3.2 Organs and Body Systems: How the Whole Body Shows Up in the Skin
Key Takeaways
Organs are structures of two or more tissue types with a specific function; the key organs for estheticians include the skin, heart, lungs, brain, liver, kidneys, stomach, and intestines.
Esthetics textbooks describe eleven body systems, and the integumentary system (skin, hair, nails, and glands) is the one estheticians treat directly.
The endocrine system's hormones affect the skin: androgens increase sebum, estrogen and progesterone can trigger melasma, and insulin problems slow wound healing in diabetes.
The circulatory system delivers oxygen and nutrients through arteries, capillaries, and veins, and the lymphatic system returns tissue fluid and supports immunity, which is the basis of lymphatic drainage massage.
The excretory organs are the kidneys, liver, lungs, large intestine, and skin, which excretes water, salt, and small amounts of waste through sweat.
From tissues to organs to systems
Section 3.1 covered the first two levels of organization, cells and the four tissue types (epithelial, connective, muscular, and nerve). The next two levels are what the NIC outline means by "organs and their function" and "systems and their functions."
- An organ is a structure made of two or more tissue types that performs a specific function. The skin is an organ: epithelial tissue (epidermis), connective tissue (dermis), nerve endings, muscle (arrector pili), and glands working together.
- A body system is a group of organs that work together on a major body function.
| Organ | Main function | Why an esthetician cares |
|---|---|---|
| Skin | Protection, sensation, temperature regulation, excretion, secretion, absorption | The organ you treat |
| Heart | Pumps blood through the body | Cardiac conditions and pacemakers are contraindications for electrical treatments |
| Lungs | Exchange oxygen and carbon dioxide | Asthma clients and aerosol or fragrance sensitivity, plus positioning for comfortable breathing |
| Brain | Controls the body through the nervous system | Seizure disorders affect light and electrical treatments |
| Liver | Removes toxic products of digestion and processes medications | Medications and alcohol affect skin and healing |
| Kidneys | Filter blood and excrete water and waste as urine | Fluid balance, and a primary excretory organ |
| Stomach and intestines | Digest food | Nutrition shows up in skin health |
| Eyes | Sight | Protect them during peels, tints, lash work, and LED |
The eleven body systems
| System | Main organs and structures | Main function | Esthetics connection |
|---|---|---|---|
| Integumentary | Skin, hair, nails, sweat and oil glands | Protective covering, sensation, temperature regulation | Everything in this guide |
| Skeletal | 206 bones, joints | Shape, support, protection, movement, and blood-cell production in red marrow | Facial bones guide massage and contouring |
| Muscular | Over 600 muscles | Movement and posture, and the facial expression muscles | Massage technique and microcurrent |
| Nervous | Brain, spinal cord, nerves | Controls and coordinates all systems | Sensation, pain, the facial and trigeminal nerves, relaxation response |
| Circulatory (cardiovascular) | Heart, arteries, veins, capillaries, blood | Carries oxygen, nutrients, and wastes | Erythema, telangiectasia, bruising, massage benefits |
| Lymphatic / immune | Lymph, lymph nodes, vessels, spleen, thymus, tonsils | Returns tissue fluid to the blood and fights infection | Lymphatic drainage, swelling, infection response |
| Endocrine | Pituitary, thyroid, parathyroid, adrenal, pancreas, ovaries, testes, pineal | Hormones that regulate growth, metabolism, and reproduction | Acne, melasma, hirsutism, healing in diabetes |
| Respiratory | Nose, pharynx, larynx, trachea, bronchi, lungs | Brings in oxygen and removes carbon dioxide | Ventilation, aerosols, client positioning |
| Digestive | Mouth, stomach, intestines, liver, pancreas | Breaks food into nutrients | Nutrition and skin, and food-related allergies |
| Excretory | Kidneys, liver, lungs, large intestine, skin | Eliminates waste | Sweat glands excrete water, salt, and small amounts of waste |
| Reproductive | Ovaries, testes | Reproduction and the sex hormones | Hormonal skin changes in puberty, pregnancy, and menopause |
The systems the exam emphasizes
Integumentary system
This system is the skin and its appendages: hair, nails, sudoriferous (sweat) glands, and sebaceous (oil) glands. Chapter 3's histology and function sections and Chapter 4's disorders all belong here. On the exam, "integumentary" is the expected answer whenever a question asks which system includes the skin.
Endocrine system
The endocrine glands are ductless and release hormones directly into the bloodstream. Exocrine glands, by contrast, use ducts. The sweat and oil glands are exocrine glands. Know the main endocrine glands and the skin effects of their hormones:
| Gland | Key hormone(s) | Skin-related effect |
|---|---|---|
| Pituitary | Growth hormone and hormones that control other glands | Often called the master gland |
| Thyroid | Thyroid hormones (metabolism) | Underactivity is associated with dry, rough skin; overactivity with warm, moist skin |
| Adrenal | Cortisol, adrenaline, adrenal androgens | Stress responses, and androgens that stimulate sebum |
| Pancreas | Insulin (from the islets of Langerhans) | Diabetes slows healing and raises infection risk |
| Ovaries | Estrogen, progesterone | Melasma in pregnancy or on oral contraceptives, and changes at menopause |
| Testes | Testosterone | Androgens increase sebum and terminal hair growth |
This is why an intake form asks about pregnancy, thyroid disease, diabetes, and hormone therapy. Each one changes how the skin responds.
Circulatory and lymphatic systems
- Arteries carry oxygenated blood away from the heart. Veins carry blood back to the heart and have valves. Capillaries are the thin vessels where oxygen and nutrients pass into tissue. Dilated capillaries appear as telangiectasia.
- Blood consists of plasma, red blood cells (which carry oxygen), white blood cells (which fight infection), and platelets (which help blood clot). Clients on anticoagulants bruise more easily, which is why Section 6.2 restricts aggressive extractions for them.
- The lymphatic system carries lymph (tissue fluid) through vessels and lymph nodes back to the bloodstream and filters out bacteria. The face drains toward the submental, submandibular, and cervical nodes, which is why lymphatic-drainage strokes move toward the neck.
Nervous system
- The central nervous system is the brain and spinal cord. The peripheral nervous system is the nerves that connect it to the body. The autonomic nervous system controls involuntary functions, with a sympathetic ("fight or flight") side and a parasympathetic ("rest and digest") side.
- Sensory (afferent) nerves carry impulses from the skin to the brain. Motor (efferent) nerves carry impulses from the brain to muscles. A relaxing facial massage shifts the client toward parasympathetic activity.
Skeletal and muscular systems
- The skeleton gives the body its shape, protects organs, provides attachment points for muscles, and produces blood cells. Section 3.1 covers the skull bones used in facial massage.
- There are three types of muscle tissue: skeletal (striated and voluntary, which includes the facial muscles), smooth (involuntary, found in vessel walls and the arrector pili), and cardiac (the heart).
Scenario: connecting systems at consultation
A client's intake form lists type 1 diabetes, hypothyroidism, and a recent pregnancy. Diabetes involves the endocrine pancreas: expect slower healing and higher infection risk, so keep extractions gentle and heat moderate. Hypothyroidism can leave the skin dry, so choose barrier-supporting, hydrating products. The pregnancy raises melasma risk through ovarian hormones, so emphasize daily sun protection. If the client's physician has given specific restrictions, follow them. The facial changes because three organ systems changed the skin.
Which body system includes the skin, hair, nails, and the sweat and oil glands?
Musculoskeletal system
Excretory system
Integumentary system
Endocrine system
A client's hormonal changes during pregnancy have produced patches of melasma. Which body system releases the hormones responsible?
The skeletal system, through calcium released from bone
The digestive system, through enzymes released by the pancreas
The endocrine system, through the ovaries' estrogen and progesterone
The respiratory system, through reduced oxygen exchange in the lungs
Which statement correctly describes the lymphatic system?
It returns tissue fluid to the blood through vessels and nodes and aids immunity
It carries motor impulses from the brain to the facial muscles
It pumps oxygenated blood from the heart out to the facial arteries and capillaries
It releases hormones directly into the bloodstream from ductless glands throughout the body
Sections you finish are checked off in the contents.