HISTOLOGY A&P 1

TISSUES Tissues - collections of similar cells working together to perform a function Tissue classification based on structure of cells, composition of noncellular extracellular matrix, and cell function Major types of adult tissues Epithelial Connective Muscle Nervous

EPITHELIAL TISSUE Cellularity - Consists almost entirely of cells Covers body surfaces, lines hollow organs, and forms glands Outside surface of the body Lining of digestive, respiratory and urogenital systems Heart and blood vessels Linings of many body cavities Has apical and basal surfaces Rests on a basement membrane Specialized cell contacts bind adjacent cells together Avascular - no blood vessels Regenerative -Replaces lost cells by cell division

What is this???? What is the name of these types of cells? Where would I find it? What might be its function? SIMPLE CUBOIDAL KIDNEYS SECRETION and ABSORPTION

Name this tissue type… What is the name? Where is it located? What is its function? Transitional Bladder, ureters, urethra Provides stretch

Name this tissue type… What is the name? Where is it located? What is this an image of? Bowman’s capsule (glomerulus of kidneys) Glomerulus Simple cuboidal tissue layer Simple squamous tissue layer What is the name? Where is it located? What is its function? Simple squamous Alveoli of lungs, kidney glomeruli, lining of vessels Filtration (kidneys), diffusion (air sacs of lungs)

Name this tissue type… What is the name? Where is it located? What is its function? Simple columnar Intestinal tract Absorption, secretion of mucus, enzymes, and other substances

Name this tissue type… What is the name? Where is it located? These structures are… cilia This is a _______ Cell? goblet What is the name? Where is it located? What is its function? Pseudostratified Ciliated Columnar Trachea and bronchial tubes Secretion of mucus, propulsion of mucus by cilia

Name this tissue type… What is the name? Where is it located? What is its function? Stratified squamous Lines mouth, vagina, esophagus, skin protection

STRATIFIED SQUAMOUS Specific types Keratinized – contain the protective protein keratin Surface cells are dead and full of keratin Non-keratinized – forms moist lining of body openings

CONNECTIVE TISSUE Most diverse and abundant tissue Main classes Connective tissue proper Cartilage Bone tissue Blood Characteristics Varying degrees of vascularity Nonliving extracellular matrix, consisting of ground substance and fibers Cells are not as abundant nor as tightly packed together as in epithelium

FUNCTIONS OF CONNECTIVE TISSUE Enclose organs as a capsule and separate organs into layers. Areolar Connect tissues to one another. Tendons and ligaments. Support and movement. Bones. Storage. Fat. Insulation. Fat. Transport. Blood. Protection. Bone, cells of the immune system

CELLS OF CONNECTIVE TISSUE Fibroblasts - secrete the proteins needed for fiber synthesis and components of the extracellular matrix Adipose or fat cells (adipocytes). Common in some tissues (dermis of skin); rare in some (cartilage) Mast cells. Common beneath membranes; along small blood vessels. Can release heparin, histamine, and proteolytic enzymes in response to injury. Leukocytes (WBC’s). Respond to injury or infection Macrophages. Derived from monocytes (a WBC). Phagocytic; provide protection Chondroblasts - form cartilage Osteoblasts - form bone Hematopoietic stem cells - form blood cells Undifferentiated mesenchyme (stem cells). Have potential to differentiate into adult cell types.

Extracellular Matrix ECM has 3 major components Protein fibers 1. Protein fibers 2. Ground substance 3. Fluid Protein fibers Collagen fibers. Composed of the protein collagen. Strong, flexible, inelastic; great tensile strength (i.e. resist stretch). Perfect for tendons, ligaments Elastic fibers. Contain molecules of protein elastin that resemble coiled springs. Returns to its original shape after stretching or compression. Perfect for lungs, large blood vessels Reticular fibers. Formed from fine collagenous fibers; form branching networks (stroma). Fill spaces between tissues and organs.

Name this tissue type… What is the name? Where is it located? What is its function? Adipose Under the skin, around the eyes, kidneys, heart. Protection, storage

Name this tissue type… What is the name? Where is it located? Fibers? Reticular Cells? lymphocytes What is the name? Where is it located? What is its function? Reticular (Loose) Connective Tissue Internal skeleton: lymph nodes, spleen Soft internal skeleton, supports other cell types

Name this tissue type… What is the name? Where is it located? What are these cells called? chondrocytes What is the name? Where is it located? What is its function? Hyaline. Embryonic skeleton, cover end of bones, trachea, nose, larynx Support, reinforce, resist compressive stress.

Name this tissue type… What is the name? Where is it located? Fiber? Collagen Fiber? Elastic Cell? What is the name? Where is it located? What is its function? Aerolar Loose connective . Fibroblast Widely distributed under epithelia Wraps and cushions organs; inflammation.

Name this tissue type… What is the name? Where is it located? ?? Fibroblasts ?? Collagen What is the name? Where is it located? What is its function? Dense Connective Tissue. Tendons, ligaments, aponeurosis Attaches muscles to bones, bones to bones.

Name this tissue type… What is the name? Where is it located? 1. Haversian Canal 2. Canaliculi 3. Lamella 4. Osteocytes in the Lacuna What is the name? Where is it located? What is its function? Osseous tissue. Bones Storage, support

What tissue is this? Where is it found? What is its function? ?? ?? ?? What important process takes place here? hematopoiesis What tissue is this? Where is it found? What is its function? Spongy bone or cancellous bone In the center of flat bones and in the ends of long bones Support

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MUSCLE TISSUE Characteristics Types Cells are referred to as fibers Contracts or shortens with force when stimulated Moves entire body and pumps blood Types Skeletal:attached to bones Cardiac: muscle of the heart. Smooth: muscle associated with tubular structures and with the skin. Nonstriated and involuntary.

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Layers of skin