6.1 Cells, Tissues, Organs & Glands

Cells, Tissues, Organs and Glands

Ohio State Board Exam Alert: The Board's blueprint places Anatomy & Physiology at 20 % of the theory examination — roughly twenty questions — and lists "Organs, Tissues, Cells, Glands" as named sub-topics under Anatomy. These are straightforward recall items, which makes them some of the cheapest marks on the paper. Do not skip them because they feel unrelated to nails.

Every structure a manicurist works on — nail plate, nail bed, epidermis, sweat gland, blood vessel, sensory nerve — is built from the same four-level hierarchy. Understanding it turns disconnected facts about the nail unit into a system you can reason about.

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1. The Organisational Hierarchy

        CELLS  ->  TISSUES  ->  ORGANS  ->  BODY SYSTEMS  ->  ORGANISM
          |           |            |             |
     basic unit   group of      two or more   organs working
     of living    similar       tissue types  together toward
     structure    cells doing   working as    one function
     and function one job       a unit

Applied to the hand: keratinocytes (cells) form stratified squamous epithelium (tissue), which together with dermis, vessels and nerves forms the skin (organ), which with hair and nails forms the integumentary system.

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2. Cells

A cell is the basic unit of all living things. Human cells vary enormously in size and shape but share three general parts:

Metabolism is the sum of the chemical processes that keep the cell alive, and it has two directions:

• Anabolism — constructive metabolism. Smaller molecules are built into larger ones; the body stores water, food and oxygen for the moment they are needed. Nail plate formation is anabolic.
• Catabolism — destructive metabolism. Larger molecules are broken into smaller ones, releasing energy for muscle contraction, secretion and heat.

The two run continuously and in balance. When they fall out of balance — through illness, malnutrition or a systemic drug — the effect shows in slow-growing, thin or ridged nails, because the matrix is one of the body's fastest-dividing tissues and is sensitive to anything that disturbs cellular energy supply.

Mitosis is the cell division by which one cell divides into two identical daughter cells. Cells reproduce by mitosis whenever adequate food, oxygen, water, suitable temperature and the ability to eliminate waste are present. The nail matrix is where mitosis produces the cells that become the nail plate; the stratum germinativum (basal layer) is where mitosis produces the cells that become the epidermis. Damage the matrix and you damage the only place a new nail plate can be made.

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3. Tissues

A tissue is a group of cells of the same kind performing a particular function. Four types make up the human body, and all four are present in a fingertip.

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4. Organs and Glands

Organs are structures composed of specialised tissues that perform specific functions. The skin is the body's largest organ, accounting for roughly 15 % to 16 % of total adult body weight, and it is the organ that concerns a nail technician most directly. Other organs commonly listed on cosmetology examinations include the brain (controls the body), heart (circulates blood), lungs (oxygenate blood), liver (removes toxic products of digestion), kidneys (excrete water and waste) and stomach and intestines (digest food).

Glands are specialised organs that remove materials from the blood and convert them into new compounds for secretion or excretion. There are two functional categories, and the distinction is a reliable exam item:

Both categories matter at the nail station.

• Sudoriferous glands regulate body temperature and eliminate waste through perspiration. They are most numerous on the palms of the hands and soles of the feet — which is exactly why enhancement adhesion fails on a plate that has not been dehydrated, why gloves become clammy, and why the feet in a pedicure basin present a warm, moist environment.
• Sebaceous glands secrete sebum, the oily lubricant that softens skin and, mixed with sweat, forms the acid mantle at roughly pH 4.5–5.5 that inhibits microbial colonisation. Sebaceous glands are found in the dermis over most of the body but are absent from the palms and soles, which is one reason hands and feet dry and crack so readily and why cuticle oil and moisturiser are genuinely functional rather than decorative.
• Endocrine glands explain systemic nail change. Thyroid dysfunction slows nail growth and produces brittle or spoon-shaped nails; pregnancy hormones commonly accelerate growth; pancreatic disease presenting as diabetes changes peripheral circulation and healing — the single most important systemic contraindication in pedicuring.

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5. Why This Appears on a Nail Examination

Three practical threads run from this section into daily practice:

1. Matrix damage is permanent in a way plate damage is not. The plate is dead keratinised tissue; the matrix is living, dividing tissue. Aggressive drilling at the proximal fold, or a blunt-force injury, can scar the matrix and produce a permanently ridged or split nail.
2. The absence of sebaceous glands on palms and soles is why hand and foot skin behaves differently from facial skin, and why a paraffin or hot-oil treatment produces a visible result there.
3. Glandular and metabolic disorders present in the nails before the client mentions them. A manicurist may not diagnose — OAC 4713-8-07(D) forbids it — but recognising that a change is systemic rather than cosmetic is what triggers a proper referral.