Integumentary System Part II Flashcards
STRUCTURES OF THE 3 LAYERS OF THE SKIN:
EPIDERMIS
DERMIS
HYPODERMIS
most superficial layer
EPIDERMIS
avascular
EPIDERMIS
stratified squamous keratinized epithelium
EPIDERMIS
first line/barrier of protection
EPIDERMIS
nutrients and oxygen diffuse from capillaries in the dermis
EPIDERMIS
contains Keratinocytes.
EPIDERMIS
is the most abundant cells in the epidermis [constitutes about 90% of the cells in the epidermis]
Keratinocytes
Contain large amounts of KERATIN.
Keratinocytes
STRUCTURES OF THE EPIDERMIS
- STRATUM BASALE [ GERMINATIVUM ]
- STRATUM SPINOSUM [SPINY LAYER]
- STRATUM GRANULOSUM (GRAINY LAYER)
- STRATUM LUCIDUM (CLEAR LAYER)
- STRATUM CORNEUM (HORN LAYER)
provides the germinal cells (necessary for the regeneration of the layers of the epidermis)
STRATUM BASALE [ GERMINATIVUM ]
separated from the dermis by a thin layer of the basement membrane
STRATUM BASALE [ GERMINATIVUM ]
after a mitotic division, a newly formed cell will undergo a progressive maturation called keratinization as it migrates to the surface.
STRATUM BASALE [ GERMINATIVUM ]
is attached to the basement membrane by Hemidesmosomes
STRATUM BASALE [ GERMINATIVUM ]
forms a strong bond between the epidermis and the dermis.
STRATUM BASALE [ GERMINATIVUM ]
forms epidermal ridges (fingerprints)
STRATUM GERMINATIVUM
dermal papillae (tiny mounds)
STRATUM GERMINATIVUM
increase the area of basement membrane
dermal papillae (tiny mounds)
strengthen the attachment between epidermis and dermis
STRATUM GERMINATIVUM
has many basal cells or germinative cells.
STRATUM GERMINATIVUM
the cells that divide in the stratum germinativum soon begin to accumulate many desmosomes on their outer surface which provide the characteristic prickles of the stratum spinosum (SS), which is often called the prickle-cell layer
STRATUM SPINOSUM [SPINY LAYER]
produced by division of stratum basale.
STRATUM SPINOSUM [SPINY LAYER]
eight (8) to ten (10) layers of keratinocytes bound by desmosomes.
STRATUM SPINOSUM [SPINY LAYER]
the progressive maturation of keratinocytes is characterized by the accumulation of keratin called keratinization.
STRATUM GRANULOSUM (GRAINY LAYER)
cells of stratum granulosum accumulate __________
dense basophilic keratohyalin granules.
these granules contain lipids, which along with the desmosomal connections, help form a waterproof barrier that functions to prevent fluid loss from the body
STRATUM GRANULOSUM (GRAINY LAYER)
“stops providing, starts producing”
STRATUM GRANULOSUM (GRAINY LAYER)
tough, fibrous protein
KERATIN
makes up hair and nails.
KERATIN
dense granules
KERATOHYALIN
is normally, only seen in the thick epidermis
STRATUM LUCIDUM (CLEAR LAYER
represents a transition from the stratum granulosum to the stratum corneum.
STRATUM LUCIDUM (CLEAR LAYER)
found only in thick skin
STRATUM LUCIDUM (CLEAR LAYER)
is the outermost layer of the epidermis
STRATUM CORNEUM (HORN LAYER)
it consists of dead cells (corneocytes) that lack nuclei and organelles
STRATUM CORNEUM (HORN LAYER)
the process of cell shedding front the surface of the stratum corneum, balances proliferating keratinocytes that form in the stratum basale is referred to as ________.
STRATUM CORNEUM (HORN LAYER)
Desquamation
the exposed surface of the skin, 15 to 20 layers of keratinized cells (horny cells).
STRATUM CORNEUM (HORN LAYER)
TYPES OF EPIDERMAL CELLS
KERATINOCYTES
MELANOCYTES
LANGERHANS CELLS
MERKEL CELLS
they are responsible for keratin formation
KERATINOCYTES
formed of many layers that continuously shed and regenerate every 2-4 weeks
KERATINOCYTES
they are arranged in many layers.
KERATINOCYTES
found in between cells of the basal layer.
MELANOCYTES
branched cells with central nuclei by EM (extracellular matrix) contains organelles for protein synthesis (rer, golgi, mitochondria and melanosomes).
MELANOCYTES
they form melanin by tyrosinase from tyrosine amino acid by converting dioxyphenyl-alanine (DOPA)
MELANOCYTES
are dendritic cells (antigen-presenting immune cells) of the skin.
LANGERHANS CELLS
found in upper layers of stratum spinosum
LANGERHANS CELLS
branched shape and central nuclei.
LANGERHANS CELLS
represents 3-8% of epidermal cells.
LANGERHANS CELLS
found in basal cell layer
MERKEL CELLS
are modified epidermal cells
MERKEL CELLS
sensory nerve fibers from terminal disk under Merkel’s cells
MERKEL CELLS
function as touch receptors.
MERKEL CELL