Chapter 11: Integumentary System Flashcards
skin appendages—nails, hair, sweat glands, and sebaceous glands are all parts of the ____ system
integumentary
At ____ ____, skin is continuous with mucous membranes lining digestive, respiratory, and urogenital tracts
mucocutaneous junctions
Skin consists of ___ ____ ___epithelium on its outer part, called the epidermis, and an inner layer of ____ connective tissue, called the dermis.
stratified squamous keratinized, fibrous
A loose layer of subcutaneous connective tissue that attaches skin to underlying structures is known as the
hypodermis
Thick skin, which is ____, is found on palms of the hands and soles of the feet
glabrous
The junction between the avascular epidermis and richly vascularized dermis is known as the ___ ___, and has downward, ridge-like extensions of the epidermis known as ___ ___
dermoepidermal border, rete ridges
dermis is divided into 2 layers:
superficial papillary layer, deeper reticular layer
the superficial layer of the dermis contains type __ and __ ____ fibers, interspersed with ____ fibers and _____
1,3, collagen, elastic, capillaries
the deeper reticular layer of the dermis includes mainly type __ collagen
1
what are the three major types of skin cancer?
basal cell, squamous cell, melanoma
the epidermis consists of cells undergoing ___, ____, maturation, and ____ as they are displaced toward the surface of the skin
mitosis, differentiation, keratinzation
deepest layer of the epidermis, consists of a single layer of closely packed cuboidal to columnar cells known as ____ resting on a basement membrane
keratinocytes, stratum basale
the ____ ___ is several cells thick in the epidermis and has polyhedral cells that become progressively flat toward the surface
stratum spinosum
this layer of the epidermis consists of three to five layers of flattened cells with their axes aligned parallel to the epidermal surface.
stratum granulosum
this layer of the epidermis is present in thick skin, but absent in thin skin and is superficial to the stratum granulosm
stratum lucidum
the outermost layer of the epidermis, made of dead cells that lack a nucleus
stratum corneum
The cells in the stratum corneum layer of the epidermis have contain the protein ___ instead of cytoplasm.
keratin
The normal time for turnover of keratinocytes from stratum basale to uppermost stratum corneum varies from ___ to__ days.
20, 75
The stratum ____ is made of interlocking cells arranged in orderly vertical ____. These cells have thickened cell membranes and lack desmosomes
corneum, stacks
These complex intercellular junctions mediate and enhance cell adhesion by anchoring keratin filaments to keratinocyte plasma membranes in the strata basale and spinosum
desmosomes.
are melanin pigment-producing cells that determine color of skin and hair
Melanocytes
The major determinant of color is not melanocyte number but ___, which is affected by corticotropin from the pituitary
activity
each melanocyte establishes contact with each other via ____ process, and are produced in membrane bound organelles known as ____
dendritic, melanosomes
_____rearrange themselves within cells in response to external cues such as UV rays
melanocytes
Darkly pigmented skin, hair, and eyes have melanosomes that contain more ___
melanin
Two major forms of melanin are found in humans, _____, which is brown to black, and _____, which is yellow to red
eumelanin, phenomelanin
Tanning of the skin caused by UV exposure represents an _____ eumelanin content of the epidermis
increased
Melanocytes are irregularly shaped and have a single round or ellipsoid ___, which may be indented
nucleus
these cells monitor and capture invading surface antigens, enter the dermis, and then migrate to the paracortex of regional lymph nodes, where they induce an immune response via antigen presentation to CD4+ and CD8+ T lymphocytes
Langerhans
Langerhans cells are most common in the strata ___ ____
spinosum and granulosum
the adhesion molecule that Langerhan cells use to form a tight intercommunicating network with adjacent cells is know as _-____.
E-cadherin
Blood vessels in the dermis _____ ____ and are involved in ______.
provide nutrients, thermoregulation
___muscular arteries and veins supply the skin as a whole while ____ arteries, veins, and capillaries are the main vasculature of the dermis.
large, smaller
An extensive network of capillaries immediately under the ____ supplies nutrients to the avascular epithelium.
epidermis
_____ also surround the matrix of hair follicles and are closely associated with sweat and sebaceous glands
Capillaries
At the arteriole end, these vascular shunts are coiled and surrounded by a row of modified smooth muscle cells serving as sphincters. These specialized structures, known as _____ _____, play a role in peripheral temperature regulation
glomus bodies
glomus bodies are under ____ vasomotor control, and will direct from the superficial to the deep plexus to reduce ___ ____.
autonomic, heat loss
Branching ____ _____ containing myelinated and unmyelinated nerve fibers make up extensive subpapillary dermal plexuses
nerve fascicles
_____ nerve fibers supply nerve endings to the epidermis
Myelinated
Nerve fibers entering the ____ lose myelin sheaths and end between epidermal cells either as free nerve endings or are closely associated to Merkel cells, where they serve as tactile receptors
epidermis
Located in dermal papillae, ___ ____ are mechanoreceptors that mediate touch
Meissner corpuscles
____ ____ are larger encapsulated receptors in deeper regions of dermis and subcutaneous tissue that act as deep pressure receptors
Pacinian corpuscles
these glands serve a thermoregulatory role and maintain body temperature by evaporative heat loss
eccrine
The tightly convoluted secretory part of a gland deep in the dermis consists of two types of cuboidal to pyramidal secretory cells:
clear and dark cells
these eccrine gland cells primarily secrete water and electrolytes
clear cells
these eccrine gland cells elaborate macromolecular substances in sweat
dark cells
_____ cells are mainly contractile and help expel sweat into the lumen of an acinus in an eccrine cell
Myoepithelial
these sweat glands are found in axillae, scrotum, prepuce, labia minora, nipples, and perianal regions and are known to be ____.
apocrine, odoriferous
apocrine cells use ____ ____ epithelium to line their sac-like lumens
simple cuboidal
the oily secretion that has an acid or musky odor in apocrine sweat glands is in response to ___ _______/
bacterial decomposition
The ______ unit consists of the hair, hair follicle, an associated arrector pili muscle, and a sebaceous gland.
pilosebaceous
Each hair comprises a free ____ and a ___, which is enclosed at its lower end by a tubular hair follicle, composed of epidermal (epithelial) and dermal (connective tissue) parts.
shaft, root
this part of the hair is two or three layers of shrunken, keratinized cuboidal cells—which rarely extends the entire length of the hair.
medulla
Peripheral to the medulla is the ___ cortex, which in colored hair contains flattened keratinized cells with pigment granules between cells.
cortex
The hair follicle consists of three segments: the upper_____and middle ____, which are permanent, and the deepest, ____ ____, which germinates hair.
infundibulum, isthmus, inferior segment
growth stage of hair is known as ___ while a period of regression is known as ____ and a resting period is known as _____.
anagen, catagen, telogen
a distended follicle that results from a keratin plug blocking sebum outflow is known as ____ ____
acne vulgaris
the external root sheath of hair corresponds to the strata ____ and _____
basale and spinosum
the internal root sheath of hair corresponds to the strata _____ and _____
granulosum and corneum
the ___ ___ is located in between the hair follicle and arrector pili muscle of hair
sebaceous gland
contraction of the ___ ____ muscle helps compress the sebaceous gland and expel sebum into the follicle neck
arrector pili
_____ is a complex oily mixture of lipids including glycerides, free fatty acids, and cholesterol
Sebum
Nails are modifications of the ____ ____ of the epidermis on the dorsal aspect of terminal phalanges of fingers and toes
stratum corneum
The undersurface of both exposed and concealed parts of the nail plate is the
nail bed
The nail is rooted in a nail ___, which is an invagination of the skin surrounded by a crescent-shaped rim of skin, the nail ___.
groove, fold
The ____ is the white crescent-shaped area of nail matrix
lunula
eponychium, or ____, is the projecting crescentic fold of stratum corneum
cuticle
______ is a chronic relapsing disorder of skin affecting 1%-3% of the population, most often at elbows, knees, scalp, and lumbosacral regions
Psoriasis
