Lecture Integumentary System Flashcards
(22 cards)
What does the integumentary system consist of?
the integumentary system consists of skin and its accessory structures
What are accessory structures?
hair
nails
glands
sensory receptors
outer, more dead layer = ____
inner, more alive layer = ____
outer, more dead layer = epidermis
inner, more alive layer = dermis
Function of integumentary system?
protective covering
barrier against harmful substances & microorganisms
regulates body temperature
limits evaporation (water loss)
contains sensory receptors
excretes some waste
Two layers of epidermis we need to know and a description of them?
Epidermis:
consists of up to 5 layers – we just need to know outer- and inner-most layers:
consists of stratified squamous epithelium
stratum corneum: consists of dead, flattened, keratinized cells
stratum basale: single row of cuboidal/columnar epithelial cells that are mitotically active; constantly regenerates epidermis
What causes skin resiliency?
skin’s resiliency is due to the protein keratin
What is keratin?
keratin – tough, fibrous waterproof protein found in skin and accessory structures
Keratinization?
keratinization occurs when keratin hardens and becomes dehydrated (loses water) and accumulates in the outermost portion of the epidermis (stratum corneum)
What is pigment in skin?
What is it produced by?
What is its functino?
the pigmentation of skin is due to the pigment melanin
produced by cells located in the stratum basale called melanocytes
melanin helps protect against DNA-damaging ultraviolet radiation found in natural light
Where is the dermis located?
What are descriptions of its layers?
the dermis is located beneath the epidermis and consists of two main layers:
papillary dermis: composed of loose connective tissue
features undulating ridges which give rise to unique fingerprints
features nerve-endings which detect light touch
reticular dermis: consists of dense connective tissue
accessory structures originate from the ____, extend into ____ or ____
accessory structures originate from the epidermis, extend into dermis or hypodermis
Accessory structures of the skin?
hair follicles
nails
skin glands (sweat and sebaceous)
Why is it important for accessory structures to remain intact when skin is damaged?
if accessory structures remain intact, injured/burned dermis can regenerate
Where is hair present?
Hair is present on all surfaces of skin except palms, soles, lips, nipples, parts of external reproductive organs
What is hair follicle?
Hair follicle: Tube-like depression of epidermal cells from which hair develops
Extends into dermis or the subcutaneous layer
Three parts of hair?
Hair bulb (dividing cells)
Hair root
Hair shaft (dead, epidermal cells)
____ ____contains blood vessels to nourish hair
Hair color is due to type and amount of ____
____ ____ ____ causes (goosebumps)
Hair papilla contains blood vessels to nourish hair
Hair color is due to type and amount of melanin
Arrector pili muscle (goosebumps)
Function of nails?
Nails: Protective coverings on ends of fingers and toes
Three parts of nails?
3 parts of a nail:
Nail plate: overlies nail bed
Nail bed: surface of skin, under nail plate
Lunula: most active growing region; pale, half-moon-shaped region at base of nail plate
Another name for sebaceous glands?
What associated with?
What do the produce?
Why is this substance important?
Where are they absent?
Holocrine glands
Usually associated with hair follicles
Produce sebum, which consists of fatty material and cellular debris
Sebum keeps hair and skin soft and waterproof
Excess sebum can result in acne
Absent on palms and soles
Another name sweat glands?
Where located?
Where originate?
Also called sudoriferous glands
Widespread in skin
Originate in deeper dermis or hypodermis as ball-shaped coils
Two types of sweat glands?
Describe?
Eccrine (merocrine) glands:
most numerous
respond to elevated body temperature
Apocrine sweat glands:
axillary and groin areas
secrete by exocytosis
respond to emotions, pain
