Tag: hormone

Posted in Psychology & Medicine

Viscera: Thyroid

Posted on by Jinavie

(Learn more about the organs of the human bodies in other posts in the Viscera series here: https://jineralknowledge.com/tag/viscera/?order=asc)

There lies a small, butterfly-shaped organ called the thyroid gland in your neck, just in front of your windpipe above the clavicles. The thyroid may not seem important given its small size, but it has the important function of controlling the body’s rate of metabolism. Metabolism is a group of chemical reactions your body relies on to function as a lifeform. Chemicals such as glucose are processed by various enzymes – biological catalysts that encourage chemical reactions – and converted in to fuel (such as ATP) that cells can use for numerous bodily functions. The thyroid produces the thyroid hormones, thyroxine and triiodothyronine, to fine-tune the rate at which these reactions occur.

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To see the function of the thyroid gland, we can look at two types of diseases: hyperthyroidism and hypothyroidism.

In hyperthyroidism, the thyroid is overactive and produces too much thyroxine. This causes the body’s metabolic rate to speed up, causing increased heart rate, weight loss, sweating, tremors and sensitivity to heat. Depending on the cause, the eyes may be affected as well, causing them to protrude forwards, giving a rather scary appearance. This disease may happen for various reasons, but the most common cause is Grave’s disease, where antibodies lock on to receptors in the thyroid to stimulate thyroxine production, much like a stuck key on a keyboard.

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Hypothyroidism is the direct opposite syndrome caused by an underactive thyroid. This causes a reduction in metabolic rate, leading to weight gain, tiredness (due to lack of energy), slow heart rate and cold intolerance. It can also be caused by an autoimmune disorder (called Hashimoto’s thyroiditis), or more commonly due to iodine deficiency, as the thyroid uses up iodine to produce thyroid hormones.

Both diseases may cause the thyroid to grow to an abnormal size, which is called goitre (seen as a large neck lump). The treatment is usually adjusting the total level of thyroid hormone produced by removing parts of or all of the thyroid, or replacing thyroid hormone if needed via medication.

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Because the thyroid uses iodine to make hormones, thyroid diseases such as thyroid cancer can be treated using an interesting method. If you inject radioactive iodine into the patient, it will make its way to the thyroid gland, which actively collects the iodine from the blood. Overactive thyroid tissue (such as in Grave’s or thyroid cancer) take up iodine at a faster rate. The iodine then delivers a focussed dose of radiation to the thyroid, leaving the other tissues in the body unharmed. This method is used for both first-line treatment of hyperthyroidism and to clean-up remaining cancer cells after thyroid surgery.

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Posted in Psychology & Medicine

Viscera: Pancreas

Posted on by Jinavie

(Learn more about the organs of the human bodies in other posts in the Viscera series here: https://jineralknowledge.com/tag/viscera/?order=asc)

The pancreas is probably the most central organ in the human body. It is situated just under the liver and stomach, surrounded by the duodenum (first part of small intestine) and lies in front of the aorta. It is shaped like a fish and thus is divided into parts named the head, neck, body and tail. The head of the pancreas tucks into the loop of duodenum and drains its contents via the pancreatic duct, which joins with the common bile duct (from the liver and gallbladder).

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The function of the pancreas is divided into two functions: exocrine and endocrine.

An exocrine gland is an organ that excretes its products out of the body (including the intestines), such as the salivary or tear glands. The exocrine function of the pancreas is the production and secretion of digestive enzymes that break down proteins, fats and carbohydrates in the small intestine. Because of this, injury to the pancreas often causes a leak of this digestive juice, causing the body to self-digest the pancreas (leading to pancreatitis) and surrounding organs.

An endocrine gland is the opposite in that it secretes its contents into the bloodstream. These glands typically produce hormones, such as the thyroid, ovaries and adrenal glands. The pancreas’ endocrine function is related to an extremely common yet deadly disease: diabetes. Within the pancreas, there are millions of cells that cluster into groups called islets of Langerhans. There are various types of cells, but the most common are the alpha-islet cells that secrete glucagon and beta-islet cells that secrete insulin. Insulin acts to lower blood sugar (glucose) levels by promoting storage and use of glucose after a meal. Glucagon acts to increase blood glucose by promoting the breakdown of glucose storage units (glycogen) and the production of more glucose by the liver. Diabetes occurs when beta-islet cells fail to produce insulin because they are destroyed by the immune system (type 1 diabetes mellitus) or become desensitised by chronically elevated blood glucose levels (type 2 diabetes mellitus).

Another important disease concerning the pancreas is pancreatic cancer. Pancreatic cancer is notorious for its deadliness as it carries a 5-year mortality rate of over 95%. This is because it usually remains hidden – without any symptoms – until it as grown substantially and spread to other organs. However, this prognosis only applies to the most common type of pancreatic cancer involving exocrine cells (adenocarcinoma). There are far rarer cancers of the pancreas that involve the endocrine cells (e.g. insulinoma), which tend to have extremely good prognoses and are usually curable.

Steve Jobs (founder of Apple Inc.) had this kind of pancreatic cancer – an islet cell neuroendocrine tumour. Despite his excellent chance of cure with chemotherapy and surgery, he refused treatment for nine months and instead relied on alternative medicine for cure. However, his disease worsened and he finally resorted to having surgery. By this stage, his disease had spread to the liver due to the nine-month delay in treatment. Spreading of cancer is called metastasis and is often an indication that the cancer is no longer curable. Jobs went against his doctors’ advice and opted for a liver transplant in the hopes of curing his cancer. Organ transplant involves suppressing the patient’s immune system (which also keeps cancers in check) to prevent rejection of the donor organ, which is why oncologists advise against transplants in cancer patients. Jobs’ condition deteriorated quickly after his liver transplant and his decisions ultimately led to his demise.

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Posted in Psychology & Medicine

Sweet Tooth

Posted on by Jinavie

It is interesting to see how people tend to use taste-related metaphors to describe other people. If a person is hostile or spiteful, we describe them as “bitter”. If a person is sullen and gloomy, we say they are “sour”. Perhaps the most extensively used taste is “sweetness”. People have a tendency of calling their loved ones sweet-related names, such as “honey”, “sweetie”, “sugar” or “sweetheart”. This is directly reflected in the tradition of giving chocolate to a loved one on Valentine’s Day. Quite obviously, this is because we find sweetness the most palatable taste and something that is nice. On a related note, could there be a relationship between sweetness and personalities?

A group of psychologists decided to study whether people who like sweet foods, or “sweet tooth”s, have a certain personality trait or not. They did a survey where participants were asked what foods they liked most out of a list of 50 foods covering five tastes (sweet, sour, bitter, salty, spicy). They also answered questions that gave an indication of their agreeableness (one of the five components of OCEAN personality traits). The psychologists then analysed whether there was an association between sweet tooths and agreeableness. Interestingly, a direct correlation was found between a liking of sweets and higher levels of agreeableness. This suggested that people who like sweet things tend to be more friendly, cooperative and compassionate.

But is the cause-and-effect relationship so simple? Could it be that sweet things cause people to be nicer? In a separate experiment, participants were randomly given a sweet food (chocolate), a not-sweet food (cracker) or no food. They were then asked to volunteer their time to help someone. It was found that those who were given something sweet were more willing to help another person compared to the other two groups.

This makes logical sense as eating sweets such as chocolate causes your brain to release a flood of hormones such as endorphin and serotonin from the absolute pleasure of the experience. These hormones make us feel happy, blissful and in love, which in turn make us more agreeable and willing to cooperate.

Although sweetness has numerous negative effects on the body such as weight gain and diabetes, there is no doubt that it is greatly beneficial for your mental health. If there is a bitter person around you, give them a good dose of chocolate to help them develop a sweeter personality. Or perhaps all they need is a sweet romance.

(Image source: http://fc04.deviantart.net/fs71/f/2010/138/c/e/Day_4___Sweets_by_Valandill.jpg)

Posted in Psychology & Medicine

Couvade Syndrome

Posted on by Jinavie

A patient comes to a doctor complaining of the following symptoms: “I can’t sleep because my teeth have been aching for the past few weeks. My head is killing me and whenever I wake up in the morning my stomach hurts and I feel nauseous and want to vomit. Sometimes I have no appetite and sometimes I crave a certain food. My breasts have gotten bigger and my stomach is bulging quite a bit.”
The patient has been married for three years and in a few months will have a beautiful daughter.
What is the diagnosis?

Most people would immediately say “Pregnancy!”. But there is one small detail that was left out: the patient is a man.
It is common sense that men cannot be pregnant. So what is this man suffering from?

Couvade syndrome is also known as sympathetic pregnancy. In other words, the husband subconsciously copies his wife’s pregnancy and suffer the same symptoms. This syndrome can be severe enough to cause labour pains, nosebleeds and even post-partum depression.
The cause has not been established, but it is likely to be psychosomatic, where psychological symptoms are expressed through physical symptoms, or due to changes in hormone levels.