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By W. Bengerd. Northwest College of Art.

If the reduction of the fracture is less than anatomical but otherwise satisfactory addition of free fibular graft can improve the chances of union buy viagra sublingual 100 mg with amex. If the patient is suffering from a generalized disease like diabetes mellitus purchase online viagra sublingual, congestive heart failure generic viagra sublingual 100 mg visa, chronic kidney or liver disease, malignancy etc. The intertrochanteric and the subtrochanteric fractures pose a number of management dilemmas depending on the fractures configuration and status of the bones. A number of different treatment modalities for management of these fractures have been proposed and tried with varying results for both intertrochanteric and subtrochanteric fractures of proximal femur. Intertrochanteric hip fractures account for approximately half of the hip fractures in the elderly; out of this more than 50% fractures are unstable. Unstable pattern occur more commonly with increased age and with low bone mineral density. The presence of osteoporosis in intertrochanteric fractures is important because fixation of the proximal fragment depends entirely on the quality of cancellous bone present, Unstable intertrochanteric fractures are those in which comminution of posteromedial buttress exceeds a simple lesser trochanteric fragment or those with subtrochanteric extension. The results of unstable fractures are less reliable and have a high rate of failure - 8%- 25%. The goal of treatment of any intertrochanteric fracture in the elderly is to restore mobility safely and efficiently while minimizing the risk of medical complications and technical failure and to restore the patient to preoperative status. Unstable intertrochanteric fractures are technically much more challenging than stable fractures; a stable reduction of an intertrochanteric fracture requires providing medial and posterior cortical contact between the major proximal and distal fragment to resist varus and posterior displacing forces. Hence Surgeons must understand implant options available and should strive to achieve accurate realignment and proper implant placement. The common problem for these fractures has been malunion, delayed union or non-union. Many newer designs of implants bas been designed for fixation of subtrochanteric fractures. The newer implants were designed to avoid bending, breakage of plates and nails, the loosening of screws and inadequate fixation. This is mainly because elderly people are unable to dissipate energy as compared to the young person, and diminished ambulatory speed. Their protective responses are also 48 diminished because of slow reaction time, weakness, disorientation and the side effect of medication. Elderly people also lack shock absorbers such as pad of fat or muscles over the trochanteric region and finally diminished bone strength because of osteopaenia allows fractures to occur with trivial fall. The injured should be referred to the higher centre earliest feasible causing no further harm. Investigations: X-rays of the pelvis including both hips and knee joint and of other areas if required, General Investigations and specific if required according to the status of the health of the patient. Investigations: X-rays of the pelvis including both hips and knee and of other areas if required, General Investigations and specific if required according to the 52 presence of any co-morbidity. In few selected ones with either osteoarthritis of hip joint or in those patients in whom union is suspected we can go for arthroplasty. Since lots of co-morbidities are common in geriatric population, a thorough preoperative medical evaluation is necessary. The detailed preoperative work up directly affects the timing of surgery and the operative procedure. Majority of these fractures should be treated operatively for ease of nursing care, rapid mobilisation, decreased mortality, decreased hospitalization and restoration of function. The operative treatment should be considered urgently, but not as an emergency procedure. The optimal time for surgical intervention appears to be after the patient is evaluated medically and any transient medical ailment corrected i. However it should not be delayed more than 48-72 hours unless intervention significantly decreases the operative risk. Also most of these patients are osteoporotic and have a high chance of getting fracture in the opposite side, so anti osteoporotic treatment should be started in all of these patients and so is the early mobilization as osteoporosis will increase if they stay in bed waiting for the union to occur. Isolated injuries can occur with repetitive stress and may occur in the presence metabolic bone diseases, metastatic disease, or primary bone tumors. The femur is very vascular and fractures can result in significant blood loss into the thigh. Up to 40% of isolated fractures may require transfusion, as such injuries can result in loss of up to 3 units of blood. This factor is significant, especially in elderly patients who have less cardiac reserve. Most femoral diaphyseal fractures are treated surgically with intramedullary nails or plate fixation. The goal of treatment is reliable anatomic stabilization, allowing mobilization as soon as possible. Surgical stabilization is also important for early extremity function, allowing both hip and knee motion and strengthening. Injuries and fractures of the femoral shaft may have significant short- and long-term effects on the hip and knee joints if alignment is not restored. The injured should be referred to the higher centre earliest feasible causing no further harm. Investigations: X-rays of the part including hip and knee and of other areas if required, x-ray of pelvis with both hips is must. General Investigations and specific if required according to the status of the health of the patient. Treatment: Conservative management of fractures in children in spica cast or with skeletal traction, Kuntscher’s nail for isthmic fractures, Interlocking Nailing in comminuted fractures, Plating for lower third fractures, Plating of shaft femur fracture in children. Investigations: X-rays of the part and of other areas if required, x-ray of pelvis with both hips is must. General Investigations and specific if required according to the presence of any co-morbidity. Introduction /description Lower leg fractures include fractures of the tibia and fibula. Fractures of the tibia generally are associated with fibula fracture, because the force is transmitted along the interosseous membrane to the fibula. The skin and subcutaneous tissue are very thin over the anterior and medial tibia and as a result of this; a significant number of fractures to the lower leg are open. Fractures of the tibia can involve the tibial plateau, tubercle, shaft, and plafond. Mode of injury Tibial plateau fractures occur from axial loading with valgus or varus forces, such as in a fall from a height or collision with the bumper of a car. Mechanisms of injury for tibia-fibula fractures can be divided into 2 categories: 58  Low-energy injuries such as ground levels falls and athletic injuries and in osteoporotic patients  High-energy injuries such as motor vehicle injuries(esp motor cycle accidents, pedestrians struck by motor vehicles, and gunshot wounds Tibial plafond fractures refer to fractures involving the weight-bearing surface of the distal tibia.

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Cartilage provides flexible strength and support for body structures such as the thoracic cage order generic viagra sublingual pills, the external ear viagra sublingual 100 mg overnight delivery, and the trachea and larynx order viagra sublingual with mastercard. Ligaments are the strong connective tissue bands that hold the bones at a moveable joint together and serve to prevent excessive movements of the joint that would result in injury. Providing movement of the skeleton are the muscles of the body, which are firmly attached to the skeleton via connective tissue structures called tendons. Each bone of the body serves a particular function, and therefore bones vary in size, shape, and strength based on these functions. For example, the bones of the lower back and lower limb are thick and strong to support your body weight. Similarly, the size of a bony landmark that serves as a muscle attachment site on an individual bone is related to the strength of this muscle. For this reason, the identification of bony landmarks is important during your study of the skeletal system. Bones are also dynamic organs that can modify their strength and thickness in response to changes in muscle strength or body weight. Thus, muscle attachment sites on bones will thicken if you begin a workout program that increases muscle strength. Similarly, the walls of weight-bearing bones will thicken if you gain body weight or begin pounding the pavement as part of a new running regimen. This may happen during a prolonged hospital stay, following limb immobilization in a cast, or going into the weightlessness of outer space. Even a change in diet, such as eating only soft food due to the loss of teeth, will result in a noticeable decrease in the size and thickness of the jaw bones. Younger individuals have higher numbers of bones because some bones fuse together during childhood and adolescence to form an adult bone. The primary functions of the skeleton are to provide a rigid, internal structure that can support the weight of the body against the force of gravity, and to provide a structure upon which muscles can act to produce movements of the body. In contrast, the upper skeleton has greater mobility and ranges of motion, features that allow you to lift and carry objects or turn your head and trunk. In addition to providing for support and movements of the body, the skeleton has protective and storage functions. The bones of the skeleton serve as the primary storage site for important minerals such as calcium and phosphate. The axial skeleton forms the vertical, central axis of the body and includes all bones of the head, neck, chest, and back (Figure 7. It also serves as the attachment site for muscles that move the head, neck, and back, and for muscles that act across the shoulder and hip joints to move their corresponding limbs. The axial skeleton of the adult consists of 80 bones, including the skull, the vertebral column, and the thoracic cage. Also associated with the head are an additional seven bones, including the hyoid bone and the ear ossicles (three small bones found in each middle ear). The thoracic cage includes the 12 pairs of ribs, and the sternum, the flattened bone This OpenStax book is available for free at http://cnx. It consists of the skull, vertebral column (including the sacrum and coccyx), and the thoracic cage, formed by the ribs and sternum. The Appendicular Skeleton The appendicular skeleton includes all bones of the upper and lower limbs, plus the bones that attach each limb to the axial skeleton. The facial bones underlie the facial structures, form the nasal cavity, enclose the eyeballs, and support the teeth of the upper and lower jaws. The rounded brain case surrounds and protects the brain and houses the middle and inner ear structures. In the adult, the skull consists of 22 individual bones, 21 of which are immobile and united into a single unit. Anterior View of Skull The anterior skull consists of the facial bones and provides the bony support for the eyes and structures of the face. The orbit is the bony socket that houses the eyeball and muscles that move the eyeball or open the upper eyelid. Located near the midpoint of the supraorbital margin is a small opening called the supraorbital foramen. Below the orbit is the infraorbital foramen, which is the point of emergence for a sensory nerve that supplies the anterior face below the orbit. The upper portion of the nasal septum is formed by the perpendicular plate of the ethmoid bone and the lower portion is the vomer bone. Each side of the nasal cavity is triangular in shape, with a broad inferior space that narrows superiorly. When looking into the nasal cavity from the front of the skull, two bony plates are seen projecting from each lateral wall. The superior nasal concha is located just lateral to the perpendicular plate, in the upper nasal cavity. Lateral View of Skull A view of the lateral skull is dominated by the large, rounded brain case above and the upper and lower jaws with their teeth below (Figure 7. The zygomatic arch is the bony arch on the side of skull that spans from the area of the cheek to just above the ear canal. It is formed by the junction of two bony processes: a short anterior component, the temporal process of the zygomatic bone (the cheekbone) and a longer posterior portion, the zygomatic process of the temporal bone, extending forward from the temporal bone. Thus the temporal process (anteriorly) and the zygomatic process (posteriorly) join together, like the two ends of a drawbridge, to form the zygomatic arch. One of the major muscles that pulls the mandible upward during biting and chewing arises from the zygomatic arch. On the lateral side of the brain case, above the level of the zygomatic arch, is a shallow space called the temporal fossa. Below the level of the zygomatic arch and deep to the vertical portion of the mandible is another space called the infratemporal fossa. Both the temporal fossa and infratemporal fossa contain muscles that act on the mandible during chewing. The zygomatic arch is formed jointly by the zygomatic process of the temporal bone and the temporal process of the zygomatic bone. The space inferior to the zygomatic arch and deep to the posterior mandible is the infratemporal fossa. This cavity is bounded superiorly by the rounded top of the skull, which is called the calvaria (skullcap), and the lateral and posterior sides of the skull. The bones that form the top and sides of the brain case are usually referred to as the “flat” bones of the skull. This is a complex area that varies in depth and has numerous This OpenStax book is available for free at http://cnx. Inside the skull, the base is subdivided into three large spaces, called the anterior cranial fossa, middle cranial fossa, and posterior cranial fossa (fossa = “trench or ditch”) (Figure 7. The shape and depth of each fossa corresponds to the shape and size of the brain region that each houses. The boundaries and openings of the cranial fossae (singular = fossa) will be described in a later section. The base of the brain case, which forms the floor of cranial cavity, is subdivided into the shallow anterior cranial fossa, the middle cranial fossa, and the deep posterior cranial fossa.

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There are some differences between the two discount viagra sublingual 100mg mastercard, but for our purposes here there will be a good bit of overlap buy discount viagra sublingual 100mg online. Autonomic structures are found in the nerves also generic viagra sublingual 100mg without prescription, but include the sympathetic and parasympathetic ganglia. Maybe you have seen an advertisement on a website saying that there is a secret to unlocking the full potential of your mind—as if there were 90 percent of your brain sitting idle, just waiting for you to use it. An easy way to see how much of the brain a person uses is to take measurements of brain activity while performing a task. Consider this possible experiment: the subject is told to look at a screen with a black dot in the middle (a fixation point). The photograph might be of a celebrity, so the subject would press the button, or it might be of a random person unknown to the subject, so the subject would not press the button. In this task, visual sensory areas would be active, integrating areas would be active, motor areas responsible for moving the eyes would be active, and motor areas for pressing the button with a finger would be active. Ongoing research pursues an expanded role that glial cells might play in signaling, but neurons are still considered the basis of this function. They are responsible for the electrical signals that communicate information about sensations, and that produce movements in response to those stimuli, along with inducing thought processes within the brain. The three- dimensional shape of these cells makes the immense numbers of connections within the nervous system possible. Parts of a Neuron As you learned in the first section, the main part of a neuron is the cell body, which is also known as the soma (soma = “body”). But what makes neurons special is that they have many extensions of their cell membranes, which are generally referred to as processes. Neurons are usually described as having one, and only one, axon—a fiber that emerges from the cell body and projects to target cells. The other processes of the neuron are dendrites, which receive information from other neurons at specialized areas of contact called synapses. The dendrites are usually highly branched processes, providing locations for other neurons to communicate with the cell body. Because the axon hillock represents the beginning of the axon, it is also referred to as the initial segment. Many axons are wrapped by an insulating substance called myelin, which is actually made from glial cells. A key difference between myelin and the insulation on a wire is that there are gaps in the myelin covering of an axon. Each gap is called a node of Ranvier and is important to the way that electrical signals travel down the axon. The length of the axon between each gap, which is wrapped in myelin, is referred to as an axon segment. At the end of the axon is the axon terminal, where there are usually several branches extending toward the target cell, each of which ends in an enlargement called a synaptic end bulb. Neurons are dynamic cells with the ability to make a vast number of connections, to respond incredibly quickly to stimuli, and to initiate movements on the basis of those stimuli. They are the focus of intense research because failures in physiology can lead to devastating illnesses. True unipolar cells are only found in invertebrate animals, so the unipolar cells in humans are more appropriately called “pseudo-unipolar” cells. Human unipolar cells have an axon that emerges from the cell body, but it splits so that the axon can extend along a very long distance. At one end of the axon are dendrites, and at the other end, the axon forms synaptic connections with a target. First, their dendrites are receiving sensory information, sometimes directly from the stimulus itself. The axon projects from the dendrite endings, past the cell body in a ganglion, and into the central nervous system. Bipolar cells have two processes, which extend from each end of the cell body, opposite to each other. They are found mainly in the olfactory epithelium (where smell stimuli are sensed), and as part of the retina. With the exception of the unipolar sensory ganglion cells, and the two specific bipolar cells mentioned above, all other neurons are multipolar. Anaxonic neurons are very small, and if you look through a microscope at the standard resolution used in histology (approximately 400X to 1000X total magnification), you will not be able to distinguish any process specifically as an axon or a dendrite. Nevertheless, even if they cannot be easily seen, and one specific process is definitively the axon, these neurons have multiple processes and are therefore multipolar. Neurons can also be classified on the basis of where they are found, who found them, what they do, or even what chemicals they use to communicate with each other. Some neurons referred to in this section on the nervous system are named on the basis of those sorts of classifications (Figure 12. Glial Cells Glial cells, or neuroglia or simply glia, are the other type of cell found in nervous tissue. They are considered to be supporting cells, and many functions are directed at helping neurons complete their function for communication. The name glia comes from the Greek word that means “glue,” and was coined by the German pathologist Rudolph Virchow, who wrote in 1856: “This connective substance, which is in the brain, the spinal cord, and the special sense nerves, is a kind of glue (neuroglia) in which the nervous elements are planted. Astrocytes have many processes extending from their main cell body (not axons or dendrites like neurons, just cell extensions). But most everything else cannot, including white blood cells, which are one of the body’s main lines of defense. One oligodendrocyte will provide the myelin for multiple axon segments, either for the same axon or for separate axons. While their origin is not conclusively determined, their function is related to what macrophages do in the rest of the body. When macrophages encounter diseased or damaged cells in the rest of the body, they ingest and digest those cells or the pathogens that cause disease. Ependymal cells line each ventricle, one of four central cavities that are remnants of the hollow center of the neural tube formed during the embryonic development of the brain. The choroid plexus is a specialized structure in the ventricles where ependymal cells come in contact with blood vessels and filter and absorb components of the blood to produce cerebrospinal fluid. These glial cells appear similar to epithelial cells, making a single layer of cells with little intracellular space and tight connections between adjacent cells. Satellite cells are found in sensory and autonomic ganglia, where they surround the cell bodies of neurons. Schwann cells are different than oligodendrocytes, in that a Schwann cell wraps around a portion of only one axon segment and no others. Oligodendrocytes have processes that reach out to multiple axon segments, whereas the entire Schwann cell surrounds just one axon segment. Whereas the manner in which either cell is associated with the axon segment, or segments, that it insulates is different, the means of myelinating an axon segment is mostly the same in the two situations.

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Integration of data derived from the several “omics” by bioinformatics will probably allow a rational insight into M order cheap viagra sublingual on line. The sequence of the genome purchase viagra sublingual 100mg on-line, and its comparison to sequences of other microorganisms reported in several databases generic viagra sublingual 100 mg fast delivery, allowed the as- signation of precise functions to 40 % of the predicted proteins and the identifica- tion of 44 % of orthologues (genes with very similar functions in a different spe- cies), leaving 16 % as unique unknown proteins. The elucidation of complete genome sequences and the development of microar- ray-based comparative genomics have been powerful tools in the progress of new areas by the application of robotics to basic molecular biology. Comparative ge- nomics and genomic tools have also been used to identify factors associated with the pathogenicity of M. Moreover, these tools allowed a de- scription of the evolutionary scenario of the genus (see Chapter 2). A major barrier for genomic studies has been the great number of genes with unknown function that have been identified. The elucidation of protein function was possible with the global analysis of bacterial proteins, giving insights into the functional role of several so far unknown proteins. Thanks to the joint contributions of biochemical techniques and mass spectrometry, up to 1,044 non- redundant proteins were reported in different cellular fractions (Mawuenyega 2005). Genomics and other molecular tools allowed studies on gene expression and regu- lation, which were unthinkable years ago. Understanding how the bacillus regulates its different genes according to environmental changes will probably lead to the comprehension of many interesting aspects of M. This chapter will address the general basics, as well as the state-of-the-art ge- nomics, transcriptomics and proteomics in relation to M. Finally, a general overview will be made on lipids, the most peculiar metabolites of this bac- terium. Expectations were generated on the elucidation of some unique characteristics of the biology of the tubercle bacillus, such as its characteristic slow growth, the nature of its complex cell wall, certain genes related to its virulence and persistence, and the apparent stability of its genome. In turn, the few genes with particularly low (< 50 %) G+C content are those coding for transmembrane proteins or polyketide synthases. This deviation to low G+C content is believed to be a consequence of the required hydrophobic amino acids, essential in any trans- membrane domain, that are coded by low G+C content codons. The posses- sion of a single rrn operon in a position relatively distant from oriC has been pos- tulated to be a factor contributing to the slow growth phenotype of the tubercle bacillus (Brosch 2000a). Another 32 different insertion sequences were found, of which seven belonged to the 13E12 family of repetitive sequences; the other insertion sequences had not been described in other organisms (Cole 1998b). Two prophages were detected in the genome sequence; both are similar in length and also similarly organized. The second prophage, PhiRv2 has proven to be much more stable, with less variability among strains (Cole 1999). A bias in the overall orientation of genes with respect to the direction of replication was also found. It was also found that the number of genes that arose by duplication is similar to the number seen in E. The lack of divergence of duplicated genes is consistent with the hypothesis of a recent evolutionary descent or a recent bottleneck in my- cobacterial evolution (Brosch 2002, Sreevatsan 1997, see chapter 2). This flexibility is useful for survival in the changing environments within the human host that range from high oxygen tension in the lung alveolus to microaerophilic/anaerobic condi- tions within the tuberculous granuloma. In total, there are genes encoding for 250 distinct enzymes involved in fatty acid metabolism, compared to only 50 in the genome of E. These proteins are believed to play an important role in survival and multiplication of mycobacteria in different environments (Marri 2006). Pro- teins in this class contain multiple tandem repetitions of the motif Gly-Gly-Ala, hence, their glycine concentration is superior to 50 %. This gene encodes the enzyme in charge of removing oxidized guanines whose incorporation during repli- cation causes base-pair mismatching (Mizrahi 1998, Cole 1999). With the aim of making the information publicly available and the search and analysis of information easier, the Pasteur Institute (http://www. This database is freely available for use on the Internet and is known as the Tuberculist Web Server http://genolist. As more information was generated, databases grew bigger, more experimental information became available, and better and more accurate algorithms for gene identification and prediction were released. The letter C was not included since it usually stands for “comple- mentary”, which means that the gene is located in the complementary strand. As expected, the classes that exhibited the greatest numbers of changes were the un- known category and the conserved hypothetical category (Table 4-1). The re- annotation of the genome sequence allowed the identification of four sequencing errors making the current sequence size change from 4,411,529 to 4,411,532 bp (Camus 2002). Comparative genomics In recent times, new technologies have been developed at an overwhelming pace, in particular those related to sequencing and tools for genome sequence data man- agement, storage and analysis. As of April 2007, 484 microbial genomes have been finished and projects are underway aimed at the sequencing of other 1,155 micro- organisms (http://www. Mycobacteria are not an exception in this titanic genome-sequencing race; since 1998, when the first myco- bacterial genome sequence was published (Cole 1998a); many genome projects have been initiated. Until April 2007, 34 projects on the genome sequencing of different mycobacterial species are finished or in-process. For this reason, these are the strains that have been used as reference strains for comparative genomics both in vitro and in silico. The next step in comparative genomics was the use of genomic subtractive hybridi- zation or bacteria artificial chromosome hybridization for the identification of re- gions of difference among the strains under analysis (Mahairas 1996, Gordon 1999). As a result, they identified 10 regions of difference, including the three previously described (Mahairas 1996). Until 2002, most studies concerning comparative genomics were based on differ- ences among the strain type M. Some excellent reviews are available on comparative genomics, made before the publication of the second M. This strain was considered to be highly transmissible and virulent for human beings (Fleischmann 2002). With the sequence of this second strain, a first approach to the bioinformatic analysis of intraspecies variability became possible. Dark gray filled cells indicate the presence in all strains tested, light gray indicate the presence in some strains, white is absence from all strains tested. These studies have been complemented with data obtained from the genome sequence of a third organism of the M. Sequencing con- firmed the absence of 11 regions of difference, and the presence of only one inser- tion in comparison to the sequenced M. The comparison of the three genomes reflects the high degree of conservation among the members of the M. However, it is important to mention that the greatest degree of variation among these bacilli is found in genes encoding cell wall components and secreted proteins. Some other changes are registered in genes coding for lipid synthesis and secretion as the mmpL and mmpS family of genes. The sequencing of whole genomes of Mycobacterium leprae (Cole 2001), Mycobacterium avium subspecies paratuberculosis (Li 2005) and of other mem- bers of the genus, such as Mycobacterium smegmatis and M.

Somatosensation (Touch) Somatosensation is considered a general sense buy viagra sublingual overnight, as opposed to the special senses discussed in this section discount 100 mg viagra sublingual with amex. Somatosensation is the group of sensory modalities that are associated with touch 100 mg viagra sublingual for sale, proprioception, and interoception. These modalities include pressure, vibration, light touch, tickle, itch, temperature, pain, proprioception, and kinesthesia. This means that its receptors are not associated with a specialized organ, but are instead spread throughout the body in a variety of organs. Many of the somatosensory receptors are located in the skin, but receptors are also found in muscles, tendons, joint capsules, ligaments, and in the walls of visceral organs. Two types of somatosensory signals that are transduced by free nerve endings are pain and temperature. These two modalities use thermoreceptors and nociceptors to transduce temperature and pain stimuli, respectively. For example, the sensation of heat associated with spicy foods involves capsaicin, the active molecule in hot peppers. Capsaicin molecules bind to a transmembrane ion channel in nociceptors that is sensitive to temperatures above 37°C. The dynamics of capsaicin binding with this transmembrane ion channel is unusual in that the molecule remains bound for a long time. Because of this, it will decrease the ability of other stimuli to elicit pain sensations through the activated nociceptor. Such low frequency vibrations are sensed by mechanoreceptors called Merkel cells, also known as type I cutaneous mechanoreceptors. Deep pressure and vibration is transduced by lamellated (Pacinian) corpuscles, which are receptors with encapsulated endings found deep in the dermis, or subcutaneous tissue. These nerve endings detect the movement of hair at the surface of the skin, such as when an 614 Chapter 14 | The Somatic Nervous System insect may be walking along the skin. For example, have you ever stretched your muscles before or after exercise and noticed that you can only stretch so far before your muscles spasm back to a less stretched state? Bulbous corpuscles are also present in joint capsules, where they measure stretch in the components of the skeletal system within the joint. The types of nerve endings, their locations, and the stimuli they transduce are presented in Table 14. Mechanoreceptors of Somatosensation Historical Name (eponymous) Location(s) Stimuli name Free nerve Dermis, cornea, tongue, joint Pain, temperature, mechanical * endings capsules, visceral organs deformation Epidermal–dermal junction, Low frequency vibration (5–15 Mechanoreceptors Merkel’s discs mucosal membranes Hz) Bulbous corpuscle Ruffini’s corpuscle Dermis, joint capsules Stretch Papillary dermis, especially in Light touch, vibrations below 50 Tactile corpuscle Meissner’s corpuscle the fingertips and lips Hz Lamellated Deep dermis, subcutaneous Deep pressure, high-frequency Pacinian corpuscle corpuscle tissue vibration (around 250 Hz) Wrapped around hair follicles in Hair follicle plexus * Movement of hair the dermis In line with skeletal muscle Muscle spindle * Muscle contraction and stretch fibers Tendon stretch Golgi tendon organ In line with tendons Stretch of tendons organ Table 14. Vision Vision is the special sense of sight that is based on the transduction of light stimuli received through the eyes. The bony orbits surround the eyeballs, protecting them and anchoring the soft tissues of the eye (Figure 14. The eyelids, with lashes at their leading edges, help to protect the eye from abrasions by blocking particles that may land on the surface of the eye. The conjunctiva extends over the white areas of the eye (the sclera), connecting the eyelids to the eyeball. Tears produced by this gland flow through the lacrimal duct to the medial corner of the eye, where the tears flow over the conjunctiva, washing away foreign particles. Movement of the eye within the orbit is accomplished by the contraction of six extraocular muscles that originate from the bones of the orbit and insert into the surface of the eyeball (Figure 14. Four of the muscles are arranged at the cardinal points around the eye and are named for those locations. However, the tendon of the oblique muscles threads through a pulley-like piece of cartilage known as the trochlea. The angle of the tendon through the trochlea means that contraction of the superior oblique rotates the eye medially. The inferior oblique muscle originates from the floor of the orbit and inserts into the inferolateral surface of the eye. Rotation of the eye by the two oblique muscles is necessary because the eye is not perfectly aligned on the sagittal plane. When the eye looks up or down, the eye must also rotate slightly to compensate for the superior rectus pulling at approximately a 20-degree angle, rather than straight up. The same is true for the inferior rectus, which is compensated by contraction of the inferior oblique. A seventh muscle in the orbit is the levator palpebrae superioris, which is responsible for elevating and retracting the upper eyelid, a movement that usually occurs in concert with elevation of the eye by the superior rectus (see Figure 14. All of the other muscles are innervated by the oculomotor nerve, as is the levator palpebrae superioris. The sclera accounts for five sixths of the surface of the eye, most of which is not visible, though humans are unique compared with many other species in having so much of the “white of the eye” visible (Figure 14. The middle layer of the eye is the vascular tunic, which is mostly composed of the choroid, ciliary body, and iris. The choroid is a layer of highly vascularized connective tissue that provides a blood supply to the eyeball. The choroid is posterior to the ciliary body, a muscular structure that is attached to the lens by suspensory ligaments, or zonule fibers. Overlaying the ciliary body, and visible in the anterior eye, is the iris—the colored part of the eye. The iris is a smooth muscle that opens or closes the pupil, which is the hole at the center of the eye that allows light to enter. The iris constricts the pupil in response to bright light and dilates the pupil in response to dim light. The innermost layer of the eye is the neural tunic, or retina, which contains the nervous tissue responsible for photoreception. The posterior cavity is the space behind the lens that extends to the posterior side of the interior eyeball, where the retina is located. The retina is composed of several layers and contains specialized cells for the initial processing of visual stimuli. The change in membrane potential alters the amount of neurotransmitter that the photoreceptor cells release onto bipolar cells in the outer synaptic layer. Because these axons pass through the retina, there are no photoreceptors at the very back of the eye, where the optic nerve begins. A significant amount of light is absorbed by these structures before the light reaches the photoreceptor cells. At the fovea, the retina lacks the supporting cells and blood vessels, and only contains photoreceptors. This is because the fovea is where the least amount of incoming light is absorbed by other retinal structures (see Figure 14. As one moves in either direction from this central point of the retina, visual acuity drops significantly. The difference in visual acuity between the fovea and peripheral retina is easily evidenced by looking directly at a word in the middle of this paragraph.

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Chapter 2 cheap viagra sublingual 100mg with amex, on early diagnosis trusted 100 mg viagra sublingual, sets challenging improvements in availability of reports by radiologists of all chest X-rays of patients attending emergency departments order viagra sublingual 100mg without a prescription. This is not current practice in all district general hospitals at the present time. The role of endo-bronchial ultrasound and biopsy of mediastinal nodes for staging of the disease is discussed in Chapter 3 on referral and diagnosis, and choice of radiological test and biopsy technique are covered in Chapter 4. It is essential to have a fully represented team participating in decision making to ensure that state-of-the-art treatment is offered to patients with the best chance of an improved outcome. The need for data collection to measure outcomes is stressed in Chapter 7, and the collection thereof, in particular the clinical data, remains the responsibility of the members of the multidisciplinary team, with support from a data manager. A summary of key information and guidance for staff dealing with patients and giving diagnoses of cancer is provided in Chapter 8. In Chapter 9, guidance is given for ways of achieving good communication with patients and professionals in primary care and the community. In Chapter 10, recommendations are made regarding requirements of a high-quality surgical service and how these standards can be measured. For more advanced, but potentially curable disease other radical treatments are described in Chapter 12 using concomitant or sequential chemo-radiotherapy or radiotherapy alone, and recommendations are made for follow-up of this group. The management of small cell lung cancer, Chapter 14, is largely unchanged, though there are recommendations for oral topotecan second line. The role of the nurse in providing information for patients and carers so that they can cope with the illness, and then deal with the consequences and long term side effects of the treatment as survivors is also discussed. As the majority of patients with lung cancer present with their disease in an advanced stage, palliative treatment of these patients is important to improve their quality of life, and in Chapter 17 this is considered in some detail, particularly in relation to some advances in specific therapies. During the coming months the clinicians will develop standards and measures against which organisations can be assessed. Measures to prevent people from taking up smoking, or helping them to quit, will reduce the number of deaths from lung cancer. In addition, patients with lung cancer undergoing curative treatment who stop smoking pre-treatment reduce the risk of complications from surgery. Rates are higher in males than females and in more socio-economic deprived groups. Incidence rates of lung cancer closely reflect past smoking prevalence with a time lag of approximately 20 to 30 years. Smoking prevalence has decreased over the past 50 years and this accounts for the decrease in the rates of lung cancer. The provision of effective smoking cessation services in an acute Trust setting remains highly variable despite evidence that delivering smoking cessation interventions to inpatients in hospital is effective (Rigotti et al. This is clearly a missed opportunity to deliver stop smoking interventions at a point at which an individual may be more susceptible to health advice and hence more motivated to quit. The key document for acute Trusts is Stop Smoking Interventions in Secondary Care. The main barriers to successful implementation tend to be administrative elements such as data collection. Lack of support from the Trust was also commonly cited as a barrier to implementing interventions. Smoking cessation interventions must be targeted to reach different population groups and provided across a range of settings. In particular, there has been an increased focus on the need to establish effective smoking cessation services in secondary care (Fiore et al. It is advisable for patients undergoing surgery to have ceased smoking for a month before the operation rather than immediately beforehand, though it is not recommended that surgery is delayed because patients continue to smoke. There are suggestions that other treatments for lung cancer are more effective if patients are no longer smoking, and for patients who have undergone radical treatment it may reduce the risk of a second tumour. Patients from the age of 16 to the end of their 18th year should be treated in a principal treatment centre (see Appendix 10 for contact details of principal treatment centres). Teenagers and young adults in this age group should be treated either in the principal treatment centre or a designated hospital. Direct referrals from radiology are seen according to each unit’s agreed operational policy. The patient is contacted initially by phone and then by letter if telephone contact cannot be made, with an explanation of why they need to be seen urgently. Investigations should be selected to offer the most diagnostic information with the least risk of harm. Where there is evidence of distant metastases, then biopsies should be taken from the metastatic site if this can be achieved more easily than from the primary site. If patients have a previous diagnosis of cancer, this should influence where the biopsy is taken from to distinguish between primary and metastatic lung cancer. Patients who are on oral anti-coagulants and new anti-platelet agents should be offered a risk assessment of the safety of discontinuing these drugs, and if necessary a second opinion should be obtained, prior to any biopsy. In some cases where anti-coagulants need to be continued, low molecular weight heparins can be substituted. As yet there is no national guidance regarding management of oral anti-platelet agents for lung biopsies. Consideration should be given to stopping clopidogrel and/or aspirin 7 days prior to the procedure. All patients should be given written information regarding diagnostic tests to enable them to give informed consent. Think carefully before performing a test that gives only diagnostic pathology when information on staging is also needed to guide treatment. Axial T1W, axial T2W should be used, while the use of contrast enhancement is optional. Coronal +/- sagittal T1W views should be taken for suspected brachial plexus involvement. A bone scan should be requested when symptoms or hypercalcaemia suggest the presence of bone metastases, or when alkaline phosphatase is raised, or for staging of small cell lung cancer. Brain imaging is advocated in patients with adenocarcinoma considered for radical therapy owing to the high incidence of metastases. Percutaneous needle biopsy is indicated in the following groups of patients:  Patients with undiagnosed pulmonary lesions not diagnosed by other approaches. Ideally, each core biopsy specimen will be put in a separate pot for individual processing, ensuring that material remains for analysis. Arrangements should be made for a safe place to recover and monitor the patient post-biopsy. Procedures should only be performed if adequate access to on-site emergency medical assistance is available (in case of need).

You hold your breath by a steady contraction of the diaphragm purchase viagra sublingual 100 mg with amex; this stabilizes the volume and pressure of the peritoneal cavity cheap viagra sublingual american express. When the abdominal muscles contract cheap 100mg viagra sublingual with mastercard, the pressure cannot push the diaphragm up, so it increases pressure on the intestinal tract (defecation), urinary tract (urination), or reproductive tract (childbirth). The inferior surface of the pericardial sac and the inferior surfaces of the pleural membranes (parietal pleura) fuse onto the central tendon of the diaphragm. To the sides of the tendon are the skeletal muscle portions of the diaphragm, which insert into the tendon while having a number of origins including the xiphoid process of the sternum anteriorly, the inferior six ribs and their cartilages laterally, and the lumbar vertebrae and 12th ribs posteriorly. The diaphragm also includes three openings for the passage of structures between the thorax and the abdomen. The inferior vena cava passes through the caval opening, and the esophagus and attached nerves pass through the esophageal hiatus. The Intercostal Muscles There are three sets of muscles, called intercostal muscles, which span each of the intercostal spaces. The principal role of the intercostal muscles is to assist in breathing by changing the dimensions of the rib cage (Figure 11. The 11 pairs of superficial external intercostal muscles aid in inspiration of air during breathing because when they contract, they raise the rib cage, which expands it. The 11 pairs of internal intercostal muscles, just under the externals, are used for expiration because they draw the ribs together to constrict the rib cage. The innermost intercostal muscles are the deepest, and they act as synergists for the action of the internal intercostals. Muscles of the Pelvic Floor and Perineum The pelvic floor is a muscular sheet that defines the inferior portion of the pelvic cavity. The pelvic diaphragm, spanning anteriorly to posteriorly from the pubis to the coccyx, comprises the levator ani and the ischiococcygeus. The large levator ani consists of two skeletal muscles, the pubococcygeus and the iliococcygeus (Figure 11. The levator ani is considered the most important muscle of the pelvic floor because it supports the pelvic viscera. It resists the pressure produced by contraction of the abdominal muscles so that the pressure is applied to the colon to aid in defecation and to the uterus to aid in childbirth (assisted by the ischiococcygeus, which pulls the coccyx anteriorly). The perineum is the diamond-shaped space between the pubic symphysis (anteriorly), the coccyx (posteriorly), and the ischial tuberosities (laterally), lying just inferior to the pelvic diaphragm (levator ani and coccygeus). Divided transversely into triangles, the anterior is the urogenital triangle, which includes the external genitals. The perineum is also divided into superficial and deep layers with some of the muscles common to men and women (Figure 11. Women also have the compressor urethrae and the sphincter urethrovaginalis, which function to close the vagina. The pectoral girdle, or shoulder girdle, consists of the lateral ends of the clavicle and scapula, along with the proximal end of the humerus, and the muscles covering these three bones to stabilize the shoulder joint. The girdle creates a base from which the head of the humerus, in its ball-and-socket joint with the glenoid fossa of the scapula, can move the arm in multiple directions. Muscles That Position the Pectoral Girdle Muscles that position the pectoral girdle are located either on the anterior thorax or on the posterior thorax (Figure 11. When the rhomboids are contracted, your scapula moves medially, which can pull the shoulder and upper limb posteriorly. Note that the pectoralis major and deltoid, which move the humerus, are cut here to show the deeper positioning muscles. Muscles that Position the Pectoral Girdle Position Target motion Prime in the Movement Target Origin Insertion direction mover thorax Stabilizes clavicle Inferior Anterior during movement by Clavicle Depression Subclavius First rib surface of thorax depressing it clavicle Anterior Rotates shoulder Scapula: surfaces of Coracoid Anterior anteriorly (throwing Scapula; Pectoralis depresses; ribs: certain ribs process of thorax motion); assists with ribs minor elevates (2–4 or scapula inhalation 3–5) Muscle Anterior Moves arm from side slips from surface of Anterior of body to front of Scapula; Scapula: protracts; Serratus certain ribs vertebral thorax body; assists with ribs ribs: elevates anterior (1–8 or border of inhalation 1–9) scapula Elevates shoulders Scapula: rotests Acromion (shrugging); pulls Scapula; inferiorly, retracts, Skull; Posterior and spine of shoulder blades cervical elevates, and Trapezius vertebral thorax scapula; together; tilts head spine depresses; spine: column clavicle backwards extends Stabilizes scapula Thoracic Medial Posterior Retracts; rotates Rhomboid during pectoral girdle Scapula vertebrae border of thorax inferiorly major movement (T2–T5) scapula Table 11. The pectoralis major is thick and fan-shaped, covering much of the superior portion of the anterior thorax. The broad, triangular latissimus dorsi is located on the inferior part of the back, where it inserts into a thick connective tissue shealth called an aponeurosis. The anatomical and ligamental structure of the shoulder joint and the arrangements of the muscles covering it, allows the arm to carry out different types of movements. The deltoid, the thick muscle that creates the rounded lines of the shoulder is the major abductor of the arm, but it also facilitates flexing and medial rotation, as well as extension and lateral rotation. Named for their locations, the supraspinatus (superior to the spine of the scapula) and the infraspinatus (inferior to the spine of the scapula) abduct the arm, and laterally rotate the arm, respectively. The thick and flat teres major is inferior to the teres minor and extends the arm, and assists in adduction and medial rotation of it. The tendons of the deep subscapularis, supraspinatus, infraspinatus, and teres minor connect the scapula to the humerus, forming the rotator cuff (musculotendinous cuff), the circle of tendons around the shoulder joint. When baseball pitchers undergo shoulder surgery it is usually on the rotator cuff, which becomes pinched and inflamed, and may tear away from the bone due to the repetitive motion of bring the arm overhead to throw a fast pitch. Muscles That Move the Forearm The forearm, made of the radius and ulna bones, has four main types of action at the hinge of the elbow joint: flexion, extension, pronation, and supination. The pronators are the pronator teres and the pronator quadratus, and the supinator is the only one that turns the forearm anteriorly. The two-headed biceps brachii crosses the shoulder and elbow joints to flex the forearm, also taking part in supinating the forearm at the radioulnar joints and flexing the arm at the shoulder joint. These muscles and their associated blood vessels and nerves form the anterior compartment of the arm (anterior flexor compartment of the arm) (Figure 11. Muscles of the Arm That Move the Wrists, Hands, and Fingers The muscles in the anterior compartment of the forearm (anterior flexor compartment of the forearm) originate on the humerus and insert onto different parts of the hand. From lateral to medial, the superficial anterior compartment of the forearm includes the flexor carpi radialis, palmaris longus, flexor carpi ulnaris, and flexor digitorum superficialis. The flexor digitorum superficialis flexes the hand as well as the digits at the knuckles, which allows for rapid finger movements, as in typing or playing a musical instrument (see Figure 11. However, poor ergonomics can irritate the tendons of these muscles as they slide back and forth with the carpal tunnel of the anterior wrist and pinch the median nerve, which also travels through the tunnel, causing Carpal Tunnel Syndrome. The muscles in the superficial posterior compartment of the forearm (superficial posterior extensor compartment of the forearm) originate on the humerus. These are the extensor radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, and the extensor carpi ulnaris. The muscles of the deep posterior compartment of the forearm (deep posterior extensor compartment of the forearm) originate on the radius and ulna. These include the abductor pollicis longus, extensor pollicis brevis, extensor pollicis This OpenStax book is available for free at http://cnx. The flexor retinaculum extends over the palmar surface of the hand while the extensor retinaculum extends over the dorsal surface of the hand. Intrinsic Muscles of the Hand The intrinsic muscles of the hand both originate and insert within it (Figure 11. These muscles allow your fingers 480 Chapter 11 | The Muscular System to also make precise movements for actions, such as typing or writing. The hypothenar muscles are on the medial aspect of the palm, and the intermediate muscles are midpalmar.

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