Integumentary System Flashcards
List some important functions of the skin
Abrasion prevention, dessication/infection prevention, body temperature regulation, absoprtion of UV for vitamin D synthesis, reception of external stimuli
What specialized cells are present in the stratum basale?
Melanocytes, Merkel cells
Cells of the upper stratum spinosum possess (x) which, when released, produce a (y) effect
Keratohyalin granules (x), waterproofing (y)
Describe contact inhibition in epidermal wound healing
Basal cells enlarge and migrate across wound until they meet each other where cells stimulate stem cells to divide and replace lost cells
Describe the basic pathways in effect during the different phases of deep wound healing: inflammatory? migratory? proliferative? maturation?
Inflammatory: peripheral blood clot, vasodilation, leukocyte infiltration; Migratory: epithelial cells bridge the wound, fibroblasts synthesize collagen/glycoprotein; Proliferative: epithelial growth, angiogensis; Maturation: scab sloughs off, epidermis normal thickness, fibroblasts decrease, scar = fibrosis
Melanocytes produce (x) (via the enzyme (y)) which serve to (z)
Melanin (x), tyrosinase (y), shield genetic material from harmful UV radiation (z)
What are the phases of deep wound healing?
Inflammatory, migratory, proliferative, maturation
What condition is characerized by hyperkeratosis and parakeratosis?
Psoriasis
Which cellular apparatuses are effected in the following pathologies: bullous pemphigoid? pempighus vulgaris?
Hemidesmosomes (BP), desmosomes (PV)
Describe the histopathogenesis of squamous cell carcinoma
Malignant tumor of keratinocytes, usually due to inactivation of p53 gene, characterized by hyperkeratosis and parkeratosis
Keratohyalin granules are composed of (x) and (y) rich proteins that appear to bind (z)
Histidine (x), cysteine (y), kertain filaments (z)
The (x) layer does not possess nuclei or organelles, but contains (y) which is believed to be produced from keratohyalin
Stratum lucidum (x), eledin (y)
(x) are derived from the bone marrow, reside in the stratum spinosum, contain (y) and function as (z)
Langerhans cells (x), Birbeck granules (y), APCs (z)
(x) are present in the stratum basale, contain (y) and receive afferent nerve sensation believed to be important in (z)
Merkel cells (x), small dense-cored granules (y), sensory mechano-receptors (z)
What are the three primary parts of hair?
Cuticle, cortex, medulla
What structures comprise the internal root sheath of a hair follicle?
Henle’s layer, Huxley’s layer, cuticle
What structures comprise the external root sheath of a hair follicle?
Continuation of stratum malpighii
What structures are external to the outer root sheath of a hair follicle?
Glassy (basement) membrane, CT sheath (dermis)
Eccrine glands are tubular coiled glands comprised of what cell types?
Dark cells, clear cells, myoepitheal cells
How are apocrine and eccrine glands similar? different?
Similar: secrete sweat, large coiled secretory portion eveloped by myoepithelial cells, not always associated w/ hair follicles; Different: age of onset, location (apocrine: axilla, nipple areola, circumanal region)
Compare eccrine and apocrine integument glands on the following characteristics: size? location? innervation? consistency?
Eccrine: small, all skin, cholinergic, watery; Apocrine: large, certain areas, adrenergic, viscous
Where are mitotic cells of sebaceous glands located?
Near ducts
Name the strata of the epithelium from deep to apical
Strata basale, spinosum, granulosum, lucidum, corneum
What is the other name given for the combined stratum basale/spinosum layers?
Stratum malpighii
The resident macrophage of the skin is the (x) and is usually located in the (y) layer
Langerhands cell (x), stratum spinosum (y)
Cells of the (x) layer possess intercellular bridges between each other, namely made of (y)
Stratum spinosum (x), desmosomes (y)
The underlying dermis possesses layers made of what type of tissue?
Papillary (loose CT), reticular (dense irregular CT)
Which stratum/a are generally not seen in thin skin?
Stratum granulosum, lucidum
Denote the epithelium of the following eccrine sweat gland parts: duct system? secretory portion?
Stratified cuboidal (duct), simple cuboidal + myoepithelial cells (secretory)
Describe the mechanism of sebaceous cell secretion
Daughter cells migrate to alveolus, produce secretory product, break down, producing sebum
Which two layers of the epithelium possess mitotic capabilities?
Strata basale, spinosum
What condition is characterized by the increased proliferation rate of mitotic cells leading to thickened epidermis?
Psoriasis
What is the most apical strata where nuclei are present?
Stratum granulosum
How may medication/substances be delivered through the skin?
Transdermal patches (nicotine, steroid, sea sickness, nitroglycerine, menopause)
What are the two general types of wound healing?
Epidermal, deep (dermal)
Are blood vessels needed/repaired in either epidermal or deep wound healing?
No (epidermal), Yes (deep)
When a scar is raised but in the normal boundary, it is said to be (x), when it extends its boundary it is said to be (y)
Hypertrophic (x), keloid (y)
What is the condition termed where hyperplasia occurs in the horny (corneum) layer of the skin?
Hyperkeratosis
What is the condition termed if nuclei are retained in the stratum corneum?
Parakeratosis
What is a condition termed if the body produces an immune response against its own tissues?
Autoimmune
What is the condition termed where there is a loss of intercellular connections (e.g. keratinocytes)?
Acantholysis
What is the condition termed if epidermal hyperplasia is present in the stratum spinosum?
Acanthosis
What is the system termed that present effects lysis effects on cells and Ab-Ag complexes (inclusive of cytokine release)
Complement system
What system can be described as having a substance being produced from one cell to have the actions of another take effect?
Complement system
Describe the histopathogenesis of psoriasis
Autoimmune T-cells migrate to dermis and secrete cytokines to signal marked epidermal growth, leads to increased epidermal (s. corneum) thickening
List some etiologies of psoriasis
Stress, bacteria, alcohol, temperature change, tattoo, medication (lithium/hormones), smoking, cuts/bruises
What condition is characterized by chronic autoimmune blistering of the skin?
Bullous pemphigoid
Describe the histopathogenesis of bullous phemphigoid
Autoantibodies (IgG) bind to basement membrane, stimulate leukocytic infiltration, eosiniphils degrade hemidesmosomes
What condition is characterized by an autoimmune separation of epidermal cells and atrophy of the prickle layer?
Pempighus vulgaris
Describe the histopathogenesis of pempighus vulgaris
Autoimmune disorder producing antibodies against cadherins/desmoplakins leading to the disruption of desmosomes
In which stratum are the effects of pempighus vulgaris most often noticed?
Stratum spinosum
Where may lesions associated with pempighus vulgaris be viewed?
Back, mouth
What condition is characterized by a loss of pigmentation of the skin, hair and eyes?
Albinism
Describe the histopathogenesis of albinism
Gene mutation that regulates melanin synthesis, inability of cell to pick up tyrosine, tyrosinase inactivity
List some long term implications of individuals with albinism
Skin cancers, reduced visual acuity, photophobia, social stigma
What condition is characterized by an autoimmune destruction of melanocytes producing a depigmentation disorder?
Vitiligo
What types of vitiligo are possible?
Focal, segmental, generalized
What treatments are available for vitligo?
Topical steroid therapy, psolaren photochemotherapy, depigmentation, autologous skin graft, micropigmentation, melanocyte transplants
In burn victims, what method is used for approximating the amount of body burned?
Rule of nines
Differentiate between a first, second and third degree burn in terms of skin damaged
First: epidermis only, Second: epidermis and dermis (BVs, blebs), Third: epidermis/dermis vacant
Differentiate between first/second/third degree burns in terms of pain felt
First/Second: pain present (meissner’s corpuscles present), Third: meissner’s corpuscles burned away
T/F: Malignant cells demonstrate pleomorphic variations
True
List some common risk factors for squamous cell carcinoma
Age (older), fair skin, disposition to sunlight exposure, carcinogen exposure
What are the general types of squamous cell carcinoma?
Superficial, infiltrative
Describe infiltrative squamous cell carcinoma
Dermis infiltrated by malignant squamous cells, islands resemble basal cells, visually have formation of squamous pearls of swirls
List a risk factor for basal cell carcinoma
UV light exposure
Describe the appearance of basal cell tumors
Surrounded by a single layer of basal cells (cuboidal), palisade arrangement
The malignant transformation of a melanocyte leads to (x) and is the (y) of skin cancer-related deaths in the U.S.
Malignant melanoma (x), leading cause (y)
List a risk factor for malignant melanoma
Caucasian/Australian/S. African races, UV exposure
T/F: Melanocytes which are malignant present similarly when compared to normal cells
False
Explain the A-B-C-D-Es associated with clinical diagnosing of skin carcinomas
Asymmetry, border irregulatiry, color variation, diameter, elevation
Areas with increased sebaceous glands are prone to (x) a disorder common in (y)
Acne (x), adolescents (y)
Which areas of the body are prone to fungal infection?
Hair
What conditions may arise from fungus origins?
Dermatophytosis, tinea vericolor, tinea corporis (ringworm), infections
What condition is characterized by benign neurofibromas located all over the body and which is congenital (chr 17)?
Neurofibromatosis (Von Recklinghausens disease)
What are the major components of the skin?
Epidermis, dermis
List some appendages of the skin
Sweat glands, hair follicles, sebaceous glands, nails
How many layers are present in the stratum basale?
One
Which type of granules found in the stratum granulosum stain darkly with H&E?
Keratohyalin (basophilic)
The most apical layer of the epidermis is known as (x) but can also be called (y) if cells are found to be flaking off
Stratum corneum (x), stratum disjunctum (y)
Melanocytes possess (x) which aid in transferring melanosomes to which strata?
Cytoplasmic extensions (x), stratum basale & stratum spinosum
The transfer of melanosomes from one cell to another is an example of what?
Cytocrine secretion
What shape do Birbeck granules look like?
Barbells
What structures are present in the upper papillary layer of the dermis and what is their function?
Meissner’s corpuscles, fine touch receptors
What structures can be found in the deeper regions of the dermis and what is their function?
Pacinian corpuscles (pressure receptors), Krause’s end bulbs (cold/pressure receptors)
Where do arrector pili muscles attach and insert?
Attach to hair follicles in dermis, insert into papillary layer of dermis
Where is the bulb of a hair follicle located?
Papillary layer of dermis
What structure overlies the crescent-shaped whitish lunula of a distal phalanx?
Eponychium
What structure is located beneath the free edge of a nail?
Hyponychium
Where are cells located which are responsible for nail growth?
Cells in the nail matrix
Describe the appearance of eccinr sweat gland myoepithelial cells
Lie on basal lamina, underlie dark cells, rich in mitochondria and glycogen
Describe the cell type within the eccrine sweat gland lumen
Stratified cuboidal (duct), many keratin filaments prominent terminal web, rich in mitochondria
Where do apocrine cells secrete their products?
Into areas superficial to duct entry from sebaceous glands
What other glands can be accredited with being apocrine in nature?
Ceruminous (wax) glands
Integument refers to the (x) and its (y)
Skin (x), appendages (y)
(x) from the epidermis interdigitate with (y) from the dermis to form an irregular contour
Epidermal pegs (x), dermal papillae (y)
(x) project to produce (y) which can be seen as raised protrusions (e.g. on the finger tips)
Dermal papillae (x), epidermal ridges (y)
How often does skin regenerate and what time of day does mitotic acitivty usually occur?
2-4 weeks, night
The (x) is the deepest layer of cells, attached directly to the basal lamina via (y)
Stratum basale (x), hemidesmosomes (y)
What shape are stratum basale cells?
Cuboidal to columnar
T/F: Melanocytes are able to be distinguished from LM
False
T/F: Langerhans cells are considered to be APCs
True
T/F: Only the cells in the stratum basale are mitotically active
False
Cells in the (x) possess large amounts of membrane-coating, keratohyalin and melanosome granules
Stratum granulosum
Compared to normal amounts of stratum cornuem present, how much stratum disjunctum is present in: thin skin? thick skin?
High percentage (thin), low percentage (apical, thick)
Where are melanocytes derived from?
Neural crest
Detection of actual melanocytes can only be possible by using what technique?
Electron microscopy
T/F: The number of melanosomes is independent of race
True
What types of fibers are present in the dermis?
Type I collagen, thick elastic fibers, Type III collagen
T/F: Meissner’s corpuscles do not possess capsules
False
Contraction of arrector pili muscles is induced by the (x) nervous system giving the appearance of (y)
Autonomic (x), goose bumps (y)
T/F: The arrector pili muscle originates in the CT sheath of the hair follicle
True
Describe the characteristics of thick skin
Thick epidermis (prominent stratum corneum), some stratum disjunctum, lacks hair follicles/sebaceous glands/arrector pili
Where is thick skin located on the body?
Palms of hands, soles of feet
Describe the characteristics of thin skin
Thin epidermis (minimal strtum corneum), some stratum disjunctum, contains hair follicles/sebaceous glands/arrector pili, thick dermis
Where is thin skin located on the body?
Most of body surface
What is a nail composed of?
Hard keratin
What glands comprise more than 90% of sweat glands?
Eccrine glands
T/F: Eccirne glands are specific to certain areas of the body
False
T/F: Myoepithelial cells surround eccrine secretory duts only (within the integument system)
True
Where are apocrine sweat glands located?
Axilla, nipple areola, circumanal region
In what layer of the integument are apocrine glands locatd?
(Deep) dermis
T/F: No part of the secretory cell becomes part of the apocrine secretion
False
Where do sebaceous glands drain into?
Neck of hair follicle
T/F: All of sebaceous cells are disposed of during holocrine secretion
True
