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1699

A medical mystery for Mother's Day...

I'd like to tell you a curious story. Jane was a 52 year old woman in need of a kidney transplant. Thankfully she had three loving sons who were all very happy to give her one of theirs. So Jane's doctors performed tests to find out which of the three boys would be the best match, but the results surprised everyone. In the words of Jeremy Kyle, the DNA test showed that Jane was not the mother of two of the boys... Hang on, said Jane, child birth is not something you easily forget. They're definitely mine. And she was right. It turns out Jane was a chimera. Chimerism is the existence of two genetically different cell lines in one organism. This can arise for a number of reasons- it can be iatrogenic, like when someone has an organ transplant, or it can be naturally occurring. In Jane's case, it began in her mum's womb, with two eggs that had been fertilised by different sperm creating two embryos. Ordinarily, they would develop into two non-identical twins. However in Jane's case the two balls of cells fused early in development creating one person with both cell lines. Thus when doctors did the first tissue typing tests on Jane, just by chance they had only sampled the 'yellow' cell line which was responsible for one of her sons. When they went back again they found the 'pink' cell line which had given rise to the other two boys. This particular type of human chimerism is thought to be pretty rare- there are only 30 case reports in the literature. (Though remarkably both House and CSI's Gil Grissom have encountered cases.) What happens far more frequently is fetal microchimerism- which occurs in pregnant women when cells cross the placenta from baby to mum. This is awesome because we used to think the placenta was this barrier which prevented any cells crossing over. Now we've found both cells and free floating DNA cross the placenta, and that the cells can hang around for decades after the baby was born. Why? As is often the case in medicine we're not sure but one theory is that the fetal cells might have healing properties for mum. In pregnant mice who've had a heart attack, fetal cells can travel to the mum's heart where the develop into new heart muscle to repair the damage. Whilst we're still in the early stages of understanding why this happens, we already have a practical application. In the United States today, a pregnant woman can have a blood test which isn't looking for abnormalities in her DNA but in that of her fetus. The DNA test isn't conclusive enough to be used to diagnose genetic conditions, but it is a good screening test for certain trisomies including Down's syndrome. Now, we started with a curious tale, so lets close with a curious fact, and one that's appropriate for Mother's Day: This exchange of cells across the placenta is a two way process. So you may well have some of your mum's cells rushing through your veins right now. In my case they're probably the ones that tell me to put on sensible shoes and put that boy down... (FYI: This is a story I originally posted on my own blog)  
Dr Catherine Carver
almost 7 years ago
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10
232

The Veins

Summary of the veins in the human body  
Philip Welsby
almost 9 years ago
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7
577

Clinical Anatomy Explained! The Development of Cardinal Veins and the Large Veins

This video goes into how the cardinal veins, a group of embryonic veins, interconnect, rescind, and develop to create the large veins of the body.  
youtube.com
almost 4 years ago
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6
85

Robot Draws Blood

This robot system can find a vein and place a needle at least as well as a human can. Veebot, a start-up in Mountain View, Calif., is hoping to automate draw...  
YouTube
over 5 years ago
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5
121

Superficial veins of the upper limb at the cubital fossa

After completion of this video session, it is expected that you will be able to: Describe the variation in the pattern of superficial veins at the roof of th...  
youtube.com
almost 4 years ago
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4
113

Coronary Arteries Walk Through

An overview coronary arteries with demonstration.  
Nicole Chalmers
almost 6 years ago
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4
126

Nerve and Blood Supply of the Tongue | Kenhub

This is an article listing all the nerves, arteries and veins responsible for the innervation and blood supply of the tongue. Start learning them here.  
kenhub.com
over 5 years ago
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4
118

Which systemic vein can be blocked by a tumor at the lung hilum?

This video is part of a playlist of short videos which are intended to combine multiple choice questions' answering experience with an improved understanding.  
youtube.com
almost 4 years ago
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4
93

Distribution of the circumflex branch of left coronary artery

This video is part of a playlist of short videos which are intended to combine multiple choice questions' answering experience with an improved understanding...  
youtube.com
almost 4 years ago
841
3
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Left Coronary Artery Angiogram

Normal angiogram of left coronary artery  
Rhys Clement
almost 10 years ago
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3
99

Coronary artery stents in Atherosclerosis

Atherosclerosis is the condition in which an artery wall thickens as the result of a build-up of fatty materials such as cholesterol.It most commonly becomes seriously symptomatic when interfering with the coronary circulation supplying the heart or cerebral circulation supplying the brain, and is considered the most important underlying cause of strokes, heart attacks, and most cardiovascular diseases, in general. A stent is a man-made 'tube' inserted into a natural passage/conduit in the body to prevent, or counteract, a disease-induced, localized flow constriction. Stents are used to counter narrowing of arteries due to plaque deposition and hardening.  
Nicole Chalmers
almost 6 years ago
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3
129

Clinical Consequences of Liver Disease

Vitamins A, D, E and K are all stored in the liver, as is vitamin B12. Therefore, in liver damage, you can’t store as many of these as you would like to.   Portal circulation Note that there are no valves in the portal circulation. The portal supply is 70% of the blood that the liver receives. The other 30% is supplied by the hepatic artery.   The four main veins that contribute to the portal system are: Splenic vein Superior mesenteric  
almostadoctor.com - free medical student revision notes
almost 6 years ago
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3
69

The Complete Guide to Vascular Ultrasound

This volume is a comprehensive how-to guide to ultrasound evaluation of vascular pathology. The book provides both the technical know-how and the analytical skills needed to obtain the maximum information from examinations and to accurately diagnose a given problem. Chapters provide detailed coverage of abdominal vasculature, peripheral arteries, hemodialysis and bypass grafts, peripheral veins, penile vessels, and the cerebrovascular system. Each chapter includes sections on anatomy, pathology, questions to ask the patient, examination techniques, diagnostic analysis, and other diagnostic tests related to the clinical problem. More than 100 full-color Doppler images demonstrate the full spectrum of pathologic findings.  
Google Books
almost 5 years ago
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2
358

Lower Limb Veins Overview - 3D Anatomy Tutorial

Lower limb veins anatomy tutorial. Check out the 3D app at http://AnatomyLearning.com. More tutorials available on http://AnatomyZone.com In this video tutor...  
youtube.com
almost 5 years ago
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2
77

Upper Limb Veins - 3D Anatomy Tutorial

Upper limb veins anatomy tutorial. Check out the 3D app at http://AnatomyLearning.com. More tutorials available on http://AnatomyZone.com. In this video tuto...  
youtube.com
over 4 years ago
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2
47

Orthostatic Hypotension - American Family Physician

Orthostatic hypotension is a physical finding defined by the American Autonomic Society and the American Academy of Neurology as a systolic blood pressure decrease of at least 20 mm Hg or a diastolic blood pressure decrease of at least 10 mm Hg within three minutes of standing. The condition, which may be symptomatic or asymptomatic, is encountered commonly in family medicine. In healthy persons, muscle contraction increases venous return of blood to the heart through one-way valves that prevent blood from pooling in dependent parts of the body. The autonomic nervous system responds to changes in position by constricting veins and arteries and increasing heart rate and cardiac contractility. When these mechanisms are faulty or if the patient is hypovolemic, orthostatic hypotension may occur. In persons with orthostatic hypotension, gravitational opposition to venous return causes a decrease in blood pressure and threatens cerebral ischemia. Several potential causes of orthostatic hypotension include medications; non-neurogenic causes such as impaired venous return, hypovolemia, and cardiac insufficiency; and neurogenic causes such as multisystem atrophy and diabetic neuropathy. Treatment generally is aimed at the underlying cause, and a variety of pharmacologic or nonpharmacologic treatments may relieve symptoms.  
aafp.org
almost 4 years ago
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1
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Focus On: Ultrasound-Guided Central Venous Access of the Internal Jugular Vein

Central venous cannulation (CVC) is an important procedure in the practice of emergency medicine.  
American College Of Emergency Medicine
over 9 years ago
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1
68

Cerebral Aneurysm

This is localised dilation of an artery within the brain. They rarely occur in veins. They are a major risk factor for subarachnoid haemorrhage.   Epidemiology & Aetiology Occur in 5% of the population Risk factors include: Arteriosclerosis Hypertension  
almostadoctor.com - free medical student revision notes
almost 6 years ago
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1
41

Cardiac Catheterization

Cardiac catheterization This is not necessarily the same as coronary angiography, although the two terms are sometimes used interchangeably. Cardiac catheterisation is the process by which you gain catheter access to the veins or arteries of the heart. Thus, in the procedures of coronary angiography, and angioplasty, you perform cardiac catheterisation as part of the procedure.    
almostadoctor.com - free medical student revision notes
almost 6 years ago
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1
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MedClip - Estimating Jugular Venous Pressure Heywood

Estimating Jugular Venous Pressure Heywood: Using neck veins to estimate central venous pressure. Created by J Thomas Heywood, special thanks to the Weaver family  
medclip.com
almost 6 years ago