Integumentary system Flashcards
What are the two parts that make up the integumentary system?
Skin and Skin derivatives
What are the other names for the skin?
integument and cutaneous membrane
What does integumentary mean in english?
covering
What are the skin derivatives composed of?
nails, hair, and glands (sweat & sebaceous)
What type of tissue if the epidermis made up of?
stratified squamous epithelial tissue
What does “strata” mean?
layers
What five layers make up the epidermis?
- basale
- spinosum
- granulosum
- lucidum
- corneum
Basale is made up of what?
1 layer, but 3 cell types
What are the three cell types make up the basale?
keratinocytes, melanocytes, tactile cells
Keratinocytes function
produce the protein keratin
What is the function of keratin?
strengthen
Keratinocytes are rich in what?
stem cells
What is the function of stem cells?
divide
Melanocytes function
produce melanin
What is the function of melanocytes?
UV protection
Desmosomes
membrane junctions
What two cells are present in the spinosum?
- keratinocytes with desmosomes
- epidermal dendritic cells
Tactile cells function
stimulate touch receptors
What are the two layers of the skin?
epidermis and dermis
What are the two layers of the dermis?
papillary layer and reticular layer
What does papillary mean?
nipple
Papillary layer function
interlocks with epidermal ridges
The reticular layer is composed of what kind of tissue?
dense irregular connective tissue, glands, hair follicles, blood vessels, and nerves
What is dense irregular connective tissue rich in?
collagen and elastin
Glands function
produce secretions
Hair follicles function
holds hair
Blood vessels functions
transport and temperature regulation
Blood vessels regulate temperature by what?
vasoconstriction and vasodilation
Nerves in the dermis
sensory and motor nerves
Sensory nerves pathway
skin to brain
Sensory nerves function
touch reception
What do sensory nerves detect?
touch, pressure, temperature, and pain
Motor nerves pathway
brain to skin
Motor nerves function
regulation of glands and muscles
Hypodermis
lowermost layer of the integumentary system
What is another name for the hypodermis?
subcutaneous layer
What kind of tissue is the hypodermis composed of?
areolar and adipose connective tissue
What are the functions of the hypodermis?
energy storage, protection, and insulation
Epidermal dendritic cell functions
immune (phagocytes)
What does “dendri” mean?
branch
What takes place in the granulosum layer?
keratinization
Keratinization
nucleus and organelles break down/keratinocytes kill themselves to create protective layer
The lucidum contains what?
thick skin only (palms/soles) 2-3 layers of pale dead keratinocytes
Corneum
30 layers of dead flat interlocking dead keratinocytes;continously pushed up and shed
Corneum
30 layers of dead flat interlocking dead keratinocytes;continously pushed up and shed
Thick skin has how many strata?
five
What parts of the body have thick skin?
palms and soles
Thin skin has how many strata?
four
What parts of the body have thin skin?
most parts of the body excluding the lucidum
Color
the result of combination several of shades
Red color is due to what?
the presence of oxygen in red blood cells
Black, brown, tan, yellow-brown and reddish shades are due to what?
type and amount of melanin
All people have the same number of what?
melanocytes
What is skin color dependent on?
age, heredity, and light exposure
Carotene
pigment acquired from yellow-orange vegetables
Where can carotene accumulate?
inside subcutaneous fat and keratinocytes
What is carotene converted to in the body?
vitamin A
What are the types of skin markings?
a nevus (mole, a birthmark), freckles, friction ridges
Nevus
harmless localized overgrowth of melanocytes (can become malignant)
Freckles
spots in the area of increased activity
Friction ridges
unique complex of arches and whorls that increase friction on contact
What are the structures derived from the epidermis?
nails, hair, and exocrine glands
Nails
plates of tightly packed keratinocytes
Nails functions
- protection of the digits (fingers and toes)
- assist in grasping objects (more so animals than humans)
Hair
strands of tightly packed keratinocytes
Location of hair
most skin except the palms, soles, and lips
Hair functions
- protection (physical/chemical damages)
- visual identification (age, sex, individuals)
- chemical signal (pheromone) dispersal
What are the three types of exocrine glands found in/on the skin?
merocrine sweat glands, apocrine sweat glands, and sebaceous glands
Merocrine gland location
widely distributed
Merocrine gland shape
tubular coiled
Where are merocrine sweat gland secretions released into?
sweat pores
Merocrine sweat glands functions
- thermal regulation
- waste removal
- antibacterial
Merocrine sweat gland secretion composition
99% water (+ ions, wastes, etc.)
Apocrine sweat gland location
axillae, areolar, and genital
Apocrine sweat gland shape
tubular coiled
Where are apocrine sweat gland secretions released into?
hair follicle
Apocrine sweat gland secretion composition
viscous mix of proteins and lipids
Apocrine sweat gland secretion function
activate during puberty (signaling)
Sebaceous gland location
near hair
Sebaceous gland shape
acinar “bunch of berries”
Where are sebaceous gland secretions released into?
hair follicle
Sebaceous gland secretion composition
sebum (oily mix)
Sebaceous gland functions
- lubrication
- conditioning
- antibacterial
What are the six functions of the integumentary system?
- Protection
- Secretion
- Absorption
- Thermal regulation
- Sensory reception
- Metabolic regulation
What does the integumentary system protect against?
toxins, microbes, UV, etc.
What elements of the integumentary system help perform the function of protection?
- being multi-layered
- dendritic cells (immune cells)
What is an example of the integumentary system performing the function of secretion?
sebum released to lubricate the surface if the skin and hair
What does the integumentary system absorb?
chemicals moving in
How does the integumentary system perform thermal regulation?
by the dermal blood vessels and sweat glands
What is the function of sensory reception by the integumentary system due to?
a variety of nerve endings within the dermis and epidermis
Under UV, keratinocytes synthesize what form of inactive vitamin D?
cholecalciferol
Cholecalciferol is modified into what other form of inactive vitamin D?
Calcidiol
Where is cholecalciferol modified in to calcidiol?
in the liver
Calicdiol is modified into what active form vitamin D?
Calcitriol
Calcitriol function
a hormone that increases the absorption of Ca and P from the skeletal system into the blood, thus regulating blood levels of Ca and P