Review for BIO 2401 Lecture Examination IV: Central Nervous System, Peripheral Nervous, Autonomic Nervous Systems, and Special Senses (Chapters 12, 13, 14, and 15) The following information is intended to make your study for the exam easier and more successful. This sheet is not totally inclusive as to the information contained on the exam but the majority of the test items will pertain to the information given. Be able to discuss, define, and/or identify the following concepts. Tell what terms or concepts are referring to and its significance. In completing the following statements, words may be used multiple times. Note: a blank “_____” may represent one or two words, unless indicated by two blanks. 1. The CNS develops from a strip of which ectoderm lies on the midline of the embryo. Specifically, this strip is called the neuroectoderm. It eventually gives rise to a hollow tube called the neural tube. 2. The neural tube is formed by fusion of the neural folds. 3. The development of (the spinal cord) would directly be affected if the posterior portion of the neural tube failed to develop properly. 4. The midbrain develops from the embryonic mesencephalon. 5. The medulla oblongata develops from the embryonic myelencephalon. 6. The cerebellum develops from the embryonic metencephalon. 7. The thalamus develops from the embryonic diencephalon. 8. What are the functions of cerebrospinal fluid?buoyancy, protection, chemical stability 9. How does cerebrospinal fluid enter in the subarachnoid space?openings in the fourth ventricle called medial and lateral apertures **4rth ventricle** 10. gyri/gyrus are ridges on the surface of the cortex. Sulcus are shallow grooves between these ridges. 11. The right and left cerebral hemispheres are joined mainly by corpus callosum fibers. 12. Identify the lobes that border of each of these fissures or sulci: longitudinal fissure; parieto-occipital fissure; lateral sulcus; central sulcus Longitudinal: right and left cerebral hemispheres Tranverse: cerebrum from cerebellum Parieto-occipital: parietal and occipital lobes Lateral sulcus: insula deep inside lateral sulcus/**parietal and temporal lobes Central sulcus: separates frontal and parietal lobes 13. What neuron structures are located in the gray matter? the white matter? Gray matter: unmyelinated portions of neurons,cell bodies, dendrites, neuroglia White matter: mostly myelinated axons 14. Association tracts connect one gyrus to another within the same cerebral hemisphere. 1 15. The corpus callosum is composed of commissural fibers. 16. The cerebral cortex is the area of conscious thought and it forms a cap over the rest of the brain, because of this, it has been called the “thinking cap.” 17. What was the significance of Brodmann’s numbering scheme? Areas of the cerebral cortex that are responsible for certain functions such as muscle contraction, sensory perception/ *identifies specific portions on the cerebral cortex and its functions 18. What is the function of the primary motor cortex? the premotor area? Primary motor cortex: located in the precentral gyrus,voluntary muscle contractions are Iniated in the primary motor cortex by large neurons. **iniate motor control** Premotor area: it is the large area involved in learned motor skills such as typing, riding a Bicycle or playing the piano and planning movements.**programmed muscle movements** 19. Loss of ability to perform skilled motor activities such as piano playing, with no paralysis or weakness in specific muscles, might suggest damage to the premotor area. 20. What is Broca's area? What is its function?controls the muscles needed for speech(larynx,tongue,cheeks), located anterior and inferior to the premotor area,known as the motor speech are, found in only one hemisphere, also involved in planning voluntary movements for speech **motor speech area** 21. Where are the pyramidal neurons cell bodies that initiate skeletal muscle contractions? Primary cortex are where large neurons/pyramidal cell’s axon extend to the spinal cord to form pyramidal tracts 22. What is the primary somatosensory area? Where is it found on the cerebrum? Post central gyrus behind the primary motor cortex, this area receives signals from sensory receptors in the skin through out the body and proprioceptors in the skeletal muscles. (sense of touch) 23. Which lobe of the cerebrum is most concerned with vision? posterior occipital 24. What is the function of the visual association area? How would a person be affected if it were damaged?interprets the image and relates it to images in memory for recognition 25. What lobe of the cerebral cortex is concerned with hearing?superior temporal 26. Explain the significance of the olfactory cortex: smell gustatory cortex; taste vestibular cortex; balance auditory cortex; receive and perceive hearing through pitch, thythm and loudness visual cortex: perceive visual stimuli and consists of 3D image using stimuli from both eyes 27. What area of the brain is possibly involved in verbalizing unfamiliar written words? Wernicke’s Area 28. Almost all sensory signals pass through the thalamus on the way to the cerebrum. It is our “relay station.” 29. What are the parts making up the basal nuclei? Caudate nuclei, putamen, globus pallidus 2 30. What are the many functions of the hypothalamus? Contral autonomic nervous system, regulates emotion, body temp, hunger, thirst, circadian rhythms-biological clock, it also controls a large portion of the endocrine system by producing hormones that control the release of other hormones,blood pressure, connected to pituitary gland 31. The pineal gland of the epithalamus is an endocrine gland that secretes melatonin, a hormone that helps regulate the sleep cycles. 32. What are the parts making up the brain stem? Midbrain, pons, medulla oblongata 33. The medulla oblongata, of the brain stem, contains nuclei that control coughing, sneezing, swallowing, and vomiting. 34. What is the function of the reticular formation? Give an example. Responsible for maintaining wakefulness and alertness and for filtering out unimportant sensory information , other components of reticular formation are responsible for maintaining muscle tone and regulating visceral motor muscles 35. The cerebellum is concerned with motor coordination and balance? 36. The white matter of the cerebellum is often referred to as the arbor vitae. 37. The limbic system is believed to be mostly concerned with the emotional aspect to behaviors, experiences, and memories. 38. What is an electroencephalogram?test that records brain activity/electrical activity of neurons, it used to help to diagnose epilepsy/seizure 39. What are the four brain waves?alpha, beta, theta and delta 40. What is REM sleep? What occurs during REM sleep?rapid eye movement sleep is when most dreaming occurs, deep sleep 41. What enhances ones ability to store information in long-term memory?using all senses in a high emotional state 42. From superficial to deep, list the meninges which cover the brain? Dura mater, subdural space, arachnoid mater , subarachnoid space, pia mater 43. The thick, leathery meningeal layer is the called the dura mater. 44. Over the brain, there are channels within the dura mater, the dural sinuses, which contain venous blood returning from the brain to the jugular veins. 45. What tissue does the epidural space in the spinal column contain?fat/adipose tissue 46. The subarachnoid space lies between what two layers of meninges? arachnoid and pia 47. What is cerebrospinal fluid? Where is it found? fluid found with in the ventricles of the brain and surrounding the brain/spinal cord What does it contain?choroid plexuses(network of cap ependymaln cells,blood plasma What secretes it? Choroid plexuses(network of capillaries) from the ventricles of the brain How does it return to the bloodstream?the CSF circulates from the lateral ventricles to the third and then the fourth ventricles. From the fourth ventricle, most of the CSF passes into the subarachnoid space although some CSF also passes into the central canal of the spinal cord. From the subarachnoid space, the CSF returns to the blood through the arachnoid villi located in the dural sinuses.*superior sagittal sinus* 3 48. What is the blood-brain barrier?protective mechanism that helps maintain a protective environment for the brain What creates this barrier?tight junctions between the endothelial cells in the capillary walls and the basement membrane and perivascular feet from astrocytes on the capillary walls What is it effective against? Creatine, urea ( wastes transported in the blood), most ions(Na+, K+ and Cl-), proteins and certain toxins have limited access or totally blocked from entering the brain What can pass through it? Substances such as 02, glucose, H2O, essential amino acids and most lipid-soluble substances; (caffeine, alcohol, nicotine and heroine) 49. Tremor at rest, shuffling walk, stooped posture, and expressionless face due to the deterioration of dopamine-secreting neurons, results in a disease called Parkinson’s. 50. What is Huntington's disease? At what age does one begin showing signs of the disorder? Fatal hereditary disorder that results from detoriation of the basal nucle and cerebral cortex 51. In the embryonic spinal cord, axons from the alar plate form interneurons and the basal plate give rise to motor neurons. 53. In the spinal cord, where is gray matter located versus white matter? Gray matter: center of spinal cord in the form o,f the letter H (or pair of butterfly wings) when viewed in a cross section **inside** White matter: six areas, three adjacent to each side of the H in the spinal cord**outside** 54. Cell bodies of the sensory neurons of the spinal nerves are located in dorsal root ganglion of the spinal cord? 55. pneumoencephalography is used to diagnose hydrocephalus, and allows X-ray visualization of the ventricles of the brain. 56. True or False: Age brings some cognitive decline. Yet despite some neuronal loss, changing synaptic connections support additional learning throughout life. True 57. Be able to list the name, Roman numeral, and general function of all twelve cranial nerves. Optic, Oculomotor,Facial,Trochlear,Vestibulocochlear,Trigeminal,Vagus,Abducens,Hypoglossal,Spinal Accessory, 58. All of the cranial motor nerves have sensory feedback fibers called proprioceptive, therefore no cranial nerve’s function is motor only. 59. Which cranial nerves, have sensory or motor functions related to the eye.optic, oculomotor trochlear, trigeminal, abducens 60. The Abducens (cranial nerve) sends impulses to the lateral rectus muscle which rotates the eye laterally. 61. There would be no sense of taste if cranial nerves 7 and 9 were destroyed, (glossopharyngeal and trigeminal) 62. Which cranial nerves are parts of the parasympathetic of the ANS? Oculomotor 3, facial 7, glossopharyngeal 9, vagus 10 4 63. Cardiac, pulmonary, and esophageal parasympathetic nerves are formed by fibers of the Vagus nerve. 64. Which cranial nerves are purely sensory nerves? Olfactory1, Optic2, Vestibulocochlear8 ,What are there specific functions? 65. Sensory fibers of the optic nerve end in which area of the cerebrum? Visual cortex in the occipital lobe and visual reflex center(superior colliculi) in the midbrain 66. Sometimes called the “great sensory nerve of the face,” Trigeminal nerve V is the largest of the cranial nerves. 67. There are 31 pairs of spinal nerves that are named and numbered according to the region and level of the spinal cord from which they emerge. They branch from the spinal column through an opening, the intervertebral foramen, between adjacent vertebrae. 68. What is the function of the meningeal branches? Where do they originate? 69. If the phrenic nerve of the cervical plexus were severed, it would have a life-threatening effect, since it travels through the thorax to innervate the diaphragm for breathing. 70. Which nerves of the brachial plexus carry proprioceptive fibers back to the CNS?all 71. Name the body's largest nerve, which consists of two major branches.sciatic nerve (tibial and common peroneal) 72. The genitofemoral nerve innervates skin of middle anterior thigh, and the external aspects of the male and female genitalia. 73. The femoral nerve innervates the skin and muscles of upper thigh, including the quadriceps femoris? 74. What is a dermatome and how are they illustrated?the cutaneous branches of each dorsal root except C1 that receives sensory information from a specific region or segment of the body and innervates with a specific area of the skin known as a dermatone 75. What do somatic nerve fibers innervate?innervate voluntary muscles form elaborate neuromuscular junctions with their effector cells and they release the neurotransmitter acetylcholine 76. What are the characteristics of reflexes (types of reflexes, nerve structures involved, initiation, effectors involved, result) most common is intrinsic 77. The quickest reflex arcs involve only two neurons. They are referred to as monosynaptic reflex. 78. If a bee sting on the left thigh causes a quick involuntary reaction of the left arm, we might say that a ipsilateral reflex arc reflex arc has occurred. Opposite-contralateral 79. While at the beach, a child reached down and touched a jellyfish. He flinched at the sudden pain, pulling his hand back. This is called withdrawal reflex 80. A complex reflex inhibits or relaxes a skeletal muscle contraction. 81. Compare and contrast the somatic nervous system and the autonomic nervous system. 82. The “resting and digesting” division of the autonomic nervous system is the parasympathetic division. 83. What are the overall effects on varies body systems when the parasympathetic division is active? 5 84. Sympathetic nerve fibers that do not synapse in the paravertebral ganglia synapse instead in collateral ganglia. 85. Most parasympathetic fibers of the cranial outflow reach their target organs by way of the vagus nerve. 86. What specific fibers of the autonomic nervous system secrete norepinephrine?post ganglionic neurons of sympathetic 87. The parasympathetic system is characterized by long preganglionic and short postganglionic fibers. 88. The sympathetic nervous system reduces blood flow to the digestive system(s). 89. The parasympathetic utilizes ACh as both the preganglionic and the postganglionic neurotransmitter. 90. The thoracolumbar division system is also called the sympathetic. 91. The preganglionic fibers in the sympathetic nervous system branch away from the ventral root through white rami that connect with a paravertebral ganglion. 92. What are the gray rami and where are they found?branches of spinal nerve, re entrance of paravertebral ganglion, part of sympathetic nervous system 93. What characteristics distinguish the autonomic nervous system (ANS) from the somatic nervous system. 94. The secretions of the adrenal medulla act to enhance the effects of sympathetic system. 95. Unlike exocrine glands that secrete their contents onto the free surface of an epithelial tissue by way of a duct, endocrine glands secrete their contents into the surrounding extracellular space. 96. steroid hormones penetrate the plasma membrane and bind to nuclear receptors. They can also bind to DNA receptors and change the genetic activity of the cell. Italic Notes -The cranial end of the neural tube grows more and forms the brain and the rest forms the spinal cord during the fourth week of development. -the cerebrum can be compared to the cap of a mushroom because it grows over the diencephalon and the brain stem - longitudinal fissure separates the right and left hemispheres -transverse fissure separates the cerebrum from the cerebellum -central sulcus separates the frontal and parietal lobes -parieto-occipital sulcus separates the parietal and occipital lobes -cerebral cortex is the area of conscious mind of speech, evaluation of stimuli,thought, memory and control of skeletal muscles; for this reason and bc of it forms a cap over the rest of the brain the cerebral cortex is called the thinking cap -voluntary muscles contractions are iniated in the primary cortex by large neurons called pyramidal cells -premotor are large area involved in learned motor skills, planning movements 6 -broca’s area controls the muscles needed for speech, motor speech area -psc/primary somatosensory cortex receives signals from sensory receptors in the skin throughout the body and proprioceptors in skeletal muscles. -somatosensory association cortex is the area where sensory information is integrate and analyzed -primary visual cortex this area perceives visual stimuli and constructs a 3d image using stimuli from both eyes -visual association area interprets the image and relates it to images in memory for recognition Pac/primary auditory they receive and perceive hearing through pitch, rhythm and loudness -the auditory association area are involved with association of hearing-speech, music and noise with memory they are necessary to speak and understand speech -association areas are independent of the primary motor and sensory areas yet they communicate with them to analyze input and form response/output -prefrontal cortex center for self control, reasoning, it is responsible in part for personality and some aspects of memory -thalamus is relay and sorting station for sensory nerve impulses traveling from the spinal cor to the cerebral cortex -hypothalamus directly below thalamus controls the ANS, regulates emotion, body temp, hunger, thirst, circadian rhythms -brain stem structures are important in maintaining life a person can suffer severe damage to the cerebral hemispheres but still live if the brain stem is not damaged -cerebral peduncles consist of pyramidal motor tracts that descend from the cerebral hemispheres to the spinal cord -the corpora quarigemina consists of two sets of white matter nuclei which are visual reglex centers(the superior colliculi) and the auditory relay centers to the sensory cortex area (the inferior colliculi) -pons means bridge, carries info between the cerebrum and the spinal cord or cerebellum or medulla oblongata -the medulla is an important autonomic reflax center because it influences cardiovascular rate, respiration, and other reflex actions like vomiting, coughing sneezing -Cerebellar processing follows a functional schemed in which the frontal cortex communicates the intent to iniate voluntary movements to the cerebellum, the cerebellum collects input concerning balance and tension in muscles and ligaments and the best way to coordinates muscle activity is relayed back to the cerebral cortex -the limbic system imposes an emotional aspect to behaviors, experiences and memories. Emotions such as pleasure, fear, anger,sorrow and affection are imparted to events and experiences(memories) -the reticular formation is responsible for maintaining wakefulness and alertness and for filtering outunimportant sensory info. Other components of the reticular formation are responsible for maintain muscle tone and regulationg visceral motor muscles. 7 -ventral roots contain motor nerve axons, transmitting nerve impulses from the spinal cord to the skeletal muscles -dortsal root ganglion is cluster of cell bodies of a sensory nerve -anterior/ventral horns are gray matter that are cell bodies of motor neurons that stimulate skeletal muscles that are located there -posterior/dorsal horns are gray matter that contain mostly interneurons that synapse with sensory neurons -lateral horns contain cell bodies of motor neurons in the sympathetic branch of the ANS CRANIAL NERVES A. Olfactory I : smell; sensory only (nasal epithelium, cribiform plate,olfactory bulb) B. Optic II: vision; sensory only (optic disk) C. Oculomotor III: “eye mover”, mixed (parasympathetic fibers) D. Trochlear IV: “pulley” (pulley shaped ligament called the trochlea) E. Trigeminal V: “the great sensory nerve of the face”, largest {3 branches: ophthalmic, maxillary, mandibular} F. Abducens VI: abduction of the eye G. Facial VII: chief motor nerve of the face (parasympathetic fibers {5 branches: temporal, zygomatic, buccal, mandibular , cervical}, sensory anterior 2/3 of tongue H. Vestibulocochlear VIII: (or Auditory/Acoustic: inner ear perception, balance I. Glossopharyngeal IX: swallowing (parasympathetic fibers) sensory for posterior tongue J. Vagus X: parasympathetic nerve to the viscera (pharync, larynx, heart, stomache, intestines, bronchi, resp reflex) K. Spinal Acessory XI: movement of shoulder/head/neck, sends fibers to pharynx for swallowing L. Hypoglossal XII: motor nerves for speech/food manipulation, and muscles of swallowing -Phrenic nerve is an important nerve of the cervical plexuses which travels through the thorac to innervate the diaphragm (breathing) -Axillary nerve innervates the deltoid muscles and shoulder along with the posterior aspect of the upper arm -Musculotaneous nerve innervates anterior skin of the upper arm and muscles of elbow flexion including biceps brachii and brachialis -sciatic nerve is the bodys larges nerve and has two parts the tibial and common peroneal -there are two types of reflexes learned/condition or intrinsic -somatic reflex is the involuntary contraction of a muscle in response to sensory input of a possible injurious stimulus -flexo/withdrawal reflex is withdrawing from painful stimuli -somatic reflexes-effector is skeletal muscle -visceral reflexes are cardiac/smooth/glands -ipsilateral reflex-one side of spinal cord -contralateral reflex-opposite side 8 -monosynpatic reflex lifting, knee jerk -polysynaptic Comparison of Autonomic and Somatic Nervous system Autonomic: motor neurons contraol smooth muscles, cardiac muscles and glands, controls visceral reflekxes. Two motor neurons the paraganglionic and postganglionic. **the ANS does not activate its effectors but merely modifies their activities** Somatic: motor neurons stimulate skeletal muscles. Single motor neuron connects to CNS. Autonomic is divided into the Parasympatheitc and Sympathetic, each system prepares the body for a different kind of situation -Parasympathetic nervous division is active during periods of digestion and rest , REST AND DIGEST, keeping the use od body energies to a minimum; It’s autonomic ganglia re located on/near the effector organ and are called the terminal ganglia; terminal ganglia lie near the target organ -Sympathetic nervous division prepares the body for situations requiring alertness or strength or situations that arouse fever, anger, excitement or embarrassment, FIGHT OR FLIGHT mode, the adrena medulla( modified sympathetic ganglion) is stimulated to release a hormone mixture of epinephrine and norepinephrine to release glucose in blood, referred to as paravertebral ganglin; sympathetic plexus allow connections -Sympathetic pathway: cell bodies of the preganglionic neurons occur in the lateral horns of gray matter of the spinal cord. 9