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History of Anatomy © The McGraw−Hill Anatomy, Sixth Edition Companies, 2001 History of Anatomy 1 Definition of the Science 2 Prescientific Period 2 Scientific Period 4 Clinical Case Study Answer 20 Chapter Summary 20 Review Activities 21 Clinical Case Study A 55-year-old women visits the village apothecary for her increasing shortness of breath. The physician, learning of the woman’s symptoms and finding swelling in her legs, makes the diagno- sis of dropsy and prescribes a course of therapy meant to rid the body of evil humors. He applies a dozen of his healthiest leeches to the woman’s legs and drains a pint of her blood by opening a vein in her arm. The ex- perience reinforces to the doctor the concept of evil humors and the effectiveness of bloodletting as a therapy. Current therapy for this condition is oral fluid restriction and medications that in- duce diuresis (increased urination) with the ultimate goal of decreasing fluid volume. It is no wonder that losing a pint of blood made this woman feel better in the short term. Unfortu- nately, repeated courses of this crude therapy left patients profoundly anemic (low red blood cell count) and actually worsened their heart failure. Throughout medical history, how has an accurate understanding of human anatomy and physiology led to better disease therapy? FIGURE: Blood letting was a technique of medical practice widely used for over two thousand years. History of Anatomy © The McGraw−Hill Anatomy, Sixth Edition Companies, 2001 2 Unit 1 Historical Perspective the structure of the body often has been stimulated by the desire DEFINITION OF THE SCIENCE of the medical profession to explain a body dysfunction. Various The science of human anatomy is concerned with the structural religions, on the other hand, have at one time or another stifled organization of the human body. The descriptive anatomical termi- the study of human anatomy through their restrictions on human nology is principally of Greek and Latin derivation. Over the centuries, peoples’ innate interest in their own bodies and physical capabilities has found various forms of ex- Objective 2 Distinguish between anatomy, physiology, and pression. Many of the Objective 3 Explain why most anatomical terms are derived great masters of the Renaissance portrayed human figures in their from Greek and Latin words. Indeed, several of these artists were excellent anatomists be- cause their preoccupation with detail demanded it. Such an artis- tic genius was Michelangelo, who captured the splendor of the Human anatomy is the science concerned with the structure of human form in sculpture with the David (fig. The term anatomy is derived from a Greek ings like those in the Sistine Chapel. The body found expression in his writings: “What a piece of work is a science of physiology is concerned with the function of the man! It is inseparable from anatomy in that structure tends to re- moving, how express and admirable! Anatomy and physiology are both In the past, human anatomy was an academic, purely de- subdivisions of the science of biology, the study of living organ- scriptive science, concerned primarily with identifying and nam- isms. The anatomy of every structure of the body is adapted for ing body structures. Although dissection and description form performing a function, or perhaps several functions. Human as the basis for understanding the structure and function of the anatomy is a practical, applied science that provides the founda- human body for many centuries. Every beginning anatomy stu- tion for understanding physical performance and body health. Explain the statement, Anatomy is a science based on ob- Empire, during which time an interest in scientific description servation, whereas physiology is based on experimentation was cultivated. Why does understanding the biology of an organism de- because it remained unchanged throughout history. Discuss the value of using established Greekor Latin pre- the inside front cover of this text), many of the terms in the de- fixes and suffixes in naming newly described body structures. Although the Greeks and Romans made significant contributions to anatomical terminology, it should be noted that many individuals from other cultures have also contributed to the science of human anatomy. As a scientific field of inquiry, human anatomy has had a PRESCIENTIFIC PERIOD rich, long, and frequently troubled heritage. The history of Evidence indicates that a knowledge of anatomy was of survival human anatomy parallels that of medicine. In fact, interest in value in prehistoric times and that it provided the foundation for medicine. History of Anatomy © The McGraw−Hill Anatomy, Sixth Edition Companies, 2001 Chapter 1 History of Anatomy 3 FIGURE 1. Presumably the location of the heart is drawn on the mammoth, and vulnerable anatomical sites are shown on the two bison.
Symptoms have to be recognized purchase 120 mg sildalis fast delivery, understood discount sildalis 120 mg online, and discussed with the healthcare team by the patient and family. Management should be individualized and flexible in light of the dynamic nature of MS. Paresthesias 51 52 NURSING PRACTICE IN MULTIPLE SCLEROSIS: A CORE CURRICULUM TABLE 11. Other causes: depression, deconditioning, medications, concommitant medical conditions (thyroid dysfunction, cardiovascular disease), sleep disturbance C. The most common cause of MS-related disability 54 NURSING PRACTICE IN MULTIPLE SCLEROSIS: A CORE CURRICULUM D. Question about other symptoms (pain, spasticity, bowel or bladder dysfunction) 7. Encourage the use of appropriate use of assistive devices (scooters, walkers, wheelchairs, transfer equipment) 3. Encourage the initiation of symptom management—pain, spasticity, bowel, bladder dysfunction 6. Medications used to manage MS-related fatigue: CNS stimulants (methylphenidate) aminopyridines (currently being studied in research) amantidine (SE: headache, dizziness, rash) modafinil (SE: headache, tachycardia, palpitations, con- traindicated in LMVP) pemoline (liver cautions) SSRI antidepressants unique antidepressants—buprioprion (Wellbutrin®) (SE: seizure risk) 9. Pain inadequately defined, identified, or measured by an observer CHAPTER 11: THE SYMPTOM CHAIN IN MULTIPLE SCLEROSIS 55 C. Acute pain trigeminal neuralgia tonic spasms lightning-like extremity pain painful Lhermitte’s sign optic neuritis and retrobulbar pain 2. Chronic pain with insidious onset dysesthetic extremity pain bandlike pain in torso or extremities back pain with radicolopathy headache F. Trigeminal neuralgia probably arises from transmission of nerve impulses in areas of demyelination. In the chronic phase, anticonvulsants such as carbamaze- pine and gabapentin are used. Less common is the painful tetanic posturing of an arm or leg, usually on one side of the body. Treatment consists of carbamazepine, clonazepam, tizanidine, and baclofen. Lightning-like extremity pain can be treated with carbamazepine, gabapentin, and phenytoin. Lhermitte’s sign responds to the above medications and also to tricyclic antidepressant medications. Headache has been reported to be causally related to demye- linating lesions. When associated with a relapse, treatment with steroids may cause resolution of headache. Optic neuritis is due to inflammation and demyelination occurring in and around pain-sensitive meninges surrounding the optic nerve. Gabapentin—useful in dysesthetic and paroxysmal pain; better SE profile than phenytoin 3. Accentuation of DTR and clonus occurs, with exaggeration of flexor reflexes C. Spasms and stiffness are common in the quadriceps, hamstrings, and gastrocnemious muscles D. May be heightened during an exacerbation, with underlying infection, and with noxious stimuli E. Reduce muscle hypertonia by stretching spastic muscles and by application of warm or cold packs 4. Develop and improve useful automatic movements and thus promote maximal function 6. Supply supportive aids such as walkers, wheelchairs, crutches, orthoses, and special shoes F. Screening for noxious stimuli will promote prompt treatment and reduction of spasticity. Medications for spasticity may be sedating and excessive doses may result in weakness CHAPTER 11: THE SYMPTOM CHAIN IN MULTIPLE SCLEROSIS 57 1. Surgically implanted pump for intrathecal baclofen delivery no systemic side effects expensive requires surgery reserved for patients in whom other interventions are unsuccessfulTremor, incoordination, and weakness A. Physical and occupational therapy may provide patient with education and assistive devices, but do not correct the underlying problemDysarthria A. Normal speech consists of five systems working together smoothly and rapidly: 1. Articulation—making quick, precise movements of the lips, tongue, mandible, and soft palate 5. Treatment consists of management of spasticity and tremor along with speech and language therapy (SLT) 58 NURSING PRACTICE IN MULTIPLE SCLEROSIS: A CORE CURRICULUM F. Are problematic speech and voice characteristics detracting from the message being communicated? Are speech, voice, and communication problems interfering with the patient’s quality of life? Are speech, voice, and communication problems perceived as troublesome by the patient and family? Normal swallowing involves intricate and rapid coordination of sensory and motor activity in the oral cavity, pharynx, and esophagus. Normal oromotor control for swallowing involves lip closure, facial tone and musculature, rotary lateral jaw motion, and pharyngeal swallow. Assessment includes a careful history (pneumonia, difficulty with liquids and solids, aspiration or choking while eating). Optimal management includes referral to a speech/language pathologist familiar with MS and its related problems.
The cerebellum consists of two hemispheres and a central constricted area called the vermis (fig buy sildalis 120 mg without a prescription. The falx cerebelli is the portion of the meninges that partially extends between the hemispheres buy sildalis 120mg online. Like the cerebrum, the cerebellum has a thin outer layer of gray matter, the cerebellar cortex, and a thick, deeper layer of white matter. Three paired bundles of nerve fibers called cerebellar pe- duncles support the cerebellum and provide it with tracts for communicating with the rest of the brain (fig. The fibers within these peduncles origi- nate primarily from specialized dentate nuclei within the cerebellum and pass through the red nucleus to the thala- mus, and then to the motor areas of the cerebral cortex. Impulses through the fibers of these peduncles provide feedback to the cerebrum. Middle cerebellar peduncles convey impulses of voluntary movement from the cerebrum through the pons and to the cerebellum. Inferior cerebellar peduncles connect the cerebellum with the medulla oblongata and the spinal cord. They contain both incoming vestibular and proprioceptive fibers and outgoing motor fibers. The principal function of the cerebellum is coordinating skeletal muscle contractions by recruiting precise motor units within the muscles. Impulses for voluntary muscular movement originate in the cerebral cortex and are coordinated by the cere- bellum. The cerebellum constantly initiates impulses to selective motor units for maintaining posture and muscle tone. A propriocep- tor is a sensory nerve ending that is sensitive to changes in the tension of a muscle or tendon. Nervous Tissue and the © The McGraw−Hill Anatomy, Sixth Edition Coordination Central Nervous System Companies, 2001 376 Unit 5 Integration and Coordination Diencephalon Corpora quadrigemina: Pineal Superior gland colliculi Inferior colliculi Midbrain Cerebellar Trochlear peduncles: nerve Superior portion Middle portion Inferior portion Cerebellum Medulla oblongata FIGURE 11. Trauma or diseases of the cerebellum, such as a stroke or Medulla Oblongata cerebral palsy, frequently cause an impairment of skeletal muscle function. There is also a loss of equilibrium, result- ing in a disturbance of gait. It is continuous with the pons anteriorly and the spinal cord posteriorly at the level of the foramen magnum (see Knowledge Check figs. Externally, the medulla oblongata resem- bles the spinal cord, except for two triangular elevations called 25. Describe the locations and relative sizes of the pons and pyramids on the inferior side and an oval enlargement called the the cerebellum. Define the terms tentorium cerebelli, vermis, arbor vitae, and with the central canal of the spinal cord and anteriorly with the cerebellar peduncles. The medulla oblongata is composed of vital nuclei and white matter that form all the descending and ascending tracts communicating between the spinal cord and various parts of the brain. Most of the fibers within these tracts cross over to the op- MYELENCEPHALON posite side through the pyramidal region of the medulla oblon- gata, permitting one side of the brain to receive information The medulla oblongata, contained within the myelencephalon, from and send information to the opposite side of the body (see connects to the spinal cord and contains nuclei for the cranial fig. The gray matter of the medulla oblongata consists of sev- eral important nuclei for the cranial nerves and sensory relay Objective 20 Describe the location, structure, and functions of the medulla oblongata. The vestibular nuclei are the center from which arise the Van De Graaff: Human V. Nervous Tissue and the © The McGraw−Hill Anatomy, Sixth Edition Coordination Central Nervous System Companies, 2001 Chapter 11 Nervous Tissue and the Central Nervous System 377 Thalamus Midbrain Pons Reticular formation Medulla oblongata FIGURE 11. The vagus (X) nerves arise from Reticular Formation vagus nuclei, one on each lateral side of the medulla oblongata, adjacent to the fourth ventricle. Portions of the cerebral cortex via the thalamic nuclei (not illustrated). The in- reticular formation are located in the spinal cord, pons, mid- ferior olivary nuclei and the accessory olivary nuclei of the brain, and parts of the thalamus and hypothalamus (fig. Three other nuclei within the medulla oblongata function Nuclei within the reticular formation generate a continuous as autonomic centers for controlling vital visceral functions. Both inhibitory and accelerator fibers arise in a state of alert consciousness and to selectively monitor the sen- from nuclei of the cardiac center. The RAS also helps the stantly travel through the vagus nerves to slow the heart- cerebellum activate selected motor units to maintain muscle tonus beat. Accelerator impulses travel through the spinal cord and produce smooth, coordinated contractions of skeletal muscles. Nuclei of the vasomotor center send in activity within the RAS, perhaps because of the secretion of spe- impulses via the spinal cord and spinal nerves to the cific neurotransmitters. A blow to the head or certain drugs and dis- smooth muscles of arteriole walls, causing them to con- eases may damage the RAS, causing unconsciousness. The respiratory center of the medulla oblongata controls the rate and depth of breathing and functions in conjunction with the respiratory nuclei of the Knowledge Check pons (see fig. Describe the major reflex centers of the medulla oblongata Other nuclei of the medulla oblongata function as centers that regulate autonomic functions. Explain the statement that the RAS is the brain’s “chief be initiated voluntarily, but once they progress to a certain point watchguard. Nervous Tissue and the © The McGraw−Hill Anatomy, Sixth Edition Coordination Central Nervous System Companies, 2001 378 Unit 5 Integration and Coordination Skin of scalp Dura mater: Periosteal layer Galea aponeurotica Meningeal layer Skull Arachnoid Arachnoid villi Subarachnoid space Pia mater Cerebral cortex Dural sinus Falx cerebri FIGURE 11.
Gravity may also act as the antagonist for certain Skeletal muscles may be classified on the basis of fiber arrange- muscles buy 120 mg sildalis free shipping. When an elevated upper appendage is relaxed discount 120mg sildalis with visa, for ex- ment as parallel, convergent, sphincteral (circular), or pennate ample, gravity brings it down to the side of the body, and the (table 9. Each type of fiber arrangement provides the muscle with distinct capabilities. Muscle fiber architecture can be observed on a cadaver or other dissection specimen. If you have the opportunity to learn the muscles of the body from a cadaver, observe the fiber ar- synergistic: Gk. Muscular System © The McGraw−Hill Anatomy, Sixth Edition Companies, 2001 Chapter 9 Muscular System 239 Origins TABLE 9. When one antagonistic group contracts, and (c) multipennate the other one must relax; otherwise, movement does not occur. Muscle fibers will atrophy if they are not periodically stim- require extensive vascularity to receive nutrients and oxygen ulated to contract. Smaller muscles generally have a single artery supplying blood and perhaps two veins returning For years it was believed that muscle soreness was simply caused by a buildup of lactic acid within the muscle fibers blood (fig. The microscopic capillary exchange between arteries and factor related to soreness, recent research has shown that there is veins occurs throughout the endomysium that surrounds indi- also damage to the contractile proteins within the muscle. This means that there must be exten- microscopic damage causes an inflammatory response that re- sive innervation (served with neurons) to a muscle to ensure the sults in swelling and pain. If enough proteins are torn, use of the entire muscle may be compromised. Staying in good physical connection of each muscle fiber to a nerve cell. Actually there condition guards against muscle soreness following exercise. A motor (efferent) Conditioning the body not only improves vascularity but enlarges neuron is a nerve cell that conducts nerve impulses to the muscle muscle fibers and allows them to work more efficiently over a fiber, stimulating it to contract. Muscular System © The McGraw−Hill Anatomy, Sixth Edition Companies, 2001 240 Unit 4 Support and Movement FIGURE 9. Contrast the following terms: endomysium and epimysium; Objective 7 Distinguish between isotonic and isometric fascia and tendon; aponeurosis and retinaculum. Give some examples of synergistic muscles and Objective 8 Define motor unit and discuss the role of motor state which muscles are antagonistic. Skeletal Muscle Fibers Despite their unusual elongated shape, muscle cells have the SKELETAL MUSCLE FIBERS AND same organelles as other cells: mitochondria, intracellular mem- branes, glycogen granules, and so forth. Unlike most other cells TYPES OF MUSCLE CONTRACTION in the body, however, skeletal muscle fibers are multinucleated Muscle fiber contraction in response to a motor impulse results and striated (fig. In addition, some skeletal muscle fibers from a sliding movement within the myofibrils in which the length may reach lengths of 30 cm (12 in. Muscular System © The McGraw−Hill Anatomy, Sixth Edition Companies, 2001 Chapter 9 Muscular System 241 Sarcolemma Sarcoplasm Myofilaments Myofibrils Striations Nucleus (a) Muscle fiber (b) FIGURE 9. A networkof membranous chan- cle myofibrils are due to the arrangement of these myofilaments. At high magnification, thin dark lines can be seen in the of transverse tubules (T tubules) runs perpendicular to the sar- middle of the I bands. The arrangement coplasmic reticulum and opens to the outside through the sar- of thick and thin filaments between a pair of Z lines forms a re- colemma. Also embedded in the muscle fiber are many threadlike peating structural pattern that serves as the basic subunit of structures called myofibrils (fig. These subunits, from Z line to proximately one micrometer (1µm) in diameter and extend in Z line, are known as sarcomeres (fig. A longitudinal section parallel from one end of the muscle fiber to the other. They are of a myofibril thus presents a side view of successive sarcomeres so densely packed that other organelles—such as mitochondria (fig. Each extend from the edge of one stack of thick myosin filaments to myofibril is composed of even smaller protein filaments, or myo- the edge of the next stack of thick filaments. Thin filaments are about 6 nm in diameter and are appearance because they contain only thin filaments. Thick filaments are about 16 nm in filaments, however, do not end at the edges of the I bands. Because thick and thin filaments overlap at the edges of each A band, the edges of the A band are darker in appear- actin: L. Muscular System © The McGraw−Hill Anatomy, Sixth Edition Companies, 2001 242 Unit 4 Support and Movement Sarcolemma Myofibrils Triad of the reticulum: Terminal cisternae A band Transverse tubule I band Sarcoplasmic reticulum Z line Mitochondria Nucleus Waldrop FIGURE 9. The central H zones thus contain only thick filaments on a single row of dark thick myofilaments in this transverse sec- that are not overlapped by thin filaments. There are numerous sarcomeres within each When a muscle is stimulated to contract, it decreases in myofibril that are out of the plane of the section (and out of the length as a result of the shortening of its individual fibers. A better appreciation of the three-dimensional struc- Shortening of the muscle fibers, in turn, is produced by shorten- ture of a myofibril can be obtained by viewing the myofibril in ing of their myofibrils, which occurs as a result of the shorten- transverse section. As the seen that the Z lines are actually disc-shaped (Z stands for sarcomeres shorten in length, however, the A bands do not Zwıschenscheibe, a German word meaning “between disc”), and shorten but instead appear closer together. The I bands—which that the thin filaments that penetrate these Z discs surround the represent the distance between A bands of successive thick filaments in a hexagonal arrangement. Muscular System © The McGraw−Hill Anatomy, Sixth Edition Companies, 2001 Chapter 9 Muscular System 243 Sarcoplasm Skeletal muscle fiber Nucleus I band Sarcolemma H zone (c) A band (a) Z line Actin myofilaments Myofibrils Myosin myofilaments (b) H zone Sarcomere H zone A band I band Myofilaments Z line FIGURE 9.
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