Flashcards in Integument & Barriers To Infection Deck (35):
List the three basic shapes of epithelial cells and describe their shape.
Squamous : squashed
Cuboidal : cube-shaped
Columnar : taller than it is wide
In regard to layering of epithelium, one layer is referred to as _________ epithelium and multilayered is referred to as ____________ epithelium.
Two special categories of epithelium are...
The integument is the __________ organ in the body (________ of body weight)
What functions does the integument provide?
Protection: physical, chemical & biological barrier
Sensation and excretion (sweat)
Synthesis of Vitamin D3
What are the differences in thick vs. thin skin?
Thick skin is only on palms and soles, has 5layers instead of 4, lacks hair and makes fingerprints (400-1400microM vs. 75-150microM)
The surfaces of palms and soles have ________ with intervening furrows.
Each ridge follows the outline of an underlying ___________ (where we see creases and wrinkles)
The tight interface at the dermal-epidermal junction is due to __________
List the 5 layers of the epidermis from outer layer to the innermost layer.
C- stratum corneum
(L- stratum lucidum in thick only)
G - stratum granulosum
S - stratum spinosum
B - stratum basale
What specific cells is the epidermis composed of? List 4.
Keratinocytes (most common)
Langerhans cells - immune specific
The mitotically active layer is the stratum _________.
Skin is replaced every _________ days.
Stratum basale consists of what type of cells?
a single layer of cuboidal/low columnar
Stratum basale sits on top of ___________ and these two are connected by a ________________
Stratum ________ is typically the thickest layer, and can thicken enough with pressure to form corns and calluses. It produces polyhedral keratinocytes and cytokeratin, which aggregates to from tonofilaments.
In the stratum ___________, cells become progressively more flattened and contain granules.
The two types of granules in the stratum granulosum are __________ and ___________. Describe each type.
Keratohyalin granules: basophilic non-membrane bound granules
Cystine and histamine rich protein
Assembles keratin into bundles
Barrier to foreign material & water
Provide a waterproof barrier
Stratum ___________ is a translucent band of cells with no organelles or nuclei and has densely packed keratin filaments.
Why does it get rid of the nucleus?
The nucleus takes up space and energy and the cells are no longer dividing so it's not needed (same as RBCs)
Stratum __________ consists of multiple layers of cells filled with mature keratin that is continuously shed.
Thick skin: 15-40 layers
Thin skin: 1-20 layers
Melanocytes are located in the stratum ________
Merkel cells are located in the stratum ________
Langerhans cells are located in the _________ layer, which is made up of the stratum _________ and stratum _________
Stratum basale + stratum spinosum
Keratinocytes make ________ & _________ granules, form ________ in stratum corners and house _______, the pigment protein.
Keratin & lamellelar
Fully keratinized cells are called ________ and are found in the stratum ________
Melanocytes produce melanin and transfer it to keratinocytes. What is melanin and what does it do?
Melanin is a pigment protein that protects nuclei from UV radiation
What is converted into what in order to be polymerized into melanin?
Tyrosine is converted into DOPA (3,4-dihyroxyphenylaline) by tyrosinase enzyme (a UV sensitive enzyme)
Langerhans cells develop in the _______from a monocyte precursor and serve as ______________ that provide defense against ___________
Merkel cells are nonencapsulated _________ for _______ touch and texture, reside in the stratum _________and are more numerous in _______skin. They are associated with _________
The dermis is made up of ________ tissue, has two layers the ________ & __________ and contains skin appendages, vasculature and sensory nerve endings.
Papillary & reticular
Which of the dermal layers is more superficial, has loose connective tissue and contains Meissner corpuscles and dermal papilla used for sensation?
What corpuscle is in the papillary layer?
Which layer of the dermis is the deeper layer of dense, irregular connective tissue with elastic fibers (more fibers and less cells)?
Between the dermal layers lies the __________, capillary branches that provide a nutrient source
In comparison the __________ is deeper with larger vasculature and lymphatics
The layer of the epithelium that consists of subcutaneous tissue (aka superficial fascia), loose CT that binds skins to underlying organs, adipocytes and an extensive vascular supply is the _________
Free nerve endings are the simplest ___________, involve numerous _______ fibers, are positioned along the _______________ and relay modalities such as temperature, touch, itching and pain.