PLN 103 Lecture 2: CHAPTER 5 phys notes

• School: Ryerson University
• Department: Physiology
• Course: PLN 103
• Professor: Juliatotosydezepetnek

Document Summary

Bodys first line of defense from things like the sun, environmental chemicals, microorganisms. Largest system of the body- 16% of body weight (3. 5kg) Properties and function of each layer is bc of the cells: keratinocyte cell. Pale and dark ppl= same # melanocytes: langerhans. Surrounds keratinocytes to ingest invaders: merkel cells. Combine to form sensory receptor for touch, pain, temp: accesory structures. Extend through epidermis to skin surface: hair, nails, glands. Cardiovascular system: blood vessels branch through the dermis. Nervous system: sensory receptors monitor touch, pressure, temperature, pain, send to central nervous system. Excretion of salt, water, and organic waste via glands. Detection of touch, pain, pressure and temp. Nutrients and o2 diffuse from capillaries to dermis. Adjacent to dermal papillae that projects into epidermis. Keratinocytes- bulk of epidermis: form several layers (strata) and contain a lot of. Thin skin= most of body (4 layers of keratinocytes) Thick skin= soles of feet, palms (5 layers of keratinocytes)