Tissues, Integument, & Endocrine System A&P Lab #2a (#’s 1-7) Tissues, Integument, & Endocrine System

Introduction 1. Complete laminate sheets provided by instructor.

Biological Hierarchy 2. Define the concept of a tissue and understand its place in the biological hierarchy (cells, tissues, organs, organ systems, organism).

Biological Hierarchy Cells are organized into layers or groups called tissues. These tissues associate and interact to form organs and specialized functions.

Tissue Classification 3. List and briefly describe the four types of animal tissues.

Tissues There are four major tissue types found in the body: epithelial, connective, muscle, and nervous.

Epithelial Tissue Characteristics 4. Describe the general characteristics and locations of epithelial tissue in the body.

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.

Anatomical Planes/Sections 5. Demonstrate the four planes commonly used in anatomy. Using fruit, cut each piece of fruit into one of the listed planes/sections. Make sure to draw all from an anterior and interior perspective. Identify cross (transverse) sections, longitudinal (sagittal) sections, frontal, and oblique sections in various applications such as the whole body, a part of the body, or a tissue.

Histology – Epithelial Tissue 6. Using microscope images and illustrations, identify the following epithelial tissues and associated structures. Be sure that you know if you are looking at a cross, longitudinal, or oblique section. Identify at least one specific place in the body where each tissue type can be found, as indicated in the textbook. (For example, transitional – lines urinary bladder).

Histology – Epithelial Tissue (cont.) 6. Specific Epithelial Structures: Apical (free) surface Basal lamina (basement membrane) Mucous (goblet) cell Cilia Karatinocytes Note: A squamous cell that secretes the protein keratin is referred to as a keratinocyte. Keratinocytes are found in the epidermis of the skin.

Histology – Epithelial Tissue (cont.) 6. Epithelial Tissue Samples: Simple Squamous Epithelium Simple Cuboidal Epithelium Simple Columnar Epithelium Stratified Squamous Epithelium Ciliated Pseudostratified Columnar Epithelium Transitional Epithelium

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

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.

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.

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.

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

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. Keratinized or non-keratinized

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

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.

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

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.

Histology - Connective Tissue #7. Describe and identify the structural characteristics of the following connective tissues and their associated elements: Connective tissue cells Matrix: Ground substance Fibers: Collagen fibers Elastic fibers Reticular fibers

Histology - Connective Tissue (cont.) #7. Classification of Connective Tissue: Loose connective tissue Dense connective tissue Special connective tissue: Cartilage Bone Blood

Histology - Connective Tissue 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.

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

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

Connective Tissue Fibers Collagenous (white) fibers: made of thick threads of collagen. They are strong, flexible, and inelastic.

Connective Tissue Fibers Elastic (yellow) fibers: Made of bundles of elastin Reticular fibers thin, collagenous fibers that form branched networks for support.

Histology - Connective Tissue #7. Using microscope images & illustrations, be able to identify each of the following connective tissues and cite one specific body location where the tissue type would occur (e.g., covering the ends of the long bone).

Histology - Connective Tissue #7. Samples of Connective Tissues: Areolar (loose) connective tissue Adipose connective tissue Reticular connective tissue Dense regular connective tissue Dense elastic connective tissue Hyaline cartilage connective tissue Elastic cartilage connective tissue Fibrocartilage connective tissue Blood & Bone (to be examined in later labs)

Areolar Connective Tissue: Areolar (loose) connective tissue binds organs together and holds tissue fluids.

Areolar 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 Connective Tissue: Adipose tissue protects, insulates, and stores fat in droplets inside the cells.

Adipose Connective 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.

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.

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

Characteristics of 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.

Characteristics of 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.

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.

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

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

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

Glandular Epithelium

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.

Types of Exocrine Gland Secretions Merocrine glands release fluid through exocytosis. Ex: salivary 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.

Types of Exocrine Gland Secretions Apocrine glands release cellular product by pinching off the free end of the cell. Ex: mammary glands.

Types of Exocrine Gland Secretions Holocrine glands secrete the entire cell full of the secretory product. Ex: sebaceous glands.

Classification of Exocrine Glands

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

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