Central Nervous System QUESTIONS AND ANSWERS 100% CORRECT

Central Nervous System QUESTIONS AND ANSWERS 100% CORRECT CNS Correct Answer: consists of brain and spinal cord - processes incoming sensory information and is the source of thoughts, emotions and memories - nerve impulses that stimulate muscles to contract and glands to secrete originate in this system types of nervous tissue Correct Answer: neurons and neuroglia neurons Correct Answer: processes electrical excitability: ability to respond to a stimulus and convert it into an action potential parts of neuron Correct Answer: cell body, dendrites, and an axon cell body Correct Answer: soma- contains single nucleus surrounded by cytoplasm- contains typical organelles (rough ER called nissl bodies) dendrites Correct Answer: multiple processes extending from cell body that receive impulses/info from another neuron or sensory receptor axon Correct Answer: single extension from cell body that propagates an impulse away from cell body toward another neuron, muscle fiber of gland cell structural classification of neurons Correct Answer: according to the number of processes extending from the cell body multiple neurons Correct Answer: have several dendrites and one axon - most neurons in brain and spinal cord are this type bipolar neurons Correct Answer: have one main dendrite and one axon - found in retina, inner ear and olfactory area of the brain unipolar neurons Correct Answer: have dendrites and one axon that fuse together to form a continuous process that emerges from cell body - dendrites function as sensory receptors that detect sensory stimuli such as touch pressure, pain or temp. - cell bodies are located in the ganglia or spinal and cranial nerves functional classification of neurons Correct Answer: according to the direction in which the nerve impulse is conveyed with respect to the CNS sensory Correct Answer: afferent neurons - contain sensory receptors at their distal ends - once stimulus activates a sensory receptor, the sensory neuron forms an action potential which is conveyed into the CNS through cranial or spinal nerves - most unipolar motor neurons Correct Answer: efferent neurons - convey action potential away from the CNS to effectors (nucleus and glands) in the periphery through cranial or spinal nerves - most are multipolar interneurons Correct Answer: association neurons - located within the CNS between sensory and motor neurons - processing incoming sensory info from sensory neurons and elicit a motor response by activating appropriate motor neurons - most are multipolar neuroglia Correct Answer: support, nurture and protect neurons and maintain the interstitial fluid that bathes them - make up half the volume of the CNS - smaller than neurons but 5-50 times more numerous - do not generate or propagate action potentials - can multiply and divide in the mature nervous (in injury or disease, they multiply to fill spaces formally occupied by neurons neuroglia of the CNS Correct Answer: classified on the basis of size, cytoplasmic processes and intracellular organization inot 4 types: astrocytes, oligodendrocytes, microglia, ependymal cells brain Correct Answer: conisists of 4 major parts: brain stem, cerebellum, diencephalon, cerebrum brain stem Correct Answer: continuous with the spinal cord and consists of the medulla oblongta, pons, and midbrain cerebellum Correct Answer: posterior to the brain stem diencephalon Correct Answer: superior to the brain stem and consists of thalamus, hypothalamus and epithalamus cerebrum Correct Answer: largest part of the brain protective covering of the brain Correct Answer: the cranium (skull) and the meninges surround and protect the brain cranial meninges Correct Answer: the outer dura mater - the middle arachnoid mater - the inner pia mater cerebrospinal fluid Correct Answer: contributes to homeostasis in 3 main ways: mechanical protection (shock-absorbing) - chemical protection (optimal environment) - circulation (allows exchange of nutrients and wastes between blood and nervous tissue flow of CSF Correct Answer: flows through the lateral ventricles -into 3rd ventricle where more CSF is added - flows through the aqueduct of the midbrain into 4th ventricle where more CSF is added - enters the subarachnoid space - then into the central canal of the spinal cord - gradually reabsorbed into the blood medulla oblongata Correct Answer: forms inferior part of brain stem - contains all sensory tracts and motor tracts that extend between the spinal cord and other parts of the brain - contains several nuclei which control vital body functions: heartbeat, blood vessel diameter, normal breathing rhythm, vomiting, swallowing, sneezing, coughing and hiccuping