Integumentary System Flashcards
What tissues make up the skin?
Epithelial and connective
What makes up the integumentary system?
Skin, hair, nails and glands
What are the 2 distinct layers of the skin?
The epidemis (the most superficial) and the dermis (a thicker layer of connective tissue).
What are the functions of the skin?
There are 5:
- Protection: A physical barrier against pathogens, physical trauma and UV radiation.
- Sensory detection: Nerve receptors are in the skin that are receptive to heat, pain and touch.
- Help regulate body temperature through water evaporation (sweating) and increasing/decreasing blood flow to the skin.
- Vitamin D production occurs in the skin.
- Excretion: Sweat helps to excrete salt & small amounts of waste.
- Nutrient storage
What is the epidermis made of?
Stratified squamous epithelial tissue that is waterproof and protective. It is avascular.
What replaces the cytoplasm in old skin cells?
A tough protein called keratin.
What are the specialized cells found in the epidermis?
Keratinocytes, melanocytes, langerhans cells and merkel cells.
What protein hardens and waterproofs the skin?
Keratinocytes
What cells produce a pigment that protects cells from ultraviolet radiation?
Melanocytes
Which are the phagocytic cells that help white blood cells?
Langerhans cells
What cells help with sensory reception?
Merkel cells
What are the 5 layers of the epidermis?
Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and stratum germinativum (basal lamina).
What is the layer that is only found in the palms and soles of the feet?
Stratum lucidum
What is the top layer of the epidermis? What is it made of?
The stratum corneum is made of dead, flat skin cells completely filled with keratin. The top layer of cells in the stratum corneum is constnatly being lost through normal everyday activities.
What cells are found only in thick skin? What is it made of?
Stratum lucidum
What does sunlight do in the skin?
Sunlight helps convert cholesterol to Vitamin D.
What is the only skin that is avascular?
Epidermis – stratified squamous epithelium
What are the functions of the skin?
- Protects underlying tissues and organs
- Excretes salt, water, and organic wastes (glands)
- Maintains body temperature
- Synthesizes Vitamin D
- Stores lipids
- Detects touch, pressure, pain and temperature
What are the 3 components of the integumentary system?
Epidermis (top layer)
Dermis (middle layer with papillary layer and reticular layer)
Hypodermis – inner layer or subcutaneous
What is the largest system of the body?
The integumentary system
What percentage of body weight is the integumentary system?
16%, and BSA (Body Surface Area) is 1.5 to 2 m2 (meters squared) in area
Drugs that are lipophyllic might be injected with what kind of needle?
hypodermic needle, at a 45 degree angle
What diffuses from capillaries in the dermis?
Nutrients and oxygen (O2)
What are the 5 strata of keratinocyes in thick skin?
Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and stratum germinativum (basal lamina).
Where are fingerprints formed?
Strutum germinativum
Where are langerhans cells located?
Stratum spinosa
What do langerhans cells do?
They are phagocytize cells that help the immune system. They are dendritic cells.
What is the only strata found in the thick layer of skin?
Stratum lucidum
What strata is replaced every 2 weeks?
Stratum corneum
Where is stratum spinosa located?
Between stratum granulosum (above) & stratum germinativum (below)
Explain stratum granulosum
The “grainy layer” where cells stop dividing and start producing keratin (tough, fibrous protein that makes up hair &nails) and keratohyalin
What is stratum lucidum
The. Lear layer that is only found in thi k skin. It covers the stratum granulosum
What is stratum corneum?
The horny layer. The exposed surface of skin, 15-30 layers of keratinization cells that are water-resistant. They shed and are replaced every 2 weeks.
What is found in the germinativum strata?
Merkel cells (which respond to touch and trigger the nervous system) and melanocytes (pigment-producing cells)
What factors influence skin color?
Melanocytes production (not the # of melanocytes), carotene and blood circulation (red blood cells)
What is keratinization?
The formation of a layer of dead protective cells filled w keratin. It occurs on all skin surfaces except the eyes. It’s the skin life cycle. It takes 15-30 days for a cell to move from stratum germinativum to stratum corneum
What are the 2 kinds of perspiration?
Insensible (intertidal fluid lost by evaporation they the stratum corneum) and sensible (water secreted by the sweat glands)
How can dehydration occur?
- From damage to the stratum corneum (burns & blisters)
2. From immersion in a hypertonic solution (I.e., sea water [osmosis])
How can hydration occur?
From immersion in a hypotonic solution (freshwater [osmosis]). It causes swelling of epithelial cells, evident on the palms and soles
What can be converted to vitamin A?
Carotene
What do melanocytes do?
Produce melanin, which protects against sun damage. UV radiation causes DNA mutations & burns that lead to cancer & wrinkles.
How does melanin affect skin color?
By the amount of melanin produced, not the number of melanocytes
What is cyanosis?
Bluish skin tint caused by lack of oxygen or red blood cells
Name 3 illnesses that cause a change in skin color
Jaundice - A buildup of bile in the liver. Turns you yellow.
Addisons’s disease: a disease of the pituitary gland that causes skin darkening
Vitiligo: loss of melanocytes that causes skin to lose color (Michael Jackson disease?)
What is another name for Vitamin D? What produces it?
Vit D = cholecalciferol, produced by epidermal cells in the presence of UV radiation
What do the liver & kidneys convert Vit D into?
Calciferol, which aids in the absorption of calcium and Phosphorus.
Insufficient Vit D causes….
Ricketts
What is the dermis made up of?
Papillary layer and reticular layer
Where is the dermis located?
Between the epidermis & the subcutaneous layer
What’s the function of the dermis?
It anchors the accessory structures (hair follicles, sweat glands)
What is the papillary layer made of?
Areolar tissue, smaller capillaries, lymphatic & sensory neurons
What is the reticular layer made of?
Dense irregular connective tissue, larger blood vessels, lymph vessels & nerve fibers. Contains collagen & elastic fibers and connective tissue proper
What is dermatitis?
Inflammation of the papillary layer, caused by infection, radiation, mechanical irritation or chemicals (poison ivy). There’s itching and pain.
What does the dermis consist of?
Collagen fibers and elastic fibers.
What are the signs of skin damage?
Sagging & wrinkles, caused by aging, UV exposure, dehydration, hormonal changes and age.
What are the integumentary accessory structures?
Hair, hair follicles, nails, sweat glands and sebaceous glands. All are located in the DERMIS and project through the skin surface.
What cell layer in the integumentary system engages in mitosis?
Stratum germinativum
What are the 2 kinds of glands?
Sebaceous (oil) and sweat (water)
Which kind of gland inhibits bacteria?
Sebaceous glands
What are the 2 kinds of sweat glands?
Apocrine (armpits, groin, nipples) and merocrine (eccrine) – palms and soles
Which gland is associated with “sensible perspiration”?
Merocrine glands
Where are merocrine glands located?
palms and soles of feet but also elsewhere on the body – widely distributed
Where are apocrine glands located?
Armpits, groin, nipples
Which glands are responsible for body odor?
Apocrine glands
Where are Langerhans cells found?
Stratum spinosum
Where are Merkel cells found?
Stratum germinativum
What do Langerhans cells do?
Immune response
What do merkel cells do?
They’re tactile cells; sensitive to touch
Explain where each of these cells are: Merkel cells, Langerham cells, melanocytes, keratinycytes
Merkel and melanocytes: germinativum. Langerhan: spinosum. Keratinocytes: corneum (and granulosum)
