Integumentary System Flashcards by casey kozak

blood flow through the skin is adjusted via _____

arteriovenous shunts

How well did you know this?

Not at all

Perfectly

integumentary system makes Vitamin ___ in response to UV radiation in sunlight, which plays an important role in ___

Vitamin D - calcium regulating hormone

How well did you know this?

Not at all

Perfectly

hypodermis =

superficial fascia - contains blood vessels and nerves supplying the dermis, sweat glands, ends of hair follicles, adipose

proliferating fibroblasts and blood vessels for wound repair come from hypodermis

How well did you know this?

Not at all

Perfectly

proliferating fibroblasts and blood vessels for wound repair of integumentary system come from

hypodermis (aka superficial fascia)

How well did you know this?

Not at all

Perfectly

thick skin is sometimes called

glabrous skin - has sweat glands but not hair/related structures

How well did you know this?

Not at all

Perfectly

differences in the thickness of thin skin are based on ___

thickness of the dermis

How well did you know this?

Not at all

Perfectly

as keratinocytes migrate to the surface of skin, they die and become

corneocytes (squames of keratin)

replaced every ~28 days

How well did you know this?

Not at all

Perfectly

what are the layers of the epidermis (beginning top to dermis)

(top) stratum corneum
stratum lucideum
stratum granulosum
stratum spinosum
stratum germinativum (basale)

(then dermis)

How well did you know this?

Not at all

Perfectly

the proliferative/germinal layer of the epidermis:

stratum germinativum (basale, directly above dermis): 1-2 cells thick

one undifferentiated stem cell in this layer can produce whole epidermis

How well did you know this?

Not at all

Perfectly

“prickle cell” layer of epidermis (cells appear to have spines)

stratum spinosum (second deepest, superficial to stratum basale) - very prominent desmosomes with keratin (intermediate filament) for mechanical strength (“spines”)

*friction blisters occur here if desmosomes are disrupted and fluid collects between keratinocytes

How well did you know this?

Not at all

Perfectly

where can lamellar or membrane coating granules be seen in the epidermis? what do the granules contain?

stratum spinosum (2nd most deep layer after stratum basale)

granules contain glycolipids and sterols that make skin waterproof

How well did you know this?

Not at all

Perfectly

where can keratohyalin granules (stain dark blue) be found in the epidermis

stratum granulosum (3rd layer)

keratohyalin granules: dense, irregular, no membrane, contain tonofilaments (keratin intermediate filaments)

fill the cell and become polymerized in final keratin product (squame of keratin at skin surface)

How well did you know this?

Not at all

Perfectly

this layer of epidermis has 15-20 layers of flattened dead corenocytes (squames)

stratum corneum (layer 2 from top): major barrier to water loss and penetration

keratohyalin granules + tonofilaments (keratin) become amorphous and cross-link with filaggrin —> flattens cells

half the thickness of thick skin

no nucleus or organelles evident, just keratin coated with lipids released from lamellar granules (from stratum spinosum)

How well did you know this?

Not at all

Perfectly

dermatoglyphics

aka fingerprints

each ridge of epidermis is a fingerprint and each epidermal ridge covers a dermal ridge

dermal ridge is subdivided by an interpapillary peg of epidermis to form 2 dermal papillae

interpapillary peg is where ducts of eccrine sweat glands enter. epidermis

How well did you know this?

Not at all

Perfectly

in thin skin, the stratum ____ is only a few cells thick and is often detached from lower layers during preparation of slides

stratum corneum

How well did you know this?

Not at all

Perfectly

transdermal medications work by…

traversing the skin layers via the lipids between cells to reach blood vessels in dermis

How well did you know this?

Not at all

Perfectly

Rhus dermatitis

aka poison ivy/oak/sumac

urushiol causes contact dermatitis (found in all parts of plant)

treatment requires immediate washing or OTC itch relief later

How well did you know this?

Not at all

Perfectly

melanocytes are found mostly in [thin/thick] skin and are derived from the ____

melanocytes found mostly in thin skin, derived from neural crest

cell bodies found in stratum germinativum (basale) but have dendrites that reach up

How well did you know this?

Not at all

Perfectly

melanin production requires this enzyme

tyrosinase: converts tyrosine to melanin

melanin is produced in melanosome, pinched off, and distributed

individuals with dark skin produce:
a. more melanocytes
b. more pigment

b. more pigment (but same number of cells) - degraded more slowly and distributed further

other than protecting DNA of stem cells, melanin also protects ____ in capillaries

folate (form of Vitamin B)

melanosomes are degraded by _____ in keratinocytes

lysosomes

this disease is caused by a defect in the transport of melanosomes, due to mutation in either myosin Va, Rab27a, or melanophillin (Rab effector). What is?

Griscelli syndrome

Langerhans cells are a special form of DC that are derived from ____

monocyte/macrophage line

proceses form a continuous layer in the stratum basale and spinosum of both thick and thin skin

Langerhans cells and their processes form a continuous layer in the stratum ____ and ____

germinativum (basale) and spinosum

Langerhans cells contain tennis-racket shaped _____ granules that….

Birbeck granules: function in uptake of microbial fragments

____ glands are associated with hair follicles

sebaceous glands are associated with hair follicles

hair ___ is the area of growth at the base of the hair in the ______ zone, cellular hair is transformed to keratin over time

hair matrix - where cells proliferate and manufacture keratin (in hair bulb, surrounded by dermal papillae) keratogenous zone - cellular hair transformed to keratin (hair is made of a mixture of keratins)

sebaceous glands produce ___ via ____ secretion

sebum: oil that keeps hair soft and waterproof holocrine secretion: sebaceous glands die and liberate contents into hair follicle stem cells at periphery of gland, oldest in the center

smooth muscle innervated by sympathetic ANS that induces piloerection of hair

arrector pili muscles - found on same side of hair follicle as sebaceous gland

what are the 2 types of sweat glands?

1. eccrine: tubular glands with coiled secretory portion (dermis or hypodermis), glands are stratified cuboidal - temperature regulation, hypotonic sweat (more water lost), NOT associated with hair follicles 2. apocrine: axilla, areola, pubic - secrete sweat after puberty, hormone sensitive, have large lumen (simple columnar), usually associated with hair follicles

tubular sweat glands with coiled secretory portion, functioning in temperature regulation and secretion of hypotonic sweat (more water lost) what are?

eccrine sweat glands

these sweat glands have a large lumen, are found in axilla, areola, pubic, and secretions are hormone regulated. what are?

apocrine sweat glands - usually associated with hair follicle

what kind of epithelium lines eccrine vs apocrine sweat glands?

eccrine: very small lumen, stratified cuboidal (temperature regulation) apocrine: very large lumen, simple columnar (hormone-mediated secretion)

specialized smooth muscle cells with clasp sweat and other glands in skin with long cytoplasmic processes

myoepithelial cells - when stimulated by ANS they contract and expel sweat quickly also found in mammary glands (sensitive to oxytocin) and salivary glands (respond to food cues)

what is the benefit of the many dermal papillae and interpapillary pegs in thick skin?

provides greater surface area for diffusion and mechanical attachment at epidermal-dermis junction

what are the 2 layers of the dermis

1. papillary layer: rich in capillaries to nourish avascular epidermis, elastic fibers 2. reticular layer: more fibrous, collagen bundles oriented in lines of tension (Langer’s line) *wounds parallel to these lines heal with little scarring, those cutting across leave noticeable scars

light touch receptors in the skin, found in papillary layer of dermis what are?

Meissner’s corpuscles

large encapsulated nerve endings found deep in the dermis or hypodermis, which function as pressure receptors

Pacinian corpuscles (look like onions)

Meissner vs Pacinian corpuscles

Meissner: light touch mechanoreceptors, papillary layer of dermis Pacinian: encapsulated nerve endings, pressure receptors, deep in dermis or hypodermis, look like layers of onion (remember Pacinian is for Pressure)

you’re looking at a histology slide of skin when you notice a structure that looks like an onion deep in the dermis, almost in the hypodermis. what is it most likely to be?

Pacinian corpuscles - pressure receptor, large encapsulated nerve ending *note these are also found in internal organs such as pancreas

Meissner’s corpuscles

light touch mechanoreceptors in the skin, found in papillary layer of dermis

these mechanoreceptors are located at the tips of primary epidermal ridges and are connected to receptors in the dermis they are sensitive to points, edges, and texture. what are?

Merkel cells

found at tips of primary epidermal ridges sensitive to points, edges, and texture

_____ are oriented parallel to collagen bundles in the dermis and are sensitive to stretch

Ruffini endings

parallel to collagen bundles in the dermis, sensitive to stretch

what structures of the skin will respond to the following sensations: a. light touch b. pressure c. points, edges, texture d. stretch

a. Meissner’s corpuscles - light touch b. Pacinian corpuscles - pressure c. Merkel cells - points, edges, texture d. Ruffini endings - stretch