Lesson · A.2.1
The integumentary system
Learn the layers of skin, its glands and appendages, and the functions the HESI A2 Anatomy and Physiology subtest expects you to know cold.
ObjectiveA.2.1Read6 minExam weightSupport and Movement ≈ 24% of Anatomy & Physiology
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See editions and pricing →What you will be able to do
- Name the layers of the epidermis and dermis in order and state what each does
- Tell apart the skin's glands (sebaceous, eccrine, apocrine) and what each secretes
- Explain how skin colour, hair, and nails signal underlying health to a clinician
What the lesson concludes
- Skin is the body's largest organ, and its epidermis, dermis, and hypodermis each have a distinct job.
- The epidermis is dead, keratinised, and waterproof at its surface, but alive and dividing at its base.
- Melanin, not thickness, is the main reason skin colour varies, and it also absorbs ultraviolet radiation.
- Sweat and sebaceous glands are separate systems: one cools the body, the other lubricates skin and hair.
- A nurse reads the skin constantly. Colour, turgor, and temperature are vital sign proxies you can see and touch.