Integumentary System Flashcards
The skin is an _____, meaning it covers and protects the underlying organs from the environment.
Epithelial structure
The ____ is composed of all four tissue types and is the largest of the body’s organ systems.
Integument
Functions of the skin:
· Keep the body contents confined
· Protects against excessively humid or dry conditions
· Protects against environmental chemicals
· Protect against infectious organisms, such as bacteria, viruses, fungi, and parasites
· Helps regulate body temperature
If you are too hot, the blood vessels in your skin ____.
Dilate; to increase blood flow to the skin and release heat to the environment.
When you get too cold, the skin’s blood vessels ____.
Constrict; to decrease blood flow to the skin and keep less heat from radiating out of the body.
____ is pigment that the skin makes when exposed to ultraviolet rays in sunlight.
Melanin
_____ is manufactured by the skin when it is exposed to sunlight and is very important in keeping bones healthy.
Vitamin D
The skin is comprised of two major layers:
1) epidermis
2) dermis
The outermost layer of skin is:
The epidermis
The epidermis may contain up to ___ layers.
5
____ is a fibrous protein that provides toughness to the cell and, therefore, to the skin.
Keratin
As a cell ages and rises towards the surface, the insides of the cell are replaced by a fibrous protein leading to the cell’s death and is called:
Keratinization
The outermost layer of the epidermis is the “horny layer” called the ____ and consists of dead, flattened, fully keratinized cells.
Stratum corneum
The second epithelial layer from the surface is the “clear layer”, called the _____. Cells here are also dead and completely keratinized.
Stratum lucidum
Below the stratum lucidum is the “granular area”, called the ______. in hairless areas, this layer may be several thick. These cells are in the process of dying; they’re losing their nuclei, and they’ve nearly stopped producing keratin.
Stratum granulosum
Just beneath the stratum granulosum is the “prickle cell layer”, called the _____. This layer consists of one to three layers of living cells that are polyhedral to slightly cuboidal in shape.
Stratum spinosum
The final, deepest layer of the epidermis is the “basal layer” called the ____. Cells are laid in a single layer of columnar to cuboidal cells that are actively dividing.
Stratum basale
Types of cells in stratum basale:
Keratinocyte - produce keratin
Melanocyte - makes melanin
The ____ provides both structural and nutritional support to the epidermis.
Dermis
The dermal components consist of:
Fibers
Ground substance
Some cells all jumbled together
Underneath all of the epidermal and dermal structures that make up the skin is the ____, or subcutaneous layer.
Hypodermis
Paw pads are composed of thick layers of ___ and ____, contain ___ epidermal layers and sweat glands, and is often pigmented.
Fat
Connective tissue
All five
The top of the nose is referred to as the:
Planum nasale; in some species it contains glands
Two unique skin structures of the horse:
Chestnut and ergot
___ is a non living structure partially composed of keratin.
Hair
______, also called coarse or guard hairs, are larger, stiffer hairs that provide the rough outer coat of most animals.
Primary hairs
____, also called fine hairs, are thinner hairs that make up the undercoat found on some animals.
Secondary hairs; animals with thicker coats have larger numbers of secondary hairs.
A specialized type of hair is the ____- also called sinus- better known as a whisker.
Tactile hair
Hairs are divided into two parts:
The shaft and the root
The hair ___ is the free portion that rises above the skin surface.
Shaft
The hair ___ is the portion of the hair beneath the surface of the skin.
Root
Attached to the hair follicle are small muscles, called the ____, embedded in the dermis.
Arrector pili muscles
Two categories of nerves are found in the skin:
Motor
Sensory
____ control movement by stimulating muscles to contract and relax.
Motor nerves
____ are responsible for making you aware of how your skin feels and what it’s touching.
Sensory nerves
The ____ phase is the active growth phase of the cycle for hair growth. During this phase, the cells of the dermal papilla and hair bulb divide to produce the keratinized cells of the hair shaft.
Anagen
____ is the resting phase. During this phase, these cells aren’t dividing, the hair isn’t growing, and the hair is retained in the hair follicle for a period of time before being shed.
Telogen
The third phase of the cycle is ____. This is a transitional phase between anagen and telogen in which hair growth slows down. A separation forms between the living cells of the dermal papilla and the dead and dying cells of the hair root and shaft.
Catagen
Three types of glands in the skin:
Sebaceous
Sweat
Other
___ are microscopic infoldings of the epidermis that are usually associated with hair follicles.
Sebaceous glands; most common gland.
Which areas of the body have the most sebaceous glands?
Hairy areas
While looking under the microscope, you see clusters of foamy-looking, fat-containing cells with an outer layer of reserve cells. What are you looking at?
Sebaceous glands
Sebaceous excretions actually reach the surface of the skin through the hair follicles when foamy cells rupture and release a substance called___, which contains___,___, and___.
Sebum
Cholesterol
Fatty acids
Waxy chemicals
Functions of sebum:
- Helps to soften skin and keep it pliable
- Forms a thin film over the stratum corneum to help it retain moisture
- Fatty acids and salts help kill bacteria
Located in the dermis, what are the second most common gland found in the skin?
Apocrine sweat glands
______ make a fluid rich in protein that mixes with ____ to form the protective film over your stratum corneum.
Apocrine sweat glands
Sebum
_______ are a form of sweat gland that are modified to produce milk.
Mammary glands
_____ are present all over the human body, especially in areas such as the armpits, hands, and feet. However, dogs and cats only have them in the footpads.
Eccrine sweat glands
______ sweat glands are located at the junction between the dermis and hypodermis.
Eccrine
Functions of eccrine sweat glands:
- help regulate body temperature by releasing water, which evaporates to carry off heat.
- helps the body excrete salts and small amounts of certain waste products, such as ammonia.
Methods cats and dogs use to regulate body temp:
• panting
• cutaneous blood vessel dilation and construction
· Raising or lowering of hairs
____ are combinations of modified sebaceous and apocrine glands that lie on each side of the anus.
Anal sacs; produce a foul-smelling secretion that may have been used in the wild to mark territory.
On the dorsal surface of the tail, dogs and cats have high concentrations of sebaceous glands and/or apocrine sweat glands called___.
Tail glands; these kinds of glands can also be found in the ear canal and produce ear wax.
Functions of claws:
· To improve traction during locomotion
· Used as a weapon for attack or defense
· Gathering food, tearing food apart, or holding food while carrying or eating it.
____ is simply a modified extension of the dermis and epidermis of the toe and is composed primarily of horny, or keratinized, epidermal tissue.
The claw
Inside the claw, where it joins the toe, lies vascular tissue, called ___, which grows from the distal bone of the toe.
The quick
The dorsal portion of the claw grows faster than the ventral portion (the ____), making the claw curve downward as it grows out.
Sole
_____ are remnants of toes that have progressively become smaller as animals evolved from a four-toed stance to a two-towed stance.
Dewclaws
____ are found in primates, have only a keratin outer surface and don’t possess a sole.
Nails
The second most common form of modified skin on the foot is the ___.
Hoof
Functions of hooves:
- to move around
* weapons to attack/defend
The hoof is made of:
Specialized horny epidermal tissue extending over the distal digit.
The ___ is the hoof’s outermost covering.
Wall
The concave portion that extends from the outside wall to the ridge in the middle of the hoof is known as the ____.
Sole; soft and sensitive
The horse has a central, roughly V-shaped ridge of soft horny material called the ____.
Frog
The ____ are the junction of the sole and the frog, where the wall turns in from the posterior part of the foot and melds with the frog.
Bars
The ___ is the soft tissue that covers the heel of the foot just behind the frog.
Bulb
____ rise through the epidermis and grow through life. They’re composed of fibers that are intertwined, packed tightly together, and bound into a single unit by keratin.
Horns
The ___ is a horns inner layer and has small, finger-like projections that extend into the keratin wall to provide support and nutrition.
Curium
Horns have their own internal blood supply and are partly supported near the base by a ____.
Horn core; it’s a hollow extension of the frontal skull bone that communicates with the sinus cavities on the front of the skull.
The ____ originates in the dermal layer and is a bony extension of the skull.
Antler
A thin outer covering of skin called the ____ supplies the antler with nutrients.
Velvet
True or false: Antlers don’t grow continuously but are shed and regrown every year.
True
The avian epidermis is relatively thin/thick, while the dermis is thinner/thicker.
Thin
Thicker
In birds, the _____ contains smooth muscles that innervate the feather follicles and aid in heat regulation.
Dermis
Birds don’t have ____ glands.
Sweat
A unique gland present in most birds is the _____ gland on the dorsal surface at the upper base of the tail. This gland secretes an oily, fatty substance that serves to waterproof the feathers.
Uropygial or preen gland
In birds, ___ and ___ grow continuously.
Claws and beaks
Six types of feathers:
1) contour
2) semiplume
3) down
4) filoplume
5) bristles
6) powder down
These are the most visible feathers and include the flight feathers of the wings in the tail.
Contour feathers
These are usually found under contour feathers and provide insulation and aid with buoyancy in waterbirds.
Semiplume feathers
These soft, fluffy feathers are located close to the skin and function primarily in insulation.
Down feathers
These barbless feathers are located on the nape and upper back and play a role in controlling feather movement.
Filoplume feathers
These feathers may be found around the eyes, nostrils, mouth, or toes and play a role in the sense of touch.
Bristles
These constantly growing feathers create a waxy powder that spreads throughout the rest of the plumage to clean it and provide waterproofing.
Powder down feathers
The process of feather replacement is called___.
Molting
The newly emerged feather is covered by an epidermal covering called the ____.
periderm
A developing feather is referred to as a___.
Blood feather
Reptile skin is keratinized and relatively ____.
Inelastic
In some reptiles, the dermis contains ____, pigment-containing cells that allow some species to change their skin color and pattern drastically.
Chromatophores
Some reptiles have structures within the dermis called _____ that provide protection.
Osteoderms
Snakes have modified scales that cover the eyes called the ____.
Spectacle or brille
The process of skin shedding in reptiles is properly termed ___.
Ecdysis (shedding of the skin)
____ is the dead skin of reptiles.
Exuvia
The epidermis of amphibians is very ____ and ____ and may contain only a single layer if keratinized skin. Aquatic species lack keratinized epidermis.
Thin
Pliable
The amphibian dermis contains ______ as well as ______.
Chromatophores
Glands that produce various secretions (can be toxic)
The soft horny covering at the proximal end of the hoof wall is called the ____.
Periople
____ characterizes secretion without the loss of cell contents.
Merocrine
Pruritis means:
Itchiness of the skin
Alopecia means:
Hair loss
____ is an inflammation of the dermis and epidermis (dermatitis) caused by tiny mites that live on or in the skin.
Mange
Define excoriations.
Deep scratches in the skin.
Define hyperkeratosis.
Thickening of the skin (stratum corneum).
Define pyoderma.
Bacterial infections on the skin often characterized by pustules.
Mites that live in the hair follicle and sebaceous glands are called:
Demodex; long, thin mites with short stubby legs.
Often found in young or immunosuppressed animals.
_____ is agonizingly itchy, and dogs with it are often miserable and unable to sleep. These round mites like to burrow into the oozing excoriations in the skin, making them particularly itchy.
Sarcoptic mange; scabies
Sarcoptes mites are initially drawn to relatively ____ areas such as ____ and ____. From here they spread to the face, neck, and up and down the legs.
Hairless
The edges of ears
Elbow caps
______ is the mite most commonly linked to mange in cats, rats, and rabbits.
Notoedres; smaller than sarcoptic mites but very similar looking.
When pets develop itchy skin and ears due to allergies it is a syndrome called:
Atopy
