Post on 22-Feb-2016
description
Bellringer: What is the largest organ of your body? What
system is it part of? Write your answer down on a fresh sheet of
paper or notetaking device!
• http://www.youtube.com/watch?v=uH_uzjY2bEE
Integumentary System
• Integument- “covering”
• Parts:– Skin– Sweat and oil glands– Hair– Nails
Functions?
Fun Facts
• Skin = 7% of your total body weight
• ~80% of dust in your home is dead skin cells
• More than 500 species of bacteria living on your skin
• 1.5-4 mm thick
3 Main Layers
Epidermis
• Epi = upon• Dermis = skin• Tough but loosely anchored• New cells created deep• Mostly dead– “Beauty is only skin deep” ?!
• 5 layers
4 Important Cells:
• Keratinocytes– Produce protein keratin which gives skin protective
qualities• Melanocytes– Produce melanin (nucleus umbrellas!)
• Langerhans– Phagocytes
• Merkel cells– Sensory cell
Stratum Basale “Basal Layer”
• Deepest• Produces keratinocytes• Mitosis hotspots• Merkel hangout
Stratum Spinosum“Prickly Layer”
• Funny shaped keratinocytes• Langerhan hangout• Tension-resisting
Stratum Granulosum“Granular Layer”
• 3-5 cell layers thick• Waterproofing• Cell death line
Stratum Lucidum“Clear Layer”
• Only in thick skin• Just a few rows of dead keratinocytes
Stratum Corneum“Horny Layer”
• 20-30 dead cells thick• 75% of epithelial thickness• Protects against abrasion and penetration
FULL OF HORNY CELLS(they’re shaped like horns)
Activities!
• Color the different layers of the epithelium
• Draw pictures of each cell type and epithelial layer using a microscope