Integumentary system Flashcards
Membranes
simplest of all organs (made up of two tissues)
Mucosae (mucous)
-lines body cavities that are open to the exterior can be simple columnar or stratified squamous
-found in respiratory, vagina, esophagus
Serosae (serous)
-line body cavities that are closed to the exterior
-visceral and parietal, no opening to the outside world, simple form
cutaneous
study as skin, now largest organ in the body
Synovial
-specialized connective soft tissue that lines the inner surface of synovial joint capsules
Function of the integument (skin)
- cover and protection from infectious agents
- body temp
- keeps water in
- protect from chemicals and sun
5.make precursor for vitamin D and calcium
6.Protect from mechanical trauma - Contain sensory receptors
Epidermis
outermost part of skin (keratinized stratified squamous epithelium)
-skin is not exactly water proof
-
stratum germinativum (basalis) (most deep)
-single layer of cells on basement membrane
- undergoes mitosis
-about 75% are keratin makers
-25% melanin makers stay there
Stratum spinosum (Malpighi)
-8 to 10 layers thick,
-looks spiny due to keratinocytes
some mitosis occurs
stratum granulosum
- 1 to 5 layers
-thin
-grainy appearance
-process of keratinization occurs
Stratum lucidum
-only found in palms and soles
-known as clear layer
stratum corneum
-broad zone from 20-30 cells
-keratin and protein accumulate inside to protect skin against penetration and abrasion
-the glycolipid layer helps keep this layer “waterproof”
keratin
-fibrous protein found in the epidermis, hair, skin, and nails that make those structures hard and water resistant
rickets
vitamin D deficiency
melanin
-dark pigment formed by cells called melanocytes, imparts color to hair and skin
-made in membrane bound granules called melanosomes
-only found in the deeper layers of the epidermis
Dermis
-made of strong connective tissue
-its cells are those found in connective tissue proper, semi-fluid matrix embedded with fibers
-has two layers papillary and reticular
Papillary layer
-thin, superficial areolar connective tissue, where fine collagen and elastin fibers are woven together. Looseness allows phagocytes and other defensive cells to wander
-finger like projections that come to the surface (fingerprints) increase friction on the body
-made of 20% LFCT
Reticular layer
-deeper layer which accounts for 80% of the thickness of the dermis made of (DFCT)
-the network of blood vessels that nourish this is called dermal vascular plexus
-has a network of collagen fibers
Hypodermis
-underneath the dermis also called subcutaneous tissue
-not part of the skin but shares some of skin’s properties
-consist mostly of adipose tissue with some areolar connective tissue
-anchors skin to underlying structures, protects us from bumps, and act as shock absorber
Hair
-forms complex structural units, the hairs are long filaments
-hair has different functions, on head it protects from hair follicles, heat loss, sunlight.
-eyelashes protect from particles and nose hairs from particles
sebaceous glands
-oil glands, simple branched alveolar glands that form all over the body but palms and soles
-secrete a substance called sebum
-these are holocrine glands
-most develop as outgrowths of hair follicles
sudoriferous glands (eccrine)
-sweat glands far more numerous than apocrine and abundant on palms, soles of the feet, forehead
-secret sweat help regulate body temperature
sudoriferous glands (apocrine)
- located mainly in the axillary (armpit) and genital area
-sweat glands that contribute to stinky smell
-larger than sweat glands, they lie deep into the dermis
nails
-form a clear protective covering over the dorsal surface of the distal part of the finger
-contain hard keratin
