List functions or types
List the functions of the Integumentary System
• Guard the body’s physical and biochemical integrity
• Maintain a constant body temperature
• Provide sensory information about the surrounding environment.
What is the structure of the skin?
• epidermis
• dermis
What are the layers of the Epidermis from the deepest to the most superficial?
– stratum basale (stratum germinativum)
– stratum spinosum
– stratum granulosum
– stratum lucidum (only in palms and soles)
– stratum corneum
The dermis is composed of what?
• collagen & elastic fibers, fibroblasts, macrophages & fat cells
The dermis contains what?
• Contains hair follicles, glands, nerves & blood vessels
What does EGF stand for?
-Epidermal growth factor
List information over the papillary region:
• Top 20% of dermis
• Finger like projections are called dermal papillae
– anchors epidermis to dermis
– contains capillaries that feed epidermis
– contains Meissner’s corpuscles (touch) & free nerve endings for sensations of heat, cold, pain, tickle, and itch
What is keratinization?
-It is the replacement of cell contents with the protein keratin; occurs as cells move to the skin surface over 2-4 weeks.
What are the glands in the skin?
• Sebaceous (oil) glands
• Sudiferous (sweat) glands
• Ceruminous (wax) glands
• Mammary (milk) glands
The two major regions of dermis are?
– papillary region
– reticular region
List 3 skin cancers:
– basal cell carcinoma (rarely metastasize)
– squamous cell carcinoma (may metastasize)
– malignant melanomas (metastasize rapidly)
List information over the Reticular Region:
• Dense irregular connective tissue
• Contains interlacing collagen and elastic fibers
• Packed with oil glands, sweat gland ducts, fat & hair follicles
• Provides strength, extensibility & elasticity to skin
– stretch marks are dermal tears from extreme stretching
• Epidermal ridges form in fetus
– fingerprints are left by sweat glands open on ridges
– increase grip of hand
What is the hair growth cycle and how long do they last?
Growth stage
– lasts for 2 to 6 years
– matrix cells at base of hair root producing length
Resting stage
– lasts for 3 months
– matrix cells inactive & follicle atrophies
What are the problems that result from burns?
– shock due to water, plasma and plasma protein loss
– circulatory & kidney problems from loss of plasma
– bacterial infection
The wide variety of colors in skin is due to three pigments
-melanin, carotene, and hemoglobin (in blood in capillaries)
The seriousness of a burn is determined by: its _____, _____, and area involved, as well as the person’s _____ and general _______.
depth, extent, age, health
Functions of Hair:
• Prevents heat loss
• Decreases sunburn
• Eyelashes help protect eyes
• Touch receptors (hair root plexus) senses light touch
What is the structure of a nail?
• Nail body
– free edge appears white
• Nail root
• Eponychium (cuticle)
What are the different types of burns?
1st degree, 2nd degree, 3rd degree
Hair consists of 4 structures:
– a shaft above the surface
– a root that penetrates the dermis and subcutaneous layer
– the cuticle
– a hair follicle
What do the different degrees of burn destroy?
First-degree
– only epidermis (sunburn)
• Second-degree burn
– destroys entire epidermis & part of dermis
– fluid-filled blisters separate epidermis & dermis
– epidermal derivatives are not damaged
– heals without grafting in 3 to 4 weeks & may scar
• Third-degree or full-thickness
– destroy epidermis, dermis & epidermal derivatives
– damaged area is numb due to loss of sensory nerves
List the functions of the skin:
Excretion, synthesis of vitamin d, cutaneous sensations, protection, blood reservoir
What are the 3 different cell shapes?
Squamous- flat and scale-like, Cuboidal- cube shaped, Columnar- tall and column-shaped
What are the four Principle Cells of the Epidermis? What do those four principles do?
• keratinocytes
– produce the protein keratin, which helps protect the skin and underlying tissue from heat, microbes, and chemicals, and lamellar granules, which release a waterproof sealant
• melanocytes
– produce the pigment melanin which contributes to skin color and absorbs damaging ultraviolet (UV) light
• Langerhans cells
– derived from bone marrow
– participate in immune response
• Merkel cells
– contact a sensory structure called a tactile (Merkel) disc and function in the sensation of touch
What are the 4 types of tissues?
Epithelial, Connective, Muscular, Nervous
Hair color is due primarily to what? Why do we get gray, dark, blond/red, or white hair?
the amount and type of melanin.
Graying of hair occurs because of a progressive decline in tyrosinase.
– Dark hair contains true melanin
– Blond and red hair contain melanin with iron and sulfur added
– Graying hair is result of decline in melanin production
– White hair has air bubbles in the medullary shaft