What is the Lymphatic System?

By Harshal Chinthala

Published 3:24 EST, September 19th, 2021

Many people don’t know about a very important system in the body, the lymphatic system, which is vital to a person’s immunity. The lymphatic system is a network of tissues, veins, and organs that work together to return lymph, which is a colorless watery fluid, to your circulatory system. This system removes toxins and waste products from the body and removes surplus fluid that drains from cells and tissues throughout the body and sends it to the circulation.The lymph fluid is then recirculated throughout the body.

A healthy lymphatic system helps with many important body processes, such as returning fluid to the circulation, filtering lymph, filtering blood, eliminating pollutants from the body, and fighting illness. The lymphatic system collects excess fluid and drains it into the bloodstream. If the lymphatic system did not remove surplus fluid from the tissues, lymph fluid would accumulate in the body, causing a swelling reaction. The lymphatic system also filters lymph. Cancer cells might adhere to neighboring lymph nodes if they break free from a tumor. For this reason, when evaluating how far cancer has spread, doctors will first examine the lymph nodes. The system also takes out various impurities. The system assists in the removal and disposal of these pollutants through sweat, bowel movements, urine, and breath. Additionally, the lymphatic system plays a role in fighting infections. 

The lymphatic system is made up of many parts. One of these is lymph, a collection of excess fluid drained from cells and tissues but not reabsorbed by the capillaries. Lymph also carries white blood cells that fight infections, known as lymphocytes. This lymph fluid is moved through lymphatic vessels. These vessels make up a network of tubes that transport lymph. Lymphatic veins collect and filter lymph as it moves toward bigger vessels known as collecting ducts. Lymphatic vessels function similarly to your veins. They run at extremely low pressure and have fluid flowing in one direction using a set of valves. The lymphatic vessels also collect the fluid at lymph nodes. Lymph nodes are bean-shaped glands that monitor and purify lymph as it passes through them. There are around 600 lymph nodes distributed throughout your body. Damaged cells and malignant cells are filtered out by the nodes. Lymphocytes and other immune system cells are stored by the lymph nodes. These lymph nodes also generate and store lymphocytes and other immune system cells, which fight and eliminate bacteria and other pathogens in the fluid. 

There are also a number of organs that make up the lymphatic system. The thymus holds white blood cells that fight off invaders. There are also tonsils and adenoids in the mouth, which trap pathogens from your food and the air you breathe. These are your body’s initial line of defense against invading organisms. One organ that is more well-known is the appendix. This organ includes lymphoid tissue and can kill germs before entering the gut and breaking the wall during absorption. A large number of people suffer from appendicitis, in which the appendix is inflamed and must be surgically removed.

There are also other problems that can occur with your lymphatic system. Many diseases can impact the lymphatic system’s channels, glands, and organs. Some occur before birth, while others occur throughout childhood. Further, others emerge as a result of illness or damage. The most frequent lymphatic system illness is lymph node enlargement, which is known as lymphadenopathy. There is also swelling due to lymphatic obstruction, which is known as lymphedema. Infection, inflammation, or malignancy are the most common causes of lymphatic system disorders.

The human body is made up of several organs and glands that are responsible for excreting poisons from the body. The lymphatic system refers to this network of organs and glands. Unfortunately, most people’s lymphatic systems get blocked and do not work correctly. A person’s lymphatic system can get out of balance due to dietary inadequacies, a high intake of processed foods, and a lack of physical activity. You can get a healthier lymphatic system through exercise. Begin with less strenuous training sessions and gradually include more intensive workouts into your regimen. Another helpful tip is to drink lots of water and stay hydrated. There are special lymphatic massages that you can do which can decrease edema and enhance lymphatic circulation throughout the body. Overall, it can be said that the lymphatic system gets overlooked, and it performs many critical functions. It is essential to take care of it just like any other system. 

Harshal Chinthala, Youth Medical Journal 2021


Ten ways to improve your LYMPHATIC HEALTH. Farm to Fit. (n.d.). 

10 ways to cleanse a CLOGGED lymphatic system. Synergy Health Associates New York, NY. (2017, August 16). 

Zimmermann, K. A. (2018, February 21). Lymphatic system: Facts, functions & diseases. LiveScience. 

Lymphatic system: Parts & common problems. Cleveland Clinic. (n.d.). 


The Complexities of Colour Blindness and its Impacts on Individuals

By Samara Macrae

Published 12:33 PM EST, Tue August 17, 2021


While commonly referred to using the term ‘colour blindness’, colour deficiency vision instead is the term used when an individual’s colour vision is impaired, and as such they may not be able to distinguish between different colours1. Colour blindness is only where the individual cannot see any form of colour, and their vision is exclusively in black and white (monochromacy). This condition is very rare, while colour deficiency vision (a form of colour blindness) can affect up to 1 in 12 men and 1 in 20 women. The most common forms of colour blindness are protanopia and deuteranopia.

2Monochromacy, or complete colour blindness, can be caused by the individual having two sets of cones (out of short wave, medium wave, and long wave) which either do not function correctly or are simply not present in the retina. This results in the individual not being able to see a full spectrum of colour as a person with normal vision (which is also known as trichromatic vision) would be able to. Achromatopsia is where there are no functional cone cells at all, and so vision is only in varying shades of black and white.

Variations of Colour Deficiency Vision

3Red-green colour blindness is the most common form of colour blindness and is divided into two types: protan colour blindness is reduced sensitivity to red light, and deuteranopia is sensitivity to green light. Colour vision is controlled by cones in the retina, a layer of the eye onto which light is focused on, and when some of these cones are ineffective or not present, this will affect the individual’s colour vision. Protanopia is the result of missing long-wavelength cones (L-cones) in the retina and affects 1.01% of men but only 0.02% of women. People with protanopia as a result of missing L-cones are ‘dichromats’, and they have cones which can only detect short and medium wavelengths. Red-green colour blindness can also occur due to L-cones being defective but still present (protanomaly) and means that individuals can have varying strengths of colour blindness – this is referred to as anomalous trichromats, as the individual can still detect short, medium, and long wavelengths using their cones. 4Deuteranopia is the second form of red-green colour blindness and is also called green-blind. In cases of deuteranopia, the medium wavelength sensitive cones are missing – and so the individual can only differentiate between 2 or 3 different shades (typically blue, yellow, and brown), while a person with normal vision can distinguish between the 7 hues of visible light. As with deuteranopia the specific cones are missing, people with this condition are dichromats. Anomalous trichromats are individuals with deuteranomaly (green-weak), which is where the green-sensitive cones are deficient. Deuteranomaly can be very mild and is any form of colour deficiency vision between (very close to) normal vision and deuteranopia. Deuteranomaly affects 5% of the global male population, but only 0.35% of the global female population. 5Tritanopia (blue-yellow colour blindness) is where the short-wavelength cones are missing or otherwise impaired. Tritanopia is where these cones are completely missing, and only long and medium-wavelength cones are in the retina – and individuals with tritanopia are dichromats. Tritanomaly is where the short-wavelength cones are deficient in some way, often due to a mutation.


Colour blindness is a sex-linked genetic disorder and is carried on the X-sex chromosome. This is why men are more likely to have colour blindness, as they only have one X-sex chromosome and so only require one recessive allele coding for colour blindness. Women have two X-sex chromosomes though, and so two recessive alleles are needed for colour blindness – meaning that if a woman only has the allele for colour blindness on only one X chromosome, she will be a carrier but not have the condition herself. As a result, a man with colour blindness can pass this condition onto his daughter, who will inherit an X-sex chromosome from him as well as the mother but cannot pass the condition onto his son – who will inherit an unaffected Y-sex chromosome from him. Unlike both protanopia and deuteranopia, tritanopia/tritanomaly is not a sex-linked genetic trait – and thus men and women are affected equally by it, though it is a rare form of colour deficient vision – as it is carried on the 7th chromosome instead of the 23rd (the X-sex chromosome). Additionally, though less commonly, colour blindness or colour deficiency vision can also be the result of damage to the eye or optic nerve – as so is not necessarily solely congenital.


While people who have colour blindness/colour deficient vision may not ever realise they have the condition, tests to ascertain whether a person is colour blind are often widely accessible. An example of such a test is the Ishihara Test for Colour Blindness. This diagnostic test was created by Dr Shinobu Ishihara, an ophthalmologist, as he was asked by the Japanese Army (in which he served as a military doctor) to devise such a test to use on those conscripted for the Army. The Ishihara Test can be used to detect red-green colour blindness/deficiencies but not the rarer form of yellow-blue colour blindness6. As part of this test, an individual is shown a series of coloured circles consisting of multiple small circles to make up a larger one. Within this larger circle, some of the smaller circles are differently coloured to make the shape of a specific number (which is different for each image). Depending on whether or not a person is able to ascertain what the number is within each image can help to indicate whether or not they have normal vision or colour deficiency vision.


Colour blindness is incurable, although some forms of colour deficiency can be lessened using corrective lenses or glasses. 7Dr Ivan Schwab, Professor of Ophthalmology at the University of California, says that such glasses or lenses “[enhance] the distinction between red and green” for the person wearing them, although full colour vision is not achievable using them. He also states: “Colour blindness glasses are made with certain minerals to absorb and filter out some of the wavelengths between green and red that could confuse the brain”. This can result in fewer colours being detected by the person’s cones, and so can allow for easier distinction between them. However, these corrective lenses or glasses do not have any effect on the optic nerve, brain, or cone cells – and furthermore, these lenses/glasses are often expensive yet yield minimal to no results, and additionally can worsen vision at night due to the fact that they work by reducing the amount of light entering the eyes and being detected.

Difficulties and Lack of Accessibility

Although many individuals with colour blindness or colour deficiency vision, as well as charities such as Colour-Blind Awareness, are campaigning for these conditions to be classified as disabilities, they are not currently. Under the 2010 Equality Act (UK), a disability is defined as “a physical or mental impairment that has a ‘substantial’ and ‘long-term’ negative effect on your ability to do normal daily activities”8. A simple but common example of how colour blindness can affect activities of everyday life is a person with deficient colour vision not being able to differentiate between unripe and ripe fruit, or raw and cooked meat. In addition, children especially can struggle in education as a result of their colour deficiency vision – and exam papers especially may not be fully accessible to them – and later in life, a person with colour blindness cannot become a pilot nor enter the army. Colour vision deficiency can also limit other future career options – particularly jobs involving heavy machinery, a job in aviation or any job predominantly based around driving. The consequences of colour blindness can also be potentially fatal – such as problems with traffic lights leading to road accidents. A person with protanopia may not be able to distinguish between the red and green traffic lights – for a person with protanopia, the lights can all look white/pale yellow – and so is potentially more likely to be involved in road accidents as a result. In Australia, since 1994 individuals with either protanopia or protanomaly have not been able to obtain a driving licence due to the increased risk of accidents.


To conclude, colour blindness is a complex condition which can be frequently misunderstood due to the multiple variations of the condition. Furthermore, there are frequent misconceptions as to what ‘colour blindness’ actually entails – as it is not any form of difficulty to distinguish between colours, but rather no colour vision at all. Education systems should work to help diagnose more children who have colour deficiency vision or colour blindness, as it can impede their daily life and schoolwork if they are unaware of their condition – and thus education facilities are unable to make education/work more accessible to them without this knowledge. Improved testing and diagnosis earlier on – especially for children in early years – can additionally mean that they do not suddenly find themselves unable to pursue a specific career path or obtain a driving licence when they are older, as they were not aware of their colour deficiency vision/colour blindness beforehand. While not life-threatening, colour blindness and colour deficiency vision can have significant impacts on daily life, and simply diagnosing these conditions earlier can help improve accessibility for all aspects of life for these individuals.

Samara Macrae, Youth Medical Journal 2021


1.   Mayo Clinic: “Colour Blindness” –

2.   Cambridge Cognition: “Could Colour Blindness be Affecting the Results of your Study?” –

3.   Colblindor: “Protanopia” –

4.   Colblindor: “Deuteranopia” –

5.   Colblindor: “Tritanopia” –

6.   Eye Magazine: “Nine decades on, a Japanese army doctor’s invention is still being used to test colour vision” –

7.   American Academy of Ophthalmology: “Do Colorblindness Glasses Really Work?” –

8.   GOV.UK: “Definition of disability under the Equality Act 2010” –


The Placenta: The Often Forgotten, Underrated Organ

By Asmita Anand

Published 4:20 PM EST, Sat June 26, 2021


Many take the role of the placenta for granted. Often discarded as ‘an afterthought of afterbirth’, it’s the only temporary organ with its role of nourishing and protecting the foetus restricted to that of human gestation. Despite its short lifespan, it plays a vital and significant part in the healthy development and growth of the foetus and to the maintenance of mankind.

In recent years, a lot of the attention surrounding placentas have tended to consist of the consumption of freeze dried placenta pills after celebrities have given birth. While some may argue it has nutritional value, a review on human placentophagy [1] discovered no evidence to support the claimed benefits and instead, a higher risk of ingestion of harmful pathogens.

In some cultures, placentas also play an important role in ancient traditions such as burial or placenta prints (art). Although we may have been unaware of the placenta’s vital functions back then, it was always considered more than just medical waste.

The Role Of The Placenta

The placenta plays a critical role during pregnancy, yet many are unaware of the importance of this organ which magically appears. Its role ranges from sustaining the foetus through substance exchange, foetal protection from pathogens and infections to metabolic transfer and hormone secretion.

The main functional units of the placenta are the finger-like chorionic villi, which increase the surface area for substance exchange. Nutrients (such as glucose, fatty acids and amino acids) from the mother are transferred via active transport across the placenta to the foetus through the umbilical cord. Oxygen passively diffuses across the placenta to the foetus, who’s foetal lungs aren’t taking part in gas exchange while in utero. The placenta will also remove waste products including carbon dioxide, water and urea between the maternal and foetal plasma.

The placenta also provides immune protection against infectious diseases to the foetus through the transfer of immunoglobulins from the mother. Lastly, the placenta is hugely responsible for the secretion of various hormones important for foetal growth and development, which prepare the foetus for life outside of the uterus. For example, it acquires the production of both oestrogen and progesterone from the corpus luteum and the first hormone it produces is hCG. [2]

Overall the placenta performs the functions of the lung, liver, gut, kidney and the endocrine system. To sum up, its multifunctionality is awesome and not appreciated enough.

The Formation Of The Placenta

The development of the placenta in pregnancy generally begins once the blastocyst has implanted in the uterine wall. Some cells from the blastocyst, known as the outer trophoblast cells, form the placenta while the others (inner cell mass) form the foetus. Hence the blastocysts consist of both these two distinct differentiated embryonic cell types (the outer trophoblast cells and the inner cell mass) . [3] The placenta is unique as it partly develops from both maternal tissue but also foetal tissue. This also means that the placenta is foreign to the mother’s system as it comprises a mix of both maternal and paternal DNA.

At the end of pregnancy the placenta will undergo several changes to decrease exchange between maternal and foetal circulatory systems. These include the increase of fibrous tissue in the core of the villus and the increase in thickness of foetal capillary basement membranes. [3]

Extraordinarily, the placenta is not rejected by the mother’s body as the trophoblasts do not trigger a maternal immune response. If maternal and foetal blood were to mix, then the mother’s immune system would inevitably kill the foetus. This is because the foetus may not have the same blood type as the mother and an immune system attack in the foetal blood supply can be caused by direct mixing of blood. The syncytiotrophoblast, the outermost layer of the placenta, facilitates the separation of the two bloodstreams.

How And Why Has It Evolved?

All living mammals except marsupials and monotremes are considered to be placental. [4] However mammals didn’t always have one and the placenta was only estimated to have evolved around 150 million to 200 million years ago.

Thus placentas have given mammals a slight advantage over other animal kingdoms by allowing them to supply their offspring with essential nutrients and oxygen vital for the development of the mammalian brain.

If it weren’t for some special viruses, humans may still be laying eggs. Evolutionary scientists have mapped the genomes of cells in the placenta and found that ‘syncytin’, a protein which allowed these cells to fuse into a wall, appeared to come from an ancient retrovirus. Unlike normal viruses, retroviruses are able to enter cells and insert copies of its RNA genome into the DNA of the host. This leads to a change in the genome of that cell. [5] The RNA is converted into DNA during infection allowing it to integrate into the chromosome of the cell. In the case of the placenta, the virus eventually created a viral protein which gave the ability for cells to fuse into a wall that we know now as the placenta. Over many generations this viral DNA must have been passed on until the entire population had evolved, turning it into a fully endogenous retrovirus. This has made retroviral infection a driver of placental mammal evolution. Ed Chuong describes this process ‘as a molecular domestication of an ancient retrovirus element’. Apart from the placenta, remnants of ancient viral infections found in our DNA are also adding more evidence that viral genes are assisting the evolution of new species. [6]

Challenges To Our Understanding Of The Placenta

There are multiple reasons as to why scientists do not know much about the human placenta. A problem that arises when trying to study the placenta is that it is not only logistically but also ethically difficult to study due to its strong link with foetal development. It is difficult to apply research since placentas differ between animals and humans as evidenced from animal studies as well. Since many of us lack this important organ (not being pregnant or a woman), it  accounts for a reason as to why it has been so understudied.

What Is The Future Of Placental Research?

Despite being understudied in the past, scientists are now striving to achieve a better understanding of the behaviour of the placenta and more information on the prevention, detection and treatment of pregnancy problems.

The gatekeeping role of the placenta facilitates its exchange of nutrients and waste between maternal and foetal circulatory systems. However we are yet to uncover the intricacies as to how the placenta is able to do this without triggering an immune response. As Y.W Loke wrote in “Life’s Vital Link”, “This ‘immunological paradox of pregnancy’ has preoccupied immunologists for well over half a century and still the solution remains tantalizingly beyond reach”. “This normally peaceful co-existence between placenta and mother throughout pregnancy is one of the most extraordinary phenomena in reproductive biology.” [7] There is hope that if we are able to understand how the placenta is able to resist rejection, it could lead to a better understanding of preventing organ rejection in transplant patients.

The placenta could also unlock better explanations of how cancer is able to evade the immune system, leading to the possibilities for new cancer treatments. This is due to the similarities between pregnancy and cancer, such as the rapid proliferation, invasion of the host and evasion of the immune system. [8] A study conducted at the Wellcome Sanger Institute [9] found that placental tissue had about five times as many mutations to a single DNA ‘letter’ to body cells which generally have a high rate of mutation. This opens up potential questions as to why the placental tissue is so mutated. Tim Coorens, who was part of the team who conducted the study, suggests its “disposability might provide a clue: as it only “lives” for nine months, it doesn’t need to invest precious resources into repairing itself”.

Furthermore, the placenta is important to our understanding of the health of babies. For example, the size of the placenta in relation to the baby’s birth weight can indicate foetal death risk. [10] There is also hope that by studying the placenta in real time physicians may be able to diagnose complications that arise from pregnancy, such as pre-eclampsia, which is when blood flow to the placenta is decreased.


It is no question that the placenta is critical to human life. Arguably it is one of the most important organs in the human body, impacting both the lifelong health of the mother and child. Fortunately, the Human Placenta Project is currently researching more into the placenta’s development and function through monitoring in real time, to uncover more information about both the least understood and studied organ. [11] As we continue to research more into this wonderfully unique organ, hopefully the “afterbirth” will no longer be an “afterthought.”

Asmita Anand, Youth Medical Journal 2021


[1] Farr, Alex et al. “Human placentophagy: a review.” American journal of obstetrics and gynecology vol. 218,4 (2018): 401.e1-401.e11. doi:10.1016/j.ajog.2017.08.016

[2] “Placental Structure, Function and Drug Transfer.” ScienceDirect, 1 Apr. 2015,

[3] “Placenta and Placental Development – Clinical Relevance.” TeachMePhysiology, 6 Mar. 2021,

[4] Britannica, The Editors of Encyclopaedia. “Placental mammal”. Encyclopedia Britannica, 19 Feb. 2021, Accessed 2 June 2021.

[5] Wikipedia contributors. “Retrovirus.” Wikipedia, 2021,

[6] Mitra, Avir. “How the Placenta Evolved from an Ancient Virus.” WHYY, 31 Jan. 2020,

[7] Loke, Y. Life’s Vital Link: The Astonishing Role of the Placenta. Illustrated, Oxford University Press, 2018.

[8] George, Alison. “The Cancer-Fighting Multi-Organ: 9 Ways the Placenta Is Amazing.” New Scientist, 1 Feb. 2021,

[9] Coorens, Tim. “Somatic Mutations Reveal Widespread Mosaicism and Mutagenesis in Human Placentas.” BioRxiv, 1 Jan. 2021,

[10] Stranden, Anne Lise. “Your placenta may reveal risk of getting preeclampsia.” sciencenorway, 25 Mar. 2020,

[11] “Human Placenta Project.” NICHD, Accessed 3 June 2021.

Fard, Maggie Fazeli. “Book Discusses the Most Underrated Organ, the Placenta.” Washington Post, 5 Aug. 2013,

Nelson, D Michael. “How the placenta affects your life, from womb to tomb.” American journal of obstetrics and gynecology vol. 213,4 Suppl (2015): S12-3. doi:10.1016/j.ajog.2015.08.015

Racaniello, Vincent. “Retroviruses Turned Egg-Layers into Live-Bearers.” Virology Blog, 14 Dec. 2017,

Health and Disease Uncategorized

Overview of Influenza


  Influenza, or the flu, is known and experienced in many lives. It is an infection that is experienced in the human body, specifically a viral infection. The risk level of Influenza varies and can be detrimental, or even deadly, to one’s life. Influenza has been very prominent throughout history, exemplified in many cases. A common example of this is shown through the 1918 Flu Pandemic, where a third of the global population was affected by the influenza virus. It was a viral origin as stated commonly for influenza, caused by the H1N1 virus. World War 1 was occurring during this time period, which had played a huge role in the spreading of the infection as expected. The lack of vaccines and safer conditions during the time did not help, and as a result, a huge amount of people were greatly affected by influenza or the flu, given that it is a contagious infection that can be spread to a multitude of people from vast, and various places.

Method of Transmission

The infection is spread to others through droplets, which can travel through the air and can potentially affect someone with influenza or the flu. It occurs, for example, if someone were to speak, the droplet will contract in the air, and be carried. It can then potentially affect anyone or anyone as the droplet can possibly be inhaled or touched, and be transferred to the body as a result. For instance, one can touch the surface where one who had influenza touched contracting any form of droplets the person may have left. They can transfer it through the touch as stated, and the respiratory system will be affected as soon symptoms will appear indicating that another person has contracted influenza or the flu, as they began exhibiting the known symptoms.


Symptoms consist of possibly fever or a cough. A sore throat can be experienced as well as aches. The symptoms experienced by one with influenza or also known as the flu can be experienced as similar to a cold, whereas the flu can be dangerous due to certain factors that are in the person who is experiencing the flu or influenza. Those who are very young such as ages up to 5 years old as well as those who are 65 and older may have a higher chance of complications due to the flu or influenza, as age plays a crucial role in regards to how much impact the person will experience in terms of having the flu or influenza. One can also experience eye pain as well as a runny nose, as they are some common symptoms experienced by those who have had influenza or the flu. Someone who may possess a weaker immune system may have a harder time in regards to combating influenza or the flu than someone who does not have any problems regarding immunity, causing one to have a higher chance of having greater risk or complications with the viral infection. Other illnesses that may be present as well in the human body of the person experiencing influenza or flu can possibly and potentially cause the person to experience greater risk or complications with the disease.


Those with pregnancy can also experience a higher chance of complications in terms of combating influenza, as well as obesity playing a role in terms of complications with the viral infection. These factors affect the varying risk level that occurs with influenza or the flu, as the level in which it will affect one depends on the personal health situation and circumstance of the one who is being affected by influenza or the flu. In terms of risk level with the viral infection, dangerous symptoms can also be experienced where immediate medical attention is needed. There could be shortness of breath which is a dangerous symptom, where one needs to get medical attention immediately due to the risk of the viral infection. Seizures are another dangerous symptom that could occur which signifies that this requires serious medical attention, and can be detrimental and dangerous. Severe pain can be experienced throughout the body, throughout the muscles, which can be proven to be very serious and detrimental due to influenza. Some other symptoms could also include dizziness or blue lips which are required of immediate medical attention, as they are emergency symptoms. Those experiencing any symptoms of influenza or the flu seek attention from medical professionals, and flu vaccinations are taken to prevent this from occurring. 

Bharathi Arivazhagan, Youth Medical Journal 2021


“Influenza (Flu).” Mayo Clinic, Mayo Foundation for Medical Education and Research, 19 Dec. 2020, 

“1918 Pandemic Influenza Historic Timeline.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 20 Mar. 2018,