Lecture #3 Flashcards
Another name for skin?
Cutaneous membrane
Definition of an organ?
Two or more tissues grouped together performing specialized functions
Accessory structures of skin/Integumentary system?
Hair, nails, glands, and sensory receptors.
What is the Epidermis and what is it composed of?
Outer layer of skin and composed of stratified squamous epithelium
What is the Dermis and what is it composed of?
The inner layer of skin composed of connective tissue and contains collagen and elastic fibers.
Subcutaneous layer/hypodermis?
Beneath dermis and insulating layer composed of adipose tissue. Not officially part of the skin.
Keratin?
Tough, fibrous, waterproof protection made in cells
Keratinization?
The process of hardening, dehydration, and keratin accumulation that occurs in epidermal cells as they migrate outward.
The five layers of skin?
Stratum corneum, stratum lucidum, stratum granulosum, Stratum spinosum, stratum basale
What is the function of the epidermis?
Protects against water loss, harmful chemicals, mechanical injury, and pathogens
How do you melanocytes function?
Located in the stratum basil they produce the pigment melanin which absorbs UV light and provide skin color.
How does tanning beds cause cancer?
The doses of UV radiation can overwhelm the body’s natural protective response against skin cancer
What are hereditary factors that affect skin color?
All people have the same number of melanocytes, yet very in the amount of melanin produced which is under genetic control.
What does the dermis contain?
Nerve cells, blood vessels, hair follicles, connective tissue, muscle fibers, and sweat and sebaceous glands
What is the function of the dermis?
Bind epidermis to underlying tissues, supplies nutrients, and sensitive to touch
The two layers of the dermis?
Papillary layer which is more superficial in the reticular layer which is deeper
Where do the accessory structures of skin originate?
They originate from the epidermis and extend into the dermis or the hypodermis.
What are the accessory structures of skin?
Hair follicles, nails, skin glands
What are the three parts of nails?
The nail plate which overlies the nail bed. The nail bed which is the surface of skin under the nail plate. And the lunula which is the most active growing area at the base of the nail plate.
What are the three parts of hair?
Hair bulb, root, and the hair shaft.
Where do you find hair follicles?
On all areas of the body except the palms, soles, lips, nipples, and parts of external reproductive organs.
What muscle causes goosebumps?
The arrector pili muscle
What is androgenic alopecia?
A form of boldness we’re here is lost in the top of the head.
Alopecia Areata?
An auto immune disease that causes hair loss.
What is one cause associated with hair loss?
Lower levels of testosterone or estrogen.
What is the function of sebaceous glands?
They produce sebum which is a fatty material that keeps the hair and skin soft and waterproof.
Acne vulgaris?
Glands become clogged with extra sebum an epithelial cells resulting in infection and inflammation.
Sudoriparous or sudoriferous glands?
Sweat glands which are the most numerous respond to body temperature.
Apocrine sweat glands?
And respond to emotion in pain.
Other types of glands?
Mammary glands which produce milk and ceruminous glands which produce earwax.
What is the function of skin?
Protective covering and a barrier, prevent some water loss, contains sensory receptors, excretes waste, helps produce vitamin D, and helps regulate body temperature.
What is normal body temp?
37°C or 98.6°F
What is the most active cells in major producers of heat in the body?
Skeletal muscle, cardiac muscle, and cells of the liver.