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Degree: Medicine (Bachelors) - Cambridge University
Hi there! My name is Ashwin, and I am a second year undergraduate reading medicine at the University of Cambridge. I passed my first year with first class honours, ranking third in the entire year group. I've always been interested in the fundamental sciences that underpin how our body can function appropriately in response to the changing demands imposed. This means that for starters, I have approached learning maths and science with a broad conceptual framework before honing in on the details. In turn, this ensures a deeper understanding, which I hope I will be able to convey through my tutorials.
My previous experience includes voluntarily tutoring maths at both Kumon and "Champions Academy," the latter being a tutorial programme for GCSE maths, targeted at impoverished students of diverse cultural backgrounds. In this setting, my patience and approachability enabled them to be frank about what they did not understand, so I could construct my sessions more effectively for everyone involved. I have also regularly engaged in more informal peer-to-peer tutoring for maths/science both on the curriculum, and above and beyond the curriculum, in the form of olympiads.
It will be my aim to seek out any fundamental gaps in the knowledge required, and help to make even quite difficult ideas seem more easy to understand, perhaps through using helpful aids or analogies. Whilst it is no doubt important to have knowledge of the exam specification in order to pass, in the long term, it is the ability to creatively solve complex problems using fundamental principles that will be the most valuable take-home skill that I will aim to install. Therefore, before attempting exam-style questions, I would like to see you demonstrate your understanding of the topic; this will make it all the more rewarding, and will prepare you for any variation on a theme of a problem.
Medical School Advice:
I was fortunate enough to be successful in my first round of medical school applications. As part of the process, I sat both the UKCAT and BMAT, achieving scores comfortably within the top decile for both. In addition, I gained offers from all of the universities (UCL, Cambridge and Bart's) where I was interviewed, so I am familiar with the variable formats and styles of questions the interviews can pose. For the interview stage to be reached, it is also necessary to have a strong personal statement that is both unique to you, and yet at the same time conveys the desire and understanding of what a career in medicine holds, as well as your capacity to adapt to the challenges faced. This can all seem quite daunting, so I hope I can pass on my advice in how to bring out the best in you, and how you can smartly approach the entire application process in an informed manner.
If you have any questions, send me a 'WebMail' or book a 'Meet the Tutor Session'!. Remember to tell me your exam board and anything you're facing particular difficulties with, so that we can construct sessions that enable you to guide your own learning with a clear focus and aim.
I look forward to getting in touch!
|Biology||A Level||£24 /hr|
|Maths||A Level||£24 /hr|
|-Medical School Preparation-||Mentoring||£24 /hr|
|-Oxbridge Preparation-||Mentoring||£24 /hr|
|-Personal Statements-||Mentoring||£24 /hr|
|.BMAT (BioMedical Admissions)||Uni Admissions Test||£26 /hr|
|.UKCAT.||Uni Admissions Test||£26 /hr|
|UKCAT||Uni Admissions Test||772.5 average|
|BMAT||Uni Admissions Test||6.8, 7.4, 4.5A|
|Before 12pm||12pm - 5pm||After 5pm|
Please get in touch for more detailed availability
Elizabeth (Parent) October 8 2016
Parveen (Parent) September 24 2016
Alex (Student) October 8 2016
Parveen (Parent) October 6 2016
First, some general advice:
It is not uncommon for medical interviews, particularly at Oxbridge, to test the interviewee's ability to think laterally, creatively or "outside of the box." When presented with an initially bizarre sounding question, it is important not to panic in the face of uncertainty, but to calmly collect your thoughts in a sequential manner and identify the crux of the question asked.
The heart is located in the superior half of the body, in the thorax. In terms of physics, this is an efficient location in the upright human, as it means that the heart is able to pump arterial blood to the extremities using relatively little energy, as the work done against gravity (for blood destined for the head/neck via the carotid arteries) is relatively low. This is a perfectly economical system for delivering arterial blood, and is crucial for adequate cerebral perfusion at a pressure low enough so as to not cause vascular trauma. But, therein lies the problem for venous return - how does the blood reaching our lowest extremities somehow combat gravity and arrive once more at the heart?
The first consideration one might have is that of the conservation of total mechanical energy (ME), assuming no energy losses. This would tell us that for a decrease in gravitational potential energy (GPE) upon descent of blood to the feet, there would be a compensatory increase in kinetic energy (KE), and in a complete series circuit, this could be reconverted to KE during its ascent, thus preserving total ME. Unfortunately, this idealised system is not applicable in our circulatory system - the velocity of blood actually slows down as it passes from the delivery vessels (arteries) to the resistance and exchange vessels (capillaries), as the total cross sectional area is greater for these smaller vessels arranged in parallel. Functionally, this increases the time available for diffusive exchange of metabolites. This is a reasonable starting point for the discussion.
How then does the body achieve adequate venous return to match cardiac output?
In a nutshell, one of the answers comes from consideration of the phenomenon of orthostatic intolerance. The classic example of this is that of the soldier standing motionless on parade and suddenly faints. In a patient in vertical position, venous pooling occurs in the leg vessels due to gravity, which can lead to a 20% loss of circulating volume and a relative hypovolaemia. If the individual is then also immobile, there will be no muscle pump to provide venous return, with a reduction in cerebral perfusion leading to cerebral hypoxia. When the individual faints and assumes a horizontal position, there is an improvement in venous return and immediate recovery of consciousness. Hence, the muscle pump is an essential return mechanism for venous blood, and a fallen soldier should in this circumstance not be helped back up!
For bonus points, it is worth appreciating the soleus muscle, one of the three superficial muscles in the posterior compartment of the leg. This is a particularly important postural/anti-gravity muscle, as it is a slow twitch muscle that is capable of sustained contraction as it is resistant to fatigue, which enables our posture to be maintained. Furthermore, it possesses crucial function as a muscle pump, as it contains large venous sinuses which fill with blood when we are upright; upon contraction of the muscle, venous return to the heart is therefore facilitated. Without this action, postural hypotension would be a recurrent problem, and would be accompanied by dizziness, fatigue and varicose veins – this is evident in those with atrophy of the muscle, for example as a result of untreated compartment syndrome (which is of considerable risk in the leg due to the thick fascia overlying the muscles).
But there is another, more subtle mechanism reinforcing venous return - the respiratory pump. Fluids generally flow down pressure gradients, a corollary of Darcy's law. Now suppose we could momentarily decrease the pressure in the right atrium - this would then set up a pressure gradient for venous blood to flow back up to the heart.
Pressures in the right atrium and thoracic vena cava are very dependent on intrapleural pressure (Ppl ) - the pressure within the thoracic space between the organs (e.g. lungs/heart/vena cava) and the chest wall. During inspiration, the chest wall expands and the diaphragm descends, making the Ppl become more negative, which leads to expansion of the lungs, cardiac chambers and the thoracic venae cavae. This expansion causes the intravascular and intracardiac pressures to fall due to the inverse pressure-volume relationship (described by Boyle's Law). Because the pressure inside the cardiac chambers falls less than the Ppl, the transmural pressure (pressure inside the heart chamber minus the Ppl) increases, which leads to cardiac chamber expansion and an increase in cardiac preload (the end diastolic volume) and stroke volume by the Frank-Starling mechanism. Furthermore, as right atrial pressure falls during inspiration, the pressure gradient for venous return to the right ventricle increases, thereby facilitating the return of blood from the feet to the heart.
Something to ponder: Extension
With the above explanation in mind, compare and contrast it with the possible physiological effects experienced by a human who is suspended upside-down for a prolonged period of time... How might their body respond differently?see more