Integumentary System Flashcards
largest single organ of the body
skin
Lies beneath the dermis that is a loose connective tissue layer containing pads of adipocytes
subcutaneous tissue or hypodermis
Extensions of the epidermis to the dermis
Epidermal ridges
Connects the dermis to the epidermis
Dermal papillae
A function of the skin that provides a physical barrier against thermal and mechanical insults such as friction and against most potential pathogens and other material.
Protective
A function of the skin that allows us to feel tactile objects
Sensory
A function of the skin that are mechanisms for accelarating heat loss (sweat production)
Thermoregulatory
A function of the skin where cells synthesize vitamin D3, needed in calcium metabolism and proper bone formation, through the local action of UV light on the vitamin’s precursor
Metabolic
A function of the skin where the effects of sex pheromones produced by the apocrine sweat glands and other skin glands are important in attraction between sexes in all vertebrates.
sexual signaling
The epidermis is composed of cells called _____
keratinocytes
antigen-presenting cells
langerhan cells
pigment-producing cells
melanocytes
tactile epithelial cells
merkel cells
single layer of basophilic cuboidal or columnar cells characterized by intense mitotic activity
Stratum basale
The important feature of the stratum basale
cytoskeletal keratins
Source of alive skin cells
Stratum basale
Refers to the thickest layer where synthesis of much keratin and other proteins takes place
Stratum spinosum
Prickle cells
Stratum spinosum
Its synthesis would give the cell a spiny extension
Stratum spinosum
Precursor for keratin
Tonofibrils
Microscopically visible bundles where keratin filaments assembles which converge and terminate at the numerous desmosomes holding the cell layers together
Tonofibrils
Consists of three to five layers of flattened cells, now undergoing the terminal differentiation process of keratinization
Stratum granulosum
Characteristic features in cells of the granular layer also include Golgi-derived ________ granules
lamellar
The precursor of protein filaggrin which is important in the aggregation of keratin granules that undergo exocytosis, producing a lipid-rich, impermeable layer around the cells
Lamellar granules
This material forms a major part of the skin’s barrier against water loss
Lamellar granules
This consists of a thin, translucent layer of flattened eosinophilic keratinocytes held together by desmosomes that is considered a subdivision of the stratum corneum.
Stratum lucidum
Stratum lucidum is well seen in ______.
Thick skin
The most differentiated cells in the skin having layers of squamous, keratinized cells filled with birefringent filamentous keratins
Stratum corneum
The most differentiated cells in the skin having layers of squamous, keratinized cells filled with birefringent filamentous keratins
Stratum corneum
The most differentiated cells in the skin having layers of squamous, keratinized cells filled with birefringent filamentous keratins
Stratum corneum
The most differentiated cells in the skin having layers of squamous, keratinized cells filled with birefringent filamentous keratins
Stratum corneum
Predominant cell type of the epidermis
Keratinocytes
Produce and distribute melanin into keratinocytes
Melenocytes
A transmembrane enzyme in Golgi-derived vesicles that catalyzes the first step in melanin synthesis
tyrosinase
Tyrosinase activity converts tyrosine into _____________which is then further transformed and polymerized into the different forms of melanin
3,4-dihydroxyphenylalanine (DOPA)
Melanin pigment is linked to a matrix of structural proteins and accumulates in the vesicles until they form mature elliptical granules about 1-μm long called ________.
melanosomes
Derived from monocytes, dendritic appearing, antigen presenting cells in the epidermis
Langerhans cells
It possesses characteristic, tennis racquet- shaped Birbeck granules
Langherhans cells
Epithelial tactile cells
Merkel cells
Low-threshold mechanoreceptors essential for sensing gentle touch
Merkel Cells
A type of cell that is abundant in highly sensitive skin like that of fingertips and at the basses of some hair follicles
merkel cells
A layer of connective tissue that supports the epidermis and binds it to the subcutaneous tissue (hypodermis)
Dermis
Lies between the papillary and reticular dermal layers from which capillary branches extend into the dermal papillae and form a rich, nutritive capillary network just below the epidermis.
microvascular subpapillary plexus
peg-and-socket variety in most skin
dermal-epidermal interdigitations
more subject to friction
palms and soles
Combinations of loops, arches, and whorls that is also known as fingerprints and footprints
dermatoglyphs
This thin sublayer of the dermis consists of loose connective tissue, with types I and III collagen fibers, fibroblasts and scattered mast cells, macrophages, and other leukocytes. From this layer, anchoring fibrils of type VII collagen insert into the basal lamina, helping to bind the dermis to the epidermis.
Papillary layer
This much thicker sublayer of the dermis consists of dense irregular connective tissue (mainly bundles of type I collagen), with more fibers and fewer cells than the papillary layer.
Reticular layer
A network of elastic fibers is also present in this type of dermis sublayer providing elasticity to the skin.
Reticular layer
In the reticular layer of the dermis sublayer, between the collagen and elastic fibers are abundant ______ rich in dermatan sulfate.
proteoglycans
Consists of loose connective tissue that binds the skin loosely to the subjacent organs, making it possible for the skin to slide over them
Hypodermis or superficial fascia
Promotes rapid uptake of insulin or drugs injected into this tissue
Extensive vascular supply
Receivers for various stimuli from the environment
Sensory receptors
The following are unencapsulated sensory receptors, except:
A. Merkel Cells
B. Free nerve endings
C. Root hair plexuses
D. Meissner corpuscles
D. Meissner corpuscles
The following are encapsulated sensory receptors, except:
A. Meissner corpuscles
B. Ruffini corpuscles
C. Lamellated corpuscles
D. Krause end bulbs
E. NOTA
E. NOTA
Tonic receptors for sustaned light touch and for sensing an object’s texture
Merkel cells
Most numerous neuronal receptors in the epidermis that respond primarily to high and low temperatures, pain, and itching, but also function as tactile receptors
Free nerve endings
A web of sensory fibers surrounding the bases of hair follicles in the retricular dermis that detects movements of the hairs
root hair plexuses
All phasic mechanoreceptors responding rapidly to stimuli on the skin
Encapsulated
Elliptical structures, consisting of sensory axons winding among flattened Schwann cells arranged perpendicular to the epidermis in the dermal papillae
Meissner corpuscles
Touch receptors that are responsive to low frequency stimuli in the papillary layer of hairless skin (lips, palms, fingertips) but decline slowly during aging after puberty
Meissner corpuscles
The wall of the rectum and urinary bladder where they produce the sensation of pressure when the surrounding tissue is distorted.
Pacinian corpuscles
Specialized for sensing coarse touch, pressure (sustained touch), and vibrations, with distortion of the capsule amplifying a mechanical stimulus to the axonal core where an impulse is initiated.
Pacinian corpuscles
Simpler encapsulated, ovoid structures with extremely thin, collagenous capsules penetrated by a sensory fiber found primarily in the skin of the penis and clitoris where they sense low frequency vibrations and cold temperature
Krause end bulbs (genital corpuscles)
Having sensory axons stimulated by stretch (tension) or twisting (torque) in the skin: E.g. pinching someone. It can also detect warm temperature.
Ruffini corpuscles
Elongated keratinized structures that form within epidermal invagination the hair follicles
Hair
the terminal dilation of a growing hair follicle
hair bulb
this is required to sustain the hair follicle
capillary network
A part of a hair extending beyond the skin surface
hair shaft
T or F. Hairs grow discontinuously, with periods of growth followed by periods of rest, and this growth occurs synchronously in all regions of the body or even in the same area.
False. It does not occur synchronously in all regions of the body or even in the same area
Hair growth cycle major phase:
a period of growth
anagen
Hair growth cycle major phase:
a period where growth is halt
catagen
Hair growth cycle major phase:
A final long period of inactivity or long rest period during which the hair may be shed
telogen
In most thick hairs, this is being formed by the large, vacuolated, and moderately keratinized cells of the hair root.
central medulla
These make up the cortex around the medulla.
Heavily keratinized, densely packed cells
Covers the cortex
cuticle
Hard palates of keratin on the dorsal surface of each distal phalanx
nail
Embedded in the dermis over most of the body, except in the skin of the palms and soles.
Sebaceous glands
A hair follicle and its associated sebaceous glands make up a _________ unit.
pilosebaceous
Cells of the sebaceous glands
sebocytes
Refers to an oil release from sebaceous gland
Sebum
A complex mixture of lipids that includes wax esters, squalene, cholesterol, and triglycerides that are hydrolyzed by bacterial enzymes after secretion.
Sebum
T or F. Secretion from sebaceous glands increases greatly at puberty, stimulated primarily by testosterone in men and by ovarian and adrenal androgens in women.
True
Helps maintain the stratum corneum and hair shafts and exerts weak antibacterial and antifungal properties
Sebum
A type of sweat gland that is widely distributed in the skin and are most numerous on the foot soles.
Eccrine Sweat glands
A physiologic response to increased body temperature during physical exercise or thermal stress that is the most effective means of temperature regulation of humans
Sweating
The development of this type of sweat glands depend on sex hormones and is not complete and functional until after puberty.
Apocrine sweat glands
What is being referred to below:
sweat pore; stratified cuboidal
eccrine
What is being referred to below:
hair shaft; simple cuboidal; larger lumen
apocrine