Organ Systems - Concept Map

The Skins Jobs: - Protection and Defense - Sensation - Secretion - Temperature Regulation The Skin - Consists of the epidermis and the dermis - The epidermis is stratified squamous epithelium - The dermis is connective tissue - The protective barrier that keeps our internal structures safe The Roles of the Layers - Epidermis: Dry barrier to water loss, with some defense - Dermis: More mechanical strength, blood supply, and defenses -Hypodermis: Padding, energy storage, temperature isolation Epidermis Structures - Dermal Papilla: Increases the surface area between epidermis and dermis, strengthens the juncture with the epidermis, and increases the amount exchange of oxygen, nutrients and waste - Blood Capillaries: Helps to transfer oxygen and other nutrients from the bloodstream to other tissues of the body and collects CO2 and other waste material - Hair Follicles: Found in the epidermis and is where hairs are formed via cell growth, it also secretes oil that nourishes the hair and skin - Sweat Pores: The tiny holes that secrete sweat (composed of 3 parts: the sweat gland, the sweat duct, and the epidermal duct) - Hair: Consists of the follicle and the shaft, and is composed of cortex and cuticle cells (sometimes medulla for thick/coarse hair) Stratum Corneum Stratum Granulosum Stratum Spinosum Stratum Basale - Contains Epithelial and Connective Tissue Hair Follicles Consist of: - Hair Matrix - Hair Bulb - Derma Pailla (blood supply here) - Hair Medulla - Hair Cortex - Epithelial Root Sheath - Connective Tissue Root Sheath The Epidermis The Hair Matrix: - Like the Stratum Basale, it includes melanocytes - Melanocytes: Produce the pigment of the hair and makes growth cyclic Sebaceous gland Epithelial Root Sheath Arrector Pili Muscle Connective Tissue Root Sheath The Bulge Hair Shaft Fibrous Tract Dermal Papilla (bulb) The Dermis Sensory and Motor Wiring - The skin contains sensory neurons - Located on dendrites are the mechanically gated ion channels - Large grade potentials trigger action potential Follicle Papilla Melanocytes Arrector Pili Muscle - Is in charge of producing heat when the body is cold - A small muscle that attaches to the hair follicle and the dermal tissue - The reason that hair stands up straight when we get cold or “cold chills” Vocab Breakdown:: - Hair Matrix: Produces the actual hair shaft as well as the Connective and Epithelial sheaths of hair - Hair Bulb: Forms the base of the hair follicle, this is where cells divide and grow to build the hair shaft - Derma Pailla: increases surface area between the epidermis and dermis, strengthens the juncture w/ the epidermis, and increases the amount of oxygen, nutrients, and waste - Hair Medulla: Usually found in thick/coarse hair and is the outermost layer of the shaft - Hair Cortex: The thickest hair layer that gives hair its pigment via melanocytes - Epithelial Root Sheath: The external sheath of a hair follicle - Connective Tissue Root Sheath: The internal sheath of a hair follicle