Chapter 5: Integumentary System Flashcards
What does the integumentary system include?
- the skin
- its accessory structures
- the 4 basic tissue types
What are the 6 accessory structures that are part of the integumentary system?
- hair
- nails
- glands
- blood vessels
- muscles
- nerves
Integument
a cutaneous membrane that covers the outer surface of the body
True or False: The skin is the largest organ.
True
About how big is the skin?
22 square ft
How much does the skin weigh?
10 - 11 lbs
What is the thickness range of the skin?
0.5 mm (eyelids) - 4 mm (heels)
How many pounds of skin epithelium is shed per year?
2 1/4 lbs
What are the 6 functions of the skin?
- covers and protects
- regulates body temperature
- senses
- synthesis of vitamin D
- important blood reservoir
- emotional expression
What are the 3 major layers of the skin?
- epidermis
- dermis
- subcutaneous layer
Epidermis Skin Layer
outer, thin layer that consists of epithelial tissue
Dermis Skin Layer
inner thick layer that consists of connective tissue
Subcutaneous Skin Layer (Hypodermis)
under dermis and consists of loose areolar/adipose connective tissue that attaches skin to the underlying tissues and organs
First Degree Burn
a burn that only affects the epidermis
Second Degree Burn
a burn that affects the epidermis and dermis and blisters may appear
Third Degree Burn
a burn that affects all 3 skin layers and requires medical attention
The epidermis is composed of ____ squamous epithelium.
keratinized stratified
4 Types of Epidermis Cells
- keratinocytes
- melanocytes
- langerhans cells
- merkel cells
Keratinocytes
produces keratin
Keratin
a tough fibrous protein that provides protection
Melanocytes
produces melanin
Melanin
prigment that protects skin from UV rays
Langerhans Cells
macrophages involved in immune response
Merkel Cells
function in the sensation of touch
What are the 5 layers (cell types) of the epidermis?
- stratum corneum
- stratum lucidum
- stratum granulosum
- stratum spinosum
- stratum basale
Stratum Basale (Stratum Germinativum)
deepest layer of epidermis, site of mitosis for production of all other layers
Stratum Spinosum
composed of 8-10 keratinocytes
Stratum Granulosum
composed of non-dividing cells filled with granules of keratin
Stratum Lucidum
only found in thick skin like fingertips
Stratum Corneum
outermost layer of epidermis composed of 20 layers of flat dead keratinocytes
True or False: Stratum Corneum is not continuously shed.
False
Keratinization
the process of filling cells from the stratum basale with waxy keratin protein as they move to the surface
Dandruff
excess of keratinized cells shed from scalp
Can constant friction stimulate the process of keratinization and produce a callus?
YES
Where are melanocytes located?
stratum basale
What are the 2 types of melanocytes in the skin?
- eumelanin
-pheomelanin
Freckles
clusters of melanin pigments
Is having more freckles a genetic trait?
YES
Nevi (sing. Nevus)
chronic, benign lesions of the skin (birthmarks or moles)
Malignant Melanoma
cancer of melanocytes
Albinism
the complete or partial absence of pigment in the skin, hair, and eyes
True or False: Albinism is also a defect of an enzyme that helps produce melanin.
True
What type of tissue is the dermis composed of?
connective tissue
What fibers are inside the connective tissue of the dermis?
collagen and elastic fibers
What are the two regions of the dermis?
papillary and reticular
Is the papillary region of the dermis below the epidermis?
YES
What type of tissue does the papillary region of the dermis contain?
areolar connective tissue
What 5 things does the areolar connective tissue in the papillary region of the dermis contain?
- collagen
- elastin
- dermal papillae,
- touch sensors
- free nerve endings
What are epidermal ridges formed by?
underlying dermal papillae
What do epidermal ridges form?
- fingerprints and footprints
- increased friction of grip
Dermatoglyphics
the study of the pattern of epidermal ridges
What type of tissue does the reticular reigon of the dermis consist of?
dense irregular connective tissue?
What does stretching the reticular region of the dermis cause?
stretch marks
What does the subcutaneous layer contain?
lamellated corpuscles that detect external pressure applied to the skin
What do blood vessels pass through to get to the dermis?
Subcutaneous Layer
What 4 things are contained in the superficial sensory receptors?
- merkel discs
- free nerve endings
- meissner corpuscles
- hair root plexuses
What is contained in deep sensory receptors?
pacinian corpuscles
3 Characteristics of Hair
- present on most surfaces
- composed of dead keratinized epidermal cells
- thickness and distribution is genetically determined
Hair helps with ____ and protects the body against the harmful effects of the sun against heat loss.
touch sensations
The 3 parts of the hair include:
- shaft (above the skin surface
- root (epithelial and dermal root sheath)
- follicle
What are 3 types of hairs?
- lanugo
- vellus
- terminal
Lanugo Hair
downy fetal body hair
Vellus Hairs
short, fine, pale hairs barely visible to the naked eye
Terminal Hairs
long, coarse, heavily pigmented hairs
What is hair color determined by?
the amount and type of melanin
Sebaceous (oil) Glands
connected to the hair follicles and secrets sebum
What are 2 important things that sebaceous glands do?
- prevents dehydration of hair and skin
- inhibits growth of certain bacteria
What are the two types of sweat glands?
- eccrine
- apocrine
3 Characteristics of Eccrine Sweat Glands
- most numerous
- secrete a watery solution
- cools body and eliminates waste
Where are Apocrine Sweat Glands found?
in the skin of axilla, groin, areolae, and bearded facial regions in adult males
True or False: Apocrine Sweat Glands no not secrete slight vicious sweat.
False
Eccrine sweat glands release sweat in response to an ___.
emotion stress
Apocrine Sweat Glands are located in the ___ layer and the excretory duct opens into ____.
subcutaneous… hair follicles
When is sweat secreted from apocrine sweat glands?
during emotional stress and sexual excitement
What causes body oder?
apocrine sweat
Ceruminous Glands
modified sweat glands in ear canal
2 Characteristics of Ceruminous Glands
- involved in producing cerumen (earwax)
- provides sticky barrier that prevents entry of foreign bodies into the ear canal
Nails
hard, keratinized epidermal cells
What are three structures of the nail?
- free edge
- transparent nail body (plate)
- nail root embedded in a fold of skin
What are the two kinds of wound-healing processes?
- epidermal wound healing
- deep wound healing
Epidermal Wound Healing
1st degree burns that only affect the epidermis
Deep Wound Healing
some 2nd degree and a lot 3rd degree burns. scar tissue will develop and function may be lost
According to the American Burn Association, a major burn includes:
- 3rd degree burns over 10% of body surface area
- 2nd degree burns over 25% of body surface area
- any 3rd degree burns to the face, hands, feet, or perineum
What happens when a burn area exceeds 70% ?
more than half of the victims die
What are 6 things that the integumentary system changes with age?
- wrinkles develop
- dehydration and cracking occurs
- sweat production increases
- fewer melanocytes (grey hair and atypical skin pigmentation
- less subcutaneous fast and a general decrease in skin thickness
- nails may become more brittle
With age, comes an increased susceptibility to ____ conditions.
pathological
What is an example of pathological conditions in older people?
pressure ulcers (bedsores)
