Chapter 5: Integumentary System Flashcards
The Skin Consists of
superficial epidermis and deeper dermis, which rests on the hypodermis
The Epidermis
Superficial Layer of the Skin
consists of stratified squamous keratinized epithelium
The Dermis
Deeper Layer of the Skin
consists of loose & dense irregular collagenous connective tissue
Hypodermis
layer of adipose tissue deep to the skin; not considered part of the integument (skin)
Integument (skin) functions
protection, sensation, thermoregulation, excretion, and vitamin D synthesis.
Most of the cells in the Epidermis are….
Keratinocytes
Keratinocytes manufacture …
Keratin
Dendritic Cells
aka lagerhans cells
Phagocytes of the immune system that protect the skin and deeper tissues from pathogens
Merkel Cells
Sensory (touch) receptors in the stratum basale
mainly found in fingertips, lips, and the base of hairs
Thick skin
Has all five epidermal strata, & very thick stratum corneum!
lacks hair follicles but has many sweat glands
The Dermis consists of…
papillary layer and the reticular layer.
Folds of the papillary layer include…
dermal papillae and epidermal ridges
Gaps between collagen fibers in the reticular layer…
Cause tension, or cleavage, lines
melanin
the primary pigment that influences skin color
Other substances that affect skin color are
Carotene and hemoglobin.
Hair, or pili, are composed of…
Dead, keratinized keratinocytes that perform protective functions and sense the environment.
Nails
Are located on the ends of digits and are derived from the epidermis.
Sweat (sudoriferous) glands
Reside in the dermis and secrete sweat by merocrine secretion.
most common sweat gland
eccrine sweat gland
Other sweat glands include…
Apocrine glands, ceruminous glands, and mammary glands.
Sebaceous glands
Secrete sebum into a hair follicle via holocrine secretion.
Skin pathologies may include
A wound, a burn, or cancer.
Epidermis layers from deepest to superficial
stratum basale, spinosum, granulosum, lucidum, corneum
papillary layer
superficial layer of the dermis (takes up 20%)
composed of loose connective tissue
reticular layer
deeper layer of the dermis (takes up 80%)
composed of dense irregular connective tissue,
contains sweat/sebaceous glands and hair follicles
dermal papillae
fold in the papillary layer of dermis where it comes into contact with epidermis and makes ridges
epidermal ridges
folded patterns of the epidermis in thick skin that enhance gripping ability
carotene
several orange or red crystalline pigments
mostly found in plants (carrots)
apocrine gland
sweat glands found in the axillae
eccrine sweat glands
glands in the skin that produce watery sweat
ceruminous glands
secrete cerumen or EAR WAX
sebum
oily secretion from sebaceous glands that lubricates and moisturizes surface of skin
