By L. Fedor. Southern Virginia University. 2018.
Both elastin and collagen are produced by smooth muscle cells buy confido 60 caps lowest price, which are the only cell type within the tunica media quality 60 caps confido. Tunica adventitia tunica media Tunica intima #16 Aorta order confido 60caps on-line, Rhesus monkey purchase confido 60caps with mastercard, Cross Section #20 Aorta, Cross Section (Elastin Stain) In slides #16 and #20 the blood vessels supply the aorta, the vasa vasorum, should be identified in the tunica adventitia. The major component of the wall of the artery is spirally arranged smooth muscle (therefore seen here in longitudinal section). Note that the nuclei are elongated and that due to contraction of the vessel wall, some of them appear corkscrew shaped. The nuclei are relatively euchromatic (as compared to those of fibroblasts in the adventitia of the vessel). The smooth muscle cells, in addition to contracting to control the diameter of the vessel, also produce collagen and elastic fiber components of the muscular part of the vessel wall. This laboratory exercise serves both as an introduction to the skin, the largest organ of the body, and as a review of the major tissues. As you study the slides of the skin, identify examples of epithelium, connective tissue, muscle and nerve. All skin is made up of three layers: Epidermis- stratified squamous keratinizing epithelium Dermis – a superficial papilllary layer of loose connective tissue, underlain by a reticular layer of dense fibrous irregularly arranged connective tissue Hypodermis – deepest layer of skin, also called subcutaneous tissue, made up of loose connective tissue and adipose tissue #4 Skin, thick skin, volar surface H&E Epidermis: The stratified squamous keratinizing epithelium of the epidermis is made up primarily of keratinocytes. The layers of the epidermis from basement membrane to skin surface include: Stratum basale: Cells of all the layers are generated from the keratinocytes in this layer. The keratinocytes in this and the overlying layers contain melanin granules that have been transferred to them by melanocytes. Because the cells pull apart during preparation, the attachment sites give the cells a spiny appearance. Stratum granulosum: The cells of this layer are recognizable by their basophilic keratohyalin granules containing filaggrin and other proteins binding tonofibrils. Stratum corneum: The superficial keratinized layer is the stratum corneum, which protects the skin against friction, infection, and water loss. They are coiled tubular glands with an acidophilic margin, which corresponds to the layer of myoepithelium. The ducts are straight as they lead through the superficial dermis to the basal aspect of the epidermis. The thin epidermis, characteristic of hairy regions, has a lacy or frayed stratum corneum whose appearance is an artifact of sectioning. In life, this layer of the epidermis would be more compact and only the most superficial keratinized cells would be desquamating. The deepest part of the hair follicle is expanded into a bulb and is invaginated by connective tissue, the dermal papilla. The follicle cells adjacent to the papilla are the germinative cells, which divide and differentiate to form the hair shaft and a multi-layered inner root sheath. Melanocytes are adjacent to the dermal papilla and contribute melanin granules to the developing hair. Sebaceous glands are associated with the hair follicle and their secretions empty into the hair follicle, between the hair shaft and the follicle wall. The arrector pili muscle is a band of Hair follicle 53 smooth muscle that inserts on the hair follicle, deep to the sebaceous glands. Recognize major parts of the respiratory track: trachea, bronchi, bronchioles, terminal bronchioles, respiratory bronchioles, alveolar duct, and alveoli. The respiratory system functions in the exchange of gases between the external and internal environments. Some regions of the respiratory system are specialized for conduction of gases and other areas function primarily in the exchange of gases. The function of each part of the respiratory system is reflected in the structure of its wall: the type of epithelium and its apical modifications, intraepithelial and subepithelial glands, cartilaginous rings and plates, smooth muscle and elastic tissue, and the relationship of capillary endothelium to alveolar epithelium. Left to right: bronchiole branching into terminal bronchiole transitioning to respiratory bronchiole with alveoli #118 Lung, (H&E) This lung slide is useful for examining larger portions of the respiratory tree and the vascular system. Note the close contact of the smallest capillaries (one red blood cell in diameter) and the simple squamous epithelium lining the alveolus.
An artery is a blood vessel that carries blood away from the heart generic 60 caps confido with amex, where it branches into ever-smaller vessels cheap 60caps confido amex. Eventually best confido 60caps, the smallest arteries generic confido 60caps on-line, vessels called arterioles, further branch into tiny capillaries, where nutrients and wastes are exchanged, and then combine with other vessels that exit capillaries to form venules, small blood vessels that carry blood to a vein, a larger blood vessel that returns blood to the heart. Arteries and veins transport blood in two distinct circuits: the systemic circuit and the pulmonary circuit (Figure 20. The blood returned to the heart through systemic veins has less oxygen, since much of the oxygen carried by the arteries has been delivered to the cells. In contrast, in the pulmonary circuit, arteries carry blood low in oxygen exclusively to the lungs for gas exchange. Pulmonary veins then return freshly oxygenated blood from the lungs to the heart to be pumped back out into systemic circulation. The systemic circuit moves blood from the left side of the heart to the head and body and returns it to the right side of the heart to repeat the cycle. The arrows indicate the direction of blood flow, and the colors show the relative levels of oxygen concentration. Shared Structures Different types of blood vessels vary slightly in their structures, but they share the same general features. Arteries and arterioles have thicker walls than veins and venules because they are closer to the heart and receive blood that is surging at a far greater pressure (Figure 20. Arteries have smaller lumens than veins, a characteristic that helps to maintain the pressure of blood moving through the system. Together, their thicker walls and smaller diameters give arterial lumens a more rounded appearance in cross section than the lumens of veins. In other words, in comparison to arteries, venules and veins withstand a much lower pressure from the blood that flows through them. Their walls are considerably thinner and their lumens are correspondingly larger in diameter, allowing more blood to flow with less vessel resistance. In addition, many veins of the body, particularly those of the limbs, contain valves that assist the unidirectional flow of blood toward the heart. This is critical because blood flow becomes sluggish in the extremities, as a result of the lower pressure and the effects of gravity. The walls of arteries and veins are largely composed of living cells and their products (including collagenous and elastic fibers); the cells require nourishment and produce waste. Since blood passes through the larger vessels relatively quickly, there is limited opportunity for blood in the lumen of the vessel to provide nourishment to or remove waste from the vessel’s cells. Further, the walls of the larger vessels are too thick for nutrients to diffuse through to all of the cells. Larger arteries and veins contain small blood vessels within their walls known as the vasa vasorum—literally “vessels of the vessel”—to provide them with this critical exchange. Since the pressure within arteries is relatively high, the vasa vasorum must function in the outer layers of the vessel (see Figure 20. The lower pressure within veins allows the vasa vasorum This OpenStax book is available for free at http://cnx. The restriction of the vasa vasorum to the outer layers of arteries is thought to be one reason that arterial diseases are more common than venous diseases, since its location makes it more difficult to nourish the cells of the arteries and remove waste products. There are also minute nerves within the walls of both types of vessels that control the contraction and dilation of smooth muscle. Both arteries and veins have the same three distinct tissue layers, called tunics (from the Latin term tunica), for the garments first worn by ancient Romans; the term tunic is also used for some modern garments. From the most interior layer to the outer, these tunics are the tunica intima, the tunica media, and the tunica externa (see Figure 20. Comparison of Tunics in Arteries and Veins Arteries Veins General Thick walls with small lumens Thin walls with large lumens appearance Generally appear rounded Generally appear flattened Endothelium usually appears wavy due to constriction of Endothelium appears smooth Tunica intima smooth muscle Internal elastic membrane Internal elastic membrane present in larger vessels absent Normally thinner than the tunica externa Smooth muscle cells and Normally the thickest layer in arteries collagenous fibers Smooth muscle cells and elastic fibers predominate (the Tunica media predominate proportions of these vary with distance from the heart) Nervi vasorum and vasa External elastic membrane present in larger vessels vasorum present External elastic membrane absent Normally the thickest layer in veins Normally thinner than the tunica media in all but the largest Collagenous and smooth arteries Tunica externa fibers predominate Collagenous and elastic fibers Some smooth muscle fibers Nervi vasorum and vasa vasorum present Nervi vasorum and vasa vasorum present Table 20. Lining the tunica intima is the specialized simple squamous epithelium called the endothelium, which is continuous throughout the entire vascular system, including the lining of the chambers of the heart. Damage to this endothelial lining and exposure of blood to the collagenous fibers beneath is one of the primary causes of clot formation. Until recently, the endothelium was viewed simply as the boundary between the blood in the lumen and the walls of the vessels. Recent studies, however, have shown that it is physiologically critical to such activities as helping to regulate capillary exchange and altering blood flow.
If you think 25 buy discount confido 60 caps online,000 genes is a lot molecular targets from several hundred to several (the number of genes in the human genome) buy confido 60caps on line, realize thousand discount confido 60caps without a prescription. Many of these new avenues of research that each gene can give rise to different variations hinge on biology buy generic confido 60 caps. Scientists estimate that humans have hundreds stepping onto center stage in 21st-century science of thousands of protein variants. Clearly, there’s lots include genomics (the study of all of an organism’s of work to be done, which will undoubtedly keep genetic material), proteomics (the study of all researchers busy for years to come. The “omics” revolution in A Chink in Cancer’s Armor Recently, researchers made an exciting step forward of so-called molecular targeting: understanding how in the treatment of cancer. Years of basic research diseases arise at the level of cells, then ﬁguring out investigating circuits of cellular communication led ways to treat them. The Food and Drug Administration described Gleevec’s approval as “…a testament to the groundbreaking scientiﬁc research taking place Doctors use the drug in labs throughout America. Each of these methods Finding new medicines and cost-effective ways to bypasses the intestinal tract and can increase the manufacture them is only half the battle. An enor amount of drug getting to the desired site of mous challenge for pharmacologists is ﬁguring out action in the body. Slow, steady drug delivery how to get drugs to the right place, a task known directly to the bloodstream—without stopping as drug delivery. Unfortunately, this rarely happens with the typical Hormones such as testosterone, progesterone, methods of delivering drugs: swallowing and and estrogen are available as skin patches. When swallowed, many medicines made forms of medicines enter the blood via a mesh of protein are never absorbed into the blood work of small arteries, veins, and capillaries in the stream because they are quickly chewed up by skin. Some of these If the drug does get to the blood from the intes include Duragesic® (a prescription-only pain tines, it falls prey to liver enzymes. For doctors medicine), Transderm Scop® (a motion-sickness prescribing such drugs, this ﬁrst-pass effect (see drug), and Transderm Nitro® (a blood vessel- page 7) means that several doses of an oral drug widening drug used to treat chest pain associated are needed before enough makes it to the blood. Despite their advantages, Drug injections also cause problems, because they however, skin patches have a signiﬁcant drawback. Both methods of administration also result in Inhaling drugs through the nose or mouth is ﬂuctuating levels of the drug in the blood, which another way to rapidly deliver drugs and bypass is inefﬁcient and can be dangerous. Pharmacologists can work around therapy for years, and doctors prescribe nasal the ﬁrst-pass effect by delivering medicines via the steroid drugs for allergy and sinus problems. If can be inhaled by people with diabetes who rely clinical trials with inhaled insulin prove that it is on insulin to control their blood sugar daily. This safe and effective, then this therapy could make still-experimental technology stems from novel life much easier for people with diabetes. Cobb of the University of Texas the proteins a code, instructing the cell to do some Southwestern Medical Center at Dallas are studying thing, such as divide or grow. Medicines By Design I Molecules to Medicines 43 by learning how to hijack molecular transporters to shuttle drugs into cells. Gordon Amidon, a pharmaceutical chemist at the University of Michigan-Ann Arbor, has been studying one particular transporter in mucosal membranes lining the digestive tract. The challenge is a chemistry wants to extend this list by synthesizing hundreds problem—most drugs are water-soluble, but of different molecules and testing them for their membranes are oily. Membranes are genomics, and bioinformatics have sped the search usually constructed to permit the entry of only for molecules that Amidon and other researchers small nutrients and hormones, often through can test. Many pharmacologists are working hard to devise ways to work not against, but with nature, 44 National Institute of General Medical Sciences Scientists are also trying to slip molecules Act Like a Membrane through membranes by cloaking them in disguise. Researchers know that high concentrations of Steven Regen of Lehigh University in Bethlehem, chemotherapy drugs will kill every single cancer Pennsylvania, has manufactured miniature cell growing in a lab dish, but getting enough of chemical umbrellas that close around and shield these powerful drugs to a tumor in the body with a molecule when it encounters a fatty membrane out killing too many healthy cells along the way and then spread open in the watery environment has been exceedingly difﬁcult. So far, Regen has only used test mole drugs can do more harm than good by severely cules, not actual drugs, but he has succeeded in sickening a patient during treatment. The ability to do this particles called liposomes to package and deliver in humans could be a crucial step in successfully drugs to tumors. Liposomes are oily, microscopic delivering therapeutic molecules to cells via capsules that can be ﬁlled with biological cargo, gene therapy.
Monthly graphs and ﬁgures detailing all outcomes and trends should be disseminated to everyone purchase 60caps confido free shipping, particularly to key individuals empowered to inﬂuence change cheap confido 60 caps visa. However generic confido 60 caps with visa, formal day surgery training programmes for anaesthetic (and surgical) trainees are rare confido 60 caps free shipping. It is essential to design a well-structured module that provides training in anaesthesia for all aspects of day surgery and exposure to the organisational challenges of running a day surgery unit. To facilitate this, it is recommended that advanced training should take place in a dedicated day surgery unit, yet few such units exist. It is important to remember that high quality day surgery requires the experience of senior anaesthetists (and surgeons) and that although the day surgery unit is an ideal environment for training junior medical staff, relying on them to deliver the service results in poorer quality patient outcomes and reduced efﬁciency [51, 52]. A list of topics that might be included in a day surgery module is shown in Appendix 5. The day surgery unit is an excellent environment for surgical and nursing training and many of the aspects covered above are equally applicable to surgical and nursing colleagues. Day surgery in special environments A number of complex and highly specialist procedures are beginning to enter the day surgery arena. In the interventional X-ray suite, uterine artery embolisation is a day case procedure, whereas endovascular aneurysm stents and several other procedures are appropriate for a short stay approach. Optimal care for these procedures should be developed by those with expertise in day and short stay surgery, working in collaboration with specialists in the management of the speciﬁc procedure. Many of these procedures are undertaken in challenging environments, such as X-ray departments. Introducing new procedures to day surgery The successful introduction of new procedures to day surgery depends on many factors, including the procedure itself and surgical, nursing and anaesthetic colleagues. It is important to evaluate the procedure while still performing it as an overnight stay and identify any steps in the process that require modiﬁcation to enable it to be performed as a day case, e. A multidis- ciplinary visit to another unit where the procedure is performed successfully as a day case can be very helpful. Initially limiting the procedure to a few colleagues (surgeons and anaesthetists) allows an opportunity to evaluate and optimise techniques and to implement step changes so that the patient can be discharged safely and with good analgesia. Once the procedure has been successfully moved to the Ó 2011 The Authors Anaesthesia Ó 2011 The Association of Anaesthetists of Great Britain and Ireland 15 Guidelines: Day case and short stay surgery. Clear clinical protocols help to ensure that all the lessons learned during the evaluation phase are clearly passed on to colleagues. Currently, there is no set absolute minimum distance between any stand-alone unit and the nearest acute or associated hospital, although large distances are uncommon. The commissioning of any new isolated stand-alone unit requires analysis of its suitability for the provision of intended services. These facilities may or may not be purpose-built and the Clinical Lead must be aware of this in managing any risk. Remoteness is a factor to be considered in the delivery of a safe and efﬁcient service. On-call commitments must be taken into account so as to avoid accidents and fatigue either in theatre or when travelling. This list is not meant to be exhaustive but gives guidance to some of the important areas that require consideration. Short stay surgery and enhanced recovery New approaches to the assessment and management of patients undergoing more complex surgery are being used to improve the quality of recovery, reduce the incidence of postoperative complications and reduce lengths of stay. Many of these techniques are based on the wider application of well- established day surgery principles and are aimed at improving the quality of recovery so that the patient is well enough to go home sooner. These strategies are variously called enhanced recovery, fast-track, accelerated or rapid recovery. Increasing numbers of hospitals are focusing on the short stay pathway and plan to manage the majority of their elective patients with stays of fewer than 72 h. To achieve the maximum beneﬁt from this, hospitals are developing 24-h stay facilities (some as part of their existing day units) and are embracing these principles. Principles of enhanced recovery Enhanced recovery is the outcome of applying a range of multimodal strategies that are designed to prepare and optimise patients before, during and after surgery, ensuring prompt recovery and discharge.
Internal Structure of the Heart Recall that the heart’s contraction cycle follows a dual pattern of circulation—the pulmonary and systemic circuits—because of the pairs of chambers that pump blood into the circulation generic 60caps confido overnight delivery. In order to develop a more precise understanding of cardiac function buy confido 60 caps on-line, it is first necessary to explore the internal anatomical structures in more detail buy discount confido 60caps on-line. Septa of the Heart The word septum is derived from the Latin for “something that encloses buy discount confido 60caps online;” in this case, a septum (plural = septa) refers to a wall or partition that divides the heart into chambers. Normally in an adult heart, the interatrial septum bears an oval-shaped depression known as the fossa ovalis, a remnant of an opening in the fetal heart known as the foramen ovale. The foramen ovale allowed blood in the fetal heart to pass directly from the right atrium to the left atrium, allowing some blood to bypass the pulmonary circuit. Within seconds after birth, a flap of tissue known as the septum primum that previously acted as a valve closes the foramen ovale and establishes the typical cardiac circulation pattern. Unlike the interatrial septum, the interventricular septum is normally intact after its formation during fetal development. It is substantially thicker than the interatrial septum, since the ventricles generate far greater pressure when they contract. It is marked by the presence of four openings that allow blood to move from the atria into the ventricles and from the ventricles into the pulmonary trunk and aorta. Located in each of these openings between the atria and ventricles is a valve, a specialized structure that ensures one-way flow of blood. The valves at the openings that lead to the pulmonary trunk and aorta are known generically as semilunar valves. In this figure, the atrioventricular septum has been removed to better show the bicupid and tricuspid valves; the interatrial septum is not visible, since its location is covered by the aorta and pulmonary trunk. Since these openings and valves structurally weaken the atrioventricular septum, the remaining tissue is heavily reinforced with dense connective tissue called the cardiac skeleton, or skeleton of the heart. It includes four rings that surround the openings between the atria and ventricles, and the openings to the pulmonary trunk and aorta, and serve as the point of attachment for the heart valves. The presence of the pulmonary trunk and aorta covers the interatrial septum, and the atrioventricular septum is cut away to show the atrioventricular valves. As much as 20–25 percent of the general population may have a patent foramen ovale, but fortunately, most have the benign, asymptomatic version. Patent foramen ovale is normally detected by auscultation of a heart murmur (an abnormal heart sound) and confirmed by imaging with an echocardiogram. Despite its prevalence in the general population, the causes of patent ovale are unknown, and there are no known risk factors. In nonlife-threatening cases, it is better to monitor the condition than to risk heart surgery to repair and seal the opening. Coarctation of the aorta is a congenital abnormal narrowing of the aorta that is normally located at the insertion of the ligamentum arteriosum, the remnant of the fetal shunt called the ductus arteriosus. If severe, this condition drastically restricts blood flow through the primary systemic artery, which is life threatening. Detectable symptoms in an infant include difficulty breathing, poor appetite, trouble feeding, or failure to thrive. In older individuals, symptoms include dizziness, fainting, shortness of breath, chest pain, fatigue, headache, and nosebleeds. Treatment involves surgery to resect (remove) the affected region or angioplasty to open the abnormally narrow passageway. Failure of the ductus arteriosus to close results in blood flowing from the higher pressure aorta into the lower pressure pulmonary trunk. This additional fluid moving toward the lungs increases pulmonary pressure and makes respiration difficult. Symptoms include shortness of breath (dyspnea), tachycardia, enlarged heart, a widened pulse pressure, and poor weight gain in infants.