Chapter 4 - Tissues

Stratified epithelium

Consists of two or more layers of cells that protect underlying tissues in locations where there is considerable wear and tear.

cell junctions

Contact point between the plasma membranes of tissue cells.

Eosinophils

white blood cells that migrate to sites of parasitic infection and allergic responses

adhering junctions

Anchored to a dense plaque of proteins inside the cell are transmembrane proteins that connect adjacent cells together; microfilaments extend from the plaque into the cytosol; Adhesion belts help resist separation of epithelial tissues.

pseudostratified columnar epithelium

Appears to have multiple layers of cells because the cell nuclei at different levels and not all cells reach the apical surface; it is actually a simple epithelium because all its cells rest of the basement membrane. Cells that do extend to the apical surface may contain cilia; other secrete mucus.

Reticular Lamina

closer to the underlying connective tissue and contains proteins such as collagen produced by connective tissue cells called fibroblasts (Lower D)

Epithelial membranes

cutaneous, mucous, serous

Fibroblasts

large flat cells that move through connective tissue and secrete fibers and ground substance

Synovial membranes

line joint cavities

Mucous membrane

lines a body cavity that opens directly to the exterior; digestive canal, respiratory, genital tract, much of urinary tract.

Merocrine secretion

secretions released by vesicle exocytosis; ex. sweat

Neuroglia

Protect and support neurons

Tissue

A group of similar cells that perform a specific function.

Basement membrane

A think extracellular layer that commonly consists of two layers, the basal lamina and reticular lamina.

Why is epithelial tissue always adjacent to connective tissue

Because epithelial tissue lacks blood vessels, and being next to blood vessel-rich connective tissue enable it to make exchanges with blood for delivery of oxygen, nutrients, and the removal of wastes.

Basal Lamina

Closer to and secreted by the epithelial cells Contains laminin, collagen, glycoproteins, and proteoglycans (Upper D)

Muscular tissue

Composed of cells specialized for contraction and generation of force. In the process, muscular tissue generates heat that warms the body.

Which tissue has blood vessels? epithelial or connective tissue?

Connective tissue

Mature connective tissue

Connective tissue that is present at birth and persists throughout life; loose, dense, cartilage, bone, blood

Gland

Consists of epithelium that secretes substances into ducts (tubes), onto a surface, or eventually into the blood in the absence of ducts.

epithelial tissue

Covers body surfaces and lines hollow organs, body cavities, and ducts it also forms glands. This tissue allows the body to interact with both its internal and external environments.

Surface epithelium

Covers or lines a surface, forms the outer covering of the skin and some internal organs and lines structures such as blood vessels, body cavities and the respiratory, digestive, urinary and genital (reproductive systems), avascular

ciliated pseudostratified columnar epithelium (Description, location, and function)

Description: Appears to have several layers because the nuclei of the cells are at various level. Have cilia Location: Lines airways of most of upper respiratory tracts. Function: Secretes mucus that traps foreign particles, and cilia sweep away mucus for elimination from body.

Nonciliated Pseudostratified Columnar Epithelium (Description, location, and function)

Description: Appears to have several layers because the nuclei of the cells are at various levels. Location: Lines epididymis, larger ducts of many glands, and parts of male urethra. Function: Absorption and Secretion

Cardiac muscle tissue

Description: Branching striated, generally uninucleate cells that interdigitate at specialized junctions (intercalated discs) Function: as it contracts it propels blood into the circulation, involuntary control Location: heart wall

Dense - Elastic connective tissue

Description: Contains elastic fibers with fibroblasts between them Location: Elastic arteries and trachea, bronchial tubes, vocal cord, ligaments of penis and vertebrae. Function: Allows stretching of various organs; Is strong and can recoil to original shape after being stretched.

Endocrine glands

Description: Endocrine gland hormones enter interstitial fluid and then diffuse into the bloodstream without flowing through a duct. Location: pituitary gland, pineal gland, thyroid, parathyroid, adrenal glands, pancreas, ovaries, testes, thymus Function: Hormones regulate many metabolic and physiological activities to maintain homeostasis.

Exocrine Glands

Description: Exocrine gland secretory products are released into ducts that empty onto an epithelium that covers or lines a surface, such as skin surface or lumen of hollow organ. Location: Sweat, oil, and earwax glands of skin; digestive glands such as salivary glands and pancreas. Function: Produce substances such as sweat to help lower body temperature, oil, earwax, saliva, or digestive enzymes.

dense - regular connective tissue

Description: Forms shiny white extracellular matrix; mainly collagen fibers regularly arranged in bundles with fibroblasts in rows between them. Location: Forms tendons, most ligaments, and aponeuroses (sheet-like tendons that attach muscle to muscle or muscle to bone). Function: Provides strong attachment between various structures. Tissue structure withstands pulling (tension) along long axis of fibers.

Smooth muscle tissue

Description: Involuntary, non-striated muscle Location: Walls of hollow internal structures such as blood vessels, airways to lungs, stomach, intestines, gallbladder, urinary bladder, and uterus. Function: Motion

Skeletal muscle tissue

Description: Long, cylindrical, multinucleate cells; obvious striations Function: motion, posture, heat production, protection. Location: In skeletal muscles attached to bones or occasionally to skin

stratified columnar epithelium

Description: Several cell layers columnar shaped. Function: Protection; secretion. Location: lines part of urethra; large excretory ducts of some glands, sugc as esophageal glands; small areas in anal mucous membrane; part of conjunctiva of eye.

Elastic Cartilage

Description: Similar to hyaline cartilage, but more elastic fibers in matrix. Function: Maintains the shape of a structure while providing strength and flexibility. Location: Supports the external ear (pinna); epiglottis.

ciliated simple columnar epithelium (Description, location, and function)

Description: Single layer of ciliated column-like cells with nuclei near the base; contains goblet cells. Location: Lines some bronchioles (small tubes) of respiratory tract, uterine (fallopian) tubes, uterus, efferent ducts of the testes, some paranasal sinuses, the central canal of the spinal cord, and ventricles of the brain. Function: Moves mucus and other substances by ciliary action.

simple cuboidal epithelium (Description, location, and function)

Description: Single layer of cube-shaped cells Function: secretion and absorption Location: Kidney tubules; ducts and secretory portions of small glands, ovary surface.

nonciliated simple columnar epithelium (Description, location, and function)

Description: Single layer of nonciliated column-like cells with nuclei near base of cells; contains goblet cells and microvilli cells. Location: Lines the gastrointestinal tract (from the stomach to the anus), ducts of many glands, and gallbladder. Function: Secretion and absorption.

Urithelium

Description: Urinary system - I stretched state it looks like stratified cuboidal epithelium, except apical layer cells tend to be large and rounded. When stretched, the sm elks become flatter, giving the look of stratified squamous epithelium.

Blood tissue

Description: blood plasma; red and white blood cells, platelets Location: in blood vessels and heart chambers Function: Red Blood cells: transport oxygen and some carbon dioxide; White blood cells: carry on immune system responses; Platelets: essential for blood clotting.

Loose - Adipose connective tissue

Description: body fat Location: Wherever areolar connective tissue is located; around yellow bone marrow, around heart and kidneys, padding around joints Function: Reduces heat loss through skin; serves as an energy reserve; supports and protects organs. Source of stem cells.

Loose - areolar connective tissue

Description: consists of fibers arranged randomly and several kinds of cells embedded in semifluid ground substances. Location: In and around nearly everybody structure below skin Function: Strength, elasticity, support

Nervous tissue

Description: consists of neurons and neuroglia Location: nervous system Function: Converts stimuli into action potential;

loose - reticular connective tissue

Description: interlacing network of reticular fiber and reticular cells. Location: Stroma of liver, spleen, lymph nodes; red bone marrow; reticular lamina of the basement membrane; around blood vessels and muscles. Function: Forms stroma of organs; binds smooth muscles tissue cells; filters and removes worn-out blood cells in spleen and microbes in lymph nodes.

mesenchyme

Description: irregularly shaped mesenchymal cells embedded in semifluid ground substances that contains delicate reticular fiber. Function: forms almost all other connective tissue types Location: primarily in embryo

Dense - irregular connective tissue

Description: made up of collagen fibers; usually irregularly arranged with a few fibroblasts. Location: Dermis of the skin Function: provides tensile (pulling) strength in many directions.

simple squamous epithelium (Description, location, and function)

Description: single layer of flattened cells Location: Lines CV and Lymphatic system. forms an epithelial layer of serous membranes of abdominal thoracic cavities. Function: Filtration, diffusion, secretion of serous membranes

Compact bone tissue

Description: the strongest form of bone tissue that makes up the bulk of the diaphysis of a long bone Location: bones in the body Function: Protection, storage, houses blood-forming tissue

Spongy bone tissue

Description: thin column called bone trabeculae; spaces between bone trabeculae are filled with red bone marrow Location: bones in the body Function: Protection, storage, houses blood-forming tissue

Fibrous Cartilage

Description: tough tissue Location: intervertebral discs, hip bones join, cartilage pads of the knee Function: support and joining structure together; resists compression, prevents bone to bone contact

Hyaline cartilage

Description: translucent cartilage, bluish white Location: ribs, nose, larynx, and trachea, most abundant cartilage Function: provide cushioning and minimize friction between the bone ends.

Stratified squamous epithelium (Description, location, and function)

Description: two or more layers of cells; As cells divide, the cells move upward toward apical layer, moving away from blood supply becoming dehydrated and less metabolically active. Function: protects tissues in areas subject to abrasion, water loss, UV radiation, foreign invasion. Location: nonkeratinized type forms the moist lining of the esophagus, mouth, and vagina; keratinized type forms the epidermis of the skin, a dry membrane.

stratified cuboidal epithelium

Description: two or more layers of cube shaped cells Location: Ducts of adult sweat glands and esophageal glands, part of male urethra. Function: Protection; limited secretion and absorption

mucous connective tissue

Description: widely scattered fibroblasts embedded in viscous, jellylike ground substance that contains fine collagen fibers. Location: umbilical cord Function: Support

Nervous tisssue

Detects changes in a variety of conditions inside and outside the body and responds by generating electrical signals called nerve action potentials (nerve impulses) that activate muscular and glandular secretions.

Lateral surface

Faces the adjacent cells on either side. May contain tight junctions, adherence junctions, desmosomes, and/or gap junctions. (B)

pathologist

I physician who examines cells and tissues to help other physicians make accurate diagnosis.

Serous membrane

Line body cavities that lack openings to the outside

hemidesmosomes

Link to the basement membrane. On the inside of the plasma membrane, integrins attach to the intermediate filaments made of the protein keratin.

Reticular fibers

Made of collagen and glycoproteins; provide support in blood vessel walls, form branching networks around various cells.

glandular epithelium

Makes up the secreting portion of glands, such as the thyroid gland, suprarenal ( adrenal glands), sweat glands, digestive glands.

apocrine secretion

Pinched off portion of cell is secretion ex. breast milk

connective tissue

Protects and supports the body and its organs. Various types of connective tissues bind organs together, store energy reserves as fat, and help provide the body with immunity to disease-causing organisms.

Neurons

Sensitive various stimuli. Convert stimuli into nerve action potentials and conduct these action potentials to other neurons, to muscle tissue, or to glands.

What is the major difference between epithelial tissue and connective tissue?

The ratio of cells to the extracellular matrix.

Cutaneous membrane

The skin; composed of epidermal and dermal layers

Tight junctions

Weblike strips of proteins fuse together adjacent plasma membranes.; These junctions protect underlying tissues from harmful substances by restricting the movement of substances like hydrochloric acid in the spaces between cells.; found in tissues lining the surface of organs and body cavities such as the stomach intestines and urinary bladder.

Neutrophils

White blood cells that migrate to sites of infection that destroy microbes by phagocytosis.

Simple Epithelium

a single layer of cells that functions in diffusion, osmosis, filtration, secretion, or absorption

mast cells

abundant along blood vessels. They produce histamine, which dilates small blood vessels during inflammation and kills bacteria.

Epithelial tissue

consists of cells arranged in continuous sheets, in either single or multiple layers.

Desmosomes

contain plaque and have transmembrane glycoproteins that extend into the intercellular space between adjacent cell membranes and attach cells to one another. Desmosome plaque attaches to elements of the cytoskeleton known as intermediate filaments, which consist of the protein keratin. The intermediate filaments extend from desmosomes on one side of the cell across the intracellular fluid to desmosomes on the opposite side of the cell.

plasmocytes

develop from B lymphocytes. They secrete antibodies that attack and neutralize foreign substances.

Macrophages

develop from monocytes and destroy bacteria and cell debris by phagocytosis

WHat are the two basic elements of connective tissue?

extracellular matrix and cells.

apical surface

faces the body surface, body cavity, lumen, or duct

Adipocytes

fat cells that store fats. They are found below the skin and around organs.

Membranes

flat sheets of pliable tissue that cover or line a part of the body

holocrine secretion

mature cell dies and becomes secretory product; cell division replaces lost cell. EX. skin

Gap Junctions

membrane proteins called connexins form tiny fluid-filled tunnels called connexons that connect neighboring cells; Enable nerve or muscle impulses to spread rapidly among cells.

mulicellular exocrine glands

merocrine secretion, apocrine secretion, holocrine secretion

Embryonic connective tissue

mesenchyme and mucous connective tissue; connective tissue present in an embryo or fetus

Nervous tissue

neurons and neuroglia

What does the extracellular matrix consist of?

protein fibers and ground substance

Avascular

relies on the blood vessels of the adjacent connective tissue to bring nutrients and remove wastes (Epithelial tissue).

Elastic fibers

stretchable but strong fibers made of proteins, elastin, and fibrillin. They are found in skin, blood vessels, and lung tissue.

Collagen fibers

strong, flexible bundles of the protein collagen, the most abundant protein in your body

Histology

study of tissues

Basal surface

the deepest layer of epithelial cells adhere to extracellular materials such as the basement membrane. (C)

Ground substance

the material between cells and fibers. It is made of water and organic molecules. It supports cells and fibers, binds them together, and provides a medium for exchanging substances between blood ...