Integument system Flashcards
The integument
Our skin that covers the body
The integument system
Composed of the skin,nails, hair, & glands
_________ is the largest organ & contains epithelial, connective, smooth muscle, & nervous tissue
The integument (skin)
What are the two main layers of the skin?
- Epidermis - which is the uppermost layer
- Dermis - which sits under the epidermis
Subcutaneous layer
Loose connective tissue that sits directly below the integument
What are the main functions of the skin?
- Protection
- Prevent dehydration
- Metabolism
- Secretion/ absorption
- Immue protection
- Temperature regulation
- Senses
Epidermis
The uppermost layer of the skin and is composed of epithelial tissues & has five layers
What are the five layers of the epidermis?
- Stratum Basale
- Stratum spinosum
- Stratum granulosum
- Stratum Lucidum
- Stratum corneum
Stratum Basale layer
Is the deepest epidermal layer & contains a single layer of cubodial or columar cells attached to a basement membrane
What are the 3 types of cells found at the stratum basale layer?
- Keratinocytes - which are most abundant & produce keratin which gives the skin its strength
- Melanocytes - produces melanin (which gives us our skin tone & protects us from UV radiation)
- Tactile cells - which are cells that when touched releases chemicals to stimulate nerves (ex merkel cells)
Stratum spinosum
Consist of several layers of keratinocytes where they dont divide & it also contains epidermal dendritic cells (Langerhans) which are immune cells that fight infections
Stratum Granulosum
Consist of 3-5 layers of keratinocytes undergoing keratinization - which fill the cell up of keratin & slow begins to die
Stratum Lucidum
Found only in thick skin (in the palms of hands & soles of feet) & contains eleidin proteins which help protect the skin from UV light
Stratum Corneum
Uppermost layer of the skin (what we see in the mirror) & contain dead cells & makes our skin waterproof
What are the 3 main types of skin variation?
- Thin & thick skin
- Skin color
- Skin markings
Thin skin
Cover the majority of the body & has only four layers (lacks the stratum lucidum)
Thick skin
Covers the palms of hands, soles of feet, & has all five layers (but doesnt have hair)
What are the 3 types of proteins that control skin coloring?
- Hemoglobin
- Melanin
- Carotene
Hemoglobin
Protein that binds oxygen in red blood cells (turns red)
Melanin
Protein produced by melanocytes which produce skin color (like black, brown, etc)
Carotene
Yellow-orange pigment obtained from food (like carrots)
What are the four main types of skin markings?
- Nevus (mole)
- Freckles
- Hemangioma
- Friction ridges
Nevus (mole)
Overgrowth of melanocytes
Freckles
Result from the overactive melanocytes (not an increase)
Hemangioma
Skin discoloration from blood vessel that form tumors
Friction ridges
Small ridges that exist in particular regions of the skin (finerprints) & they increase friction which allows us to grab things & walk barefoot
Dermis
Sits under the epidermis & contains connective tissue
What are the two layers of the dermis?
- Papillary layer
- Reticular layer
Papillary layer
Uppermost area that touches the epidermis & contain dermal papillae which are projection into the epidermal ridges (looks like egg crates)
Reticular layer
Is the deepest layer of the dermis & contains irregular coneective tissue & collagen fibers
Lines of cleavage
Parallel aligned bundles of collagen & elastic fibers in the dermis (important because have to cut parallel to them to have fast healing)
Striae ( stretch marks)
Forms when there is too much stress on the fibers & tears the collagen fiber
What two types of fibers are in the lines of cleavage?
- Collagen fibers - which resist stress
- Elastic fibers- allow to stretch & recoil of the skin
Subcutaneous layer (hypodermis )
Lies under the dermis & is not part of the skin & contains the subcutaneous fat which contain adipose tissue
Nails
Are modification of the stratum corneum layer of the epidermis which provide protection to fingers & toes
Free edge of the nail
Is the white free edge at the nail tip (that you bite or clip off)
Nail Plate
Surface of the nail
Nail body
Pinkish section of the nail & contains the lunula which is the white area in our nail
Nail root
The section of the nail that is under the skin & contains the nail matrix which is where nail grows
Nail bed
Underneath the nail plate & contains living epidermal cell layers
Nail folds
Are skin around the nail
Eponychium
Epidermis extending onto the nail body
Hyponychium
The thick stratum corneum below the nail
____ is found everywhere on the body except palms, soles, lips & other areas
Hair
What are the different types of hair?
- Langugo
- Vellus
- Terminal hair
Lanugo hair
Is a think colorless downy hair type that is on a third -trisemster fetus
Vellus
Hair that is lightly pigmented & that replace lanugo hair at birth (found on upper/lower limbs)
Terminal hair
Replaces vellus & is colored hair (ex eyebrows, eyelashes, etc)
What are the function of the hair ?
- Protection
- Facial expression
- Retains heat
- Senses
- Identifications
- Responds to chemical signals
What are the three zones of the hair structure?
- Hair bulb
- Hair root
- Hair shraft
Hair bulb
Is made up of epithelial cells & is the origin of hair in the dermis
Hair papilla
Is made up of connective tissue & surrounds the hair bulb
Hair Shaft
Is the visible part of the hair that extends out from the skin’s surface (the hair we see)
Hair Matrix
Is adjacent to the hair papilla & where the cell divison occurs
Medulla
Is the remnant of the matrix that contains keratins
Cortex
Consist of serval layers of cells that surrounds a newly developed hair
Cuticle
Is a single cell layer around the cortex tht coats the hair
Hair follicle
Surround the hair root
Arrector pili
Are regions of smooth muscle that extends from the hair follicle & also responds to temp & emotions (ex goosebumps)
What are the 3 phase of hair growth?
- Anagen Phase
- Catagen phase
- Telogen phase
Anagen Phase
Is an active growth phase that can last from 18 months to 7 years
Catagen Phase
Is a regression period, where there is no cell division
Telogen phase
Is a resting phase & the hair sheds
Sweat glands
Produce Sweat, located in the reticular layer & they have sweat gland duct that transport secretions to the epidermal surface
Sweat pore
Is the opening on the epidermal surface
Merocrine sweat glands
Are the most abundant type of sweat glands & produce sweat to the surface of the skin through exocytosis
Apocrine sweat glands
Release secretion through exocytosis (send them to hair follicles not the surface of the skin) & also has an odor & become active during puberty
Sebaceous glands
Are holocrine glands that produce sebum (an oily, waxy secretion)
Ceruminous glands
Are modified apocrine glands in the ear canal which secrete cerumen (earwax) to protect the eardrum from forgein particles
Mammary glands
Are modified apocrine sweat glands in the breast & is functional only in pregant women to produce breastfeeding milk