Ch 21- Integumentary System Flashcards
What are the functions of the Integumentary System?
-Protection
First line of defense against bacteria, virus , protect underlying structures from UV.
-Body temp regulation- blood vessels dilate if too hot and constrict if too cold
-Sensory
-Regulate water loss
What is sebum?
Sebum is acidic, which retards growth of bacteria
What do Langerhans cells do?
phagocytize pathogens and alert the immune system to the presence of pathogens
What vitamin does the skin produce?
Vitamin D production Needed for calcium absorption Useful to digestive and skeletal systems Small amounts of UV radiation are needed Vitamin D leaves the skin and enters the liver and kidneys
What are the two layers of the skin?
2 layers- Epidermis and Dermis Epidermis Outer, thinner region Made of stratified squamous epithelium Five layers (strata)
What is the epidermis?
Most superficial layer, Deepest epidermal layer
Contains melanocytes
Traps UV radiation and prevents damage to underlying layers of the skin
Contains Langerhans cells – macrophages
Sensory nerves
Free nerve endings – pain and temperature sensations
Tactile cells (Merkel cells) – touch sensations
What is Stratum spinosum
Contains keratinocytes , above basale
Makes keratin— protein that makes the epidermis waterproof and resistant to pathogens
Contains melanocytes and Langerhans cells
What is Stratum granulosum?
Contains granules
Act in waterproofing and production of keratin fibers
Middle layer …cells begin to die
What is Stratum lucidum?
Soles of your feet and palm of hands
Thin layer of dead cells
What is Stratum corneum ?
Cells are keratinized (hardened)
Serves as a mechanical barrier against microbes
Thick layer of dead cells forming an impermeable layer
What is dermis?
Numerous sensory nerve fibers, hair follicles, oil and sweat glands
Elastic fibers stretch to allow movement of muscles and joints
Collagenous fibers prevent skin from being torn
Binds the epidermis to the subcutaneous tissue
where all four types of major tissues are found
Papillary layer - Finger prints (dermal papillae). Provides epidermis with nutrition, dissipated heat, pain and touch receptors.
Reticular layer - thickest layer with arteries, veins, glands and attaches the epidermis to the subcutaneous layer
What is Hypodermis?
Composed of
Adipose (fat) and loose connective tissue
Blood vessels and nerves
Energy storage in adipose tissue
Injections given in this area are called hypodermic or subcutaneous
What are accessory organs
Hair follicles
Arrector pili muscles
Nails
Sweat and oil glands
Hirsutism – characterized by excessive body and facial hair in women due to increased production of male sex hormone
Alopecia – hair loss
Androgenic alopecia – male pattern baldness
Alopecia areata – sudden onset of patchy hair loss
What is the Sudoriferous (sweat) glands consisting of?
Eccrine
Watery sweat
Activated by heat
Apocrine Thicker sweat with more proteins, in armpit and groin areas Activated by nervousness or stress
How does inflammation promote healing?
Extra blood to area
Extra nutrients for skin repair
Defensive cells
