hormone
More Less

Related notes for PSL300H1

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit