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Leopold's Maneuvers for Childbirth Mohamed 34,315 Views • 2 years ago

Leopold's Maneuvers are difficult to perform on obese women and women who have hydramnios. The palpation can sometimes be uncomfortable for the woman if care is not taken to ensure she is relaxed and adequately positioned. To aid in this, the health care provider should first ensure that the woman has recently emptied her bladder. If she has not, she may need to have a straight urinary catheter inserted to empy it if she is unable to micturate herself. The woman should lie on her back with her shoulders raised slightly on a pillow and her knees drawn up a little. Her abdomen should be uncovered, and most women appreciate it if the individual performing the maneuver warms their hands prior to palpation. First maneuver: Fundal Grip While facing the woman, palpate the woman's upper abdomen with both hands. A professional can often determine the size, consistency, shape, and mobility of the form that is felt. The fetal head is hard, firm, round, and moves independently of the trunk while the buttocks feel softer, are symmetric, and the shoulders and limbs have small bony processes; unlike the head, they move with the trunk. Second maneuver After the upper abdomen has been palpated and the form that is found is identified, the individual performing the maneuver attempts to determine the location of the fetal back. Still facing the woman, the health care provider palpates the abdomen with gentle but also deep pressure using the palm of the hands. First the right hand remains steady on one side of the abdomen while the left hand explores the right side of the woman's uterus. This is then repeated using the opposite side and hands. The fetal back will feel firm and smooth while fetal extremities (arms, legs, etc.) should feel like small irregularities and protrusions. The fetal back, once determined, should connect with the form found in the upper abdomen and also a mass in the maternal inlet, lower abdomen. Third maneuver: Pawlick's Grip In the third maneuver the health care provider attempts to determine what fetal part is lying above the inlet, or lower abdomen.[2] The individual performing the maneuver first grasps the lower portion of the abdomen just above the symphysis pubis with the thumb and fingers of the right hand. This maneuver should yield the opposite information and validate the findings of the first maneuver. If the woman enters labor, this is the part which will most likely come first in a vaginal birth. If it is the head and is not actively engaged in the birthing process, it may be gently pushed back and forth. The Pawlick's Grip, although still used by some obstetricians, is not recommended as it is more uncomfortable for the woman. Instead, a two-handed approach is favored by placing the fingers of both hands laterally on either side of the presenting part. Fourth maneuver The last maneuver requires that the health care provider face the woman's feet, as he or she will attempt to locate the fetus' brow. The fingers of both hands are moved gently down the sides of the uterus toward the pubis. The side where there is resistance to the descent of the fingers toward the pubis is greatest is where the brow is located. If the head of the fetus is well-flexed, it should be on the opposite side from the fetal back. If the fetal head is extended though, the occiput is instead felt and is located on the same side as the back. Cautions Leopold's maneuvers are intended to be performed by health care professionals, as they have received the training and instruction in how to perform them. That said, as long as care taken not to roughly or excessively disturb the fetus, there is no real reason it cannot be performed at home as an informational exercise. It is important to note that all findings are not truly diagnostic, and as such ultrasound is required to conclusively determine the fetal position.

Neurotransmitter in action 3D Animation Mohamed 19,756 Views • 2 years ago

Neurotransmitter 3D Animation
on Tuesday, December 21, 2010

Neurotransmitters are endogenous chemicals which transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to receptors in the membrane on the postsynaptic side of the synapse. Release of neurotransmitters usually follows arrival of an action potential at the synapse, but may also follow graded electrical potentials. Low level "baseline" release also occurs without electrical stimulation. Neurotransmitters are synthesized from plentiful and simple precursors, such as amino acids, which are readily available from the diet and which require only a small number of biosynthetic steps to convert. The chemical identity of neurotransmitters is often difficult to determine experimentally. For example, it is easy using an electron microscope to recognize vesicles on the presynaptic side of a synapse, but it may not be easy to determine directly what chemical is packed into them. The difficulties led to many historical controversies over whether a given chemical was or was not clearly established as a transmitter. In an effort to give some structure to the arguments, neurochemists worked out a set of experimentally tractable rules. According to the prevailing beliefs of the 1960s, a chemical can be classified as a neurotransmitter if it meets the following conditions: * There are precursors and/or synthesis enzymes located in the presynaptic side of the synapse. * The chemical is present in the presynaptic element. * It is available in sufficient quantity in the presynaptic neuron to affect the postsynaptic neuron; * There are postsynaptic receptors and the chemical is able to bind to them. * A biochemical mechanism for inactivation is present. There are many different ways to classify neurotransmitters. Dividing them into amino acids, peptides, and monoamines is sufficient for some classification purposes. Major neurotransmitters: * Amino acids: glutamate, aspartate, D-serine, γ-aminobutyric acid (GABA), glycine * Monoamines and other biogenic amines: dopamine (DA), norepinephrine (noradrenaline; NE, NA), epinephrine (adrenaline), histamine, serotonin (SE, 5-HT), melatonin * Others: acetylcholine (ACh), adenosine, anandamide, nitric oxide, etc. In addition, over 50 neuroactive peptides have been found, and new ones are discovered regularly. Many of these are "co-released" along with a small-molecule transmitter, but in some cases a peptide is the primary transmitter at a synapse. β-endorphin is a relatively well known example of a peptide neurotransmitter; it engages in highly specific interactions with opioid receptors in the central nervous system. Single ions, such as synaptically released zinc, are also considered neurotransmitters by some[by whom?], as are some gaseous molecules such as nitric oxide (NO) and carbon monoxide (CO). These are not classical neurotransmitters by the strictest definition, however, because although they have all been shown experimentally to be released by presynaptic terminals in an activity-dependent way, they are not packaged into vesicles. By far the most prevalent transmitter is glutamate, which is excitatory at well over 90% of the synapses in the human brain. The next most prevalent is GABA, which is inhibitory at more than 90% of the synapses that do not use glutamate. Even though other transmitters are used in far fewer synapses, they may be very important functionally—the great majority of psychoactive drugs exert their effects by altering the actions of some neurotransmitter systems, often acting through transmitters other than glutamate or GABA. Addictive drugs such as cocaine and amphetamine exert their effects primarily on the dop

Aortic Aneurysm 3D Animation Mohamed 18,376 Views • 2 years ago

Most intact aortic aneurysms do not produce symptoms. As they enlarge, symptoms such as abdominal pain and back pain may develop. Compression of nerve roots may cause leg pain or numbness. Untreated, aneurysms tend to become progressively larger, although the rate of enlargement is unpredictable for any individual. Rarely, clotted blood which lines most aortic aneurysms can break off and result in an embolus. They may be found on physical examination. Medical imaging is necessary to confirm the diagnosis. Symptoms may include: anxiety or feeling of stress; nausea and vomiting; clammy skin; rapid heart rate. In patients presenting with aneurysm of the arch of the aorta, a common symptom is a hoarse voice as the left recurrent laryngeal nerve (a branch of the vagus nerve) is stretched. This is due to the recurrent laryngeal nerve winding around the arch of the aorta. If an aneurysm occurs in this location, the arch of the aorta will swell, hence stretching the left recurrent laryngeal nerve. The patient therefore has a hoarse voice as the recurrent laryngeal nerve allows function and sensation in the voicebox. Abdominal aortic aneurysms, hereafter referred to as AAAs, are the most common type of aortic aneurysm. One reason for this is that elastin, the principal load-bearing protein present in the wall of the aorta, is reduced in the abdominal aorta as compared to the thoracic aorta (nearer the heart). Another is that the abdominal aorta does not possess vasa vasorum, hindering repair. Most are true aneurysms that involve all three layers (tunica intima, tunica media and tunica adventitia), and are generally asymptomatic before rupture. The most common sign for the aortic aneuysm is the Erythema nodosum also known as leg lesions typically found near the ankle area. The prevalence of AAAs increases with age, with an average age of 65–70 at the time of diagnosis. AAAs have been attributed to atherosclerosis, though other factors are involved in their formation. An AAA may remain asymptomatic indefinitely. There is a large risk of rupture once the size has reached 5 cm, though some AAAs may swell to over 15 cm in diameter before rupturing. Before rupture, an AAA may present as a large, pulsatile mass above the umbilicus. A bruit may be heard from the turbulent flow in a severe atherosclerotic aneurysm or if thrombosis occurs. Unfortunately, however, rupture is usually the first hint of AAA. Once an aneurysm has ruptured, it presents with a classic pain-hypotension-mass triad. The pain is classically reported in the abdomen, back or flank. It is usually acute, severe and constant, and may radiate through the abdomen to the back. The diagnosis of an abdominal aortic aneurysm can be confirmed at the bedside by the use of ultrasound. Rupture could be indicated by the presence of free fluid in potential abdominal spaces, such as Morison's pouch, the splenorenal space (between the spleen and left kidney), subdiaphragmatic spaces (underneath the diaphragm) and peri-vesical spaces. A contrast-enhanced abdominal CT scan is needed for confirmation. Only 10–25% of patients survive rupture due to large pre- and post-operative mortality. Annual mortality from ruptured abdominal aneurysms in the United States alone is about 15,000. Another important complication of AAA is formation of a thrombus in the aneurysm.

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