Integumentary System Flashcards
Function of the papillary layer
Nourishes and supports the epidermis
What are the accessory structures?
Hair follicles, exocrine glands, and nails
What are the two types of cutaneous membrane?
Epidermis and dermis
What are some functions of the integumentary system?
Physical protection, synthesis/storage of lipids, coordination of immune response, sensory information, synthesis of vitamin D3, excretion, thermoregulation
What are the layers of the epidermis (deep to superficial)?
Stratum basale, stratum spinousum, stratum granulosum, stratum lucidum, stratum corneum
Characteristics of stratum corneum
Most superficial, flattened dead cells, thick plasmalemma, no organelles,relatively dry, protects against bacteria, keratinization
Characteristics of stratus lucidum
Only on thick skin, appears glassy, lack organelles, keratin filaments that are oriented parallel, flattened nuclei
Characteristics of stratum granulosum
Most superficial layer of skin in which all cells have a nucleus, make water resistant layer, where calluses stem from, formation of keratohyalin, formation of keratin
What forms calluses?
Increased friction of the skin stimulates an increased rate of synthesis for keratin and keratohyalin within the stratum granulosum
Characteristics of stratum spinosum
Where cells begin to differentiate into a keratinocyte, thickest layer for support, tonofibrils, melanocytes, langerhans cells
Tonofibrils
Begin and end at the macula adherens, they connect and strengthen cell junctions
What are desmosomes of the stratum spinosum called?
Macula adherens
What ties keratinocytes and stratum spinosum together?
Macula adherens and tonofibrils
Characteristics of the stratum basale
Deepest epidermal layer, contain stem cells, melanocytes, and merkel cells. Where cell division occurs
What are the cells of the epidermis?
Basal cells, keratinocytes, merkel, and langerhans
What is the cutaneous plexus?
Artery and vein in the hypodermis
What is the other name for the hypodermis?
Subcutaneous layer
What loose connective tissue make up the papillary layer?
Areolar connective tissue
What kind of tissue makes up the reticular layer?
Dense irregular tissue
Why is dense irregular tissue used in the dermis?
It can be stretched in many directions
What are epidermal ridges?
Found in stratum basale. Genetically determined they are our fingerprints. They increase surface area of the ski and increase friction for a firm grasp.
Dermal papillae
Projections of the dermis towards the epidermis
Melanosomes
Intracellular vesicles with melanin that color keratinocytes until destroyed by lysosomes.
Where does the Melanosome transfer occur in light skin individuals?
Stratum basale and stratum spinosum causing cells of the superficial layers to lose pigmentation
Where does Melanosome transfer occur in dark skin individuals?
Occurs in stratum basale, stratum spinosum, and stratum granulosum making skin darker and more persistent
Subpapillary plexus
Small arteries enter a branching network in the papillary layer
What are two reasons blood circulation must be regulated in the skin?
Thermoregulation and equal distribution to other organs
Tactile discs
Touch receptors of the skin
Pacinian Corpsucle
Deep pressure and vibration. Located in the reticular layer
Meissners Corpsucle
Light touch sensation. In papillary region
Ruffini Corpsucle
Nerve for stretching. Between papillary and reticular layer. Chili pepper in diagram
Merkel cells
Located in the epidermis. Fine touch in stratum basale. Yellow and star shaped in the model
What are the names of the tactile discs (tactile receptors)?
Pacinian Corpsucle, Ruffini Corpsucle, Meissners Corpsucle, and Merkel cells
What are functions of the subcutaneous layer (hypodermis)?
Allowing independent movement between skin and tissues, energy reserve (for infants), shock absorb (for infants), useful method for injecting drugs
The organs that form hair are __________
Hair follicles
Hair papilla
Peg of connective tissue containing capillaries and nerves. Located at the Epithelium at the hair follicle base
Hair bulb
Epithelial cells that surround the hair papilla
What is the medulla of hair?
The core
What does the medulla of hair contain?
Soft keratin, which is soft and flexible
Cortex of hair
Matrix cells closer to the edge of the developing hair. Contains hard keratin that gives hair its stiffness
What kind of cells make up the cuticle of hair?
Dead Keratinized cells
Hair root function
Attaches hair to the hair follicle
Hair shaft
Part of hair we see on the surface
What makes up the hair follicle structure?
Internal root sheath, external root sheath, and glassy membrane
Internal root sheath
Surround the hair root . Ends at sebaceous gland
External root sheath
Extends from skin surface to hair matrix.
Glassy membrane
Thickened basal lamina of hair, wrapped in a dense connective sheath
Root hair plexus
Provides sensitivity to movement of hair
Arrector pilli muscle
Ribbon of smooth muscle that extends from the papillary layer of the dermis to the connective sheath of the hair follicle. Elevates hair. Responsible for goosebumps
Lanugo
Unpigmented hair in embryonic development
What are the three types of hairs?
Vellus hairs, intermediate hairs, and terminal hairs
Vellus hairs
Peach fuzz hair found on body surfaces (facial hair)
Terminal hair
Heavily pigmented hair that can be curly (ex pubic hair or head hair)
Intermediate hair
Hair that changes in distribution (ex upper and lower limbs)
Sebaceous glands
Found in dermis, using Holocrine secretion. They can simple alveolar or simple branched alveolar. Secrete sebum
Sebum
Oily secretion that provides lubrication and inhibit bacterial growth. Protects keratin of hair shaft
Sebaceous follicles
Sebaceous glands that communicate directly with the epidermis and do not produce hairs. They are found on face, back, nipples, and male sex organs
Folliculitis
Inflammation caused by bacteria in glands or follicles
Furuncle
Boil caused by blockage in glands
Sudoriferous Apocrine sweat glands
Sweat glands that release secretions into hair follicles in armpits, nipples, and groin
Sudoriferous Eccrine (merocrine) sweat glands
Coiled tubular sweat glands that secrete sweat playing a role in thermoregulation, excretion, and protection
Myoepithelial cells
Underlying basal lamina they squeeze sweat glands and discharge secretions
Ceruminous glands
Modified sweat glands in external auditory canal. Make cerumen
Cerumen
Ear wax
Nail body covers the ________
Nail bed
Where does nail production occur?
Nail root
What bounds the nail body?
Nail grooves and nail folds
Eponychium (cuticle)
Region that connects the nail to the skin
Lunula
Pale crescent near base of nail where blood vessels are obscured
Hyponychium
Free edge of nail body that extends over a thickened stratum corneum
