The Integumentary System Flashcards
What is the functions of Skin (5)
Reception Protection Regulate body Temperature (through blood vessels behind and adipose tissue) Excretion Glands (also temp control) Absorb (vit. D)
Skin Receptors (3 general classification)
Mechanoreceptors - touch and pressure
thermoreceptors - Respond to cold and warmth
Nociceptors -respond to pain
What Are the three Skin layers
Epidermis, the Dermis, and the hypodermis
Epidermis Properties
4-5 layers of cells shed and replaced
Produce keratin, pigment and immune cells
Derived from ectoderm,
No bood vessels or blood supply
Dermis Properties
Has collagen and elastin
contains blood vessels, nerve endings, hair follicles, glands
these things must be there to maintain the epidermis
dervided from mesoderm
Hypodermis Properties
Loose connective tissue and varying adipose tissue
Rete Apparatus
Interface betwen the dermis and epidermis holding it tight together
The Dermal Ridges
are the papillae extending up from the dermis, stains way lighter than the epidermal
The Epidermal Ridges
Downward projections from the epidermis
Stains darker
Epidermis Cell Structure
Stratified squamous keratinized epithelium
Contains free nerve endings
Four Cell Types of Epidermis
Keratinocytes, melanocytes, langerhans, merkel
Keratinocytes Properties
Largest population of cells in skin, have five layers to it.
Function - produce keratin, lipids, and lipoproteins
Divide at night - cytomorphosis
Cytomorphosis
The division of keratinocytes at night
What are the five zones of the keratinocytes in the epidermis from basal to outside
Stratum Basale, Stratum spinosum, Stratum granulosum, stratum lucidum, stratum corneum (keratin)
Stratum lucidem is only present in soles and palms for extra protection
Connections of the Stratum Basale
Desmosomes connect laterally and to the stratum spinosum
Hemidesmosomes connect it to the basal lamina
Keratin Production by Keratonicytes Order
Stratum Basale - begin syntehsizing intermediate filaments called tonofilaments
Lower and Upper Stratm Spinosum - tonofilaments bundle to tonofibrils in lower. In upper the cells produce keratohyalin granules
Stratum Granulosum - substance from keratohyalin grandules combine with tonofibrils coverting to keratin
Stratum Corneum - cytoplasm replaced by keratin
Lamellar Bodies
Keratinocytes also produce aka membrane coating granules. They help water proof make hydrophobic
They contain glycophospholipid
How is lamellar bodies produced
stratum grandulosum lipid contents of lamellar bodies are extruded in to the intercellular spaces, making hydrophobic barrier
Melanocytes (location and contents
located in stratum basale
contains tyrosine converts tyrosine to melanin. melanin transferred to keratinocytes via melanosomes to keratinocytes
Melanin
pigment, and reason for tanning
Melanosomes
transferres melanin to keratinocytes
Langerhans
dendritic cell containing birbeck granules of unknown function
It is an APC phagocyte
Merkel Cells
mechanoreceptor - found in deep part of epidermes. attached to nerve endings
sense light touch
What are the two dermis layers
Papillary Layer
Reticular Layer
Papillary Layer
Immediately under the epidermis,
elastic fiver and type III collagen
Also anchoring fibris Type VII collage
Capillary loops - see capillary walls that support epidermis
Reticular Layer
Type I collagen an elastic
location of sweat glands, sebaceous glands
hair follicles and smooth muscle cells
see many wavy and pink
What are the glands in the reticular
Sweat glands
Sebaceous glands
Sweat Glands Name and type of excretion
Eccrine sweat glands, mode is merocrine so basic exocytosis.
Myoepithelial cells
share a basal lamina of acinar cells. The myoepithelial is smooth muscle to propel
Acinus
The secretory unit. the Acinus cells are surrounded by myoepithelial cells
Sweat glands name and mode of secretion
Apocrine sweat glands
Apocrine secretion. So it pinches off peices of cell when secreting
delivers product in same canal as the hair follicle. found in areaola and anal region
Sebaceous Glands mode of secretion and facts
Not on hands and feet
secretory product called Sebum
done through holocrine secretion so the whole cell is destroyed
Sebum
the oil secretion of a sebaceous gland
Hair follicles muscle
arrector Pili muscles that change the angle
The four skin receptors
Merkel - in the epidermis for light touch in papilla
Meissner - in the dermis for light touch at same longitude of merkel
Pacinian Corpuscle - looks like an onion for pressure
Ruffini Organ - stretch organ
