By X. Zakosh. American InterContinental University.

As a result order 12.5mg coreg otc, a large part of the neural function of the eyes is concerned with moving the eyes and head so that important visual stimuli are centered on the fovea discount 25mg coreg free shipping. The inner segment contains the nucleus and other common organelles of a cell order coreg 12.5 mg online, whereas the outer segment is a specialized region in which photoreception takes place. There are two types of photoreceptors—rods and cones—which differ in the shape of their outer segment. The rod-shaped outer segments of the rod photoreceptor contain a stack of membrane-bound discs that contain the photosensitive pigment rhodopsin. The cone-shaped outer segments of the cone photoreceptor contain their photosensitive pigments in infoldings of the cell membrane. There are three cone photopigments, called opsins, which are each sensitive to a particular wavelength of light. The pigments in human eyes are specialized in perceiving three different primary colors: red, green, and blue. Rod outer segments are long columnar shapes with stacks of membrane-bound discs that contain the rhodopsin pigment. Cone outer segments are short, tapered shapes with folds of membrane in place of the discs in the rods. A single unit of light is called a photon, which is described in physics as a packet of energy with properties of both a particle and a wave. The energy of a photon is represented by its wavelength, with each wavelength of visible light corresponding to a particular color. Wavelengths of electromagnetic radiation longer than 720 nm fall into the infrared range, whereas wavelengths shorter than 380 nm fall into the ultraviolet range. All other colors fall between red and blue at various points along the wavelength This OpenStax book is available for free at http://cnx. Specifically, photons cause some of the double-bonded carbons within the chain to switch from a cis to a trans conformation. Before interacting with a photon, retinal’s flexible double-bonded carbons are in the cis conformation. A photon interacting with the molecule causes the flexible double-bonded carbons to change to the trans- conformation, forming all-trans-retinal, which has a straight hydrocarbon chain (Figure 14. The G protein changes the membrane potential of the photoreceptor cell, which then releases less neurotransmitter into the outer synaptic layer of the retina. Until the retinal molecule is changed back to the 11-cis-retinal shape, the opsin cannot respond to light energy, which is called bleaching. When a large group of photopigments is bleached, the retina will send information as if opposing visual information is being perceived. The photoisomerization is reversed by a series of enzymatic changes so that the retinal responds to more light energy. The three color opsins have peak sensitivities of 564 nm, 534 nm, and 420 nm corresponding roughly to the primary colors of red, green, and blue (Figure 14. The absorbance of rhodopsin in the rods is much more sensitive than in the cone opsins; specifically, rods are sensitive to vision in low light conditions, and cones are sensitive to brighter conditions. In a darkened 620 Chapter 14 | The Somatic Nervous System room, there is not enough light to activate cone opsins, and vision is entirely dependent on rods. The three types of cone opsins, being sensitive to different wavelengths of light, provide us with color vision. By comparing the activity of the three different cones, the brain can extract color information from visual stimuli. For example, a bright blue light that has a wavelength of approximately 450 nm would activate the “red” cones minimally, the “green” cones marginally, and the “blue” cones predominantly. The relative activation of the three different cones is calculated by the brain, which perceives the color as blue. If you think that you can see colors in the dark, it is most likely because your brain knows what color something is and is relying on that memory. This first fiber in the pathway synapses on a thalamic cell that then projects to the visual cortex in the occipital lobe where “seeing,” or visual perception, takes place. This video gives an abbreviated overview of the visual system by concentrating on the pathway from the eyes to the occipital lobe. The video makes the statement (at 0:45) that “specialized cells in the retina called ganglion cells convert the light rays into electrical signals. Spinal Nerves Generally, spinal nerves contain afferent axons from sensory receptors in the periphery, such as from the skin, mixed with efferent axons travelling to the muscles or other effector organs. The dorsal root contains only the axons of sensory neurons, whereas the ventral roots contain only the axons of the motor neurons. Some of the branches will synapse with local neurons in the dorsal root ganglion, posterior (dorsal) horn, or even the anterior (ventral) horn, at the level of the spinal cord where they enter. Other branches will travel a short distance up or down the spine to interact with neurons at other levels of the spinal cord. A branch may also turn into the posterior (dorsal) column of the white matter to connect with the brain. For the sake of convenience, we will use the terms ventral and dorsal in reference to structures within the spinal cord that are part of these pathways.

The tenth cranial nerve called vagus discount coreg 6.25mg visa, give branches to the larynx generic coreg 25mg on line, lungs cheap coreg 6.25 mg online, and heart and digestive organs. The Spinal Cord: The spinal cord is a cord of nervous tissue, the thickness of a little finger and about 12cm long. It connects above with the medulla where the back of the neck joins the skull and extends to the level of the first lumbar vertebrae. Functions of the Spinal Cord: 1) Receives motor impulses from the frontal lobe of the cerebrum, and passes them on to muscles via the spinal nerves. If you touch something hot, the message received in the spinal cord is immediately flashed to the muscles of the arm; before the news reaches the brain you have taken your hand away. It is a loose covering and under is a space called ‘theca’ (sub arachnoid space) containing cerebro spinal fluid (C. A little cerebrospinal fluid is sometimes removed by ‘lumbar puncture’ to help in diag­ nosing disease of the nervous system. Functions of Cerebrospinal Fluid: Ø It acts as a water cushion to protect the brain and spinal cord from shocks and jarring. The Autonomic Nervous Systems It is the second system of the nerves that controls the movements of the involuntary muscles and the secretion of the glands. We have no control over these nerves although they are closely connected with the central nervous system. Sympathetic Systems: This consists of two chains of ganglia (groups of nerve cells) one on each side of the vertebral column. The results of the sympathetic nerve stimuli are: 1) dilated pupils 2) the heart beats quicker 3) breathing is quicker and deeper 4) the blood pressure is raised 5) digestion is slowed down 6) sweating is increased and 7) anal and urethral sphincters tighten up. It is the means by which food, oxygen, water and other requirements are conveyed to the tissue calls, and their waste products are carried away. It is about the size of a person’s clenched fist and weighs around 300 gm in a man and 250gm in a woman. The right and left sides of the heart are totally separated by a muscular wall and there is no communication between them. The right side of the heart receives the deoxygenated (impure) blood collected from the different parts of the body through small and big veins, which enters the lungs. In the lungs the blood is oxygenated and carbon­di­oxide and metabolic waste are removed The left side of the heart receives (pure) blood from the lungs and supplies it to the entire body through the major blood vessel (aorta) and its numerable branches (arteries and capillaries). The left ventricle generates greater pressure than the right ventricle to enable the bold to be pumped throughout the body. The coronary arteries branch out (left and right coronary arteries) from the root of the aorta near its origin from the left ventricle. Both the coronary arteries branch of into smaller vessels, which are distributed all over the surface of the heart. For efficient pumping, it is necessary for the heart to beat at a reasonable rate of 60 – 90 beats per minute, which is achieved through controlled electrical impulses (conductive system). Plasma is important for the life of the tissue cells, conveying to them water and nourishment, and carrying away their waste products. They are very tiny disc with no nucleus, and are filled with haemoglobin, which is made from iron and protein. They can change shape and squeeze through the small bood vessel walls in order to fight gems that have entered the tissues. In acute infection many more leucocytes are produced to help in the fight (leucocytosis) 2) Lymphocytes are produced in the spleen and lymph glands. They are found mainly grouped together in the neck, axilla, and groins and in the pelvic and abdominal cavities. Functions of Lymph: Lymph glands help to protect the body from infection by 1) Filtering the lymph to prevent germs from getting into the blood stream, and fighting to overcome them. Once the food is digested, it must be transferred to the blood stream and the process by which this transfer occurs is called absorption. The Alimentary Canal: The alimentary canal is a long muscular digestive tube extending through the body. Functions of Digestive System: 1) Break down the food substances into small particles 2) Digestion of food substances. The alimentary canal,which is a continuous, passage way beginning at the mouth, where the food is taken in and terminating at the anus where the solid products of digestion, which are not absorbed, are expelled from the body. The accessory organs – which are vitally necessary for the digestive process, do not happen to be the part of the alimentary canal. They are: 1) Mouth – with the help of saliva from three pairs of salivary glands, 2) Stomach – with the help of gastric juice from the stomach wall and 3) Small intestine – with the help of pancreatic juice from the pancreas bile juice from the liver and the intestinal juice from the small intestine.

The group were concerned that patients with persistent dysphagia were at risk of malnutrition and that those patients who remained dysphagic after 3 days should have access to detailed instrumental examination 12.5 mg coreg mastercard. They also felt that it is important to distinguish whether or not tube feeding is required cheap 6.25 mg coreg with visa, and that if tube feeding is required then it is commenced as soon as possible 6.25mg coreg sale. There was concern from the group that the recommendation was based on relatively little evidence. R44 If the admission screen indicates problems with swallowing, the person should have a specialist assessment of swallowing, preferably within 24 hours of admission and not more than 72 hours afterwards. R45 People with suspected aspiration on specialist assessment or who require tube feeding or dietary modification for 3 days should be: q reassessed and be considered for instrumental examination q referred for dietary advice. They may rarely be mis-inserted in the trachea, or not inserted far enough into the oesophagus with the risk in both cases that feed may be introduced into the trachea. There are rare risks of perforation particularly in patients who have difficulty cooperating with the procedure. These risks are in general outweighed by the benefit of adequate feeding but there is little evidence to suggest the optimum time for tube insertion. Occasionally, perhaps in a severely ill patient with a poor prognosis, a decision will be made to withdraw active treatment and insertion of a feeding tube may not be appropriate. Non-commencement or withdrawal of feeding is a difficult decision which should be made in full consultation with the patient (where possible) and family, as well as the multidisciplinary team, taking into account the patient’s best interest, any advance directives and the Mental Capacity Act 2005. The clinical question to be addressed is when is the most appropriate time to initiate tube feeding in patients with acute stroke who cannot swallow safely. The study compared early with delayed feeding, but that in reality people could be randomised up to 3 days post event and then took 1–2 days to start feeding, so this may lead to underestimation of the possible benefit/harm of very early feeding. Patients were followed up at 6 months by a person blinded to the intervention they had received. Although the confidence intervals for the effect of early feeding are wide, meaning that the data are consistent with significant benefit or harm, it was felt by the group to be more biologically plausible to have a small benefit from early tube feeding rather than a negative effect. The clinical question to be addressed is whether patients who are not identified as being malnourished should receive nutritional supplementation after stroke. The majority of patients had relatively minor strokes due to the exclusion criteria of not having a swallowing impairment. Although routine nutritional supplementation is not associated with improved outcomes there is no evidence in the trial to support withholding of focused supplementation from those who are assessed as malnourished. There is evidence from systematic review179 of benefits of nutritional supplementation in malnourished elderly people. For those at risk of malnutrition, nutrition support should be initiated, which may include oral nutritional supplements, referral for dietary advice and/or tube feeding. R50 Screening for malnutrition and the risk of malnutrition should be carried out by healthcare professionals with appropriate skills and training. R52 Nutrition support should be initiated for people with stroke who are at risk of malnutrition. This may include oral nutritional supplements, specialist dietary advice and/or tube feeding. R53 All people with acute stroke should have their hydration assessed on admission, reviewed regularly and managed so that normal hydration is maintained. Although most therapy interventions have not been subjected to randomised controlled trial, they have been derived from extensive experience. Therapists and nurses use mobilisation programmes that aim to reduce secondary complications of immobility such as infection, venous thromboembolism, orthostatic hypotension and infection. In addition, therapy interventions are used to position patients in order to reduce the likelihood of contractures and shoulder subluxation, and to avoid hypoxia. There are potential adverse effects of early mobilisation, for example blood pressure changes and falls. There is indirect evidence that reduction of complications through early mobilisation contributes to the reduction of deaths and better outcomes in stroke unit care compared to general ward care,181 but evidence is lacking. There is, however, evidence to show that patients on stroke units currently spend a small proportion of their time (13% of the working day) engaged in activities with the potential to reduce the complications of immobility. The clinical questions to be addressed are whether patients with acute stroke should be mobilised early and whether there is any benefit in placing them in specific positions. One study (N=156) from China evaluated physiotherapy initiated within 1 week of stroke onset. The intervention consisted of one 45-minute session a day, 5 days a week for a total of 4 weeks. This was compared with patients who received no professional or regular physiotherapy for the entire time they were admitted in hospital. The use of a non-active treatment comparison represents a considerable methodological limitation of this study.

Weaknesses • If previous pregnancy occurs buy 12.5 mg coreg amex, • Heart diseases 25 mg coreg amex, • High blood pressure discount coreg 6.25mg without prescription, • Breast-feeding mother; and • Women who smoke and who are over 35 years old. Progestin only pill The content of progestin in the contraceptive pills is less than what is contained in the combined oral contraceptive pills. Weaknesses • Requires taking one pill every day without interruption and always at exactly the same time of the day and so is hard to always remember; • Less effective to prevent pregnancy compared to the combined oral contraceptive pills; and • Has problems such as irregularity of menstrual cycles, 42 Family Health Who uses single oral contraceptive pills? Procedures in the provision of single oral contraceptive pills: • Introduce yourself and greet politely the family planning service client; • Assess the client’s knowledge about family planning services and ask about her health conditions; • Ask if the client is on menstruation; • Register the client; • Show and demonstrate to the client the single oral contraceptive pills in the package; 43 Family Health • Carefully explain to the client to take one of the following steps; - To start taking the single contraceptive pills 24 hours after her menstruation started; or th - Start on the 5 day of menstrual period; • Carefully explain to the client to take every evening at the same time before sleep or sexual intercourse one pill from the package with water and without chewing; • The client should take regularly contraceptive pill every evening at the same time with or without sexual intercourse; • If the client forgets to take her pill, she must be told to take the missed pill and also continue on her normal schedule; • Even if the client forgets to take two successive pills, she must be told to take pills and continue on her normal schedule. In addition she must be advised to use condom; • A woman must be told to go to the health extension worker to seek advice when she faces health problems while on the single oral contraceptive pills; and • Carefully inform a woman who has received one-month supply of single oral contraceptive pills, to take the pills according to instructions and to come back on the exact date of next appointment. Mechanism of action • Condom holds the sperm and prevents it from spilling in the vagina and the cervix. Weaknesses • Most people are reluctant to use condoms; • Can be broken due to inappropriate use during sexual intercourse; 45 Family Health • Disposal of condoms need precaution • Creates itching feeling on the genitals of some males. Mechanism of action • Prevent ovulation; • Makes cervical mucus too thick and difficult for the sperm to pass through to the uterus; and • Makes the lining of the uterus too thin for the fertilized egg to implant itself. Who can use the injectables Clients who want to delay pregnancy for a specified time period; Clients who cannot take contraceptive estrogen containing contraceptive; Those who want to space birth; Comfortable and better quality contraceptive for many clients; Contraindications: Pregnancy or suspected for pregnancy; Vaginal bleeding that have not been medically cheeked and confirmed for any type of cause; 47 Family Health Breast cancer or suspected for breast cancer; If menstrual cycle has already stopped not because of pregnancy or breast feeding; Liver diseases or gall bladder diseases; Heart diseases; High blood pressure; and Post-natal and breastfeeding mothers should not use at least for six months. Implantable contraceptives: Noreplant is long acting contraceptives that contain progesterone hormone. Mechanism of action • Prevents the release of egg from the ovaries; and 48 Family Health • Thickens the cervical mucus and difficult for the sperm to pass through to the uterus; Advantages • Highly effective in preventing pregnancy; • Serves for a long period and avoids concern about frequent appointments and its daily administration; • Prevents excess menstrual bleeding; • The user can ask for the removal of the implants at any time when she decides to have a child or other reason. Contraindication: • Women suspected for pregnancy; • Those hiving cancer of the uterus, heart diseases and, liver diseases; • Those who have uterine bleeding for unknown causes; and • Are epileptic and are on anti-epileptic drug regularly. Role of health extension workers • Cannot insert the inplant and infer interested clients to the nearby Health Facility • Disseminate information or educate potential users • clients to nearby health facility • Undertake home visits to follow up Female voluntary surgical contraception: • This is a procedure that requires surgical intervention. Weaknesses: • As with any surgical procedure, there are always risks, including: - Haemorrhage - Infection - Anaesthetic complications - Visceral injury • Sterilization may fail from spontaneous re-canalization of a fallopian tube and may result in an ectopic pregnancy, blocked ducts, or fistula formation, but voluntary reversibility cannot be assumed. Advantages • Highly effective than all the other contraceptives; • Administered within few minutes • Prevention of pregnancy is ever lasting or permanent; and Disadvantage • Service requires adequate number of trained health workers; • Cannot be provided by health extension workers; • Cannot be reversed, once it is done; • Takes longer time counselling clients; and • There could exist minor problems related to the procedure. Reported failure rates per 100 users per year for different contraceptive methods vary greatly around the world, as can be been from the above table. Periodic abstinence (or natural family planning) is associated with 10- 30 pregnancies per 1000 users, while those relying on the diaphragm 56 Family Health experience 4-25 pregnancies per 100 and those using Spermicides experience 10-25 pregnancies 100. Women who use combined oral contraceptives experience 1 - 8 pregnancies per 100 users per year, while failure rates among those who rely on injectables and implants average less than 1 pregnancy per 100 annually. Practical Session Family Planning Methods Male condoms may be right for you There are a number of factors you should consider before deciding whether male condoms are the right contraceptive method for you. As with any method of contraception, you should first talk to your health care provider or a counsellor at your local clinic or hospital before using condoms as a contraceptive method. Lammay not be an appropriate method If all of the following are true: ♦ Your baby is less than six months old. As with any method of contraception, you should first talk to your health care provider or a counsellor at your local clinic or hospital before using withdrawal as a contraceptive method. Withdrawal may be an appropriate method If any of the following is true: ♦ You find other contraceptive methods unacceptable for religious or other reasons. You and your partner may start using withdrawal as soon as you resume sexual intercourse after the abortion. Are fertility awareness right method Fertility awareness methods include the calendar/rhythm method, the basal body temperature method, the cervical mucus method, and the standard days method. There are a number of factors you should 62 Family Health consider before deciding whether fertility awareness methods are right for you. Fertility awareness methods may be appropriate methods If any of the following is true: ♦ You find other contraceptive methods unacceptable for religious or other reasons. Fertility awareness methods are not appropriate methods If any of the following is true: ♦ You have a partner who is unwilling to avoid unprotected sexual intercourse during the fertile period of each cycle. In your survey do appropriate consultation of services such as: ♦ Decrease waiting time ♦ Take adequate time with the client ♦ Set conducive clinic hours and days ♦ Consider staff age and gender Family planning facilities ♦ Make waiting rooms adequate ♦ Adequate, ventilated well lighted examination rooms ♦ Use teaching aids/posters, charts, flip charts etc. It is an area where inter-sectoral collaboration with social workers, teachers, religious groups, agricultural workers etc is very appropriate. Counselling is the process of helping clients confirm or make informed and voluntary decisions about their individual care. It is a two-way exchange of information that involves listening to clients and informing them of their options. Informed choice is a voluntary, well-considered decision that an individual makes on the basis of options, information, and understanding. The decision making process should result in a free and informed decision by the individual about whether or not he or 67 Family Health she desires to obtain health services and, if so, what method or procedure he or she will choose and consent to receive. Informed consent is the communication between a client and a health extension worker that confirms the client has made an informed and voluntary choice to use or receive a medical method or procedure. Informed consent can only be obtained after the client has been given information about the nature of the medical procedure, associated risks and benefits, and other alternatives. Voluntary consent cannot be obtained by means of special inducement, force, fraud (criminal deception), deceit (dishonest trick), duress (compulsion), bias, or other forms of coercion or misrepresentation.