Skin, Hair and Nails: Your Built-In Spacesuit

 Hey! Ready to dive deep into another adventure about the human body with me? Today we're gonna be talking about the one body system on which you spend the most money on. You like to decorate it with fancy accessories, ink and paint and try to make it look and smell good in the hopes of attracting hoes. Today, we're talking about your skin, hair and nails which together make up your Integumentary System!

A lot of compelling questions are gonna be answered today, like What does hair conditioner do? Why the hell is everyone obsessed with open pores? Do all these creams that we use actually do something? How to control sweating or body odor? What's up with wrinkles?

Let's dive right into it!

The Integumentary System

This system consists of your skin, hair, nails, sweat and oil glands. It all acts as a protective mechanism for the body. Your largest organ is your skin, although when you think about organs, you probably think about your heart or lungs.

How important is the Sensation of Pain?

And to answer this, let me tell you about a case study....

Chintu was born into a middle class family who weren't that educated, and although an accidental child 💀, he was received with great love. When he grew up, he won't do his homework and his mom decided that the only way to handle him was with a traditional beating. But she realised, he did not feel pain as he was getting beaten up, and its very strange cause he just wouldn't feel it. Their parents thought their boy is strong but they didn't know he had a genetic condition.

As he grew up, he would occasionally get into school fights too and people realised he would not feel pain. Then something tragic happened,

His favourite cousin got cancer and sadly, passed away, but at his funeral, guess who was the only person who was not crying-  C H I N T U

What the hell, bro your cousin just died, why aren't you crying??? 

His parents realised he literally could not feel pain, may it be emotional or physical, it was like a superpower, he couldn't feel pain at all. 

To many of us, it seems like a gift from god, but trust me, you do not want that cause what happened later will shock you.

One day, Chintu woke up and started vomiting and coughing blood, his parents finally took him to the doctor, something they should have done long ago. The doctor diagnosed him with a fatal pneumonia, but this did not make sense as Chintu was feeling completely fine, turns out he could not feel the pain pneumonia had been causing him because he was just too damn strong!

The sensation of pain is there to tell your body how to react to certain situations, it makes you aware of your body's limits and keeps you emotionally healthy. Chintu could not love someone cause he wouldn't even feel the pain of losing them neither would he feel pain if his hand was burnt, which means he would not know when to stop, he could not listen to his body.

Skin

Our skin is the first line of defense for the body, it helps regulate temperature, maintain balance of fluids and synthesize vitamin D. 

Actually, that's kind of a lie cause you see, the sun's UV rays triggger a molecule in our skin which creates an inactivated version of that vitamin D and transports it to the liver and kidneys, which convert that vitamin D to activated D or calcitriol. This is now transported to the bones to be used by the body. 

Vitamin D helps control calcium levels in blood and acts as a hormone deciding which protein cells build. 

Skin has 3 layers:

1. Epidermis-Outermost layer made up of stratified squamous epithelia, the layer which we can actually see.

It Contains lots of dead cells called Keratinocytes which contain keratin, a fibrous protein which gives structure, durability and water proofing.

2. Dermis- The middle layer containing all the blood vessels, nerve fibers, hair follicles etc. This is the main functioning layer. Its made up of Dense Irregular Connective Tissue.

3. Hypodermis- Innermost layer made up of Adipose connective tissue. 

Epidermis

The epidermis contains loads of keratinocytes and we lose millions of them everyday, so much so that our epidermis gets replaced fully every 3-4 weeks. 

This is the reason that tattoo needles need to penetrate into the dermis to stay on for years. 

The epidermis contains different types of specialised cells each with different jobs.

• Melanocytes- These are spider shaped cells with long cellular extensions and their job is to create melanin, the pigment which gives your skin its colour. 
• More melanin actually helps in protecting you from sunlight. That is the reason people who live close to the equator have darker skin,
• whereas people who live close to the poles have lighter skin
•     The no. of melanocytes is roughly same in all people, its the width of their cellular extensions which decides the amount of melanin they will produce.
• Langerhans Cells- These are immune system cells in the epidermis which have long tendrils creeping in between keratinocytes. Their job is to ingest the unwanted invaders of the skin.
• Tactile or Merkel Cells- They are present deep within the epidermis, close to the dermis and bind with neurons to form a sensory receptor for touch.

The epidermis has 4 layers everywhere except the palms of hands and soles of feet, where it has 5 layers. The epidermis on the palm of hands and soles of feet is known as Thick Skin and the epidermis everywhere else on the body is known as Thin Skin. 

The layers of the epidermis are:

1. Stratum Corneum- Outermost layer, has around 20-30 sheets of dead keratinocytes. This layer gets sloughed off easily.
2. Stratum Lucidum- This layer is what's missing in the thin skin. Its just 3-4 layers of dead keratinocytes.
3. Stratum Granulosum- This layer contains living keratinocytes starting to die and other cells undergoing keratinization.
4. Stratum Spinosum- This layer is where regeneration starts taking place. Mitosis is taking place and some keratinocytes are forming whereas some are new and fresh.
5. Stratum Basale- This is the innermost layer containing merkel cells and its just one single layer of columnar cells where new keratinocytes are forming actively. This layer connects to the Dermis.

The epidermis is avascular (epithelial tissue), so it has no blood supply. The keratinocytes are forming at the innermost layer and getting their blood supply from the dermis, as these cells get pushed upwards by new cells forming beneath them, they get away from the dermis, lose oxygen and die. Then they get absorbed in the air after they reach the outermost layer.

Why Sunscreen? What's Sunburn?

Although the UV radiation from the sun helps us synthesize vitamin D, it has big disadvantages too if we are exposed to it for a long time. UV radiation can lead to skin cancer as it can alter the skin cells' DNA, it can also give us sunburn if exposed for a very long time. Sunburn damages the DNA and causes resness, pain and swelling. Sunburn temporarily depresses the immune system too as the epidermis contains immune cells and causes elastic fibers to clump up.

We can use sunscreen to prevent this. Organic sunscreens act as a filter which absorbs harmful UV rays whereas inorganic ones scatter the light away. SPF (Sun Protection Factor) is a measure of how much of the rays the sunscreen blocks. SPF 25 blocks 96% and SPF 50 blocks 98%, in regions like India, SPF 50 is usually preferred. For acne prone skin, inorganic sunscreen is preferred more. Applying sunscreen daily is useful for preventing sunburn and skin cancer. 

Open Pores: What the Hell are they? Moisturisers do What? 

Open pores are basically enlarged openings of hair follicles and oil glands. They appear larger in oily skin as excess sebum (oil) enlarges them more. 

While you cannot physically close them, you can use over-the-counter creams containing niacinamide or salicylic acid to regulate oil production. Clay masks or exfoliation can help tighten the skin too. 

Using moisturisers is essential as they hydrate the skin which helps regulate oil production, leading to less clogged pores (excess sebum production can block pores) and hydration helps "plump" the skin. A lot of people nowadays are using Hyaluronic acid containing moisturisers as it plumps the skin pretty fast and holds a lot of water.

Dermis

Now that we have bullied the epidermis enough, let's talk about the main guy, the Dermis.

 This middle layer contains lots of collagen and elastin fibers and all the blood vessels, nerve fibers, hair follicles and oil and sweat glands.

It has 2 layers:

1. Papillary Dermis- Just below the epidermis, it contains areolar connective tissue. It has lots of tiny projections called Dermal Papillae. 
2. These tiny protrusions form friction ridges which help improve the grip of our hand and form us fingerprints! 
3. Reticular Dermis- This is 80% of the dermis and its what contains the blood vessels, nerve fibers, sweat glands, oil glands and hair follicles. This layer is made up of Dense Irregular Connective Tissue. 

The Dermis also contains Cutaneous Sensory Receptors, they are part of the nervous system and receive stimuli from outside environment. 

They register sensation of touch. They have different types known as Corpuscles:

• Meissner or Tactile Corpuscles- They detect light touch and are found in hairless skin. 
• Lamellar Corpuscles- These detect sensations of pressure like when someone puts a hand on your shoulder.

Hair follicles have receptors too. That's why you can feel the light breeze on your hair. 

Hypodermis

Your Subcutis or Hypodermis is made up of adipose connective tissue. It helps store fat, provides insulation and acts as a cushion. This is where most of your body fat hangs out, so blame it if you are fat.

Skin Colour Changes

Different changes in skin colour can indicate different diseases. 

• Cyanosis or bluish colouring of skin indicates poor circulation, heart problem, oxygen deprivation. This is because blood depleted of oxygen gets darker in colour and looks bluish when seen through lips and skin.
• Erythema or redness indicates inflammation or allergy as blood vessels dliate (vasodilation) for better blood flow.
• Jaundice is a yellowing of the skin signifying underlying liver disorder or failure. Yellow bile starts accumulating in blood and eyes get yellow first.

Sweat or Perspiration

Your Sudoriferous or sweat glands are present in the dermis. Sweat helps cool your body down, regulates temperature and very small amounts of uric acid and ammonia are eliminated through sweat.

 There are 2 types of perspiration:

1. Insensible Perspiration- This is the unnoticeable sweat which your body produces everyday to maintain your homeostasis.
2. Sensible Perspiration- This is the much more noticeable sweat which you would notice if you are working out or playing. It also is just a cooling mechanism for the body.

Sudoriferous glands are of 2 types-

1. Eccrine Glands- These are present mostly everywhere in the body, pretty abundant and secrete an odorless sweat. They start with a duct in the dermis and open into a pore in the skin.
2. Apocrine Glands- These glands are present only in the armpits and groin and they start developing around puberty. 
3. These glands are very less in number and secrete a kind of deluxe sweat which contains fats and proteins. When bacteria feast on this sweat, it creates an odor. These glands are attached to hair follicles and secrete their sweat through them.

Mammary Glands which secrete milk in lactating people and Ceruminous glands which secrete cerumen or ear wax are 2 modified types of apocrine glands.

Deodorants, Yay or Nay? Other ways to control Sweating?

Deodorants, definitely yay! Apocrine gland sweat is the kind of sweat you don't want on a date. Deodorants attack the bacteria present in the sweat, so it does not smell or create an odor. 

Another way to control sweating is using antiperspirants, which use ions to block the pores altogether so you don't perspire. 

Perfume on the other hand is more of a cosmetic product and provides an artistic scent which does hide body odor but not its main purpose.

Oil Glands 

Oil or Sebaceous glands secrete sebum from their ducts onto pores. Sebum is an oily substance which helps slow water loss and lubricates the skin and hair. These glands have small ducts on limbs but large ducts on the face, neck and chest. They don't have ducts in the thick skin (palms of hand and soles of feet).

Blackheads occur when too much oil is produced and it clogs a pore, but the pore stays open so the oil gets oxidised and turns black, it isn't dirt, its just oil.

Whiteheads on the other hand are closed pores, same thing, too much oil + closed pore, oil stays white.

We can treat both of these with Salicylic acid as it moderates sebum production.

Pimples are when a whitehead gets infected by bacteria and the immune system sends out immune cells to fight, causing inflammation, the red painful bump, often filled with pus.

Pimple patches can be used to treat this.

Why does our Skin Wrinkle?

Our skin wrinkles primarily because of aging as it loses its elasticity. All the collagen and elastin fibers in the dermis get stretched again and again for several years as we do facial expressions such as smiling, frowning etc, so they lose their flexibility. 

Their isn't much you can do to stop this except very expensive anti-aging treatments and controlling diet and lifestyle changes to slow it down.

Skincare and Skin Hygiene

According to doctors, for the average person, a skincare routine should be Moisturiser after the shower, Sunscreen if going out in the sun and using facewash once in day and once in night. This much is enough for the common person to have a healthy and good looking skin. If you have acne or dry or oily skin, the perimeters change but this is roughly what is needed.

Shower should be 5-10 minutes max, make sure to apply soap to every part of the body and wash it out with water, but the water should not be too hot or cold.

Hair and Nails

Let's not forget about the other essential parts of our Integumentary System, our hair and nails! 

Hair are just long flexible strands of dead keratinocytes. Nails are essentially the same thing. They grow the same way too!

A hair has 2 parts, A Root and a Shaft. The shaft is where keratinization is complete and the root is where the keratinocytes are still growing. 

The outermost part of a hair is called the cuticle which is just a single layer of dead keratinocytes. New young cells get pushed up by developing cells beneath them and as the cells go upwards, they lose oxygen and die.

The Nail Bed and Root are the 2 parts of a nail growing the same way as hair. 

Nails look red as they sit on a bed of capillaries. The white part at the base is called a Lunule. It is the part where keratinization is still happening. 

You might have noticed a white patch on your nails sometimes, its most often a cause of trauma though sometimes can be attributed to fungal infections or lack of several nutrients if present on more than 1 nail persistently.

Fun Fact: Toenails actually grow slower than fingernails so you can get away from cutting them for longer!

What does Conditioner Do? 

Conditioner makes your hair smooth as it smoothens out the rough patches between dead keratinocytes in the cuticle. Conditioning your hair every day is not really bad but not advisable either but it depends on the individual.

Im sure we all know that shampoo is used for the scalp to prevent dandruff and keep it healthy by washing it once in a while. Remember, the frequency of shampooing your hair depends person to person, for example, if you are sweating a lot everyday, maybe you should shampoo everyday but if not, then 2-3 times a week is the usual. But using it everyday can rid the hair of its natural oils.

Hair Care Routine

Oiling can be beneficial for your hair. Its recommended to do it once in a week, though for some people more or less might be better. For example, curly hair can be oiled twice in a week to combat brittleness. Oiling hair makes them hydrate well and improves blood circulation to scalp but make sure to wash the oil off in 30-60 minutes.

Shampooing based on sweating and dandruff management is crucial, otherwise 2-3 times a week is fine. Conditioning after shampooing is generally advisable. 

Now, lets talk about hair products. A lot of people use serums or leave in conditioner creams or sea salt sprays to style their hair. All of this is fine from an aesthetic point of view, but make sure to use these once a day in moderation to prevent hair damage. A general rule with most sprays is 2-3 puffs max.

Why Does Hair Colour Change? How to Prevent It? 

Hair colour changes because the cells which produce melanin for your hair work in regulation with a hormone. If you are taking too much stress or aging, the hormone feedback loop gets disturbed and melanin stops being produced as stem cells stop becoming melanocytes, so hydrogen peroxide builds up in hair and they turn grey. 

To prevent this, you can use hair colour, permanent or temporary but this does not have a fix.

Balding, Why? Just Why?

Balding is also just a consequence of aging, it relies heavily on genetics. Hair usually ages and hair growth slows down. The effective thing which works to actually stop is hair replacement or other hair therapies available, medicines can be used too but therapies often show better results.

Remember, if you are losing 50-100 strands of hair in a day, its normal, the problem is only when you lose large clumps of hair.

Fun Fact!

If you have straight hair and go bald, your hair may actually grow back curly. Same applies in the opposite too, Curly hair to bald to straight hair. 

P.S.- Reference to my other blogs which will make it easier to understand this one. You can visit all of my blogs at deeparshbhanot.blogspot.com

Phew! This was it for this blog!! I know I might have stretched it a bit too much but there were some important things needed to be answered. But hey it was fun, I enjoyed exploring the dimensions of hair, skin and nails with you guys. See you next time!!

By,

Deeparsh Bhanot