Exam (elaborations) BSC 2346 (BSC2346) BSC 2346 Module 02 Lab Worksheet: The Integument

BSC 2346 Module 02 Lab Worksheet: The Integument.Introduction This week’s lab will focus on the integument system including the anatomy and physiology of the skin and accessory glands. Objectives Objectives for this week’s lab include: 1) Label the anatomy of the skin, 2) Analyze the health of the skin, 3) Demonstrate the effects of various sensory organs within the integument, and 4) Analyze an integumentary case study. Overview The integumentary system consists of the skin (epidermis and dermis) along with the accessory organs including the hair, nails and various glands. The skin is composed of the epidermis and dermis. The hypodermis is technically not part of the integument but is typically studied because of its close association with the skin. The epidermis is composed of stratified epithelial tissue and contains five distinct layers with the stratum basale being the most diverse. Melanocytes are found within the stratum basale and secrete a pigment called melanin that determines our skin color and protects us from the harmful effects of UV radiation. The main cell of the epidermis is the keratinocyte, which secretes keratin. Keratin providesprotective properties to the skin, including ‘waterproofing’; hair and nails are composed of compacted keratin. Keratinocytes have a life cycle of about 30-45 days before they are scraped and flaked off the body. The dermis is deep to the thin layer of the epidermis, is much thicker in size and is largely composed of connective tissue but also contains muscle and nerve tissue. Unlike the epidermis, the dermis contains a rich supply of blood and lymphatic vessels along with nerve fibers. The dermis also contains collagen fibers (provides structural support), elastic fibers (provides elasticity), sensory organs along with the origins of the hair follicles and glands. The skin contains two types of glands: Sweat and sebaceous glands. There are two classifications of sweat glands, which includeeccrine and apocrine sweat glands. Both produce various forms of sweat secretions. Sebaceous glands produce sebum, which is an oily secretion that prevents the skin from drying out. It is vital to understand that the epidermis is continuously going through a regeneration process as new keratinocytes are produced, old ones are flaked off. The dermis on the other hand doesn’t go through a regenerative, it’s cells and structures are permanent. Any permanent damage to the skin will be a result of damage to the dermis. Permanent tattoos are a result of changes to the dermis; any changes to the epidermis are temporarily with the exception of skin cancer. Skin cancer is prevalent within the United States and will affect one of three cells found in the epidermis: Basal cells, keratinocytes, and/or melanocytes. Examination of various skin lesions commonly utilizes the ABCDE rule. There are three degrees or classifications to thetypes burns that can occur, 1st, 2nd or 3rd. The evaluation of burns, include determining the layers of skin affected and utilizing the “rule of nines” to determine the percentage of body surface burned. Materials  Anatomical models of the skin and histology slides of the integument  Woods lamp  Magnifying glass  Index cards, toothpicks and pennies