09a: Integument Flashcards
The integument is a(n) (X) (structure/system/other).
X = organ system
T/F: Integument is both the largest and the heaviest organ system.
True
Integumentary system accounts for (X)% of TBW.
X = 16
The integument includes:
Skin and its appendages (glands, hair, nails, sensory receptors)
Integument contains which tissue type(s)?
Epithelial, connective, nervous, muscle
Epithelial tissue in integument is (X), which includes which layers?
X = epidermis
Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale
Connective tissue in integument is (X), which includes which layers?
X = dermis
Papillary and reticular layers
The integument forms from:
- Ectoderm (epidermis)
2. Mesenchyme (dermis)
Keratinocytes are derived from (X), which are distributed in/on (Y).
X = stem cells Y = stratum basale
Asymmetric cell division of (X) produces:
X = stem cell
Another SC and a committed cell
Symmetric cell division of (X) produces:
X = stem cell
Either two SC or two committed cells
SC division is (parallel/perpendicular) to basement membrane.
Can be either
As an embryo grows in size/surface area, SC undergo (parallel/perpendicular) division.
Parallel
As cell layers increase in stratification, SC undergo (parallel/perpendicular) division.
Perpendicular
Adult homeostasis primarily involves (parallel/perpendicular) division.
Both
What are the stages in the hair growth cycle?
- Anagen
- Catagen
- Telogen
Active hair growth occurs in (X) stage and lasts how long?
X = anagen
2-6 years
In Anagen stage, which specific structure(s) are changing?
Hair follicle and shaft are growing
Reduced hair growth occurs in (X) stage and lasts how long?
X = catagen
3 weeks
Normally, about (X)% of scalp hair is in the anagen phase.
X = 90
In the catagen phase, the (X) (shortens/grows).
X = hair follicle
Shortens
Normally, about (X)% of scalp hair is in the catagen phase.
X = 1
The resting phase of hair growth is called (X) and lasts how long?
X = telogen
2-4 months
What events occur at the end of the telogen phase?
Hair sheds (follicle remains); cycle restarts
Normally, about (X)% of scalp hair is in the telogen phase.
X = 10-15
What is the location of SC of hair?
Bulge region of hair follicle
The (X) are responsible for repopulating the hair bulb after (Y) phase.
X = SC Y = telogen
Hair growth/loss is strongly dependent on:
Receptors in hair follicle cells
(X) hormones regulate hair growth by:
X = male/female sex
Bind receptors on dermal papillae cells in bulge region
The hair follicle is essentially (X) cells that have grown into which integumentary layer?
X = epithelial
Into the dermis
Hair plays a role in which key function(s)?
- Temp regulation
2. Sensation
When SC divides in parallel fashion, the orientation of the mitotic spindle is:
Perpendicular to basement membrane
Keratinocytes are involved in which major (X) functions of skin?
X = protective
- Against abrasion/shearing
- Against dehydration
- Against pathogens
Tonofilaments are (X), responsible for (Y).
X = bundles of keratin Y = structural strength and elasticity
A lipid envelope forms around the keratinocytes in which stage of differentiation? The lipid comes from (X).
Cells differentiating from stratum granulosum to stratum corneum cells;
X = lamellar bodies
Physical attachment among keratinocytes is attributed to which structure(s)?
desmosomes
Physical attachment between keratinocytes and basal lamina is attributed to which structure(s)?
hemidesmosomes
Pemphigus is a pathology in which:
Body makes Ab against Desmoglein (one of the proteins in the desmosome)
Most important components of lipid envelope in stratum corneum.
- Acylglucosylaceramide
2. Cholesterol sulfate
List the structural proteins present in stratum corneum (from superficial to deep)?
- Involucrin
- Loricrin
- Small Pro-rich proteins
(X) is a protein that contributes to keratin filaments bundling into (Y).
X = filaggrin Y = tonofilaments
Cells in (dermis/epidermis) produce antimicrobial peptides.
Both dermis and epidermis
Endocrine function of keratinocytes includes:
Vitamin D synthesis
(X) cells contain 7-dehydrocholesterol, which can be converted to (Y) if:
X = keratinocyte Y = Pre-vitamin D3
Exposed to UV
Pre-vitamin D3 migrates from (X) to (Y) before transportation to which organ(s)?
X = epidermis Y = blood vessels in dermis
To liver then kidney
Increased UV exposure will (increase/decrease) Ca absorption by GI tract.
Increase
Increased UV exposure will (increase/decrease) Ca re-absorption by kidney
Increase
Increase vitamin D synthesis has which effect on (X) ion concentration in blood?
X = Ca
Increases Ca concentration (via increase absorption from GI tract/kidney)
Pathologies associated with vitamin D deficiency are:
- Osteomalacia
2. Rickets
Langerhans cells are resident (X) cells of the (Y) layer.
X = dendritic Y = epidermal
Langerhans are derived from (X) in the (Y).
X = CMP (common myeloid progenitor) Y = bone marrow
T/F: Helper T-cells present antigen to Langerhans cells.
False - other way around
List steps that occur when antigen encounters Langerhans cell.
- Langerhans phagocytoses antigen
- Migrates to lymph nodes
- Presents antigen to helper T-cells
Main function of melanocytes.
Protect integument and underlying tissues from UV radiation
(X) produce pigment, (Y), that’s contained in granules called (Z).
X = melanocytes Y = melanin Z = melanosomes
The enzyme (X) converts (Y) to melanin.
X = tyrosinase Y = tyrosine
Cytocrine secretion is the process by which:
Melanosomes are transferred to keratinocyte from melanocyte
T/F: There’s an uneven density of melanocytes in different skin regions.
True
Describe impact of tanning.
Exposure to UV light causes photo-oxidation of melanin, which makes them darken.
Darker skin in certain ethnic groups is a result of:
Increased melanin production and rate of transfer
T/F: Dark-skinned individuals have more melanocytes.
False
T/F: Dark-skinned individuals have larger melanosomes.
True
T/F: Tanning causes a notable increase in melanocyte density.
False
Free nerve endings in integument detect:
Pain and T
Merkel cells detect:
Gentle touch
Meissner corpuscles detect:
Light touch
Pacinian corpuscles detect:
Pressure and vibration
Hair follicle mechanoreceptors detect:
hair movement
Ruffini endings detect:
Skin stretch and joint deformation
Which mechanisms contribute to control of body T by integument?
- Activation of eccrine sweat glands
2. Vasodilation of cutaneous blood vessels
Eccrine sweat glands secrete:
Watery substance that decreases body T through evaporation
Eccrine sweat glands are located entirely in (dermis/epidermis/hypodermis).
Gland is in dermis, but duct extends up into epidermis
Primary activating factor of eccrine sweat glands.
Cholinergic innervation from sympathetic NS