Neurobiology Exam 2.txt

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Neurobiology Exam 2.txt
2011-02-26 14:37:33
Neuro test

Neurobiology test 2
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  1. Neuro Test 2
  2. Describe the function of the olfactory glands.
    Make mucous that lines the epithelium, coat olfactory epithelium (helps to dilute odorants), reduce friction.
  3. Describe the olfactory pathways.
    Axons leaving olfactory epithelium: collect into 20 or more bundles, penetrate cribriform plate of ethmoid, reach olfactory bulbs of cerebrum where first synapse occurs. Axons leaving olfactory bulb: travel along olfactory tract to reach olfactory cortex, hypothalamus, and portions of limbic system (w/o 1st synapsing in the thalamus)
  4. Describe the components of the lamina propria of the olfactory organ.
    Areolar tissue, blood vessels, nerves, olfactory glands.
  5. Compare and contrast the regenerative properties of olfaction, audition, and equilibrium.
    Olfaction- yes audition- no equilibrium- no.
  6. Compare and contrast filiform papillae, fungiform papillae, and circumvallate papillae
    3 types of lingual papillae: Filiform papillae- provide friction and do not contain taste buds. Fungiform papillae: contain five taste buds each. Circumvallate: contain 100 taste buds each.
  7. Describe the distribution of taste receptors.
    Taste receptors(or gustatory receptors) are distributed on tounge and portions of Pharynx and Larynx. Clustered into taste budsTaste
  8. Describe the six taste sensations.
    Sweet, Salty, Sour, Bitter, Umami (chicken/beef broths, glutamate), Water (receptors in pharynx). Salt and sour- chemically gated ion channels-stim produces depolarization of cell. sweet, bitter, and umami- g proteins = gustducins.
  9. Describe the components and boundaries of the outer, middle, and inner ear.
    The External Ear: Auricle to tympanic membrane (eardrum), Middle ear/Inner ear boundary is oval window.
  10. Describe the function of the auditory ossicles.
    Auditory ossicles conduct vibrations to inner ear.
  11. Describe the function of the inner ear.
    Equilibrium and hearing.
  12. Compare and contrast the functions of the semicircular canals, cochlea, and saccule and utricle.
    semicircular canals- contain semicircular ducts. Receptors stimulated by rotation of head. Cochlea- contains cochlear duct, receptors provide sense of hearing.Utricle & Saccule- provide equilibrium sensations
  13. Describe how rotational movements are sensed.
    the saccule and the utricle are going to sense rotational and linear movement.(Movement of fluid within the horizontal semicircular canal corresponds to rotation of the head around a vertical axis (stereocilia bending produces receptor potentials in hair cells)
  14. Describe the relationship between the frequency of a perceived sound and stimulation of the cochlear duct.
    determined by which part of cochlear duct is stimulated.
  15. Describe the steps that occur in the production of an auditory sensation.
    sound waves arrive at tympanic membrane. movement of the tympanic membrane causes displacement of the auditory ossicles. movement of the stapes at the oval window establishes pressure waves in the perilymph of the vestibular duct. pressure waves distort the basilar membrane on their way to the round window of the tympanic suct, vibrations of the basilar membrane causes vibration of hair cells against the tectorial membrane. information about the region and the intensity of stimulation is relayed to the CNS over the cochlear branch of the cranial nerve VII
  16. Describe how the spiral ganglion is formed
    how is it formed???? the ganglion on the cochlear nerve, located within the modiolus, sending fibers peripherally to the organ of Corti and centrally to the cochlear nuclei of the brain stem.
  17. Describe the functions of the vestibular nuclei
    Integrate sensory information about balance and equilibrium from both sides of head. Relay information from vestibular complex to cerebellum. Relay information from vestibular complex to cerebral cortex. (Provide conscious sense of head position and movement) Send commands to motor nuclei in brain stem and spinal cord.
  18. Describe the path of light entering the eye.
    En route to the retina, lightsuccessively travelsthrough: 1) the cornea 2) the aqueous humorof the anterior chamber 3) the pupil 4) the lens 5) the vitreous humor
  19. Describe the characteristics of the retina.
    light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina. The retina is a complex, layered structure with several layers of neurons interconnected by synapses. The only neurons that are directly sensitive to light are the photoreceptor cells. These are mainly of two types: the rods and cones. Rods function mainly in dim light and provide black-and-white vision, while cones support daytime vision and the perception of colour. A third, much rarer type of photoreceptor, the photosensitive ganglion cell, is important for reflexive responses to bright daylight.Neural signals from the rods and cones undergo complex processing by other neurons of the retina. The output takes the form of action potentials in retinal ganglion cells whose axons form the optic nerve.
  20. Describe a cause of glaucoma.
    improper drainage or excessive production of aqueous humor may lead to glaucoma. increased intraocular pressure, blockage in the canal of schlemm
  21. Describe the functions of tears.
    lubrication and oxigenation. nutrients.
  22. Compare and contrast the actions of parasympathetic and sympathetic activation on papillary muscle groups.
    Circular (constrictor) muscles act to Decrease the pupil size under parasympathetic control. Radial (dilator) muscles act to increase the pupil size under sympathetic control
  23. Describe what is meant by a visual acuity rating of 20/20.
    From 20 feet away you can see what a person is supposed to see from 20 feet away. (400/20= from 20 feet you see what a person sees at 400 feet)
  24. Describe the relationship between a hair cell and the quantity of neurotransmitter that it may release.
    determined by number of hair cells stimulated
  25. Compare and contrast the focal distance of light from a near versus far object.
    close object logn focal distance. (If the object moves closer, the focal point then moves behind the retina.)
  26. Compare and contrast the focal distance of light traveling through a round or flat lens.
    flat lens = long focal distance. for round lens= the closer the light source the longer the focal point. the rounder the lens the shorter the focal distance.
  27. Compare and contrast myopia and hyperopia.
    refractive error (ametropia),in which light rays come to a point focus eitherbehind the retina (hyperopia) or in front of it (myopia). solution to hyperopia is a corrective (convex) lensthat augments the eye�s defective refractive power byconverging the light rays to a focus on the retina. solution to myopia is a corrective (concave) lens that reduces the eye�s excess refractive power by diverging the light rays to a focus on the retina.
  28. Describe the neural wiring from a photoreceptor.
    Visual information is transmitted from photoreceptors to bipolar neurons and ganglion neurons before exiting the eye via the optic nerve (CN II).
  29. Describe the properties and functions of the lacrimal glands.
    production of tears.
  30. Describe the properties and functions of the fibrous tunic of the eye.
    mechanical supoprt, protection. (composed of the sclera and cornea)
  31. Describe the properties and functions of the vascular tunic of the eye.
    The vascular tunic includes the iris, ciliarybody, and choroid. blood supply, help regulate light in the eye, secrete aqueous humor, shape.
  32. Describe the properties and functions of the neural tunic.
    The neural tunic is the actual retina containing the photoreceptors. retina and photoreceptor cells.
  33. Compare and contrast the cornea, iris, pupil, lens, ciliary body, canal of Schlemm, fovea, posterior chamber, and anterior chamber.
    cornea- lacks blood vessels, connective tissue of corea secrete tenomodulin (prevents blood vessel growth), lack immune cells. iris- disk shaped with muscle that controls size. modulate amount of light entering eye. color determined by # of pigment producing melanocytes. pupil- opening in eye. lens- lens that light passes through (can accomodate). ciliary body- encircles lens, contains musculature that adjusts the refractive power of lens. canal of Schlemm- drainage for aqueous humor. fovea-the cone density is highest and its central region is rod-free (sharp vision). posterior chamber- contains vitreous humor. anterior chamber contains aqueous humor.
  34. Describe the 3 different types of cones and their properties.
    high acuity and color vision during day time when light levels are higher. red, green, blue cones. if all simulated equally color would be white.
  35. Describe the steps of photoreception in rods.
    Step 1: Absorption of a photon by a visual pigment leads to opsin activation and a change in the retinal configuration to initiate visual signaling. PhysiologyThe converted rhopdopsin molecule activates about 100 molecules of the G-protein transducin, each of which activates a molecule of phosphodiesterase. Each PDE breaks down 100s of molecules of cGMP, which causes several 100s of Na+ channels to close. The membrane hyperpolarizes and the rate of neurotransmitter release declines in the presence of light. Molecular cascade: 1) A photon converts a rhodopsin molecule (11cis-retinal + opsin to all-trans-retinal + opsin) 2) This activates 100 molecules of the G-protein transducin. 3) Each of which activates a cGMP phosphodiesterase molecule. 4) Each causes the breakdown of 100�s molecules of cGMP. 5) Which close several hundred Na+ channels. 6) The photoreceptor hyperpolarizes and fewer transmitters are released
  36. Describe the 2 commissural fibers that connect the two hemispheres.
    Corpus Callosum, anterior commisure.
  37. Describe a potential deficit associated with damage to the visual association area.
    words- can recognize letters not words.
  38. Describe the most common location of Broca�s area.
    production of language
  39. Describe the general functions of the prefrontal cortex.
    personality, insight, foresight.
  40. Describe the general functions of the parietal lobe.
    Tactile (integrates sensory information from different modalities, particularly determining spatial sense and navigation.)
  41. Describe the general functions usually associated with hemispheric lateralization.
    left is related with reading writing math. producing and responding to language. right- senses and recognition-faces and voices.
  42. Compare and contrast CT, MRI, and PET
    Computed tomography (CT)-brain-imaging method using computer controlled X-rays of the brain. Magnetic resonance imaging (MRI)-brain-imaging method using radio waves and magnetic fields of the body to produce detailed images of the brain. Functional MRI (fMRI) �computer makes a sort of �movie� of changes in the activity of the brain using images from different time periods. Positron emission tomography (PET)-brain-imaging method in which a radioactive sugar is injected into the subject and a computer compiles a color-coded image of the activity of the brain with lighter colors indicating more activity.
  43. Describe how visual field defects may result by specific lesions of the visual system.
  44. Brain Slides