Chapter 5: Integumentary System Flashcards
What are the two different parts of the integument?
Cutaneous Membrane and Accessory structures.
What is part of the cutaneous membrane?
Epidermis (keratinized cells), Dermis (papillary layer, and dense irregular), and hypodermis
What is part of the accessory structures?
Hair, nails, and glands.
What are the functions of the skin?
Protection
Excretion
Body temp regulation
melanin
keratin
Vitamin D3
Lipids
Touch, pressure pain, and temperature.
What are the layers of the epidermis?
Stratum basale
Stratum Spinosum
Stratum Granulosum
Stratum Lucidum (only in thick skin)
Stratum Corneum
Keratinocytes
Cells form several layers and contain large amount of keratin.
Where are keratinocytes found?
Stratum Corneum Layer
Where are melanocytes found?
Stratum Basale Layer
Langerhans’ cells
Phagocytes, immune cells that eat infectious agents
Where are langerhans’ cells found?
Stratum Spinosum
Merkel cells
Sensory nerve endings (tactile)
Where are Merkel cells found?
Found in startum basale layer
Stratum Basale
Deepest layer
One layer of cuboidal cells.
Rapid cell division
Epidermal growth factor
Forms the epidermal ridges (fingerprints)
Dermal Papillae (tiny mounds)
There are two specialized cells- merkel and melanocytes!
Stratum Spinosum
Around 10 layers
Some cells are still dividing
Begins making keratin and is bound together by desmosomes to adjacent cells.
Langerhans’ cells stimulate defense against microorganisms.
Straum Granulosum
Grainy layer
3 to 5 layers that have stopped diving and are flatter.
Prekeratin is now keratohyalin (mature keratin)
These cells are filled with lamellated granules (lipids)
Cells begin to die
Keratohyalin forms dense cytoplasmic granules that promote the dehydration of cells.
Stratum Lucidium
Clear layer
Only in thick skin
The function is unknown
Stratum Croneum
Layer is exposed to the external environment
Cells are filled with keratin and are coated with lipids from lamellated granules.
Thin skin has around 15 layers
Thick skin has around 30 layers
The dead cells are still interconnected by desmosomes.
TWO weeks before they shed or are washed away.
Water resistant not waterproof
Carotene
Orange-yellowish pigment
It is found in carrots
Melanin
Brownish to black pigment
Stored in vesicles (melanosomes) that are later transferred to keratinocytes for pigment.
Jaundice
The liver is unable to excrete bile resulting in yellowish pigments on the skin due to it accumulating in body fluids.