Human Anatomy Chapter 5 Flashcards
The integumentary system is composed of
Skin, hair, nails, sweat glands, sebaceous glands, mammary glands
Skin
Most visible organ of the body, helps protect from the environment, helps to regulate body temperature and excretes when necessary, helps synthesize and store lipids, and vitamin D3, helps coordinate immune response to pathogens and cancers, can sense information
Cutaneous membrane
Epidermis, dermis
Accessory structures
Hair follicles, exocrine glands, nails
Epidermis
Superficial epithelium
Dermis
Underlying connective tissue, deep is hypodermis, known as subcutaneous layer or superficial fascia, not part of integument
Accessory structures
Hair follicles, exocrine glands, sweat glands/sebaceous glands, nails
Function of Integumentary system
Physical protection, regulation of body temperature, excretion of products, synthesis of products, sensation, immune defense
Keratinocytes
Produce a tough protein called keratin
Melanocytes
Pigment cells located deep in the epidermis, produce melanin (skin color)
Merkel cells
Sensory cells
Langerhans cells
Wandering macrophages
Stratum basale
Consists of basal cells
Location of melanocyte: produce melanin (lack of melanin results in albinism)
Cells in the area are undergoing active reproduction
Skin surfaces that lack hair contain specialized cells known as Merkel cells
Deepest basal layer
Stratum Spinosum
Keratinocytes are bound together by desmosomes
Tonofibrils are associated with the desmosomes
Langerhans cells are most common in the superficial portion
Some keratinocytes divide in this layer
Stratum Granulosum
Keratinocytes produce lots of keratin and keratohyalin
Excess synthesis produces calluses
Keratin fibers develop as cells become thinner and flatter
Stratum Lucidum
Found in palms of hands and soles of the feet
Appears as a glassy layer in thick skin only
Stratum Corneum
Superficial layer
Consists of interlocking, dehydrated, dead cells
Allows slow water loss by insensible perspiration
Contains multiple layers of flattened, dead, interlocking keratinocytes
Thick skin
Found on palms and soles, made of five layers of cells
Thin skin
Found on the rest of the body
Made of four layers of cells, because the stratum lucidum is typically absent
Dermal ridges
Stratum germinativum forms dermal ridges
Ridges (dermal papillae) extend into the dermis
Creates ridges we call fingerprints