By G. Trompok. West Chester University of Pennsylvania. 2018.
When this type of hearing loss correction of the underlying problem can occurs discount alfuzosin 10 mg otc, the individual is said to have cen- restore diminished hearing generic alfuzosin 10 mg otc. In this type of deafness, loss may result from buildup of earwax in there is a disruption of the ability of the the ear canal, a foreign object in the ear, sound stimulus to reach the hearing cen- infection of the middle ear (otitis media), ters of the brain, or the hearing center in or hardening of the small bones in the ear the brain incorrectly receives and process- (otosclerosis) that are important for con- es signals. Some- cause the nerve function cannot be times conductive hearing impairments restored, associated hearing loss is usual- cannot be corrected and hearing aids may ly permanent. Although the cause of sen- be used to amplify sound and restore nor- sorineural loss should be evaluated mal loudness. Conductive hearing losses are medically, individuals with sensorineural Hearing Loss and Deafness 147 hearing loss should also consult with a the most severe type of hearing loss. The conductive component may lend The degree of hearing loss is common- itself to medical treatment while the sen- ly deﬁned on the basis of the audiogram, sorineural component remains. The audio- uals in some instances may beneﬁt from gram is a method of recording the softest ampliﬁcation. Normal hear- loss experienced with mixed hearing im- ing sensitivity ranges from –10 to +20 pairments and the success of intervention decibels. A general guide for describing the depend on the degree and type of sen- degrees of hearing loss associated with sorineural damage. Duration of Loss or Age of Onset Another classiﬁcation of hearing loss is Table 5–1 Functional Implications of Degrees based on when the hearing loss occurred: of Decibel Loss • Prelingual hearing loss occurs before 26–40 Mild hearing loss. In ideal listening the individual acquires language, usu- conditions, hearing is minimally ally before the age of 3. Degree of Hearing Loss Hears loud conversational speech that is close by. Has difﬁculty Hearing loss can also be classified hearing in group situations. Conversational • Hard of hearing refers to individuals speech severely affected. May hear (or feel from usually have difﬁculty understanding than 90 vibrations) only very loud sounds.
It is a common con- genital deformity of the hand buy generic alfuzosin 10mg on line, although it also occurs in the foot order alfuzosin 10mg on-line. The condition can be effectively treated surgically if the procedure is done at an early age. Describe the structure of each of the long bones of the lower ing or breaking of a bone. Radiographs are often used to diagnose extremity and the position of each of the tarsal bones. Which bones of the foot contribute to the formation of the classified in several ways, and the type and severity of the frac- arches? Pathologic fractures, for example, result from diseases that weaken the bones. Most fractures, however, are called traumatic fractures because they are caused by injuries. The following are descriptions of several kinds of traumatic fractures (fig. The fractured bone is exposed to the Minor defects of the extremities are relatively common malfor- outside through an opening in the skin. The fracture has separated the bone into two an extra digit is incompletely formed and does not function. The bone is splintered into Polydactyly is inherited as a dominant trait, whereas syndactyly several fragments. An incomplete break (partial fracture), in is not certain whether it is abnormal positioning or restricted which one side of the bone is broken, and the other side movement in utero that causes this condition, but both genetics is bowed. Skeletal System: The © The McGraw−Hill Anatomy, Sixth Edition Appendicular Skeleton Companies, 2001 190 Unit 4 Support and Movement A greenstick fracture is incomplete, A partial (fissured) fracture A comminuted fracture is and the break occurs on the convex involves an incomplete break. A transverse fracture is complete, An oblique fracture is complete, A spiral fracture is and the fracture line is horizontal. A fracture of either or both of the distal ends of the Certain fractures seem to resist healing, however, even with this tibia and fibula at the level of the malleoli. New techniques for treating fractures include applying weak electrical currents to fractured bones. The broken portion of the bone is driven in- cantly reducing the time of immobilization.
It is no wonder that losing a pint of blood made this woman feel better in the short term order 10mg alfuzosin visa. Unfortu- nately cheap alfuzosin 10mg on line, 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.
Its death is caused by a lack Zona reticularis of certain steroid hormones that are produced and secreted by the cortex of the adrenal gland discount alfuzosin 10 mg without a prescription. The glucocorticoid hormones buy generic alfuzosin 10 mg on line, cortisol and corticos- Medulla: 10–20% terone, play essential roles in adjusting the metabolism of carbohydrates, lipids, and proteins in liver, muscle, and adi- pose tissues during fasting, which assures an adequate sup- ply of glucose and fatty acids for energy metabolism de- spite the absence of food. The mineralocorticoid hormone aldosterone, another steroid hormone produced by the ad- renal cortex, stimulates the kidneys to conserve sodium Catecholamines and, hence, body fluid volume. The glucocorticoids also enable the body to cope with Androgens physical and emotional traumas or stresses. The physiological importance of this action of the glucocorticoids is empha- Cortisol sized by the fact that adrenalectomized animals lose their ability to cope with physical or emotional stresses. Even when Aldosterone given an appropriate diet to prevent blood glucose and body sodium depletion, an adrenalectomized animal may die when exposed to traumas that are not fatal to normal animals. These hormones are the catecholamines, ep- androgen dehydroepiandrosterone, which is related chem- inephrine and norepinephrine, which have widespread ically to the male sex hormone testosterone. The molecu- effects on the cardiovascular system and muscular system lar structures of these hormones are shown in Figure 34. Many small arteries branch from the aorta and renal arteries and enter the cortex. These vessels give rise to capillaries that course radially through the cortex and ter- FUNCTIONAL ANATOMY OF THE minate in venous sinuses in the zona reticularis and adrenal ADRENAL GLAND medulla; therefore, the hormones produced by the cells of the cortex have ready access to the circulation. The human adrenal glands are paired, pyramid-shaped or- The cells of the adrenal cortex contain abundant lipid gans located on the upper poles of each kidney. This stored lipid is functionally significant be- renal gland is actually a composite of two separate en- cause cholesterol esters present in the droplets are an im- docrine organs, one inside the other, each secreting portant source of the cholesterol used as a precursor for the separate hormones and each regulated by different mech- synthesis of steroid hormones. The outer portion or cortex of the adrenal gland completely surrounds the inner portion or medulla and makes up most of the gland. During embryonic develop- The Adrenal Medulla Is a Modified ment, the cortex forms from mesoderm; the medulla arises Sympathetic Ganglion from neural ectoderm. The adrenal medulla can be considered a modified sympa- thetic ganglion. The medulla consists of clumps and strands The Adrenal Cortex Consists of of chromaffin cells interspersed with venous sinuses.
The proximal convoluted tubule reabsorbs about 70% of ter permeability alfuzosin 10mg visa, which is increased by arginine vaso- filtered Na discount 10 mg alfuzosin mastercard, K , and water and nearly all of the filtered pressin (AVP). Genetic defects in kidney epithelial cells account for sev- organic anions and organic cations. They normally maintain a stable internal environ- of protein metabolism in humans), uric acid (an end-prod- ment by excreting appropriate amounts of many sub- uct of purine metabolism), and creatinine (an end-product stances in the urine. This chapter considers 8) They are the major production sites of certain hor- the basic renal processes that determine the excretion of mones, including erythropoietin (see Chapter 11) and various substances. The kidneys perform a variety of important functions: 9) They degrade several polypeptide hormones, in- 1) They regulate the osmotic pressure (osmolality) of cluding insulin, glucagon, and parathyroid hormone. Dialy- sis and kidney transplantation are commonly used treat- Na and water excretion. Several physio- eases but is most often due to inflammation of the logical and psychological problems persist, however, in- glomeruli (glomerulonephritis) or urinary reflux and infec- cluding bone disease, disorders of nerve function, hyper- tions (pyelonephritis). Renal damage may occur over tension, atherosclerotic vascular disease, and many years and may be undetected until a considerable disturbances of sexual function. When GFR has declined to infection and, with hemodialysis, clotting and hemor- 5% of normal or less, the internal environment becomes so rhage. Dialysis does not maintain normal growth and de- disturbed that patients usually die within weeks or months velopment in children. Anemia (primarily a result of defi- if they are not dialyzed or provided with a functioning kid- cient erythropoietin production by damaged kidneys) was ney transplant. It may restore complete molecules through a selectively permeable membrane. In 1999, about 12,500 kidney trans- Two methods of dialysis are commonly used to treat pa- plant operations were performed in the United States. The powerful drugs used to inhibit graft rejec- urea) diffuse into the introduced solution, which is then tion compromise immune defensive mechanisms so that drained and discarded.