Body Membranes Epidermis of Skin Chapter 4 Review 1

Review Questions MUCOUS MEMBRANE Which moist epithelial membrane lines body cavities that open to the exterior? MUCOUS MEMBRANE

Review Questions VISCERAL PERICARDIUM What would the innermost serous membrane covering the outside of the heart be called? VISCERAL PERICARDIUM

Review Questions LUBRICATION BETWEEN SEROUS MEMBRANES What is the function of serous fluid? LUBRICATION BETWEEN SEROUS MEMBRANES

What is the only connective tissue membrane? Review Questions What is the only connective tissue membrane? SYNOVIAL MEMBRANE

Where are synovial membranes found? Review Questions Where are synovial membranes found? JOINT CAVITIES

Review Questions INTEGUMENTARY SYSTEM Which system is made up of the skin, nails, associated glands, and hair? INTEGUMENTARY SYSTEM

Review Questions KERATIN Which protein exists on the skin to prevent your body from absorbing water like a sponge when submerged (i.e. swimming, bathing)? KERATIN

Which type of tissue makes up the epidermis? Be specific! Review Questions Which type of tissue makes up the epidermis? Be specific! STRATIFIED SQUAMOUS EPITHELIAL TISSUE (KERATINIZED!)

What are the two main layers of the skin? Review Questions What are the two main layers of the skin? EPIDERMIS DERMIS

Name three functions of the skin. Review Questions Name three functions of the skin. There are a lot… we will look at them in a second 

Functions of Integument Insulates and cushions Protects from mechanical damage, chemical damage, thermal damage, ultraviolet radiation, bacteria Keratin – prevents water loss from body surface Capillary network and sweat glands regulate heat loss (thermoregulation); blood reservoir Mini-excretory system: urea, salts, water lost when sweat Manufactures proteins important to immunity and synthesizes vitamin D Sensory receptors part of nervous system located here – touch, pressure, temperature, pain – provide info about external environment

4 types of cells Keratinocytes: 90% Langerhans cells Merkel cells produce keratin and lamellar granules Langerhans cells mount immune response Scattered throughout epidermis Merkel cells contact sensory neurons (epidermal/dermal junction) Melanocytes: 8% produce pigments to absorb UV radiation (stratum basale)

Review Questions Place the layers of the epidermis in order from most superficial to deepest layer. 1. stratum basale 2. stratum corneum 3. stratum spinosum 4. Stratum lucidum 5. Stratum granulosum 2, 4, 5, 3, 1

Stratum basale (stratum germinativum): produce new keratinocytes/ tonofilaments for attachment *melanocytes found here

Stratum spinosum: tonofilaments for strength and stability

Stratum granulosum: flattened dying cells- release keratin and lamellar granules

Stratum lucidum: only in thick layers (i.e. palms of hands & soles of feet) flattened dead cells

Stratum corneum: flattened, dead, continually shed ¾ of epidermal thickness Durable, protects deeper cells from environment and water loss; resists biological, chemical, physical damage

Review Questions Place the following events of keratinization and epidermal growth in order of occurrence: 1. Dead cells are shed 2. Stratum basale cells divide 3. Tonofilaments are converted to keratin by keratohyalin 4. New cells push toward the surface 5. Cells reach stratum granulosum and undergo apoptosis 2, 4, 5, 3, 1

Review Questions STRATUM BASALE Which layer of the epidermis must be damaged in order to warrant a skin graft? STRATUM BASALE

What type of cell is malfunctioning when psoriasis occurs? Review Questions What type of cell is malfunctioning when psoriasis occurs? KERATINOCYTE