Chapter 6: Integumentary System Flashcards
What are the main functions of the integument?
- Protection from External Environment (Physical barrier)
- Prevention of Water Loss and Water Gain (transpiration)
- Vitamin D Synthesis (Vitamin D –> cholecalciferol –> calcitriol)
- Secretion (sweat, sebum)
- Absorption (transdermal administration)
- Temperature regulation (vasoconstriction, vasodilation)
- Immune Function (epidermal dendritic cells)
- Sensory reception (tactile sensory receptors)
Name the tissue types that compose the epidermis, dermis, and hypodermis
stratified squamous epithelium, areolar & dense regular connective tissue, adipose connective tissue
List the four major types of cells that make up the epidermis and their functions
keratinocytes, melanocytes, tactile cells, dendritic cells
What are the five layers of the epidermis from deep to superficial?
Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum
What are the characteristics of stratum basale?
basal layer, simple cuboidalor low columnar cells connected to basement membrane; keratinocytes, melanocytes, tactile cells
What are the characteristics of stratum spinosum?
spindly layer; daughter cells of underlying keratinocytes stem cells; keratinocytes differentiate here; contains dendritic cells; all cells connected by desmosomes
What are the characteristics of stratum granulosum?
3-5 layers, keratinization begins here; keratinization results in cell death
What are the characteristics of stratum lucidum?
only in thick skin, 2-3 cell layers; keratinized cells are filled with eleiden which is a byproduct of keratinizaiton
What are the characteristics of stratum corneum?
20-30 layers of dead anucleated, keratinized cells; 2 weeks to get keratinized cells, 2 weeks to shed keratinized cells; exocrine sweat glands secretions prevent microorganism growth
What are the two layers of the dermis from deep to superficial?
reticular layer & papillary layer
What are characteristics of the dermal papillary layer?
areolar connective tissue; has dermal papillae and epidermal ridges that interlock and increase the area of contact between epidermis and dermis; each papilla contains capillaries that supply nutrients to the cells of the epidermis; has sensory nerve cells
What are the characteristics of the dermal reticular layer?
dense irregular connective tissue; large bundles of collagen fibers that extend in all directions; surrounds hair follicles, sebaceous glands, sweat glands, nerves, and blood vessels
What structures are found in the dermis?
connective tissue proper and collagen fibers, dendritic cells, blood vessels, sweat glands, sebaceous glands, hair follicles, nail roots, sensory nerve endings, arrector pili
How are fingerprints formed?
friction ridges left behind due to sweat and oil glands releasing secretions; unique identifiers to individual
What factors normally contribute to skin color?
hemoglobin (red), melanin (tan, black, brown: melanocyte activity), carotene (yellow-orange from beta-carotene foods)
What are freckles?
high melanocyte production
What are nevi?
mole; overgrowth of melanocytes; can sometimes become malignant
Describe jaundice in terms of skin coloring
yellow; liver
Describe cyanosis in terms of skin coloring
blue; lack of oxygen
Describe erythema in terms of skin coloring
red; physical exertion or strong emotions
What is albinism?
inherited recessive condition where the enzyme needed to produce melanin is nonfunctional; white hair, pale skin, pink irises
What are striae?
stretch marks
What is the location and function of Merker cells?
tactile cells; touch sense
What is the location and function of Meissner’s corpuscle?
low pressure touch; superficial closer to epidermis
