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