Nervous System Exam 4 Study Guide PDF

**[Nervous System -- Exam 4 -- Study Guide]** Describe the 4 types of neurons: - Anaxonic -- all processes appear the same; rare; seen in brain - Bipolar -- one process axon; one process dendrite; centrally located cell body; seen in retina & inner ear - Unipolar -- one process, axon;...

**[Nervous System -- Exam 4 -- Study Guide]** Describe the 4 types of neurons: - Anaxonic -- all processes appear the same; rare; seen in brain - Bipolar -- one process axon; one process dendrite; centrally located cell body; seen in retina & inner ear - Unipolar -- one process, axon; dendrites branch off one end & telodendria branch off of the other; cell body off to the side attached to axon; seen in sensory neurons of PNS - Multipolar -- many processes branching off cell body; one axon and many dendrites; most common type of neuron; includes motor neurons Describe the neuroglia of the CNS - Ependymal cells -- produce and monitor CSF - Microglia -- cleanup cells; remove debris & pathogens - Astrocytes -- form and monitor blood brain barrier; produce scar tissue upon damage to CNS; produce chemical that inhibit growth of axons after injury - Oligodendrocytes -form myelin sheath on axons of CNS Describe the neuroglia of the PNS - Satellite cells -- control chemical environment around cell bodies of PNS - Schwann cells -- form myelin sheath around axons of cells in PNS The resting potential of a neuron is \_\_-70mV\_\_\_\_ Describe: - Threshold - -60mV; membrane potential that triggers action potential - Depolarization -- with influx of positive ions through membrane; causes the membrane potential to become positive - Repolarization -- positive ions leave the membrane; membrane potential returns to negative (returns to resting potential) - Hyperpolarization -- membrane potential becomes too negative (less than -70mV) Describe the sodium-potassium pump (how much of what ion in & how much of what ion out) Active; pumps 3Na+ out for every 2K+ in Describe the following gradients: - Chemical -- flow of ions based on concentration gradients - Electrical -- movement of ions based on electrical charge; opposite charges attract; like charges repel - Electrochemical -- combination of chemical and electrical gradients Briefly describe the following diseases: - Multiple sclerosis -- demyelinating disorder - Parkinson's disease -- decreased dopamine production by substantia nigra - Alzheimer's disease -- decrease in higher order cerebral function, memory etc - Cerebral palsy -- group of disorders that effect voluntary motor function, can be genetic, due to substance use of mother, birth trauma - Amyotrophic lateral sclerosis -- progressive degeneration of CNS motor neurons - Rabies -- damages the CNS through retrograde flow, beginning at the axon terminals - Myasthenia gravis -- degenerative, progressive loss of ACh receptors; results in gradual weakness - Botulism -- caused by toxin, results in lack of ACh release; causes paralysis of effected muscles - Rigor mortis -- stiffness in muscles after death; no ATP; cross bridges cannot release - Polio -- loss of voluntary muscle function - Tetanus -- caused by bacterial toxin; results in sustained uncontrolled muscle spasm What functional cortex is in which lobe of the brain? - Frontal lobe \_\_\_personality & decision making\_\_\_\_\_\_\_\_ cortex - Occipital lobe \_\_visual\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ cortex - Temporal lobe \_\_\_\_auditory\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ cortex - Parietal lobe \_\_\_\_general sensory & voluntary motor\_\_\_\_\_\_\_\_ cortex - Insula lobe \_\_\_\_olfactory\_\_\_\_\_\_ & \_\_\_\_gustatory\_\_\_\_\_\_\_\_ cortex Describe the path of cerebrospinal fluid (CSF) through the brain. Lateral ventricles interventricular foramen third ventricle cerebral aqueduct fourth ventricle central canal There are \_\_31\_\_\_ pairs of spinal nerves. - \_\_\_\_\_8\_\_\_\_\_\_ cervical nerve - \_\_\_\_\_\_12\_\_\_\_\_ thoracic nerves - \_\_\_\_5\_\_\_\_\_\_\_ lumbar nerves - \_\_\_\_\_\_5\_\_\_\_\_ sacral nerves - \_\_\_\_\_\_1\_\_\_\_\_ coccygeal nerves There are \_\_12\_\_\_\_ pairs of cranial nerves. What cranial nerve is responsible for 75% of the parasympathetic outflow? CN X -- Vagus Nerve Describe the effect of increased sympathetic activity (fight or flight). Increased heart rate, blood pressure, respiratory rate, blood flow to skeletal muscle, dilation of respiratory passages, mental focus, pupil dilation Describe the effect of increased parasympathetic activity (rest and digest). Increased urinary and digestive functions, increased blood flow to digestive organs, decreased heart rate, blood pressure and respiratory rate, pupil constriction Describe the parts of the synapse Presynaptic cell (neuron); synaptic cleft; post-synaptic cell (neuron, muscle, glandular cells) Describe stretch reflexes. Monosynaptic, fastest reflex, involves 2 neurons, simplest reflex What are the examples of stretch reflexes? Patellar, biceps, triceps, calcaneal/ankle jerk Describe the functional areas controlled by the left hemisphere. Speech and writing center, general interpretive area, auditory cortex of right ear, right visual field of both eyes, math, logic and reasoning areas Describe the functional areas controlled by the right hemisphere. Auditory cortex of left ear, left visual field of both eyes, spatial reasoning, recognition of facial expression, artistic Describe the following structures: They are all extensions of the dura mater; where are they located? - Falx cerebri -- between cerebral hemispheres - Falx cerebelli -- between cerebellar hemispheres - Tentorium cerebelli -- between cerebrum and cerebellum Describe the basic function of the following brain & spinal cord structures: - Hypothalamus -- connection between nervous and endocrine systems - Thalamus -- sensory relay center - Epithalamus -- pineal gland; responsible for circadian rhythms; produce melatonin - Pons -- connects cerebellum and cerebrum - Medulla oblongata -- all signals pass through here; contains centers for autonomic reflexes and visceral functions - Cerebellum -- connects sensory input with cerebral cortex - Cerebrum -- thoughts, memory, sensation, voluntary motor - Limbic system -- emotional connections - Corpus callosum -- white matter tract that connects the right and left cerebral hemispheres - Grey commissure -- connects wings of grey matter; location of decussation (crossing over from one side to the other) - White commissure -- connects white matter tracts - Arbor vitae -- white matter of cerebellum - Superior colliculus -- visual reflexes - Inferior colliculus -- auditory reflexes - Conus medullaris -- pointed tip of spinal cord at the L1-L2 level - Filum terminale -- terminal thread of spinal cord that attaches it to the sacrum - Cauda equina -- horses tail; strands of nerve fibers extending from end of spinal cord - Mamillary body -- part of hypothalamus; controls feeding reflexes - Preoptic area -- part of hypothalamus; regulates body temperature - Supra-optic nucleus -- part of hypothalamus; secretes ADH (antidiuretic hormone) - Suprachiasmatic nucleus - part of hypothalamus; regulates circadian rhythms What structures make up the brain stem? Midbrain; pons; medulla oblongata What structures make up the diencephalon? Hypothalamus; thalamus; epithalamus (pineal gland) Match the embryonic brain structure with the adult structure it forms. Adult structure 5^th^ week embryo 4^th^ week embryo Cerebrum telencephalon prosencephalon Hypothalamus, thalamus, epithalamus diencephalon prosencephalon Midbrain mesencephalon mesencephalon Medulla oblongata myelencephalon rhombencephalon Pons & cerebellum metencephalon rhombencephalon What is the basic action of each functional cortex? - Auditory cortex - hearing - Visual cortex -- vision (sight) - Gustatory cortex - taste - Olfactory cortex - smell - Frontal eye field -- scanning text - General interpretive area -- math, logic, word formation Which of the cranial nerves are sensory only? CN I, II, VIII (olfactory, optic, vestibulocochlear) Describe the function of the reticular activating system When the reticular activating system is stimulated/active a person is awake and alert Describe each of the brain wave types seen on the EEG: - Alpha -- normal, awake, alert adult - Beta -- seen in a person that is concentrating, under stress or under psychological tension - Theta -- seen in children and intensely frustrated adults - Delta -- seen in sleeping adults and in infants; otherwise indicates brain damage The dorsal root ganglia contains what? Unipolar, sensory cell bodies What are the 5 steps in the reflex arc? Activate receptors; activate sensory nerves; integration center; activate motor nerve; activate peripheral effector Describe continuous propagation. Unmyelinated axons; slow Describe saltatory propagation. Myelinated axons; fast Describe synaptic delay. Time it takes for neurotransmitters to cross synapse; the more synapses the longer the process takes. The conus medullaris is located at \_\_\_L1/2\_\_\_\_\_\_\_ spinal level. Describe synaptic fatigue. With overstimulation, neurotransmitters are used faster than they can be recycled, synapse cannot function properly until neurotransmitters are replaced Match the region of the spinal cord with the nuclei that are found there: - Posterior gray horn sensory visceral and somatic - Lateral gray horn motor visceral - Anterior gray horn motor somatic List the spinal meningeal layers and spaces from superficial to deep. (From spine spinal cord) Epidural space dura mater subdural space arachnoid mater sub arachnoid space pia mater Which of the terms identified above is NOT present in the skull brain? Epidural space Describe the Babinski test. What would a positive exam look like? Who would normally have this? What does it indicate in others? Positive Babinski when lateral aspect of foot is stroked, toes fan apart Positive Babinski is normal in people \2 years positive Babinski indicates severe damage to motor tract