Integumentary System Flashcards
It covers the body and is the major external barrier between the outside world and the body.
skin
It represents the interface between the internal body and the external environment.
Skin
It has important protective functions and is constantly renewing itself.
Skin
The primary role of the skin
protection (this includes protection from physical injury, including UV light, and providing a barrier to pathogens)
It is crucial to an animal’s thermoregulation, sensing of its environment, and energy and metabolic functions.
skin
Skin is crucial to?
*to an animal’s thermoregulation
*sensing of its environment
*energy and metabolic functions
It also provides environmental protection, producing pigment and vitamin D, and sensory perception.
skin
The skin also provides what?
*environmental protection
*producing pigment and vitamin D
*sensory perception
It is the body’s largest organ and may represent 12%–24% of an animal’s body weight depending on the species and age.
Skin
Skin may represent how many percent of an animal’s body weight depending on the species and age?
12%–24%
skin consists of the following structures: (5)
*epidermis
*basement membrane zone
*dermis
*appendageal system
*subcutaneous muscles and fat
a genetic disorder that affects the skin, in which there is no melanin production
Albinism
It is a secretion involves exocytosis of membrane-bound secretory vesicles.
Apocrine
This is the major secretion form of epitrichial glands (often referred to as just “apocrine glands”) and eccrine glands.
Apocrine
Apocrine is the major secretion form of what glands?
apocrine glands and eccrine glands
a type of stem cell found in the stratum basale and in the hair matrix that continually undergoes cell division, producing the keratinocytes of the epidermis
Basal cell
extension of the papillary layer of the dermis that increases surface contact between the epidermis and dermis
Dermal papilla (plural = dermal papillae)
the dermis layer of skin between the epidermis and hypodermis, composed mainly of
what?
connective tissue containing blood vessels, hair follicles, and sweat glands
a structure that forms an impermeable junction between cells
elastin fibers made of the protein elastin that increase the elasticity of the dermis
Desmosome
A secretion involves the rupture of the secretory cell, thereby releasing the cytoplasmic contents.
Holocrine
This is the major secretion form of sebaceous glands.
Holocrine
It is a fibers made of the protein elastin that increase the elasticity of the dermis
Elastin fibers
It is a clear protein-bound lipid found in the stratum lucidum that is derived from keratohyalin and helps to prevent water loss epidermis outermost tissue layer of the skin
Eleidin
Eleidin is derived from?
keratohyalin
It is a connective tissue connecting the integument to the underlying bone and muscle
Hypodermis
skin and its accessory structures
Integumentary system
A structural protein produced by keratinocytes that contribute significantly to the structural integrity of the epidermis.
Keratin
It is a granulated protein found in the stratum granulosum
Keratohyalin
A general term referring to epithelial cells of the epidermis, including those of the stratum basale, stratum spinosum, stratum granulosum, and stratum corneum.
Keratinocytes
A specialized dendritic cell found in the stratum spinosum that functions as a macrophage
Langerhans cell
A pigment that determines the color of hair and skin
Melanin
Cells derived from the neural crest produce the pigment melanin.
Melanocytes
It reside within the basal layers of the epidermis, producing and then transferring melanin to keratinocytes.
Melanocytes
An intercellular vesicle that transfers melanin from melanocytes into keratinocytes of the epidermis
Melanosome
It is receptor cell in the stratum basale of the epidermis that responds to the sense of touch
Merkel cell
A superficial layer of the dermis, made of loose, areolar connective tissue
reticular layer deeper layer of the dermis; it has a reticulated appearance due to the presence of abundant collagen and elastin fibers
Papillary layer
A secretory epithelial cells that contribute to the production of sebum, a lipid-rich fluid that coats hair and the epidermis. Clusters of these comprise sebaceous glands.
Sebocytes
Clusters of sebocytes comprise of what?
sebaceous glands
It is the deepest layer of the epidermis, made of epidermal stem cells
Stratum basale
It is the most superficial layer of the epidermis
Stratum corneum
It is the layer of the epidermis superficial to the stratum spinosum
Stratum granulosum
It is a layer of the epidermis between the stratum granulosum and stratum corneum, found only in thick skin covering the palms, soles of the feet, and digits
Stratum lucidum
It is the layer of the epidermis superficial to the stratum basale, characterized by the presence of desmosomes
Stratum spinosum
A skin condition in which melanocytes in certain areas lose the ability to produce melanin, possibly due an autoimmune reaction that leads to loss of color in patches
Vitiligo
Three primary components of the skin
a. Epidermis
b. Dermis
c. Subcutaneous tissue (also known as the hypodermis or subcutis)
two layers of the skin
Epidermis and Dermis
an outer part, which originates from the ectoderm
epidermis
A deeper layer, which is a derivative of mesenchyme.
dermis
It differentiate into follicles, from which hairs arise
Hair buds
Hair buds differentiate into ________, from which hairs arise
follicles
It form as outgrowths of the walls of hair follicles.
Sebaceous and sweat glands
These are highly keratinized epidermal structures enclosing the distal phalanx.
Hooves and claws
It is derive from surface ectoderm, cover most of the skin
Avian species, feathers
Avian species, feathers, which derive from __________ , cover most of the skin
surface ectoderm
The integumentary system comprises the following: (8)
skin
hair
skin glands
hooves
claws
digital pads
horns
feathers
Although it is a modified skin gland, its development is included in association with the female reproductive system.
mammary gland
It is the body’s external covering and largest organ.
skin
This is a complex structure that functions as a protective layer against physical, mechanical, chemical, and biological injury.
Skin
functions of the skin
- as a protective layer against physical, mechanical, chemical, and biological injury
- body temperature regulation, reception of external sensory stimuli, secretion, immune responses, vitamin D synthesis, and body surface pigmentation
- protects internal organs and serves as a barrier to infectious organisms and to noxious and injury-producing agents.
prevents dehydration from the loss of water and is an important part of the immune system.
number of appendages, including hair, sweat glands, feathers, and scales develop from _______.
ectoderm
Through __________ in the skin, we are able to detect temperature, pain, touch, and pressure.
sensory receptors
Through ___________ and _____________, the skin is able to cool the body and regulate its internal temperature.
sweat glands and superficial blood vessels
It provides the first line of defense against infection by sealing and protecting the underlying organ systems from the invasion of pathogenic organisms.
skin
Because the _________ is avascular, the cells begin to die.
epidermis
It is the outermost layer of the epidermis which is continuously flaking off in as much as it contains the oldest dead cells that have been pushed up and away from the blood supply of the dermis several weeks ago.
corneum
It contains highly organized receptors discriminately distributed throughout the body surface dedicated to signaling the central nervous system (CNS) of changing environmental conditions such as temperature or the compression.
Skin
It is the most important in maintaining an internal homeostatic environment so the body organs can function in an orchestrated way. If the temperature is increasing due to the contraction of muscles in sporting activities or in life-threatening reactions, many sweat glands must be activated to increase water evaporation which will prevent the temperature from increasing to levels unsupportable for living functions.
Maintenance of body temperature
The sweat glands on the palms of the hand and soles of the feet are designed to what?
increase grasping effectiveness
Sweat glands on the hands and most of the body are classified as what?
eccrine or merocrine type
The sweat glands under the arms and in the genital areas are classified as what?
apocrine sweat glands
This gland secret body fluids containing unique body chemicals which generate characteristic odors which become our signature. These odors are easily recognized by family dogs and other animals
apocrine sweat glands
It is a multilayered epithelial structure composed of keratinocytes that produce the structural protein keratin.
epidermis
Epidermis is composed of what?
Keratinocytes
It produce the structural protein keratin.
keratinocytes
It is reminiscent of a brick wall, with the keratinocytes representing _____, and intercellular matrix representing the _______.
epidermis
bricks
mortar
From innermost (young) to outermost (old) the layers of the EPIDERMIS are:
stratum basale
stratum spinosum
stratum granulosum
stratum lucidum
stratum corneum
The deepest/innermost layer of the epidermis.
stratum basale
It is a single layer of cuboidal keratinocytes that directly above and attach to the dermis
stratum basale
The two primary functions of the stratum basale are:
1) proliferation
2) attachment of the epidermis to the dermis.
Cells of the stratum basale essentially represent _________ responsible for the generation of all cells of the epidermis.
germinal cells
These cells are the most mitotically active keratinocytes and are the least differentiated
Germinal cells
Stratum basale keratinocytes divide and then “push up” towards the surface, differentiating into cells of the _________.
stratum spinosum
It forms the “floor” of the epidermis and the junction of the epidermis and dermis.
basement membrane
Three major functions of the basement membrane include:
1) forming an adhesion interface between the epidermis and underlying dermis
2) acting as a physical barrier
3) forms the foundation for the generation, differentiation, and repair of the epidermal keratinocytes.
Cells of the stratum basale attach to the basement membrane via protein structures.
hemidesmosomes
These are additional fibrils, which connect the keratinocytes of the stratum basale to the dermis, and the basement membrane to the dermis also provide structural integrity of the dermal-epidermal interface.
Hemidesmosomes
Two other cell types are found dispersed among the basal cells in the stratum basale.
a. Merkel cell
b. Melanocyte
It is the first cell which functions as a receptor and is responsible for stimulating sensory nerves that the brain perceives as touch.
Merkel cell
These cells are especially abundant on the surfaces of the hands and feet.
Merckel celld
It is the second cell. A cell that produces the pigment melanin.
melanocyte
It gives hair and skin its color, and also helps protect the DNA in the nuclei of living cells of the epidermis from ultraviolet (UV) radiation damage.
Melanin
It is located directly above the stratum basale.
stratum spinosum
Cells of the stratum spinosum have prominent cell-to-cell junctions, termed _________, that appear as spiky membrane projections on histology. For this reason, these are referred to as “prickle cells”.
desmosomes
Cells of the stratum spinosum have prominent cell-to-cell junctions, termed desmosomes, that appear as spiky membrane projections on histology. For this reason, desmosomes are referred to as __________.
prickle cells
These are protein complexes that firmly attach keratinocytes to their surrounding cells (intercellular, between cells), thereby providing significant structural integrity.
Desmosomes
These are intracellular (within cells) protein complexes that anchor desmosomes to the cell membranes.
Tonofilaments
The stratum spinosum of canine inguinal skin is ____________, whereas the stratum spinosum of the canine footpad is often ___________.
1-2 cell layers thick
>20 cell layers thick
What is the primary function of the skin?
protection
It sits above the stratum spinosum and directly below the stratum corneum.
stratum granulosum
It is a thin layer of keratinocytes containing dense, basophilic (blue/purple) cytoplasmic structures called keratohyalin granules.
stratum granulosum
dense, basophilic (blue/purple) cytoplasmic structures called __________
keratohyalin granules
It contain components responsible for keratinization, including fibrous proteins (keratohyalin) and a lipid-rich secretory product.
Keratohyalin granules
It should be noted that the stratum granulosum is not apparent in all regions of the skin, particularly in regions of _________.
thin skin (e.g. canine inguinal and axillary skin)
It is a thin, transparent layer of keratinocytes that are becoming less round and have a flatter shape.
stratum lucidum
This is only present in the thicker skin of the palms, soles and digits.
stratum lucidum layer
Its main function is to reduce friction between the stratum corneum and stratum granulosum.
Stratum lucidum
• The stratum lucidum layer is only present in the what areas?
thicker skin of the palms, soles and digits.
What is the main function of stratum lucidum?
to reduce friction between the stratum corneum and stratum granulosu
The name itself comes from the Latin for “clear layer,” which describes the transparency of the cells themselves.
Stratum lucidum
The name stratum lucidum comes from the Latin for “_________,” which describes the transparency of the cells themselves.
clear layer
