CH 5 Tissues p. 90. Names and shapes

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1 CH 5 Tissues p. 90 Tissues are structured differently, which leads to their differences in function. There are four major Tissue Types: Epithelial, Connective, Muscle, and Nervous (Review from CH 1: Define tissue) Epithelial Tissues: p. 92 A.General Characteristics 1. cover organs, line body surfaces. Ex: Intestinal lining, skin, Lining of respiratory system, Fallopian tubes, ureters 2. anchored to a basement membrane; made of tightly packed cells w/ little intercellular material, lack blood vessels; are replaced frequently function in protection, secretion, absorption, excretion, and sensory reception. (p. 92) (hypothesize why lack of blood vessels and why tightly packed) Names and shapes Epithelial tissue is named according to it s layering and shape. Layering: simple or stratified Shape: cuboidal, columnar, squamous think pair share: decide what each term means (what layer or what shape) 3 4 A. Stratified Squamous Epithelium p made up of layers of flattened cells that are designed to protect underlying layers. 2. It makes up the outer layer of skin, and lines the mouth, throat, birth canal (vagina), and anal canal. In the skin, outer layers of cells undergo keratinization; however, this process does Not occur where tissues remain moist in The throat, birth canal (vagina), or anal canal. Fig. 5.5 p

2 What is Keratin? Think Pair Share Explain Keratinization. What is the important function or result of keratinization? Why is it not necessary to keratinize the stratified squamous of the throat? B. Simple Squamous Epithelium p single layer of thin, flattened cells. 2. suited for diffusion, functions in the exchange of gases in the lungs and lines blood and lymph vessels & body cavities. (why thin and flattened) 7 8 Fig. 5.1 p. 93) C. Simple Cuboidal Epithelium p single layer of cube-shaped cells with centrally located nuclei. 2. functions in secretion and absorption in the kidneys, and in secretion in glands Fig. 5.2 p. 94 D. Stratified Cuboidal Epithelium p consists of two to three layers of cuboidal cells lining a lumen of the mammary glands, sweat glands, salivary glands, and pancreas. 2. Several layers of cells provide greater protection than one single layer

3 Fig. 5.6 p. 96 I. Glandular Epithelium 1. designed to produce and secrete substances into ducts or body fluids. 2. Glands that secrete products into ducts are exocrine; those that secrete into body fluids and blood are called endocrine Glands are classified by the ways they secrete their products. a. Merocrine glands release products by exocytosis (pancreas) are grouped as serous which produce a watery fluid or mucus which produce a thicker, protective substance. b. Apocrine glands lose portions of their cell bodies during secretion (mammary glands). c. Holocrine glands release entire cells (sebaceous glands) Table 5.2 p. 98 E. Simple Columnar Epithelium 1. made up of a row of elongated cells, nuclei are located near the basement membrane. may be ciliated lines the uterus, stomach, and intestines, protects underlying tissues, secretes digestive fluids, and absorbs nutrients. 18 3

4 3. Mucus-secreting goblet cells can be found among columnar cells. Fig. 5.3 p. 94 F. Pseudostratified Columnar Epithelium p appear layered due to the positions of nuclei within the row of cells, but are not truly layered. 2. Cilia may be present, along with mucus-secreting globlet cells, that line and sweep debris from respiratory tubes Fig. 5.4 p. 95 G. Stratified Columnar Epithelium p consists of several layers of cells and is found in the vas deferens, male urethra, and parts of the pharynx. fig H. Transitional Epithelium p designed to distend and return to its normal size, as it does in the lining of the urinary bladder. 2. This design provides distensibility and keeps urine from diffusing back into the internal cavity. Fig. 5.8 p

5 Table 5.3 p. 99 Connective Tissues: p. 98 A. General Characteristics 1. Bind, support, protect, serve as frameworks, fill spaces, store fat, produce blood cells, protect against infection, and repair tissue damage. 2. Unlike epithelial tissues, have a lot of matrix, or intercellular material, and have good blood supplies (except cartilage) B. Major Cell Types p The fibroblast is the most common cell type, and is a fixed, star-shaped cell that secretes fibers and is large. Fig Wandering macrophages function as scavenger cells and defend against infection. Fig Mast cells are large and are located near blood vessels where they release heparin and histamine. Fig C. Connective Tissue Fibers p. 99 on 1. Strong collagenous fibers (white), made of collagen, add strength. 2. Elastic fibers (yellow), made of elastin, are stretchy and add flexibility. 3. Reticular fibers are thin collagenous fibers that form supportive networks 28 Fig p. 100 D. Loose Connective (areolar) Tissue p. 100 on 1. Forms delicate, thin membranes throughout the body that bind body parts together such as skin and underlying organs. 2. The majority of the cells are fibroblasts that are separated by a gel-like ground substance that contains collagenous and elastic fibers

6 Fig p. 101 E. Adipose Tissue p It is loose connective tissue designed to store fat. 2. found beneath the skin, around joints, padding the kidneys and other internal organs, and in certain abdominal membranes Fig p. 101 F. Dense Connective Tissue p Consists of densely packed collagenous fibers and is very strong Lacks a good blood supply. 2. It is part of tendons and ligaments G. Cartilage p A rigid connective tissue that provides a supportive framework. It lacks a blood supply system and heals slowly. 2. Cartilage cells (chondrocytes) lie within lacunae in the gel-like fluid matrix. 3. hyaline cartilage, The most common, has many collagen fibers, is found at the ends of bones, and in respiratory passages. 5. Elastic cartilage (elastic fibers) is found in the external ears and the larynx. 6. Fibrocartilage (collagenous fibers) is a tough, shock-absorbing tissue found in intervertebral disks, the knees and pelvis. Fig p

7 H. Bone p most rigid connective tissue, has mineral salts and collagen in the matrix. 2. supports the body, protects, forms muscle attachments and is the site for blood cell formation. Hyaline Fig Bone cells (osteocytes) are found within lacunae and are arranged in circles (osteons) Elastic Fig p Bone has a good blood supply, enabling rapid recovery after an injury. 38 Fig p. 104 I. Blood p Composed of cells (red and white) suspended in a liquid matrix called plasma. 2. It functions to transport substances throughout the body. Fig. 5.2 p Table. 5.4 p. 105 Muscle Tissues: p. 105 A. General Characteristics 1. Muscle cells, or fibers, can contract, consist of three major types

8 B. Skeletal Muscle Tissue 1. Attached to bone and can be controlled (voluntary). 2. The cells (muscle fibers) are long and cylindrical, striated, have many nuclei, and contract from nervous impulse. Fig p. 105 C. Smooth Muscle Tissue 1. Lacks striations, has one nucleus, and looks spindleshaped. 2. involuntary muscle, found in the walls of internal organs, in the digestive tract, blood vessels, and urinary bladder Fig p. 106 D. Cardiac Muscle Tissue 1. Found only in the heart, consists of branching fibers that are connected to each other with intercalated disks. 2. This involuntary muscle has a single nucleus in each cell but is striated Fig p. 106 Table 5.5 p

9 Nervous Tissues: A. Found in the brain, spinal cord, and nerves. Fig p. 107 B. Neurons, or nerve cells, conduct nervous impulses while helper cells, or neuroglia, support and nourish the neurons, provide myelin