Organizational Levels
All living things are made of ____.
Cells
Controls the cell; houses the genetic material
Nucleus
Skin protects the rest of the body by keeping out many threats from the environment, such as pathogens, damaging solar radiation, and other nasty things.
Protection
Composed of ___ cells.
Epithelial Cells
–Sits just below the epidermis.
–Increases the surface area between two surfaces – increasing friction – fingerprints
Papillary Region
Cells arise from other ___.
Cells
Cell powerhouse; site of cellular respiration
Mitochondria
The skin’s outer layers are more or less impermeable to water, keeping water and salts at an optimum level inside the body and preventing excess fluid loss. A small amount of excess water and some cellular waste are eliminated through the skin.
Water Balance
Manufactures and stores keratin.
Kerotinocytes
–Metabolically active layer
–This layer produces the hair, nails, and sweat
Reticular Region
One cell divides into two daughter ells, each of them complete but smaller than the original cell
Mitosis
Binds amino acids together under the direction of mRNA to make protein
Ribosomes
Many types of sensory organs are embedded in your skin, including receptors for heat and cold, pressure, vibration, and pain.
Incoming Messages
____ gives hair and skin its color.
Melanin
Subcutaneous layer
Hypodermis
Groups of organs that work together to meet a major physiological need
Organ System
Modifies proteins into functional form; packages cellular products in sacs called vesicles in which products can cross the cell membrane to exit the cell
Golgi Apparatus
The skin and hair are messengers to the outside environment, mainly to other humans. People get information about your state of health by looking at your skin and hair.
Outgoing Messages
Melanogenesis is the production of melanin in response to ___ radiation – tanning.
UV
____ anchor the hypodermis to the muscle tissue.
Fibers
___ is a structure made of many cells – usually several different kinds of cells – that perform a specific function.
Tissue
Plays an important role in protein synthesis; participates in transporting cell products, involved in metabolizing (breaking down) fats as well as drugs
Endoplasmic Reticulum
Sebaceous glands in the skin, usually associated with a hair follicle, produce a waxy substance called sebum for waterproofing. Sweat glands in the skin make sweat.
Substance Production
Melanin is produced, released from the ___ and absorbed by skin cells the move to the surface, die, and fall off.
Melanocytes
Functions of the hypodermis include ____, storage of energy, and help in the anchoring of skin.
Insulation