By Y. Mirzo. Saint John Fisher College. 2018.
This diagram indicates the tongue regions that are maximally sensitive to different tastes cheap torsemide 10 mg mastercard heart attack proove my heart radio cut. Trigeminal nerve Trigeminal ganglion Geniculate ganglion Lingual nerve Facial nerve Uvula Tongue Glossopharyngeal nerve Chorda tympani nerve Vagus nerve Laryngeal nerve FIGURE 15 generic torsemide 10 mg overnight delivery hypertension guideline update jnc 8. The chorda tympani nerve is the sensory branch of the facial nerve innervating the tongue. Branches from the paired vagus (tenth cranial) nerves and the trigeminal (fifth cranial) nerves also provide some sensory innervation. The hypoglossal (twelfth cranial) nerve (not shown) provides motor innervation to the tongue. The lingual nerve transmits general sensory information from the tongue (hot, cold, pressure, and pain). Sensory Organs © The McGraw−Hill Anatomy, Sixth Edition Coordination Companies, 2001 Chapter 15 Sensory Organs 499 The sensory pathway that relays taste sensations to the brain mainly involves two paired cranial nerves (fig. Taste sensations passing through the nerves just Principal Functions Principal Functions mentioned are conveyed through the medulla oblongata and thalamus to the parietal lobe of the cerebral cortex, where they Eyelid: protection Lens cap: protection are interpreted. Conjunctiva: protection Lens filter: protection Cornea and lens: focus incoming Lens system: focuses incoming light Because taste and smell are both chemoreceptors, they com- light waves waves plement each other. We often confuse a substance’s smell with its taste; and if we have a head cold or hold our nose while eat- Iris and pupil: regulate amount of Variable aperture system: regulates ing, food seems to lose its flavor. Distinguish between papillae, taste buds, and gustatory mi- Pigment epithelium: maintains Black interior of camera: maintains crovilli. Which cranial nerves have sensory innervation associated Retina: contains photosensitive Film: material coated on one side with taste? What are the sensory pathways to the brain cones and rods that respond to with photosensitive emulsion where the perception of taste occurs? Formation of the sensory components of the eye is com- sider, for example, the extremely keen eyesight of a hawk, which plete at 20 weeks, and the accessory structures have been soars high in the sky searching for food, or the eyesight of the owl, formed by 32 weeks. Predatory species, such as cats, Objective 11 Describe the accessory structures of the eye have eyes that are directed forward, allowing depth perception. Objective 13 Describe the neural pathway of a visual Accessory Structures of the Eye impulse and discuss the neural processing of visual information. Accessory structures of the eye either protect the eyeball or en- able eye movement. Protective structures include the bony orbit, eyebrow, facial muscles, eyelids, eyelashes, conjunctiva, The eyes are organs that refract (bend) and focus incoming light and the lacrimal apparatus that produces tears. Eyeball move- rays onto the sensitive photoreceptors at the back of each eye. The spe- cialized photoreceptor cells can respond to an incredible 1 bil- lion different stimuli each second. Further, these cells are Orbit sensitive to about 10 million gradations of light intensity and Each eyeball is positioned in a bony depression in the skull 7 million different shades of color. Seven bones of the The eyes are anteriorly positioned on the skull and set just skull (frontal,lacrimal,ethmoid,zygomatic,maxilla,sphenoid, far enough apart to achieve binocular (stereoscopic) vision when and palatine) form the walls of the orbit that support and pro- focusing on an object. Sensory Organs © The McGraw−Hill Anatomy, Sixth Edition Coordination Companies, 2001 500 Unit 5 Integration and Coordination FIGURE 15. Eyebrows the eyelids over the eye, and contraction of the levator palpebrae su- perioris muscle elevates the upper eyelid to expose the eye. Eyebrows consist of short, thick hairs positioned transversely The eyelids protect the eyeball from desiccation by reflex- above both eyes along the superior orbital ridges (figs. Eyebrows shade the eyes from the sun and prevent perspi- anterior surface of the eyeball. Reflexively blinking as a moving ration or falling particles from getting into the eyes. Underneath object approaches the eye is obviously of great protective value. Contraction of either of these muscles causes the eye- The palpebral fissure (fig. The shape of the palpebral fissure is el- liptical when the eyes are open. The medial commissure, which is broader than the lat- with attached skeletal muscle that make them movable.
At ﬁrst order torsemide 10mg amex blood pressure low symptoms, individu- drug dosage is gradually tapered during als may take illegal narcotics primarily for the withdrawal period proven 10mg torsemide blood pressure medication that starts with an l. Repeated admin- may be enrolled in a maintenance program istration rapidly produces tolerance and in which they do not undergo detoxiﬁca- intense physical dependence. Eventually, tion but rather receive maintenance dos- as the dosage and/or frequency of drug es of an opiate substitute along with administration increases, individuals need counseling. The goal of such programs is to continue to take the drug regularly to ﬁrst to help individuals return to a social- avoid symptoms of physical withdrawal. Drugs that are injected increase individuals’ risk of Stimulants contracting HIV infection or hepatitis C if needles are shared. Adding adulterants to Acting directly on the central nervous substances or using nonsterile techniques system, stimulants create an increased state of injection may also produce medical of arousal and concentration and speed up complications. Individuals may (inﬂammation of tissues), thrombophle- take stimulants for such effects as in- bitis (inﬂammation of a vein with associ- creased alertness and increased sense of ated clot formation), septicemia (presence well-being, increased conﬁdence, reduc- of toxins in the blood), and bacterial tion of fatigue, or decrease in appetite. They can be taken Withdrawal symptoms vary in severity orally, topically, intravenously, or by inhala- and duration, depending on the particu- tion. In addition to central nervous system 216 CHAPTER 7 CONDITIONS RELATED TO SUBSTANCE USE effects, stimulants have generalized sys- lasts only a matter of minutes, however, temic effects, including an increase in heart and is often followed by irritability, rest- rate, an increase in blood pressure, a rise in lessness, and depression. The aftereffects body temperature, and the constriction of of crack can be so intense that individuals peripheral blood vessels (Sarnyai, Shaham, continue to smoke it, despite obvious & Heinrichs, 2001). It Aside from its psychological, social, and may be taken orally, used intranasally vocational consequences, cocaine use can (snorted), smoked, or injected intraven- have serious medical consequences. The technique of free-basing basing or smoking crack can lead to pul- cocaine, which gained popularity in the monary complications. Chronic use of 1980s, involves heating a ﬂammable sol- intranasal cocaine may cause ulceration or vent such as petroleum or ether, and then perforation of the nasal septum. The process intoxication can produce neurologic effects, “frees” cocaine hydrochloride from its such as confusion, anxiety, hyperexcitabil- salts and adulterants, converting it to a ity, agitation, and violence. The effects are the result of acute cocaine toxi- free-base cocaine can be inhaled or city, which is dose related, in which indi- smoked, usually with a water pipe, for viduals can experience stroke or seizures, direct absorption through the alveoli in severe hyperthermia (increased body the lungs. The technique rapidly delivers temperature), arrhythmia (irregular heart- high concentrations of cocaine to the beat), myocardial infarction (heart brain and results in blood levels as high attack), and, in some instances, sudden as those for self-injection. Cocaine psychosis, another side The free-basing technique can cause effect of cocaine use, is manifested by additional disability caused by the burns paranoia, panic, hallucinations, insomnia, from ﬁres started during the free-basing and picking at the skin. The level of tolerance for cocaine episode can last from 24 to 36 hours. Dependence is produced proﬁt on its sale, may cause additional very rapidly. Its concentrated form and its route result from the nature of the substance of administration make its potency many used to cut the cocaine or from the dosage times greater than that of cocaine alone. Adulterants such as talc or corn- The euphoric effect produced by crack starch can cause complications ranging Use Disorders Involving Other Substances 217 from inﬂammation to embolus (undis- psychoactive responses to the drug depend solved matter in the blood). Often, users report a sense of time tain of cocaine’s potency, the effects are slowing and an impairment in their abil- not always predictable. The withdrawal ity to learn new facts while they are under syndrome from cocaine consists of a crav- the inﬂuence of the drug. Because it is not unusu- an increase in heart rate, dilation of the al for individuals who are cocaine depend- bronchioles, and dilation of the peripher- ent to also be dependent on other drugs, al blood vessels. Because of the stimulato- a withdrawal reaction from other sub- ry effect on the heart, cannabis use may stances may be experienced as well. Chronic smoking amphetamine is crystalline methampheta- of cannabis produces inflammatory mine (“ice”), which is highly addictive changes in the lungs that contribute to the physically and psychologically (Lukas, development of chronic conditions such 1997). The technique is similar to that more, the use of other drugs, including of smoking free-base cocaine. Ice has alcohol and tobacco, may compound greater strength and more enduring the adverse effects of cannabis. Greater ple, the combination of tobacco and stimulation to the brain makes it more cannabis use is thought to increase the risk dangerous mentally because it creates a of lung cancer. Toxic lev- orally, oral consumption can delay its els can produce severe paranoid thinking effects for up to an hour, and the effects with hallucinations.
The role of before–after studies of therapeutic impact in the evaluation of diagnostic technologies 10 mg torsemide blood pressure heart rate. Computerized cranial tomography: effect on diagnostic and therapeutic planns buy 20 mg torsemide overnight delivery blood pressure medication what does it do. Diagnostic impact of the erythrocyte sedimentation rate in general practice: a before–after analysis. Relation between sampling device and detection of abnormality in cervical smears: a meta-analysis of randomised and quasi-randomised studies. Carotid endarterectomy for asymptomatic carotid stenosis: a meta-analysis. Although the “gaussian” definition is traditionally common, the “therapeutic definition” of normal is the most clinically relevant. The four most relevant types of question are: q Phase I questions: Do patients with the target disorder have different test results from normal individuals? The answer requires a comparison of the distribution of test results among patients known to have the disease and people known not to have the disease. This can be studied in the same dataset that generated the Phase I answer, but now test characteristics such as sensitivity and specificity are estimated. To get the appropriate answer, a consecutive series of such patients should be studied. These questions have to be answered by randomising patients to undergo the test of interest or some other (or no) test. Introduction When making a diagnosis, clinicians seldom have access to reference or “gold” standard tests for the target disorders they suspect, and often wish to avoid the risks or costs of these reference standards, especially when they are invasive, painful, or dangerous. No wonder, then, that clinical researchers examine relationships between a wide range of more easily measured phenomena and final diagnoses. These phenomena include elements of the patient’s history, physical examination, images from all sorts of penetrating waves, and the levels of myriad constituents of body fluids and tissues. Alas, even the most promising phenomena, when nominated as diagnostic tests, almost never exhibit a one-to-one relationship with their respective target disorders, and several different diagnostic tests may compete for primacy in diagnosing the same target disorder. As a result, considerable effort has been expended at the interface between clinical medicine and scientific methods in an effort to maximise the validity and usefulness of diagnostic tests. This book describes the result of those efforts, and this chapter focuses on the specific sorts of questions posed in diagnostic research and the study architectures used to answer them. At the time that this book was being written, considerable interest was being directed to questions about the usefulness of the plasma concentration of B-type natriuretic peptide in diagnosing left ventricular dysfunction. Because real examples are far better than hypothetical ones in illustrating not just the overall strategies but also the down-to-earth tactics of clinical research, we will employ this one in the following paragraphs. To save space and tongue twisting we will refer to the diagnostic test, B-type natriuretic peptide, as BNP and the target disorder it is intended to diagnose, left ventricular dysfunction, as LVD. The starting point in evaluating this or any other promising diagnostic test is to decide how we will define its normal range. This chapter deals with the strategies (a lot) and tactics (a little) of research that attempts to distinguish patients who are “normal” from those who have a specific target disorder. Before we begin, however, we need to acknowledge that several different definitions of normal are used in clinical medicine, and we confuse them at our (and patients’) peril. Because the mean of a gaussian distribution plus or minus 2 standard deviations encloses 95% of its contents, it became a tempting way to define the normal several years ago, and came into general use. It is unfortunate that it did, for three logical consequences of its use have led to enormous confusion and the creation of a new field of medicine: the diagnosis of non-disease. First, diagnostic test results simply do not fit the gaussian distribution (actually, we should be grateful that they do not; the gaussian distribution extends to infinity in both directions, necessitating occasional patients with impossibly high BNP results and others on the minus side of zero! The third harmful consequence of the use of the gaussian definition of normal is shared by its more recent replacement, the percentile. Recognising the failure of diagnostic test results to fit a theoretical distribution such as the gaussian, some laboratorians have suggested that we ignore the shape of the distribution and simply refer (for example) to the lower (or upper) 95% of BNP or other test results as normal. Although this percentile definition does avoid the problems of infinite and negative test values, it still suggests 21 THE EVIDENCE BASE OF CLINICAL DIAGNOSIS that the underlying prevalence of all diseases is similar – about 5% – which is silly, and still contributes to the “upper-limit syndrome” of non-disease because its use means that the only “normal” patients are the ones who are not yet sufficiently worked up. This inevitable consequence arises as follows: if the normal range for a given diagnostic test is defined as including the lower 95% of its results, then the probability that a given patient will be called “normal” when subjected to this test is 95%, or 0.
Integumentary System © The McGraw−Hill Anatomy torsemide 10 mg without prescription heart attack is, Sixth Edition Companies torsemide 10 mg line blood pressure top number, 2001 124 Unit 4 Support and Movement FIGURE 5. A heterotransplant (xenograph—between two different species) can serve as a tempo- If extensive areas of the stratum basale of the epidermis are de- rary treatment to prevent infection and fluid loss. The process includes seeding the synthetic skin A skin graft is a segment of skin that has been excised with basal skin cells obtained from healthy locations on the from a donor site and transplanted to the recipient site, or graft bed. This treatment eliminates some of the problems of As stated in chapter 4, an autograft is the most successful type of skin grafting—for example, additional trauma, widespread tissue transplant. It involves taking a thin sheet of healthy epi- scarring, and rejection, as in the case of skin obtained from a dermis from a donor site of the burn or frostbite patient and cadaver. Integumentary System © The McGraw−Hill Anatomy, Sixth Edition Companies, 2001 Chapter 5 Integumentary System 125 (a) (b) (c) FIGURE 5. General body responses include a temporary elevation of wound does occur (fig. Integumentary System © The McGraw−Hill Anatomy, Sixth Edition Companies, 2001 126 Unit 4 Support and Movement FIGURE 5. The scab that forms from the clot and ingest dead cells and foreign debris. Mechanisms are activated area is repaired and the protective scab is sloughed off. These responses are collectively referred to as develop into scar tissue (fig. The collagenous fibers of inflammation and are characterized by redness, heat, edema, and scar tissue, are more dense than those of normal tissue, and pain. Inflammation is a response that confines the injury and scar tissue has no stratified squamous or epidermal layer. The closer the edges fibroblasts from connective tissue at the wound margins. To- of a wound, the less granulation tissue develops and the less gether with new branches from surrounding blood vessels, granu- obvious a scar. This is one reason for suturing a large break in lation tissue is formed. Integumentary System © The McGraw−Hill Anatomy, Sixth Edition Companies, 2001 Chapter 5 Integumentary System 127 FIGURE 5. Special ointments are applied to the cuts to retard healing and promote scar formation. Aging of the Skin As the skin ages, it becomes thin and dry, and begins to lose its elas- ticity. Collagenous fibers in the dermis become thicker and stiffer, and the amount of adipose tissue in the hypodermis diminishes, mak- ing it thinner. Skinfold measurements indicate that the diminution of the hypodermis begins at about the age of 45. With a loss of elas- ticity and a reduction in the thickness of the hypodermis, wrinkling, Clinical Case Study Answer or permanent infolding of the skin, becomes apparent (fig. The blistering and erythema characteristic of second-degree burns is a During the aging of the skin, the number of active hair fol- manifestation of intact and functioning blood vessels, which exist in licles, sweat glands, and sebaceous glands also declines. In third-degree burns, the entire quently, there is a marked thinning of scalp hair and hair on the dermis and its vasculature are destroyed, thus explaining the absence of extremities, reduced sweating, and decreased sebum production. In addition, nerve endings and other nerve end organs Because elderly people cannot perspire as freely as they once did, that reside in the dermis are destroyed in third-degree burns, resulting they are more likely to complain of heat and are at greater risk in a desensitized area. By contrast, significant numbers of these struc- tures are spared and functional in second-degree burns, thus preserving for heat exhaustion. The third-degree burn areas will all require because of the loss of insulating adipose tissue and diminished skin grafting in order to prevent infection, one of the skin’s most vital circulation. In second-degree burns, the spared dermis serves somewhat of skin to dry and crack frequently.
Depending on the number of processes order torsemide 10 mg with mastercard hypertension occurs when, we distinguish between unipolar 10mg torsemide amex hypertension in pregnancy, bipolar, or multipolar neurons. The Nerve Cell: Structure and Staining Patterns 19 2 6 1 5 4 E Impregnation of F Impregnation of 2 boutons (synapses) neurofibrils 7 3 3 8 B Nerve cell in the 3 brain stem 9 3 3 C Nerve cell in the anterior horn of the spinal cord 9 A Neuron, diagram D Pyramidal cell in the cerebral cortex 11 7 3 10 B–D Equivalent images of nerve cells: cellular stain (Nissl) and silver impregnation (Golgi) Kahle, Color Atlas of Human Anatomy, Vol. The availability of methods for studying the structure and function of cells, tissues, and The longest processes of nerve cells, the organs is often the limiting factor in ex- axons (which can be up to 1m long in panding our knowledge. Certain terms and humans), cannot be traced to their target interpretations can only be understood if area in histological sections. In order to the background of the method used is demonstrate the axonal projections of neu- known. Therefore, the methods commonly rons to different brain regions, axonal trans- used in neuroanatomy are presented here port (p. The Nissl Very long fiber connections can be visual- method has proven helpful because of excel- ized (C–E) by means of tracers (e. However, the different types of taining the cell bodies of the corresponding nerve cells are essentially characterized by population of neurons; the tracers are then their long processes, the dendrites and the taken up by the axon terminals or by the cell axon, which are not stained by the Nissl bodies of the projection neurons, respec- method. When using retrograde transport (C), these processes as possible, thick sections the tracer is injected into the assumed tar- (200µm) are required. By means of retrograde transport can be demonstrated in such thick sections. When it is now possible to stain individual nerve using anterograde transport (E), the tracer is cells by filling them with a dye using rec- injected into the region of the cell bodies of ordingelectrodes(A). Labeled axon terminals technique is that electrical signals can be will be visible in the assumed target zone if recorded from the neuron in question at the the labeled neurons indeed project to this same time. An important characteristic of nerve cells is their specific neurotransmitter or messenger substance by which communication with other nerve cells is achieved. By means of immunocytochemistry and the use of anti- bodies against the messenger substances themselves, or against neurotransmitter- synthesizing enzymes, it is possible to visual- ize nerve cells that produce a specific trans- mitter (B). Again, these immunocytochemi- cally stained nerve cells and their processes Kahle, Color Atlas of Human Anatomy, Vol. Methods in Neuroanatomy 21 C–E Visualization of projections by means of retrograde and an- terograde axonal transport of tracers C Retrograde transport A Visualization of a neuron by means of an intracellularly in- jected marker D Retrograde transport from differ- ent projection zones of a neuron E Anterograde transport to different projection zones of a neuron B Immunocytochemical visualization of a cholinergic neuron using an antibody against choline acetyltransferase Kahle, Color Atlas of Human Anatomy, Vol. The mitochondria are the site (A–C) of cellular respiration and, hence, of energy generation. Numerous enzymes are local- Electron micrographs show the cell nucleus ized in the inner membrane and in the (A–C1) to be enclosed by a double-layered matrix, among others the enzymes of the membrane(A2). Itcontainsthenuclearpores citric acid cycle and respiratory-chain (oxida- (BC3) that probably open only temporarily. The karyoplasm of the nucleus contains finely dispersed chromatin granules, which The Golgi complex consists of a number of consist of DNA and proteins. The nucleolus dictyosomes (A–C14), which are stacks of (A–C4), a spongiform area of the nucleus flattened, noncommunicating cisternae. The forming side receives transport vesicles from the endoplasmic reticulum. At the In the cytoplasm, the Nissl bodies appear as margins of the maturing side, Golgi vesicles roughendoplasmicreticulum (A–C5), a lamel- are formed by budding. The Golgi complex lar system of membranes that enclose flat- is mainly involved in the modification (e. To maintain the long axon The numerous lysosomes (A–C17) contain (up to 1m long), it is essential that the cell various enzymes (e. The rough endoplasmic reticulum communicates with the perinuclear space (BC9) and with the marginal cisternae (A10) below the cell sur- face. Marginal cisternae are often found at sites where boutons or glial cell processes are attached. The cytoplasm is crossed by neurofilaments and neurotubules (A–C11) that are arranged into long parallel bundles inside the axon.