By T. Gnar. Clark Atlanta University. 2018.
Osler published his celebrated Principles and Practice of Medicine in 1892 vasodilan 20 mg fast delivery blood pressure 8560, one year before Charcot’s death buy vasodilan 20mg line blood pressure pulse. As an internist always resistant to the concept of medical specialization, Osler was inﬂuential in propogating information to generalists on many neurological conditions, including Parkinson’s disease. Osler was less forthcoming than Charcot in appreciating the distinction between bradykinesia and weakness, and he sided with Parkinson in maintaining that mental function was unaltered. Osler was particularly interested in pathological studies and alluded to the concept of Parkinson’s disease as a state of accelerated aging (22). Brissaud was a close associate of Charcot and contributed several important clinical observations on Parkinson’s disease in the late nineteenth century. Most importantly, however, he brought neuropathological attention to the substantia nigra as the potential cite of disease origin. In discussing a case of a tuberculoma that destroyed the substantia nigra and in association with contralateral hemiparkinsonism, he considered the currently vague knowledge of the nucleus and its putative involvement in volitional and reﬂex motor control. Extending his thoughts, he hypothesized that ‘‘a lesion of the locus niger could reasonably be the anatomic basis of Parkinson’s disease’’ (23). Horowski R, Horowski L, Vogel S, Poewe W, Kielhorn F-W. An essay on Wilhelm von Humboldt and the shaking palsy. London: Whittingham and Rowland for Sherwood, Neeley and Jones, 1817. London: Whittingham and Rowland for Sherwood, Neeley and Jones, 1804–1811. Annotated reprinting: essay on the shaking palsy by James Parkinson. Oeuvres Completes` 1:161– 188, Paris, Bureaux du ProgresM` e´dical, 1869. Lectures on the Diseases of the Nervous System, 105–107, translated by G. Historical art and document collection, Christopher G. Oeuvres Completes` 9:215–228, Paris, Bureaux du ProgresM` e´dical, 1888. Clinical Lectures on Diseases of the Nervous System, 208–221, translated by E. Nouvelle Iconographie de la Salpeˆtriere` 1898; 11:489–516. Philadelphia College of Physicians, Original manuscript and document collection. Nature et pathogenie de´ la maladie de Parkinson (lec¸on 23, 488– 501). Lec¸ons sur les Maladies Nerveuses: la Salpeˆtriere,` 1893–1894. Rajput, Alex Rajput, and Michele Rajput University of Saskatchewan, Saskatoon, Saskatchewan, Canada Epidemiology is the study of large numbers of individuals to ascertain incidence, life expectancy, prevalence, time trends, preceding and associated illnesses, and other factors in a disease. Contrasted to laboratory studies in which the experimental conditions can be controlled, epidemiology examines natural events that may have been inﬂuenced by health care, economic, and social factors. Epidemiology is broadly divided into four categories—descriptive, analytic, clinical, and experimental—although there is considerable overlap (1). Descriptive epidemiology deals with incidence, age and sex distribu- tion, life expectancy, and prevalence rates. Analytic epidemiology is aimed at identifying factors that are positively or negatively associated with the illness and hence may be causally linked. Because the events that signiﬁcantly inﬂuence the epidemiology of a disease cannot be controlled, it is important that any bias that may confound the observations be identiﬁed and avoided or adjusted for.
However purchase vasodilan 20 mg mastercard hypertension 10, the anatomy can only provide information in the widest sense in that its limits are only the maximum possibilities and the physiological realities are likely to be only a subset of the anatomical possibilities (31) cheap vasodilan 20mg with mastercard hypertension renal failure. Further, as the complexities of anatomical organization and interconnections increase, it will become increasingly difﬁcult to predict function from the structure. This is particularly true if, as is likely, the interactions are highly nonlinear. Any new model would require as its basis the same anatomical facts that underlie the current anatomical model. However, as will be seen, there may be emergent properties of the new dynamical models that are not intuitive from the current anatomical model and, therefore, represent such a quantitative change as to be qualitatively different. Hierarchical Processing The macro-neuron approach leads to structures that are then linked with a very speciﬁc directional aspect, for example, the cortex projects to Pt, which in turn projects to GPi, which projects to the VL thalamus. Consequently, the presumption has been that information is processed within the cortex, which is relayed to Pt for processing. When completed, the information is then relayed to GPi and so on. This has led to attempts to identify speciﬁc functions unique to each structure and to demonstrate timing differences of changes in neuronal activities associated with behavior. For example, experiments attempted to demonstrate that the GPi or Pt nucleus became active before the MC. The results of these experiments were either inconclusive or failed to demonstrate the anticipated timing differences (8,32–34). The anatomically derived hierarchical conceptual approach fails to distinguish anatomical proximity form physiological proximity. The presumption is that neurons in close proximity to each other (such as being within the same nuclei or restricted region of cortex) interact to carry out speciﬁc physiological functions. However, it is quite possible, indeed probable in the case of the basal ganglia, that neurons in different and separate structures are more directly linked physiologically than adjacent neurons in the same structure. For example, the majority of neuronal recording studies of simultaneously recorded putamen neurons in close proximity are not cross-correlated, demonstrating very little if any physiological interactions. Yet, there is a very precise and robust physiological interaction between cortex and Pt neurons. Physiologically, it may make better sense to consider neurons tightly linked in the cortical- basal ganglia-thalamic circuit as being the more fundamental physiological working unit, rather than any of the separate nuclei or cortical structures. The degree of independence between these circuits has been discussed at length (35–37). Evidence for separate basal ganglia-thalamic-cortical loops comes from anatomical studies. Studies using viruses to trace anatomical projections across synapses suggest that there is little or no anatomical overlap between those circuits serving cognitive, limbic, or motor functions (36). However, these studies were not done at the levels of resolution of neuronal populations related to individual extremities or muscles. Recent functional magnetic resonance imaging (fMRI) studies have suggested overlap in areas of the Pt representing the face, ﬁngers, and toes (38). Electrophysiological studies can estimate the degree that electrical activities in individual neurons are coupled using cross-correlation techniques. Little evidence of coupling is found for pallidal neurons, although more couplings have been found for tonically acting striatal neurons, which are probably cholinergic interneurons (35). An alternative to the anatomically based hierarchical conceptual approach posits that physiological function, such as responding to a go signal, initiating a movement, or completing a movement, is represented in separate basal ganglia-thalamic-cortical circuits. Processing within the circuit is virtually simultaneous within the components of the circuit. There is a hierarchical structure, but it is in physiological terms not anatomical. Thus, during behaviors such as making a movement to a target in response to a go signal, the basal ganglia-thalamic-cortical circuit related to responding to the go signal is hierarchical to the basal ganglia-thalamic- cortical circuit that is associated with movement initiation. This, in turn, is hierarchical to the circuit whose activity changes are preferentially related to reaching the target. This hierarchical organization of function is paralleled by differences in the timing of activity changes in these circuits.
Epinephrine—treatment of asthma generic vasodilan 20mg without prescription hypertension labs, anaphylaxis order 20 mg vasodilan blood pressure medication causing heart palpitations, shock thyroiditis E. Parathyroid glands—secrete parathyroid hormone (PTH), G. Androgens—promote healing which increases blood calcium levels H. Estrogen and progesterone—contraception, symptoms of D. Epinephrine and norepinephrine—act as neurotrans- V. Body’s response to stress involves nervous and endocrine 2. Hormones of adrenal cortex (outer region) systems, hormones a. Glucocorticoids—released during stress to raise nu- B. Fight-or-flight response mediated by brain: hypothalamus, trients in blood; e. Hormones help body, meet stressful situations; can be balance; e. Unmanaged stress can be harmful; stress management E. Pancreas—islet cells of pancreas secrete hormones techniques help maintain overall health 1. Lack or poor cellular response causes diabetes melli- A. Aging-associated changes linked with endocrine system tus changes—loss of muscle and bone tissue (1) Type I—requires insulin B. Main clinical conditions associated with endocrine system (2) Type II—may be controlled with diet and exer- involve pancreas, thyroid cise 1. Adult-onset diabetics mellitus (3) Gestational—occurs curing pregnancy 2. Sex glands—needed for reproduction and development of menopause—only common treatment for age-associated secondary sex characteristics endocrine failure 260 CHAPTER TWELVE Questions for Study and Review Building Understanding Fill in the blanks 1. Chemical messengers carried by the blood are called 4. Local hormones active in promoting inflammation are 2. The part of the brain that regulates endocrine activity . Red blood cell production in the bone marrow is stim- ulated by . Matching Match each numbered item with the most closely related lettered item. A disorder caused by overproduction of growth hormone in the adult. A disorder caused by underproduction of parathyroid hormone. A disorder caused by underproduction of thyroid hormone. A disorder caused by overproduction of growth hormone in the child. A disorder caused by underproduction of antidiuretic hormone. A target tissue responds to a hormone only if it the hormones released from each division and describe has the appropriate the effects of each. Uterine contractions and milk ejection are promoted by d. Name the hormone released by the thymus gland; by 14.
In the capillaries of various tissues (particularly adipose tissue purchase vasodilan 20 mg fast delivery prehypertension meaning in hindi, muscle trusted 20 mg vasodilan 4, and the lactating mammary gland), lipoprotein lipase (LPL) digests the triacylglyc- erols of VLDL, forming fatty acids and glycerol (Fig. The glycerol travels to the liver and other tissues where it is used. Some of the fatty acids are oxidized by muscle and other tissues. After a meal, however, most of the fatty acids are con- verted to triacylglycerols in adipose cells, where they are stored. These fatty acids are released during fasting and serve as the predominant fuel for the body. Glycerophospholipids are also synthesized from fatty acyl CoA, which forms esters with glycerol 3-phosphate, producing phosphatidic acid. Various head groups H H are added to carbon 3 of the glycerol 3-phosphate moiety of phosphatidic acid, gen- erating amphipathic compounds such as phosphatidylcholine, phosphatidylinositol, O C C Hydrocarbon tail and cardiolipin (Fig. In the formation of plasmalogens and platelet-activat- O ing factor (PAF), a long-chain fatty alcohol forms an ether with carbon 1, replac- O C Fatty acid ing the fatty acyl ester (Fig. Cleavage of phospholipids is catalyzed by phos- O pholipases found in cell membranes, lysosomes, and pancreatic juice. O P O Head group Sphingolipids, which are prevalent in membranes and the myelin sheath of the central nervous system, are built on serine rather than glycerol. In the synthesis of O– sphingolipids, serine and palmityl CoA condense, forming a compound that is Fig. Reduction of this compound, followed by addition of a Carbon 1 of glycerol is joined to a long-chain second fatty acid in amide linkage, produces ceramide. Carbohydrate groups fatty alcohol by an ether linkage. The fatty attach to ceramide, forming glycolipids such as the cerebrosides, globosides, and alcohol group has a double bond between car- gangliosides (Fig. The addition of phosphocholine to ceramide produces bons 1 and 2. These sphingolipids are degraded by lysosomal enzymes. By the time of discharge, he had gained back 8 of the 22 lb he had lost and weighed 133 lb. Veere developed a craving for “sweet foods” O such as the candy he bought and shared with his new friend. After 6 months of this H N C Fatty acid high-carbohydrate courtship, Percy had gained another 22 lb and now weighed 155 lb, just 8 lb more than he weighed when his depression began. He became con- cerned about the possibility that he would soon be overweight and consulted his die- O Carbohydrate titian, explaining that he had faithfully followed his low-fat diet but had “gone over- board” with carbohydrates. He asked whether it was possible to become fat without Glycolipid eating fat. General structures of the sphin- Cora Nari’s hypertension and heart failure have been well controlled on golipids. Ceramide is sphingosine with a medication, and she has lost 10 lb since she had her recent heart attack. Her fatty acid joined to its amino group by an fasting serum lipid profile on discharge from the hospital indicated signif- amide linkage. Sphingomyelin contains phos- icantly elevated serum low-density lipoprotein (LDL) cholesterol level of 175 phocholine, whereas glycolipids contain car- mg/dL (recommended level for a patient with known coronary artery disease = 100 bohydrate groups. While still in the hospital, she was asked The dietician did a careful analysis of Percy Veere’s diet, which was to obtain the most recent serum lipid profiles of her older brother and her younger indeed low in fat, adequate in pro- sister, both of whom were experiencing chest pain. Her brother’s profile showed tein, but excessive in carbohydrates, espe- normal triacylglycerols, moderately elevated LDL cholesterol, and significantly cially in refined sugars. Percy’s total caloric suppressed HDL cholesterol levels. Her sister’s profile showed only hypertriglyc- intake averaged about 430 kilocalories (kcal) eridemia (high blood triacylglycerols). This excess carbohydrate was being Colleen Lakker was born 6 weeks prematurely. She appeared normal until converted to fats, accounting for Percy’s about 30 minutes after delivery, when her respirations became rapid at 64 weight gain. A new diet with a total caloric breaths/minute with audible respiratory grunting.
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