The specialized nodal and conducting cells of the heart are responsible for heartbeat. These specialized nodal and conducting cells tend to contract weakly because they contain very few contractile cells (myofibrils). What makes these cells unique is that they can easily generate an action potential (electrical impulse that causes the heart to beat) without the assistance of neurotransmitters or any nervous system input like any regular neurons. Along with these special properties of self-excitability, these cells can also rapidly conduct impulses to atrial and ventricular muscles. This explains why after death, the heart continues pumping because of the nodal and conducting cells; this is because the nodal and conducting cells are not hooked up with any neurotransmitters. Therefore, these specialized cells provide a self-excitatory system for the heart to generate impulses and a transmission system for rapid conduction of impulses in the heart.
almost 7 years ago
Boosting men's testosterone levels could potentially prevent deaths from heart disease and type 2 diabetes, UK doctors and scientists say.
almost 7 years ago
These videos are designed for medical students studying for the USMLE step 1. Feel free to comment and suggest what you would like to see in the future, and ...
almost 7 years ago
In my own experience of GPs and stories from others, the widest variation in practice I have seen is of one particular type of patient. Middle aged/elderly, maybe a few cardiac risk factors, often with a history of reflux disease - presenting to GP with mild/moderate cardiac-sounding chest pain of days duration, which they are not generally concerned about. +/- equivocal histories of SOB, nausea, or sweating if pressed. My question is - is it sensible to send these people in via 999 blue lights? How will it help them? They are often taking aspirin already, and presumably after days of ischaemia the myocardium is well and truly dead if it was MI and so they wouldn't be candidates for PCI or thrombolysis. It would seem to me that the cardiac problem to rule out in these patients is unstable angina, not MI. Is there anything to be done for this presentation cardiac-wise other than aspirin and referral to chest pain clinic, if not happy to send home with reassurance re: oesophageal spasm?
almost 9 years ago
BP and cholesterol are major contributors to cardiovascular disease. Most people only start becoming aware of how high their BP and cholesterol is in middle age. Often by then there has already been significant damage to the cardiovascular system. Would it be sensible for health conscious young people to ask their GP for a cholesterol blood test roughly once a year? Therefore, enabling them to alter their diet and control their weight at a younger age and potentially reduce later heart disease.
over 8 years ago
Can someone pleeeaase tell me what territories the LCX supplies in a left dominant circulation? My best guess is this: Usually people are right dominant, so the RCA supplies (the RV, the inferior LV AND the posterior LV / septum, as it gives off the PDA. When people are left dominant, the LCX take over the posterior septum / LV, but leaves the inferior wall to the RCA... Am I about right or is there more to it? Thanks Elliot
over 7 years ago
This month’s case is by Barbara J. Mroz, M.D. and Robin R. Preston, Ph.D., author of Lippincott’s Illustrated Reviews: .Physiology (ISBN: 9781451175677). For more information, or to purchase your copy, visit: http://tiny.cc/PrestonLIR, with 15% off using the discount code: MEDUCATION. The case below is followed by a choice of diagnostic tests. Select the one lettered selection that would be most helpful in diagnosing the patient’s condition. The Case A 54-year-old male 2 pack-per-day smoker presents to your office complaining of cough and shortness of breath (SOB). He reports chronic mild dyspnea on exertion with a daily cough productive of clear mucus. During the past week, his cough has increased in frequency and is now productive of frothy pink-tinged sputum; his dyspnea is worse and he is now short of breath sometimes even at rest. He has had difficulty breathing when lying flat in bed and has spent the past two nights sleeping upright in a recliner. On physical examination, he is a moderately obese male with a blood pressure of 180/80 mm Hg, pulse of 98, and respiratory rate of 22. His temperature is 98.6°F. He becomes winded from climbing onto the exam table. Auscultation of the lungs reveals bilateral wheezing and crackles in the lower posterior lung fields. There is pitting edema in the lower extremities extending up to the knees. Question Which if the following tests would be most helpful in confirming the correct diagnosis? A. Spirometry B. Arterial blood gas C. Complete blood count D. B-type natriuretic peptide blood test E. Electrocardiogram Answer? The correct answer is B-type natriuretic peptide blood test. Uncomfortable breathing, or feeling short of breath, is a common medical complaint with multiple causes. When approaching a patient with dyspnea, it is helpful to remember that normal breathing requires both a respiratory system that facilitates gas exchange between blood and the atmosphere, and a cardiovascular system that transports O2 and CO¬2 between the lungs and tissues. Dysfunction in either system may cause dyspnea, and wheezing (or bronchospasm) may be present in both cardiac and pulmonary disease. In this patient, the presence of lower extremity edema and orthopnea (discomfort when lying flat) are both suggestive of congestive heart failure (CHF). Elevated blood pressure (systolic of 180) and a cough productive of frothy pink sputum may also be associated symptoms. While wheezing could also be caused by COPD (chronic obstructive pulmonary disease) in the setting of chronic tobacco use, the additional exam findings of lung crackles and edema plus systolic hypertension are all more consistent with CHF. What does the B-type natriuretic peptide blood test tell us? When the left ventricle (LV) fails to maintain cardiac output (CO) at levels required for adequate tissue perfusion, pathways are activated to increase renal fluid retention. A rising plasma volume increases LV preload and sustains CO via the Frank-Starling mechanism. Volume loading also stimulates cardiomyocytes to release atrial- (ANP) and B-type (BNP) natriuretic peptides. BNP has a longer half-life than ANP and provides a convenient marker for volume loading. Plasma BNP levels are measured using immunoassay; levels >100 pg/mL are suggestive of overload resulting in heart failure. How does heart failure cause dyspnea? Increasing venous pressure increases mean capillary hydrostatic pressure and promotes fluid filtration from the vasculature. Excess filtration from pulmonary capillaries causes fluid accumulation within the alveoli (pulmonary edema) and interferes with normal gas exchange, resulting in SOB. Physical signs and symptoms caused by high volume loading include: (1) Lung crackles, caused by fluid within alveoli (2) Orthopnea. Reclining increases pulmonary capillary hydrostatic pressure through gravitational effects, worsening dyspnea when lying flat. (3) Pitting dependent edema caused by filtration from systemic capillaries, an effect also influenced by position (causing edema in the lower legs as in our ambulatory patient or in dependent areas like the sacrum in a bedridden patient). What would an electrocardiogram show? Heart failure can result in LV hypertrophy and manifest as a left axis deviation on an electrocardiogram (ECG), but some patients in failure show a normal ECG. An ECG is not a useful diagnostic tool for dyspnea or CHF per se. Wouldn’t spirometry be more suitable for diagnosing the cause of dyspnea in a smoker? Simple spirometry will readily identify the presence of airflow limitation (obstruction) as a cause of dyspnea. It's a valuable test to perform in any smoker and can establish a diagnosis of chronic obstructive pulmonary disease (COPD) if abnormal. While this wheezing patient is an active smoker who could have airflow obstruction, the additional exam findings above point more to a diagnosis of CHF. What would an arterial blood gas show? An arterial blood gas measures arterial pH, PaCO¬2, and PaO2. While both CHF and COPD could cause derangements in the values measured, these abnormalities would not necessarily be diagnostic (e.g., a low PaO2 could be seen in both conditions, as could an elevated PaCO¬2). Would a complete blood count provide useful information? A complete blood count could prove useful if anemia is a suspected cause of dyspnea. Test result BNP was elevated (842 pg/mL), consistent with CHF. Diuretic treatment was initiated to help reduce volume overload and an afterload reducing agent was started to lower blood pressure and improve systolic function.
Lippincott Williams & Wilkins
over 8 years ago
Many know that engaging in regular physical activity and exercise will tremendously improve one’s health and overall well-being. This goes the same, if not tenfold, for individuals suffering with diabetes. However, before rushing in a high intensity or physically straining physical régime, consult with your diabetes care provider. Make sure to discuss your plans take note of any precautions that may be needed to be made prior or during these activities. It will be interesting to know that individuals with type 2 diabetes who do participate in some exercise (even at work) reduce their risk for heart disease. Remember that a physical examination that focuses on the signs and symptoms of diseases affecting the heart and blood vessels, eyes, feet, nervous system, and kidneys must be made in advance before any extensive work out plan takes into action. Any strenuous strength training or high-impact exercise is generally not recommended for people with uncontrolled diabetes. Such strain caused by these exercises can weaken blood vessels in the eyes of patients who suffer from the common diabetic complication known as retinopathy. High-impact exercise can also injure blood vessels in the feet. In fact, diabetes can contribute to foot problems in several ways: diabetic neuropathy; which is a nerve disorder that causes numbing and pain in the hands, legs and feet as well as damage to internal organs; also poor circulation to the feet is another problem that can be associated due to diabetes. Keeping this in mind it is imperative to keeping your feet healthy, investing in some great therapeutic footwear like these can be a great step in moving toward healthy feet! One thing is for sure, physical activity can increase the health in anyone’s life. Always make sure to take care of your body and take the extra precautions needed in order to maintain proper health.
over 8 years ago
Introduction to Obesity One of my favourite past-times is to sit in a bar, restaurant, café or coffee shop and people watch. I am sure many of you reading this also enjoying doing this too. People are fascinating and it is intriguing to observe: what they do; how they act; what they wear and what they look like. My family and I have always observed those around us and discussed interesting points about others that we have noticed. When I first came up to visit Birmingham University my family all sat in a coffee shop in the centre of Birmingham and noticed that on average the people walking past us looked much slimmer than what we were used to seeing back in south Wales. Now, when I go home it is more painfully obvious than ever that the people in my home region are much, much heavier than they should be and are noticeably bigger than they used to be even a short number of years ago. This change in the population around me is what first made me seriously think about obesity, as a major problem affecting the world today. Nowadays obesity is all around us! It is noticeable, it is spreading and it should worry us all. Not just for our own individual health but also for the health of our society. Obesity affects everything from the social dynamic of families, to relationships at school or work, to how much the NHS costs to run. Obesity is a massive problem and if we as a society don’t start getting to grips with it, then it will have huge implications for all of us! I am currently in my 5th year at medical school. While I have been here I have taken a keen interest in obesity. The physiology, the psychology, the anatomy, the statistics and the wider affects on society of obesity have all been covered in curriculum lectures and extra curriculum lectures. I have taken part in additional modules on these subjects and sort out many experts in this field while on hospital placements. Obesity is fascinating for some many reasons and I thought that it would be a great topic to write some blogs about and hopefully start some discussions. Warning For my first blog on the topic of obesity I quickly want to write a bit about myself and my battle with weight. Everyone’s favourite topic is themselves, but I like to think that’s not why I have written this and I hope it doesn’t come across as a narcissistic ramble. I don’t intend to try and make myself come off well or suggest that I have all the answers (because I know very well that I don’t) and I hope it doesn’t come across like that. I want to write a bit of an autobiography because I wish to demonstrate how easy it is to go from a chunky kid to a technically obese teenager to a relatively fat adult without really realising what was happening. Chunky Child to Fat adult While planning this blog I realised that my Meducation profile picture was taken when I was at my all time fattest. At the graduation ceremony at the end of my 3rd year at university after completing my intercalation I was over 19 stones. At 6 foot 2” this gave me a BMI of >33 which is clinically obese. I had a neck circumference of >18”, a chest circumference of 48”, a waist of >40”, a seat of >52” and a thigh circumference of >28” per leg. Why do I know all of these rather obscure measurements? Partly because I am quite obsessive but mainly because I had to go to buy a tailor made suit because I could no longer buy a suit from a shop that I could fit into and still be able to move in. The only options left to me where massive black tent-suits or to go to a tailors. After the graduation I sat down at my computer (whilst eating a block of cheese) and compared my face from the graduation photos to pictures I had taken at the start of university and the difference in shape and size was amazingly obvious. I had got fat! I realised that if I had a patient who was my age and looked like me with my measurements then I would tell him to lose weight for the good of his health. So, I decided that finally enough was enough and I that I should do something about it. Before I describe how I got on with the weight management I will quickly tell the back story of how I came to be this size. I have always been a big guy. I come from a big family. I have big bones. I had “puppy fat”. I was surrounded by people who ate too much, ate rubbish and were over weight themselves, so I didn’t always feel that there was anything wrong with carrying a bit of tub around the middle. When I went to comprehensive school at age 12 I had a 36” waist. I thought I carried the weight quite well because I was always tall and had big ribs I could sort of hide the soft belly. Soon after arriving at the new school I had put on more weight and for the first time in my life I started to get bullied for being fat! And I didn’t like it. It made me really self-aware and knocked my confidence. Luckily, we started being taught rugby in PE lessons and I soon found that being bigger, heavier and stronger than everyone else was a massive advantage. I soon got my own back on the bullies… there is nowhere to hide on a rugby field! This helped me gain my confidence and I realised that the only way to stop the bullying was to confront the bullies and to remake myself in such a way as that they would be unable to bully me. I decided to take up rugby and to start getting fit. I joined a local club, starting playing regularly, joined a gym and was soon looking less tubby. Reflecting (good medical jargon, check) on my life now I can see that my PE teachers saved me. By getting me hooked on rugby they helped get me into many other sports and physical activity in general and without their initial support I think my life would have gone very differently. Rugby was my saviour and also later on a bit of a curse. As I grew up I got bigger and bigger but also sportier. I started putting muscle on my shoulders, chest and legs which I was convinced hid how fat I actually was. I developed a body shape that was large but solid. I was convinced that although I was still carrying lots of excess weight I no longer looked tubby-fat. When I was 14 my PE teachers introduced me to athletics. They soon realised that I was built for shot putt and discuss throwing and after some initial success at small school competitions I joined a club and took it up seriously. At this age I had a waist of about 38” but was doing about 3-4 hours of exercise almost everyday, what with rugby, running, gym, swimming and athletics – in and out of school. My weight had by now increased to roughly 15 stones and my BMI was over 30. I was physically fit and succeeding at sport but still carrying quite a lot of fat. I no longer thought of myself as fat but I knew that other people did. Between the ages of 14 and 18 I started to be picked for regional teams in rugby and for international athletic competitions for Wales. My sporting career was going very well but the downside of this was that I was doing sports that benefited from me being heavier. So the better I got the heavier I wanted to become. I got to the stage where I was eating almost every hour and doing my best to put on weight. At the time I thought that I was putting on muscle and being a huge, toned sports machine. It took me a while to realise that actually my muscles weren't getting any bigger but my waist was! By the time I had completed my A-levels I was for the first time over 18 stones and had a waste of nearly 40”. So, at this point I was doing everything that I had been told that would make me more adapted for my sport and I was succeeding but without noticing it I was actually putting on lots of useless excess weight that in the long term was not good for me! During my first year of university I gave up athletics and decided that I no longer needed to be as heavy for my sports. This decision combined with living away from home, cooking for myself and walking over an hour a day to and from Uni soon began to bear fruit. By the summer of my first year at Uni, aged 19, I had for the first time in my life managed to control my weight. When I came to Uni I was 18 stone. After that first year I was down to 14 stone – a weight I had not been since I was 14 years old! I had played rugby for the Medical school during my first year but as a 2nd row/back row substitute. These positions needed me to be fit and not necessarily all that heavy and this helped me lose the weight. During my second year I began to start as a 2nd row and was soon asked to help out in the front row. I enjoyed playing these positions and again realised that I was pretty good at it and that extra weight would make me even better. So between 2nd year and the end of 3rd year I had put on nearly 5 stone in weight and this put me back to where I started at my graduation at the end of 3rd year. The ironic and sad thing is about all this that the fatter, less “good looking” and unhealthier I became, the better I was adapted for the sports I had chosen. It had never occurred to me that being good at competitive sports might actually be bad for my health. The Change and life lessons learnt At the beginning of my 4th year I had realised that I was fatter than I should be and had started to pick up a number of niggly injuries from playing these tough, body destroying positions in rugby. I decided that I would start to take the rugby less seriously and aim to stay fit and healthy rather than be good at a competitive sport. With this new attitude to life I resolved to lose weight. Over the course of the year there were a number of ups and downs. I firstly went back to all the men’s health magazines that I had stock piled over the years and started to work out where I was going wrong with my health. After a little investigation it became apparent that going running and working out in the gym was not enough to become healthy. If you want to be slim and healthy then your diet is far more important than what physical activity you do. My diet used to be almost entirely based on red meat and carbs: steak, mince, bacon, rice and pasta. Over the year I changed my diet to involve far more vegetables, more fibre, more fruit, more salad and way less meat! The result was that by Christmas 2012 I was finally back below 18 stones. The diet had started to have benefits. Then came exams! By the end of exams in April 2013 I had gone back up 19 stones and a waist of >40”. I was still spending nearly 2 hours a day doing weights in the gym and running or cycling 3 times a week. Even with all this exercise and a new self- awareness of my size, a terrible diet over the 3 week exam period had meant that I gained a lot of fat. After exams I went travelling in China for 3 weeks. While I was there I ate only local food and lots of coffee. Did not each lunch and was walking around exploring for over 6 hours a day. When I got back I was 17.5 stone, about 106kg. My waist had shrunk back down to 36” and I could fit into clothes I had not worn in years. This sudden weight loss was not explained by traveller’s diarrhoea or any increased activity above normal. What made me lose weight was eating a fairly healthy diet and eating far less calories than I normally would. I know this sounds like common sense but I had always read and believed that if you exercised enough then you could lose weight without having to decrease your calorie intake too much. I have always hated the sensation of being hungry and have always eaten regular to avoid this awful gnawing sensation. I had almost become hunger-phobic, always eating when given the opportunity just in case I might feel hungry later and not because I actually needed to eat. The time in China made me realise that actually I don’t NEED to eat that regularly and I don’t NEED to eat that much. I can survive perfectly ably without regular sustenance and have more than enough fat stores to live my life fully without needing to each too much. My eating had just become a habit, a WANT and completely unnecessary. After being home for a month I have had some ups and downs trying to put my new plans into action. Not eating works really easily in a foreign country, where it’s hot, you are busy and you don’t have a house full of food or relatives that want to feed you. I have managed to maintain my weight around 17.5 stones and kept my waist within 36” trousers. I am counting that as a success so far. The plan from now on is to get my weight down to under 16.5 stones because I believe that as this weight I will not be carrying too much excess weight and my BMI will be as close to “not obese” as it is likely to get without going on a starvation diet. I intend to achieve this goal by maintain my level of physical activity – at least 6 hours of gym work a week, 2 cardio sessions, tennis, squash, cycling, swimming and golf as the whim takes me. BUT MORE IMPORTANTLY, I intend to survive off far fewer calories with a diet based on bran flakes, salad, fruit, nuts, chicken and milk. I am hoping that this very simple plan will work! Conclusion Writing this short(-ish) autobiography was quite cathartic and I would really recommend it for other people who are trying to remake themselves. Its helped me put my thoughts in order. Over the years I wanted to lose weight because I wanted to look better. This desire has now matured into a drive to be not just slimmer but healthier; I no longer want to be slimmer just for the looks but also to reduce the pressure on my joints, to reduce the pressure on my cardiovascular system, to reduce my risks of being fat when I am older, to hopefully reduce the risk of dying prematurely and to some extent to make life cheaper – eating loads of meat to prevent hunger is expensive! I hope this blog has been mildly interesting, but also informative of just how easy it is for even a health conscious, sporty individual to become fat in our society. I also wanted to document how difficult it is to lose weight and maintain that new lower weight for any prolonged length of time. At some point I would like to do a blog on the best methods for weight loss but that may have to wait until I have found what works for me and if I do actually manage to achieve my goals. Would be a bit hypercritical to write such a blog while still having a BMI yo-yoing around 32 I feel! Thought for the day 1 - Gaining wait is easy, becoming fat is easy, losing fat is also technically easy! The hard part is developing AND then maintaining a healthy mental attitude towards your weight. The human body has evolved to survive starvation. We are almost perfectly made to build up high density fat stores just in case next year’s crops fail and we have to go a few months on broth. I will say it again – We are designed to survive hard conditions! The problem with the modern world and with modern society is that we no longer have to fight to survive. For the first time in human history food is no longer scarce… it is in fact incredibly abundant and cheap (http://www.youtube.com/watch?v=-Z74og9HbTM). It is no surprise that when a human body is allowed to eat want and how much it craves and then do as little activity as possible, that it puts on fat very quickly. This has to be one of the major ironies of our age – When the human race has evolved society enough that we no longer need to have fat stores in case of disaster, that we are now the fattest humans have ever been! 2 – The best bit of advice I was ever given is this: “Diets ALWAYS fail! No matter what the diet or how determined you are, if you diet then within 2 years you will be the same weight or heavier than you are now. The only way to a healthy body is through a healthy LIFESTYLE CHANGE! You have to make changes that you are prepared to keep for a long time.”
over 8 years ago
Metaphors and analogies have long been used to turn complex medical concepts into everyday ones, albeit with fancy terminology. Having been involved with many 3D animations on the topics of Blood Pressure, arteriosclerosis, cholesterol and the like, we find that often a metaphor goes a long way to building understanding, credibility and even compliance with patients. One of my favorite analogies is what we call the arterial highway. Much like their tarmacked counterparts, arteries act as conduits for all the parts that make your body go. A city typically uses highways, gas lines, water pipes, railways and other infrastructure to distribute important materials to its people. Your body is much the same, except that it does it all in one system, the cardiovascular system. This is used to deliver nutrients, extract waste, transport and deliver oxygen and even to maintain the temperature! The arteries can do all these things because of their smart three-layered structure. Our arteries consist of a muscular tube lined by smooth tissue. They have three layers named – the Adventitia, Media and Intima. Each is designed with a specific function and through the magic of evolution has developed to perform its function perfectly. The first is the Tunica Adventitia, or just adventitia. It is a strong outer covering over the arteries and veins. It has special tissues that are fibrous. The fibers let the arteries flex, expanding and contracting to accommodate changes in blood pressure as the blood flows past it. Unlike a steel pipe, arteries pulsate and so must be at once be flexible, and strong. Tunica Media - the middle layer of the walls of arteries and veins is made up of a smooth muscle with some elasticity built in. This layer expands and contracts in a rhythmic fashion, much like a Wave at a baseball game, as blood moves along it. The media layer is thicker in arteries than in veins, and importantly so, as arteries carry blood at a higher pressure than veins. The innermost layer of arteries and veins is the Tunica Intima. In arteries, this layer is composed of an elastic lining and smooth endothelium - a thin sheet of cells that form a type of skin over the surface. The elastic tissue present in the artery can stretch and return, allowing the arteries to adapt to changes in flow and blood pressure. The intima is also a very smoothe, slick layer so that blood can easily flow past it. Every layer of the artery has developed evolutionary traits that help your arterial system to maintain flexibility, strength and promote blood flow. Diseases and conditions like high cholesterol or high blood pressure, diabetes and others prevent the arteries from doing their function well by creating blockages or increasing the stress on one or more of the layers. For example, high blood pressure causes rips in the smooth lining of the Intima. Anybody who has experienced a pipe burst in a house knows that the damage can be extreme and can never fully be restored. Understanding the delicate functions of the arterial structure gives good incentive to treat them better. Conditions like high blood pressure, high cholesterol and lifestyle diseases such as diabetes create tears, holes, blockages, and can disrupt the functions of one or more layers. Getting patients to visualize the effect of bad eating habits on their anatomy helps to increase patient compliance. In modern society, the concept of highways goes hand in hand with the concept of traffic jams. Patients understand that the arterial highway is one that can never be jammed.
Mr. Rohit Singh
over 8 years ago
Great people make mistakes. Unfortunately, medicine is a subject where mistakes are not tolerated. Doctors are supposed to be infallible; or, at least, that is the present dogma. Medical students regularly fall victim to expecting too much of themselves, but this is perhaps not a bad trait when enlisting as a doctor. If it weren’t for mistakes in our understanding, then we wouldn’t progress. Studying a BSc in Anatomy has exposed me to the real world of science – where the negative is just as important as the positive. What isn’t there is just as important as what is. If you look into the history of Anatomy, it truly is a comedy of errors. So, here are three top mistakes by three incredibly influential figures who still managed to be remembered for the right reasons. 3. A Fiery Stare Culprit: Alcmaeon of Croton Go back far enough and you’ll bump into someone called Alcmaeon. Around the 5th century, he was one of the first dissectors – but not an anatomist. Alcmaeon was concerned with human intellect and was desperately searching for the seat of the soul. He made a number of major errors - quite understandable for his time! Alcmaeon insisted that sleep occurs when the blood vessels filled and we wake when they empty. Perhaps the most outrageous today is the fact that he insisted the eyes contained water both fire and water… Don’t be quick to mock. Alcmaeon identified the optic tract, the brain as the seat of the mind (along with Herophilus) and the Eustachian tubes. 2. Heart to Heart Culprit: Claudius Galen Legend has it that Galen’s father had a dream in which an angel/deity visited him and told him that his son would be a great physician. That would have to make for a pretty impressive opening line in a personal statement by today’s standards. Galen was highly influential on modern day medicine and his treatise of Anatomy and healing lasted for over a thousand years. Many of Galen’s mistakes were due to his dissections of animals rather than humans. Unfortunately, dissection was banned in Galen’s day and where his job as physician to the gladiators provided some nice exposed viscera to study, it did not allow him to develop a solid foundation. Galen’s biggest mistake lay in the circulation. He was convinced that blood flowed in a back and forth, ebb-like motion between the chambers of the heart and that it was burnt by muscle for fuel. Many years later, great physician William Harvey proposed our modern understanding of circulation. 1. The Da Vinci Code Culprit: Leonardo Da Vinci If you had chance to see the Royal Collection’s latest exhibition then you were in for a treat. It showcased the somewhat overlooked anatomical sketches of Leonardo Da Vinci. A man renowned for his intelligence and creativity, Da Vinci also turns out to be a pretty impressive anatomist. In his sketches he produces some of the most advanced 3D representations of the human skeleton, muscles and various organs. One theory of his is, however, perplexing. In his sketches is a diagram of the spinal cord……linked to penis. That’s right, Da Vinci was convinced the two were connected (no sexist comments please) and that semen production occurred inside the brain and spinal cord, being stored and released at will. He can be forgiven for the fact that he remarkably corrected himself some years later. His contributions to human physiology are astounding for their time including identification of a ‘hierarchal’ nervous system, the concept of equal ‘inheritence’ and identification of the retina as a ‘light sensing organ’. The list of errors is endless. However, they’re not really errors. They’re signposts that people were thinking. All great people fail, otherwise they wouldn’t be great.
about 8 years ago