PowerPoint Presentation to accompany Hole ’ s Human Anatomy and Physiology, 9/e by Shier, Butler, and Lewis

Chapter 5 Tissues

Cells are organized into layers or groups called tissues. There are four major tissue types found in the body: epithelial, connective, muscle, and nervous. These tissues associate and interact to form organs and specialized functions.

Epithelial Tissue Epithelium functions in protection, secretion, absorption, and excretion. It is composed of tightly packed cells anchored to a basement membrane. Epithelium lacks blood vessels and rapidly divides. Epithelial tissues are classified by cell shape and number of cell layers.

Simple Squamous Epithelium Simple squamous epithelium consists of a single layer of thin, flat cells that fit tightly. Figure 5.1

Simple Squamous Epithelium It functions in filtration, diffusion, osmosis, and covers surfaces. It is found in air sacs of the lung, walls of capillaries, lines blood vessels, and covers the membranes that line body cavities.

Simple Cuboidal Epithelium Simple cuboidal epithelium consists of a single layer of cube- shaped cells. Figure 5.2

Simple Cuboidal Epithelium It functions in secretion and absorption. It is found on the surface of the ovaries, linings of kidney tubules, linings of the ducts of certain glands.

Simple Columnar Epithelium Simple columnar epithelium is a single layer of elongated, column- shaped cells. Figure 5.3

Simple Columnar Epithelium It functions in protection, secretion, and absorption. It can be ciliated or nonciliated.

Simple Columnar Epithelium Specialized goblet cells secrete mucus. It is found lining the uterus, stomach, and intestines.

Pseudostratified Columnar Epithelium Pseudostratified columnar epithelium is a single layer of elongated cells that appears to be more than one layer. Figure 5.5

Pseudostratified Columnar Epithelium It is often ciliated and contains goblet cells. It functions in protection, secretion, and movement of mucus and cells. It is found lining the respiratory passages.

Stratified Squamous Epithelium Stratified squamous epithelium consists of many layers of cells with flat cells on the outer layers. Figure 5.6

Stratified Squamous Epithelium It functions in protection. It is found in the outer layer of the skin, linings of the oral cavity, throat, vagina, and anal cavity.

Stratified Cuboidal Epithelium Stratified cuboidal epithelium consists of two to three layers of cubed- shaped cells. Figure 5.7

Stratified Cuboidal Epithelium It functions in protection. It is found in the linings of the mammary glands, sweat glands, salivary glands, and pancreas.

Stratified Columnar Epithelium Stratified columnar epithelium consists of a top layer of elongated cells, and lower layers of cube- shaped cells. Figure 5.8

Stratified Columnar Epithelium It functions in protection and secretion. It is found in the vas deferens, part of the male urethra, and parts of the pharynx.

Transitional Epithelium Transitional epithelium consists of many layers of cube-shaped and elongated cells. Figure 5.9a

Transitional Epithelium It functions in distensibility and protection. It is found in the inner lining of the urinary bladder, ureters and part of the urethra. Figure 5.9b

Glandular Epithelium Glandular epithelium is composed of cells that produce and secrete substances. Exocrine glands secrete products into ducts. Endocrine glands secrete products into tissue fluid or blood. A unicellular exocrine gland is the mucous- secreting goblet cell.

Multicellular Glands A simple gland communicates with the surface through one unbranched duct. Figure 5.10

Multicellular Glands A compound gland communicates with the surface through a branched duct. Tubular glands are epithelial-lined tubes. Alveolar (acinar) glands have saclike endings.

Glandular Secretion Merocrine glands release fluid through exocytosis. Ex: salivary glands. Figure 5.11

Glandular Secretion Apocrine glands release cellular product by pinching off the free end of the cell. Ex: mammary glands.

Glandular Secretion Holocrine glands secrete the entire cell full of the secretory product. Ex: sebaceous glands.

Merocrine Secretion Most exocrine glands are merocrine. There are two types of merocrine cells, serous and mucous. Serous fluid is watery with a high enzyme concentration. Mucous cells secrete a mucus, a thick fluid rich in the glycoprotein, mucin.

Connective Tissues Connective tissue is the most abundant tissue in the body. Extracellular material, matrix, makes up the bulk of the tissue. Matrix is composed of fibers and ground substance. Connective tissue cells usually can divide.

Connective Tissue Cell Types Fibroblasts secrete protein into the matrix. Figure 5.13

Connective Tissue Cell Types Macrophages originate as white blood cells. They can move and phagocytize foreign particles. Figure 5.14

Connective Tissue Cell Types Mast cells release heparin, which prevents blood clotting, and histamine, which aids in the inflammatory response. Figure 5.15

Connective Tissue Fibers Collagenous fibers, white fibers, are made of thick threads of collagen. They are strong, flexible, and inelastic. Figure 5.16

Connective Tissue Fibers Elastic fibers, yellow fibers, are made of bundles of elastin. Reticular fibers are thin,collagenous fibers that form branched networks for support.

Loose Connective Tissue Loose connective tissue or areolar tissue binds organs together and holds tissue fluids. Figure 5.18

Loose Connective Tissue It is cells (fibroblasts) in a fluid-gel matrix. It forms thin membranes found beneath the skin, between muscles, and beneath epithelial tissue.

Adipose Tissue Adipose tissue protects, insulates, and stores fat in droplets inside the cells. Figure 5.19

Adipose Tissue It consists of cells (adipocytes) in a fluid-gel matrix. It is found beneath the skin, around the kidneys, behind the eyes, and on the heart.

Reticular Connective Tissue Reticular connective tissue supports organs. Figure 5.20

Reticular Connective Tissue It is composed of thin, collagenous fibers and cells in a fluid-gel matrix. It is found in the walls of the liver, spleen, and lymphatic organs.

Dense Connective Tissue Dense connective tissue binds organs together. Figure 5.21

Dense Connective Tissue It is composed thick collagenous fibers, thin elastic fibers and fibroblasts in a fluid-gel matrix. It is found in tendons, ligaments, and the dermis of the skin.

Elastic Connective Tissue Elastic connective tissue supports, protects, and provides a flexible framework. Figure 5.22

Elastic Connective Tissue It consists of elastic fibers and fibroblasts in a solid-gel matrix. It connects vertebrae and is found in the walls of arteries and airways.

Cartilage Cartilage is a rigid connective tissue. The matrix consists of collagenous fibers in a gel-like ground substance. Cartilage cells, chondrocytes, are found in small chambers, lacunae. Cartilage is covered with a thin layer of connective tissue, the perichondrium. Cartilage lacks blood vessels.

Cartilage Cartilage cells, chondrocytes, are found in small chambers, lacunae. Cartilage is covered with a thin layer of connective tissue, the perichondrium. Cartilage lacks blood vessels.

Hyaline Cartilage Hyaline cartilage supports, protects, and provides a framework. It is the most common type of cartilage. Figure 5.23

Hyaline Cartilage It is found in the ends of bones, nose, and rings in the respiratory passages. Hyaline cartilage provides the embryonic model for the skeleton.

Elastic Cartilage Elastic cartilage supports, protects, and provides a flexible framework. Figure 5.24

Elastic Cartilage Its matrix contains many elastic fibers. It is found in the outer ear and part of the larynx.

Fibrocartilage Fibrocartilage supports, protects, and absorbs shock during body movement. Figure 5.25

Fibrocartilage It is the toughest type of cartilage. It is found between the vertebrae (intervertebral discs), in the knee and parts of the pelvic girdle.

Bone Bone supports, protects, provides a framework for muscle attachment. Figure 5.26

Bone It is composed of cells (osteocytes) in a hard calcified matrix. The osteocytes are located in layers, lamellae, organized into osteons.

Bone It is found in the skeleton and middle ear.

Blood Blood transports gases, nutrients, and wastes, defends against disease, and acts in clotting. Figure 5.27

Blood It is composed of cells and platelets in a fluid matrix, the blood plasma. It is found within the blood vessels.

Muscle Tissue Muscle tissue is contractile. Muscle fibers can shorten and thicken. There are three types of muscle tissue: skeletal, smooth, and cardiac.

Skeletal Muscle Skeletal muscles attach to bones and are controlled by conscious effort. Figure 5.28

Skeletal Muscle It is also called voluntary muscle.

Skeletal Muscle The muscle cells have many nuclei and exhibit light and dark banding patterns called striations. Skeletal muscles contract in response to nerve signals.

Smooth Muscle Smooth muscle appears smooth because it lacks striations. Smooth muscle action is not under conscious control and it is called involuntary. Figure 5.29

Smooth Muscle The cells are spindle-shaped with a central nucleus. Smooth muscle is found in the stomach, intestines, uterus, and blood vessels.

Cardiac Muscle Cardiac muscle tissue is found only in the heart. Figure 5.30

Cardiac Muscle The striated cells are joined end to end with a specialized intercellular junction called an intercalated disk. Cardiac muscle is under involuntary control. Figure 5.30

Nervous Tissues Nervous tissues are found in the brain, spinal cord, and peripheral neurons. Figure 5.31

Nervous Tissues Nerve cells or neurons sense changes and transmit signals.

Nervous Tissues Neuroglia are cells that support and bind nervous tissue. They supply nutrients, carry on phagocytosis, and play a role in cell to cell communication.