tissues


	VCC East Campus, Spr '07, Dr. Mason BSC 1005L, Mon. 7-9:45 p.m., Wed. 10:00-12:45


	Lab #5, pp. 57-76 Human Body Tissues


	Read each section listed below, study the excellent photomicrographs and color drawings of the various tissues and complete the questions and tables as directed. Then complete the worksheet that is at the end of these notes. You will receive an additional summary handout of tissues in lab to help with the matching below. Use the flash cards I've created and quiz each other as to the tissue type of each picture glued to the card. Identification of obvious different tissues will be on your test; ex. blood, skeletal muscle, adipose, etc. Introduction and Figure 5.1 pp. 57-59 Read the introduction on p. 57. Know the definition of tissue and the levels of organization: cells --> tissues --> organs --> organ systems All tissues in our body are divided into one of 4 categories: epithelium covers body surfaces, lines body cavities connective binds, supports, connects body parts muscle moves body parts nerve receives stimuli, conducts impulses Epithelial Tissue, pp. 60-63 Read and study the pictures of the different types of epithelial tissues. You can answer the questions and complete Table 5.1, p. 63 simply by reading and observing the pictures. You need to know the five types listed in Table 5.1. Epithelial tissues are classified according to shape and whether they are a single or multiple layers: simple = single layered stratified = multiple layers pseudostratified = appears multi-layered because of different height cells but really a single layer squamous = flat irregular shaped cells cuboidal = cube-shaped cells columnar = long narrow "column-shaped" cells goblet cells = specialized cells within some epithelial tissues that secrete mucus; ex. goblet cells are found within epithelium lining the digestive and respiratory tracts cilia = extensions from the main part of the cell containing stiff rods of straw-like proteins called microtubules. They appear hair-like in appearance under the light microscope. Cilia beat back and forth uniformly to move mucus along the surface of the epithelium. The pseudostratified columnar epithelium of the respiratory tract is ciliated. microvilli = finger-like cell membrane projections, like cilia, but not stiff. They cover the surface of the small intestinal epithelium and function to increase surface area for food absorption Muscle Tissue, pp. 64-66 Read and study the pictures of the different types of muscle tissues. You can answer the questions and complete Table 5.2, p. 66 simply by reading and observing the pictures. There are 3 different types of muscle tissues: skeletal muscle - large cylindrical-shaped cells with several nuclei. The contractile proteins (actin and myosin) within the cells are highly organized and give a striped or striated appearance in the light microscope. Skeletal muscles are attached to our bones and are responsible for body movement and are therefore under our voluntary control. cardiac muscle - smaller branched cells that also appear striated because of the actin and myosin arrangement. Each cell has a single nucleus. This type of muscle is found in our heart and is not under our voluntary control. [An intercalated disk is the zig-zag cell membranes of 2 adjacent cardiac muscle cells.] smooth muscle - smallest of the 3 muscle cells, each cell appears spindle-shaped with a single nucleus and straitions are not visible in the light microscope. Smooth muscles line various internal organs such as our blood vessels, digestive system, respiratory system, etc. Obviously smooth muscle is also not under our voluntary conscious control. All three muscle types contain special contractile proteins called actin and myosin. Nervous Tissue, p. 67 Read and study the picture of a motor neuron. You can answer the questions simply by reading and observing the picture. Nervous tissue actually has 2 cell types: neurons - conduct electrical impulses neuroglia cells - provide support, protection, nourishment to the neurons. Know the 3 parts to a neuron: dendrite, cell body, and axon Connective Tissue, pp. 68-72 Read and study the pictures of the different types of connective tissues. You can answer the questions and complete Table 5.3, p. 72 simply by reading and observing the pictures. Connective tissue can be divided into 2 general categories: connective tissue proper: loose fibrous connective tissue and dense fibrous connective tissue specialized connective tissues: adipose, bone, cartilage, blood Most all connective tissue (except adipose) contains lots of extracellular proteins and other molecules made by the cells and secreted outside. These extracellular substances are collectively referred to as matrix. Different types of connective tissues are characterized by different types of matrices: for example, bone matrix contains a lot of dense calcium minerals, and fibrous connective tissue matrix contains lots of collagen and elastic protein fibers. Depending on the density of the matrix substance, the cells can be trapped in cavities called lacunae: for example, bone and cartilage cells are in lacunae. Skip 5.5, p. 73 Skin, pp. 74-75 Read about the 2 layers of skin and the connecting subcutaneous layer and study the picture of the skin. You can answer the question simply by reading and observing the picture. Skin has 2 layers: epidermis = stratified squamous epithelium dermis = dense fibrous connective tissue rich in capillaries (small microscopic blood vessels), sweat and oil glands, hair follicles, and specialized nerve receptors for touch, pressure, heat, cold, and pain. subcutaneous layer: also called hypodermis -- a layer of loose connective tissue and adipose connects the skin to the underlying muscle and functions to insulate and protect the underlying body parts. Laboratory Review, p. 76 Complete #1-17. Tissue Matching Worksheet 1. Match each general tissue category to the appropriate feature. connective tissue epithelium nervous tissue muscle 1) ____ lines cavities, tubes, covers body 2) ____ conducts electrical impulses 3) ____ has contractile properties 4) ____ binds and connects body parts 5) ____ one side of this sheet of cells is embedded in a basement membrane of extracellular "glue" 6) ____ Many glands such as sweat glands and salivary glands are composed of this tissue. 7) ____ protein junctions from cell to cell create a continuous sheet 8) ____ Matrix is usually abundant in this general tissue type. 2. Match each characteristic to the appropriate connective tissue. bone dense fibrous connective tissue loose fibrous connective tissue cartilage adipose blood 1) ____ matrix of collagen with calcium and phosphate mineral deposits 2) ____ matrix called plasma 3) ____ matrix contains collagen with a ground substance of chondroitin and glucosamine which absorbs much water 4) ____ cells trapped in cavities called lacunae around a solid matrix (2 answers) 5) ____ tissue of the nose, ear, intervertebral discs, ends of long bones. 6) ____ ligaments and tendons are made of this type of connective tissue 7) ____ energy storage tissue that also serves to insulate and protect; contains little matrix 8) ____ type of connective tissue that binds skin to underlying muscle 9) ____ matrix composed of collagen and elastin fibers (2 answers) 10) ____ collagen and elastin fibers are densely packed, orderly stacked 11) ____ cells that make and secrete the matrix are called chondrocytes 12) ____ cells that make and secrete the matrix are called osteocytes 13) ____ cells that make and secrete the matrix are called fibroblasts (2 answers) 14) ____ cells in this tissue are called adipocytes 15) ____ only type of connective tissue whose matrix is NOT made by the cells 3. Match each characteristic to the appropriate muscle tissue or tissues. Skeletal muscle Smooth muscle Cardiac muscle 1) ____ cells are long, cylindrical in shape with many nuclei 2) ____ cells appear striated (striped) in appearance under the microscope (more than one answer) 3) ____ small spindle-shaped cells with no striated appearance 4) ____ cell shape appears branching 5) ____ only muscle tissue mostly under our voluntary control 6) ____ heart muscle 7) ____ lines many internal organs 8) ____ contains actin and myosin contractile proteins (more than one answer) 4. Skin Matching epidermis subcutaneous layer (also known as hypodermis) dermis 1) ____ layer that contains keratin 2) ____ not really a layer of skin 3) ____ layer that contains hair follicles, sebaceous glands, sweat glands, nerve endings, blood capillaries, etc. 4) ____ composed of dense fibrous connective tissue 5) ____ composed of stratified squamous epithelium 6) ____ composed of loose connective tissue and fat deposits 7) ____ binds skin to underlying muscle 8) ____ layer that contains melanocytes