Central Nervous System Review Guide PDF

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Mark Wireman, Bio-201 lecture review guide...

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Directions: You will learn best if you WRITE OUT THE QUESTIONS AND A ANSWERS NSWERS ON SEPARA SEPARATE TE SHEETS OF PA PAPER!!! PER!!! 1. What two structures make up the CNS? a. Brian b. Spinal Cord 2. Review the meanings of rostral and caudal. a. Rostal is towards the forehead b. Caudal is towards the spinal cord 3. What region comprises the bulk of the volume of the human brain? Cerebrum is 83% of brain volume 4. Explain the difference between a gyrus and a sulcus. Gyrus are folds and Sulcus are grooves 5. What is a fissure in the brain? A Longitudinal fissure divides cerebral hemispheres 6. Explain the difference between nuclei and tracts in the brain. a. Nuclei are deeper masses of gray matter b. Tracts are bundles of axons (white matter) 7. Compare and contrast grey and white matter in the brain. a. Gray matter: neuron cell bodies, dendrites, and synapses -forms cortex over cerebrum and cerebellum -forms nuclei deep within brain b. White matter: bundles of axons -forms tracts that connect parts of brain 8. List the three meninges and the two spaces. Which of these three is located deepest (closest to the brain)? Under which layer does CSF circulate? Arachnoid mater. Under which of these are the dural sinuses located? Periosteal layer. Where would a subdural hematoma occur if someone got hit in the head? Dura mater. SUPERFICIAL TO DE EP DEEP a. Dura mater: outermost, tough membrane -outer periosteal layer against bone -epidural space -subdural space Two layers: Periosteal layer (outer layer) and Meningeal layer (inner layer) b. Arachnoid mater: subarachnoid space c. Pia mater 9. Describe the pathophysiology of meningitis? Explain why a spinal tap may be performed. Meningitis: inflammation of the meninges, bacterial and virus invasion of the CNS through the nose and throat Spinal tap examines the CSF for search of infection 10. Label the locations of the following ventricles: a. Lateral ventricle b. Third Ventricle c. Fourth Ventrilce

11. What two ventricles of the brain do each of the following connect: a. Interventricular foramen: lateral ventricle and third ventricle b. Cerebral aqueduct: third ventricle and fourth ventricle 12. Predict the effects if either of the above were to become occluded. 13. Where is cerebrospinal fluid made? Formed by the choroid plexus How is it circulated? From choroid plexus > through ventricles > central canal of spinal cord > into subarachnoid space around the brain, spinal cord, and cauda equine What is its purpose in the CNS? Forms cushion for brain and other CNS organs (spinal cord), gives buoyancy to the brain (which reduces its weight by 97%), transports nutrients, chemical messengers, and waste Spend some time looking at the choroid plexus! Choroid plexus: specialized ependymal cells and capillaries- secrete CSF into ventricles, remove waste, adjust composition 14. Explain the role of arachnoid villi and arachnoid granulations on the circulation of CFS. Arachnoid villi: extensions of subarachnoid space, extend through dura mater to superior sagittal sinus Arachnoid granulations: large clusters of villi, absorb CSF into venous circulation 15. What causes hydrocephalus? Obstruction of CSF which causes enlargement of the head in babies and brain damage in adults 16. Compare and contrast the structures involved AND the functions of both blood brain barrier and the blood CSF barrier. Blood Brain barrier: 1) endothelium -including the least permeable capillaries of the body 2) permeable to lipid-soluble materials -alcohol, O2, CO2, nicotine and anesthetics 3) circumventricular organs -blood has direct access in the breaks within the 3rd and 4th ventricles -monitors glucose, pH, osmolarity and others -route of HIV virus to invade the brain CSF Barrier: 1) at the choroid plexus are ependymal cells joined by tight junctions 17. Which portions of the brain make up the brain stem? Midbrain, Pons, and Medulla oblongata 18. The midbrain is responsible for which functions? 1) Coordinates head and eye movement when visually following a moving object or spot something out of the corner of our eye 2) Coordinates head reflex movement to unexpected auditory stimulus 19. What is the major function of the pons? 1) Helps maintain normal rhythm of breathing 20. Which portion of the brain stem adjusts the force and rate of heartbeat, vomiting, sneezing, etc? Medulla Oblongata 21. Which major region of the brain coordinates skeletal muscle contractions needed for smooth, coordinated movements of our daily lives?

The Cerebellum 22. List the three bilaterally symmetric structures of the diencephalon. Thalamus, Hypothalamus, Epithalamus a. Which of these three makes up the major portion of the diencephalon? The Thalamus b. Which of these three regulates hunger and fullness? The Hypothalamus c. Which portion serves as a gateway between the cerebral cortex and the rest of the body (where a sorting out and “editing” process occurs)? The Thalamus d. Which portion of the diencephalon is responsible for regulation body temperature (and does so by initiating sweating or shivering)? The Hypothalamus e. Which portion contains the gland responsible for the sleep/wake cycle? The Epithalamus f. What hormone helps regulate the sleep/wake cycle? Melatonin 23. What are some of the structures that comprise the "limbic" system? Hippocampus, Amygdala Where in the brain are they located? Cerebral hemispheres and diencephalon What are the general functions of the limbic system? Recognize fear, anger, danger, happiness, resolving problems, mental conflicts, organize sensory and cognitive information into a new memory, emotional memory 24. Describe the role of the basal ganglia, using Parkinson’s disease to aid in your explanation. Be specific! With Parkinson’s disease, you lose control of movement/muscle tone which causes you to begin trembling due to the lack of Dopamine 25. What are some of the functions of the reticular formation. Alertness (levels of consciousness) 26. Compare the roles of association fibers, commissural fibers, and projection fibers of white matter. Association fibers: fibers that connect areas of the cerebral cortex within the SAME hemispheres of the cerebral cortex Commissural fibers: fibers that connect one cerebral hemisphere to the other Projection fibers: fibers that connect the cerebrum and other parts of that brain and/or spinal cord 27. The cerebrum is also called the forebrain 28. Where is the corpus callosum located? Between the Left and Right Hemispheres What is its primary function? Aids communications between cerebral areas and between cerebral cortex and lower CNS (ie: spinal cord) 29. The gray matter makes up which portion of the cerebrum? Cerebral Cortex The white matter makes up which portion of the cerebrum? Corpus Callosum 30. Locate the following of the cerebrum: a. Longitudinal fissure b. Central sulcus c. Precentral gyrus d. Postcentral gyrus

31. List the four major lobes of the cerebrum AND the main functions of each lobe. Frontal lobe  Voluntary motor functions  Planning, mood, smell, and social judgment Parietal Lobe  Receives and integrates sensory information Occipital Lobe  Visual center of brain Temporal Lobe  Areas for hearing, smell, learning, memory, emotional behavior 32. Describe the location AND functions of the sensory association areas of the cerebrum. Somesthetic association area (parietal lobe)  Position of limbs, location of touch or pain; shape, weight and texture of an object Visual association area (occipital lobe)  Identify things we see  Faces recognized in temporal lobe Auditory association area (temporal lobe)  Recall the name of a piece of music or identify a person by his voice 33. Describe the location AND functions of the area(s) of the cerebrum involved in motor control. Precentral gyrus (primary motor area) relays signals to spinal cord  Pyramidal cells called upper motor neurons  Supply muscles of contralateral side 34. What does contralateral motor control refer to? Make sure to explain what decussate means! That the right hemisphere controls left side of body and the left hemisphere controls right side and decussate is the crossing in the medulla 35. Why are the face and hands represented by such a large region of the cerebral cortex? 36. Compare and contrast the locations AND functions of Wernicke and Broca’s area in the cerebral cortex. Wernicke area (Posterior): permits recognition of spoken and written language and creates plan of speech Broca area (Anterior): generates motor signals of larynx, tongue, cheeks and lips & transmits to primary moto cortex for action 37. Discuss the idea of working memory and impulse control in the prefrontal cortex. Integrates information from association areas, performs abstract intellectual activities 38. What is a lobotomy?

Cutting a piece of the brain that effects your actions 39. Describe, in detail, the concept of lateralization. Left hemisphere (categorical hemisphere)  Specialized for spoken and written language, sequential and analytical reasoning (math and science), analyze data in a linear way Right Hemisphere (representational hemisphere)  Perceives information more holistically, perception of spatial relationships, pattern, comparison or special senses, imagination and insight, music and artistic skill Highly correlated with handedness  91% of people right handed are left side dominant Lateralization develops with age  females have more communication between hemispheres

40. Label each of the major structures/regions in the cross section of a human brain: a. Primary auditory area- temporal lobe b. Primary visual area- occipital lobe c. Control of heart rate- medulla oblongata d. Respiratory control-pons e. Sleep/awake cycle- epithalamus f. Blood pressure control- hypothalamus g. Somatic motor areah. Language/speech comprehension area- Wernicke area & Broca area i. Broca's area- anterior j. Primary sensory areak. Seat of intelligence, abstract reasoning- prefrontal cortex l. Relay station for incoming sensory informationm. Olfactory area41. MEMORIZE the names, numbers, functions, and whether or not each cranial nerve is sensory, motor, or both! Craniall Nerves: 12 Crania  Olfactory Nerve (CN I) - Sensory fibers only - Sense of smell

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- Damage causes impaired sense of smell Optic Nerve (CN II) - Sensory fibers only - Visual Acuity - Damage causes blindness in visual field Oculomotor Nerve (CN III) - Motor fibers - Eye movement, opening of eyelid, construction of pupil, focusing - Damage cause drooping eyelid, dilated pupil, double vision, difficulty focusing and inability to move eye in certain directions Trochlear Nerve (CN IV) - Motor fibers only - Eye movement - Damage cause double vision and inability to rotate eye down and in (looking at your nose) Trigeminal Nerve (CN V) - Both sensory AND motor fibers - Sensory to face: touch, pain, and temperature - Motor: muscle of mastication Abduncens Nerve (CN VI) - Motor fibers only - Provides eye movement - Damage results in inability to rotate eye laterally and at rest eye rotates medially Facial Nerve ((CN CN VII) - Both sensory AND motor fibers - Motor: facial expressions; salivary glands and tear, nasal and palatine glands - Sensory: taste on anterior 2/3’s of tongue, damage produces sagging facial muscles and disturbed sense of taste Nerve Vestibulocochlear Nerv e (CN VIII) - Sensory fibers only - Provides hearing and sense of balance - Damage produces deafness, dizziness, nausea, loss of balance and nystagmus - 512 or 1024 Hz Weber on forehead of Rinne for bone and air conduction Glossopharyngeal Nerve (CN IX) - Both sensory and motor fibers - Swallowing, gagging - Sensations from posterior 1/3 of tongue, taste Vagus Nerve ““W Wanderer” (CN X) - Both sensory and motor fibers - Swallowing, speech Accessory Nerve (CN XI) - Motor fibers only - Swallowing, head, neck and shoulder movement Hypoglossal Nerve (Cn XII) - Motor fibers only

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42. Predict what effects damage to each of the cranial nerves might cause. For example, a person will have trouble moving their right eye in which directions if the Oculomotor Nerve (CN III) is damaged. 43. Compare and contrast tonic and phasic receptors. Draw a couple of graphs! Tonic: are always active (slow-adapting) i.e proprioception- knowing where your body is at all times, pain- longer lasting Phasic: are normally inactive, become active for a short time whenever change occurs i.e thermoreceptors

44. Use a graph to explain the concept of adaptation. Allows your brain to prioritize, nervous system quickly adapts to stimuli that are painless and constant

45. Pain receptors = Nociceptors 46. Where are pain receptors found? Superficial portions of the skin, joint capsules, within the periosteum of bones, around walls of blood vessels 47. What are the two types of pain receptor fibers and what types of information do each of them carry? Myelinated Type A: carry sensation of fast pain, or prickling pain (injection or deep cut) Type C: carry sensation of slow pain 48. Where might one find thermoreceptors? The dermis, skeletal muscles, the liver, the hypothalamus 49. Compare and contrast, in detail, the three classes of mechanoreceptors. You will see baroreceptors for sure next semester when we learn about the cardiovascular system! Mechanoreceptors:

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1. Tactile receptors: provide the sensation of touch, pressure, and vibration 2. Baroreceptors: detect pressure changes in the walls of blood vessels and in portions of the digestive, reproductive, and urinary tracts 3. Proprioceptors: monitor the positions of joints and muscles, most structurally and functionally complex of general sensory receptors Where might you find chemoreceptors? Carotid bodies, near the origin of the internal carotid arteries on each side of the neck Briefly, how do they work? You will also see these when we study the cardiovascular system. Describe the difference in terms of location AND function of what matter and gray matter in the spinal cord. Exterior white matter- conduction tracts Internal gray matter- mostly cell bodies Compare and contrast the dorsal and ventral horns of the spinal cord. Dorsal horns: SENSORY NEURONS Ventral horns: MOTOR NEURONS Compare and contrast afferent and efferent neurons. Diagram AND explain the differences between upper and lower motor neurons. Upper motor neuron: cell body lies in a CNS processing center (i.e cerebral cortex) Lower motor neuron: cell body lies in a nucleus of the brain stem or spinal cord Where do most motor fibers decussate as they descend? Medulla Oblongata (OPTIONAL) Draw out the following MOT MOTOR OR pathways from the brain to the spinal cord, making sure to include what type of information is relayed in each pathway: a. Corticobulbar tract b. Lateral corticospinal tract c. Anterior corticospinal tract What are the “pyramids” in the medulla of the brainstem? Corticospinal pathway: provides voluntary control over skeletal muscles, system begins at pyramidal cells of primary motor cortex, axons of these upper motor neurons descend into brain stem and spinal cord to synapse on lower motor neurons that control skeletal muscles Predict the effects of an upper vs. a lower motor neuron lesion.

59. Briefly describe the components and functions of the medial and lateral pathways.

Medial pathway: primarily concerned with control of muscle tone and gross movements of neck, trunk, and proximal limb muscles Lateral pathway: primarily concerned with control of muscle tone and more precise movements of distal parts of limbs 60. Review the role(s) of the basal ganglia Provide background patters of movement involved in voluntary motor activities 61. Summarize the inputs and outputs of the cerebellum involved with motor control....