CHAPTER 16 Skin

Integumentary system

Hệ thống da và các cấu trúc phụ (tóc, móng, tuyến)

Sebaceous glands

Tuyến bã nhờn - sản xuất bã nhờn, một chất tiết dầu

Sweat glands

Tuyến mồ hôi - sản xuất mồ hôi, một chất tiết dạng nước

Nerve fibers

Sợi thần kinh - thụ thể cho cảm giác như đau, nhiệt độ, áp lực, và xúc giác

Epidermis

Biểu bì - lớp ngoài cùng hoàn toàn bao gồm các tế bào của da, chứa keratin

Dermis

Hạ bì - lớp mô liên kết dày đặc, chứa collagen

Subcutaneous layer

Lớp dưới da - lớp mô chứa mỡ dày

Basal layer

Lớp đáy - lớp sâu nhất của biểu bì, nguồn gốc của tất cả các tế bào khác trong biểu bì

Melanocytes

Special cells in the basal layer of the epidermis that contain melanin pigment transferred to other epidermal cells, determining skin color.

Eumelanin

Brown-black pigment more common in darker skin, providing protection from UV rays.

Pheomelanin

Red-yellow pigment more prevalent in lighter skin, less protective against UV rays.

Dermis

Layer below the epidermis containing blood vessels, nerves, and accessory skin organs like hair follicles and sweat glands.

Subcutaneous Layer

Specializes in fat formation, predominant in adipocytes, important for body tissue protection, insulation, and energy storage.

Hair Fiber

Composed of keratin-filled cells, growth similar to epidermal skin layer, with melanocytes providing pigment to hair cells.

Hair Color

Concentration of eumelanin and pheomelanin cause variations in hair color, such as black, brown, blond, red, and gray.

Lunula

The semilunar whitish region at the base of the nail plate, visible in most thumbnails, with its color due to air mixed with keratin and nuclei-rich cells.

Nail Growth

Nails are hard keratin plates covering toes and fingers, growing about 1 mm per week for fingernails and taking about 12 months for toenails to be completely replaced.

Sebaceous Glands

Glands in the dermal layer secreting sebum, influenced by sex hormones, lubricating the skin and contributing to blackhead formation and acne.

Sweat Glands

Eccrine sweat glands found on body surfaces, producing almost pure water sweat, controlled by the sympathetic nervous system to regulate body temperature.

Apocrine Glands

Special sweat glands active from puberty onward, larger than eccrine glands, concentrated near reproductive organs and armpits, producing odorless sweat broken down by bacteria to create body odor.

Apocrine sweat gland

One of the large dermal exocrine glands located in the axilla and genital areas. It secretes sweat that, in action with bacteria, is responsible for human body odor.

Sebaceous gland

Oil-secreting gland in the dermis that is associated with hair follicles.

Melanin

Skin pigment. It is formed by melanocytes in the epidermis. Eumelanin is brown-black pigment, whereas pheomelanin is red-yellow.

Epidermis

Outermost layer of the skin.

Adipocyte

Fat cell.

Dermis

Middle layer of the skin.

Keratin

Hard protein material found in the epidermis, hair, and nails. Keratin means horn and commonly is found in the horns of animals.

Collagen

Structural protein found in the skin and connective tissue.

Subcutaneous layer

Innermost layer of the skin, containing fat tissue.

Hair follicle

Sac within which each hair grows.