Lab 3 - lab report PDF

Preview

Summary

lab report...

Description

Exercise #7 Integumentary system

The main function of the integumentary system is protection; mechanical, chemical, thermal, bacterial. Also protects against loss of water, and produces vitamin D. Allows us to sense pain, touch, pressure, hot and cold. Also protection from U.V. rays of the sun. Structure The skin is made up of two main layers; the Epidermis and the Dermis.

The epidermis is the superficial layer, made up of epithelium and connective tissue. The dermis is the deeper layer and is bound at undulating borders. Hypodermis is underlying adipose tissue layer, not part of the skin. Epidermis is keratinized stratified squamous epithelium, four layers. Cells of the epithelium: Keritinocytes/ Keratin Cells, produce keratin (waterproofing). Melanocytes produce melanin, which provides protection against the sun's rays. A freckle is many melanocytes. A Langerhans cell/ Epidermal Dendritic Cell is a macrophage, part of the immune response. Merkel cell is a tactile sensory cell. Layers of the Epithelium; Stratum Basale or Germanitivum is the layer just above the dermis, a single cell layer thick, contains 1/4 melanocytes. Stratum Spinosum is a layer that contains intermediate filaments of prekeratin protein and is the last purely living layer, contains langerhans cells. Stratum Granulosum is a layer that contains thin lamellated granules (water proofing) of glycolipid, and keratohyalin granules, and intermediate filaments which form keratin fibrils. Stratum Lucidum is found only in thick skin, is a layer of flattened keratinocytes, dead layer. Startum Corneum is 20 to 30 layers of dead flattened, keritanized cells. Dermis 2 layers of dense irregular connective tissue. The Papillary Layer is an uneven with finger-like projections called the Dermal Papillae, attach to the epidermis form the fingerprints. This layer is highly vascularized and contains meissner's corpusles.

The Reticular layer is full of arteries and veins, sweat (sudoriferous) sebaceous glands, pressure receptors. Also contains collagen and elastic fibers, fibroblasts, adipose cells, macrophages. As body temperature rises, the arteries in the skin dilate allowing more blood to the surface, and heat to be dissipated through the skin. As body temperature goes down the blood vessels of the skin constrict to conserve heat inside the body. Bedsores (Decubitus Ulcers) are due to a restriction of normal blood supply to the skin. Skin color is due to; melanin, carotene, and oxygenation of the blood. Jaundice is a yellowing of the skin, due to liver damage. Addison's Disease is characterized by a bronzing of the skin due to a hypoactive adrenal cortex. Appendages of the skin: Glands Hair Nails All are derived from the epidermis from the stratum basale. Cutaneous Glands (2) Sebateous glands are found everywhere, but the palms of the hands and the soles of the feet. The glands empty into hair follicles producing Sebum (oil) and cell fragments. The sebum acts as a lubricant to soften and moisten hair, keep it healthy and not brittle. Blackheads are dried sebum and bacteria. Acne is an infection of the sebaceous glands. Sudoriferous glands are sweat glands. They release sweat or perspiration through pores. There are two types; Eccrine glands produce clear perspiration and are found everywhere. Apocrine glands produce milky fat-rich perspiration and are found in the axillary and genital regions. This perspiration is a bacterial medium. Hair Found everywhere, but the palms of the hand and the soles of the feet. The Hair Follicle encloses the Hair root, which contains the Hair Bulb that holds the Papilla that nourishes the growing hair. Hair outside of the skin is called the shaft. Hair bulb contains the cells that

hair forms from, hair is keratinized dead cells. Arrector Pili are smooth muscle bands that connect to the hair follicle to the papillary layer of the dermis. These muscles pull hair upright releasing sebum. Nails are a horn-like derivative of the epidermis. The Nail Matrix is a thickened nail bed responsible for nail growth (germinal cells). The Lunula is the white cresent above the cuticle also known as the Eponychium. Burns 1st degree burn epidermis is damaged. 2nd degree the epidermis is destroyed and the dermis is damaged. 3rd degree both the epidermis and the dermis is destroyed and the hypodermis is damaged. Fingerprinting Fingerprints are unique genetically, comprised of three patterns; arches, loops and whorls. Only loops and whorls are used for identification. Exercise #8 Classification of Covering and Lining membranes

Epithelial membranes made of epithelial sheet and connective tissue. An example of an epithelial membrane is Cutaneous (skin).

Mucous Membrane made up of epithelial cells and loose connective tissue ( Lamina Propria). These membranes line cavities and secret mucous (usually), by goblet cells. Serous membranes line external body cavities and secrete serous fluid that cuts down friction. Serous membranes also line blood vessels (previously covered). Synovial membranes are composed entirely of connective tissue. They line cavities surrounding joints, smooth surface and lubricate.

Good Luck on the First lab exam!!!!!!!!!!!!!!!...