Tuesday, 30 June 2015

UNDERSTAND THE BASIC HAIR & SCALP STRUCTURES | LET'S SKETCH

Hair comes in a few types, colours and shapes. Despite these differences, what is hair at it's most basic structure? I found no better way to gain a thorough understanding than to go back to the drawing board. In this post, I make this learning fun by sketching. I sketch my interpretation of what I have learnt about the hair and scalp.

For the full sketch process, click HERE or scroll down to the video at the end of this post. I hope you have fun! Lets start!

Diagram sketch of hair and scalp structure
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A. Three Major Layers Of The Skin Surrounding Your Hair.
  • Before touching on the hair strand itself, it is helpful to know about the supporting members of the strands which you see as your hair. 
  • In order to promote health in hair, the vital members underneath, where you can't see, play a great role. In fact, without the skin, our inner bodies and organs will be hanging out! Not a pretty sight. Looking at my sketch above, you can see the three main sections with curly brackets on your right hand side. 
  • These sections are the Epidermis, the Dermis and the Subcutaneous Tissue.

1. The Epidermis
  • The Epidermis is the top most part of the skin structure. 
  • When you look at your scalp or hands, it is what you see, though it has more parts to it than what you see. It is always working to keep you normal. 
  • The Epidermis protects you from infections caused by bacteria and 'germs' (pathogens) around us. It is full of cells which are both young and old. Younger cells which are deeper in your skin and older cells nearer the top. 
  • The younger cells are constantly moving up, journeying their way towards the surface. As they go up, they age. 
  • The top part of the skin has the oldest cells, which then rise up to become dead skin which is shed. Or dandruff on your scalp. There are other factors which contribute towards dandruff.
Diagram sketch of epidermis structure
Epidermis
2. The Dermis
  • The Dermis is the second and middle layer of the skin. It is where most of your actual hair strand is located. It is like a cushion which helps to prevent stress and strain on your body.
  • In here, you have the hair follicle which is like a pocket which holds your hair strand. 
  • Also in the Dermis, you can find some sections of the structures which cause you to sweat. Sweat Glands.
  • The Dermis also has some nerve endings for your senses.
Diagram sketch of dermis structure
Dermis
  • You will also find various structures such as the Arrector Muscles, blood vessels which carry nutrients and oxygen to your hair so that they can grow, the Sebaceous Glands and more of the young cells being produced and journeying their way up to your Epidermis. These structures are shown below.
Diagram sketch of dermis structure dermal papillae
Dermis
3. The Subcutaneous
  • The Subcutaneous is the lowest layer of your scalp and skin. It has a lot of fat cells, fibres and white blood cells for your immune system.
  • It helps keep your skin in place and anchored like a ship. 
  • Here you will also find some collagen and elastin which help stretch your skin. 
  • More blood vessels can be found here, where they tangle over each other on their journeys around your skin. These are indicated in red and blue in the sketch.
  • The bottom of your Sweat Glands are normally located here also.
Diagram sketch of subcutaneous structure
Subcutaneous

B. Hair Follicles, Sebaceous Glands, Arrector Pili & The Sweat Glands

4. The Hair Follicle
  • The Hair Follicle is where your hair strand is housed. It is found in the Dermis of your skin and has other layers to it.
  • Normally, each hair shoots from their own Follicle. 
Diagram sketch of hair follicle structure
Hair Follicle
  • It has a loop at it's base which holds a bundle of blood vessels for carrying nutrients and oxygen.
  • This bundle of vessels, called the Dermal Papillae, has extensions which travels up around the Dermis.
    Diagram sketch of dermis structure dermal papillae
    Dermal Papillae
  • Two of the important structures attached to the Follicle are the Sebaceous Gland and the Arrector Pili. 

5. The Sebaceous Gland
  • The Sebaceous Gland is where the natural oil or Sebum for your scalp comes from. The oil sometimes travels down the strands, and depending on the shape of your hair strand, the journey is easy or difficult. Simply put, an easy oil journey down the strand may equal to moisturised and soft hair. A tricky journey may equal to dry and frizzy hair.
Diagram sketch of sebaceous gland structure
Sebaceous Gland
6. The Arrector Pili
  • The Arrector Pili is a muscle which attaches your hair strand to the skin. It is what causes your hair to move when you are cold. This muscle also raises and lowers the hair strand, trapping warm air in winter while blocking out the sun in summer.
Diagram sketch of arrector pili structure
Arrector Pili
7. The Sweat Gland
  • The Sweat Gland is where your sweat is produced. The base of this gland is mostly found in the Subcutaneous layer of the skin. The sweat travels up to your scalp or skin.
Diagram sketch of sweat gland structure
Sweat Gland

C. The Hair Bulb, Root & Shaft

8. The Hair Bulb & Root
  • The round bulge at the base of the Follicle is called the Hair Bulb.
  • It is what you can sometimes see when you do uproot your hair strand.
  • The Root is above the Bulb and consists of a few layers. The root is in the Dermis.
Diagram sketch of hair bulb structure
Hair Bulb
9. The Hair Shaft
  • The Hair Shaft is what is also known as Strand. This is made up of three main parts. The Medulla, the Cortex and the Cuticle.
  • Part of the Shaft is what is seen outside of our scalp as hair, whiles part of it is in the scalp.
  • It grows approximately 6 inches a year, however, this varies from person to person based on factors like genetics.
  • The strand is basically dead cells, Keratin, and it has different stages in it's growth cycle.
Diagram sketch of hair strand shaft structure
Hair Shaft
Diagram sketch of hair medulla structure
Hair Medulla

D. Let's Cut Across A section Of The Hair Shaft
When you take a hair strand and you cut across it, this is what  it is made up of on a basic level. As mentioned above, there are three main parts and these are the Medulla, the Cortex and the Cuticle.

10. The Medulla
  • The Medulla may or may not be present in the hair. 
  • It is likened to the lead in a pencil. 
  • Its purpose is not exactly known, however, it is often known to be especially present in larger, darker and coarser hairs, less present in finer hairs and sometimes not present at all.
Diagram sketch of hair medulla structure
Hair Medulla
11. The Cortex
  • The Cortex of the hair strand is mostly dead protein Keratin
  • It is like the meat of the hair strand.
  • In the Cortex, you will also find the colour pigment Melanin which gives hair its colour.
  • Melanin is most present in darker hair, less in lighter hair and not present in white hair.
Diagram sketch of hair cortex structure
Hair Cortex
  • Inside the Cortex, the Keratin are arranged specifically to enable your hair to be flexible and and able to bend.
Diagram sketch of hair keratin structure
Keratin Inside The Cortex
12. The Cuticle
  • The Cuticle is like the skin of your hair.
  • The Cuticle itself is colourless.
  • Melanin is more concentrated closer to the Cuticle of the strand.
  • Cuticles opens and closes depending on the environment around your hair.
  • They can contribute to dry, brittle dull hair or soft shiny moisturised hair, together with other external and internal factors.
  • When opened, the Cuticle could leave your hairs core prone to damage and loss of moisture.
  • When closed they protect your hair, lock in moisture and also cause shine and softness with the addition of surface oils and shine inducing products like artificial hair serums.
Diagram sketch of cuticle structure
Hair Cuticle
This is my basic but fun introduction to the structure of the hair and scalp. I hope you found this informative and fun! Please don't forget to share, Tweet and Google Plus this post.


As Promised, Here Is The Video Demonstration Of The Sketches Above.

xoxo
Yvonne Dzifa

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2 comments

  1. Thanks, Dzifa for the detailed explanations.

    ReplyDelete
  2. You are welcomed. thanks for reading too! 😊

    ReplyDelete

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