Chapter 4

gland (exocrine and endocrine)

Exo- secrete chemicals into ducts Endo- secrete chemicals into the blood

Types of neuron

Multipolar, bipolar, and unipolar

which tissue type forms glands?

epithelial

Tissue Types

epithelial connective muscle nervous

Parts of neuron and definitions

- Cell body: contains nucleus - Axon: cell process; conducts impulses away from cell body; usually only one per neuron - Dendrite: cell process; receive impulses from other neurons; can be many per neuron

Tissues

-Collections of specialized cells and their extracellular matrices.

Cell connections

-Form permeability* layer -Bind cells together -Provide mechanism for intercellular communication -Adaptation to physical stress

Connective Tissue Categories

-Loose -Dense -Connective tissue with special properties -Cartilage -Bone -Blood

Serous Membrane Names

-Pericardium refers to heart. -Pleura refers to lungs and thoracic cavity -Peritoneum refers to abdominopelvic cavity

Dense Irregular Elastic Connective Tissue

Bundles and sheets of collagenous and elastic fibers Fibers oriented in multiple directions Strong but elastic, stretch and recoils in multiple direction ex. heart in aorta

merocrine glands

Cells of the gland produce secretions by active transport or produce vesicles that contain secretory products, and the vesicles empty their contents into the duct through exocytosis.

Dense Regular Elastic Connective Tissue

Collagen and elastic fibers Elastic fibers more prevalent Able to stretch and recoil Collagen fibers give strength (for when you shout) EX. Vocal chords

Which of the following statements concerning connective tissue is true?

Collagen fibers provide strength to dense connective tissue.

Dense Irregular Collagenous Connective Tissue

Collagen fibers running in all directions Able to withstand stretching in all directions Also in sheaths, organ capsules and scars Ex. near dermis

Connective Tissue Function

Enclosing and separating (capsules around organs) Connecting tissues to one another (tendons and ligaments) Supporting and moving (bones) Storing, cushioning and insulating (fat) Transporting (blood) Protecting (white blood cells, mast cells)

Mucous Membrane

Epithelium + Basement Membrane + Lamina Propria + Muscle Layer (optional) Many of them have goblet cells (mucus) Variable function depending on location (protection, absorption, secretion, etc.)

Free surfaces

Free surfaces of epithelium •Smooth: reduce friction •Villi (singular, villus): between 0.5 and 1.5 mm •Microvilli: between 1 and 0.1 µm -Stereocilia: elongated microvilli for sensation and absorption (example, hair cells in the inner ear) •Cilia: move materials across the surface •Folds: in transitional epithelium where organ must be able to change shape. Urinary system (ureters and urinary bladder). You will also see folds in the digestive system •Villi and microvilli and folds increase surface area for absorption or secretion (for example, small intestine)

What type of tissue is contractile

Muscle tissue

Nervous tissue

Neurons or nerve cells have the ability to produce action potentials

Synovial Membrane

Only connective tissue, in synovial joints Produce synovial fluid The best "lubricant" in the world!

Dense Regular Collagenous Connective Tissue

Organized collagen fibers Able to withstand great pulling forces in direction of fibers orientation Minimum differences between tendons and ligaments matrix Ex. Ligament and tendon

Which of the following is CORRECTLY matched with its function

Receptor proteins- attached to ligand molecules

Apocrine gland

Secretory products are stored in the cell near the lumen of the duct. A portion of the cell near the lumen containing secretory products is pinched off the cell and joins secretions produced by a merocine process.

Holocrine gland

Secretory products are stored in the cells of the gland. Entire cells are shed by the gland and become part of the secretion. The lost cells are replaced by other cells deeper in the gland.

Serous Membrane

Simple squamous epithelium+basement menbrane+loose connective tissue Produces serous fluid - protection from friction Line cavities in the body - visceral vs. parietal Named for specific cavities/organs

Tissue Repair

Substitution of dead/damaged cells by viable/functional cells

Neuroglia

Support cells of the brain, spinal cord and nerves, nourish, protect, and insulate neurons

A symporter will transport____ across the plasma membrane

Two different ions or molecules in the same direction

Hemidesmosomes

attach epithelial cells to basal membrane.

Labile

capable of mitosis through life: skin, mucous membranes, hemopoietic tissue, lymphatic tissue

Tight junction

hold cells together and prevent the diffusion of molecules, nutrients, etc between cells. "Sealing" or "gate" function.

Permanent

if killed, replaced by a different type of cell. Limited regenerative ability: nervous, skeletal and cardiac muscle

Desmosomes

keep cells together during stretch, keep cell together during stress.

Molecules that serve as a chemical signal to open or close gated ion channels are______

ligands

The extracellular material of tissues is called

matrix

stable

no mitosis after growth ends; but can divide after injury: liver, pancreas, endocrine cells

Smooth (muscle)

nonstriated, involuntary muscle

Gap junctions

ntercellular communication and signaling, movement of ions, small molecules.

Which of the following is a function of epithelial tissue?

secretion and absorption of molecules

Glands

secretory cell, group of cells or organs. -can be a single cell or an organ. -Pancreas is exocrine and endocrine

Epithelial layer of shapes

simple, stratified, pseudostratified

Epithelial shape of cells

squamous, cuboidal, columnar

Adhesion belt

stabilization of cell-cell adhesion

Cardiac (Muscle)

striated and involuntary

Skeletal (Muscle)

striated and voluntary

Connective with special property

• Cells: adipocytes • Two types- • Yellow (white at birth, most abundant, wide distribution in body). Scant ring of cytoplasm surrounding single large lipid droplet. Nuclei flattened and eccentric • Brown (axillae, neck and near kidneys) - multiple lipid droplets of varying size. Nuclei are round and almost centrally located Ex. in mammary gland

Connective with special property

• Fine network of reticular fibers (mostly collagen type I) • Irregularly arranged • Made by reticular cells • Provides a superstructure for lymphatic and hemopoietic tissues • Location: within lymph nodes, spleen and bone marrow

Connective Tissue Characteristics

•Abundant - found in every organ •More extracellular matrix (ECM) than cells •Many diverse types •Performs variety of important functions...

Loose Connective Tissue

•Also known as areolar tissue •Loose packing material of most organs and tissues (= stroma) •Attaches skin to underlying tissues, but also throughout the body •Contains collagen, reticular, elastic fibers and variety of cells •Cell types: fibroblasts, mast cells, lymphocytes, adipose cells, macrophages

Muscle Tissue

•Characteristics -Contracts -Is excitable - conducts electrical impulses -Moves entire body, pumps blood, among other functions

Extracellular Matrix (ECM)

•Components -Protein fibers •Collagen which is most common protein in body (mainly collagen types I and II) •Reticular fill spaces between tissues and organs (mostly collagen type III) •Elastic returns to its original shape after distension or compression -Ground substance •Shapeless background •Hyaluronic acid, proteoglycans, adhesive molecules (e.g., fibronectin) -Fluid - blood (plasma)

Cartilage

•Composed of chondrocytes located in spaces called lacunae •Next to bone firmest structure in body •Ground substance: Proteoglycans and hyaluronic acid complexed together (aggrecan*) trap large amounts of water. Tissue can spring back after being compressed •Avascular and no nerve supply (difficult healing) •Types of cartilage - determined by matrix composition -Hyaline -Fibrocartilage -Elastic

Additional Serous Membrane info

•Cover the organs of trunk cavities and line the cavity •Fist represents an organ •Inner balloon wall represents visceral serous membrane •Outer balloon wall represents parietal serous membrane •Cavity between two membranes filled with lubricating serous fluid that is produced by the membranes •Inflammation of the serous membranes

epithelial tissue characteristics

•Covers body surfaces inside and out and forms glands •Mostly cells packed closely together •In general, it has a free surface and a basal surface (basement membrane) •Specialized cell contacts •Avascular (nurtured by diffusion) •In some cases, cells are rapidly worn away •Regenerates

Basement Membrane

•Extracellular: formed by secretions of both epithelium and connective tissue. -Attachment of epithelium to connective tissue - acellular "glue" . -Thin, but complex, different layers made of collagens types IV and VII (maybe others), fibrillin, laminins, integrins, perlecan, etc. (you do not need to memorize the names of these proteins!) -Most but not every epithelium has a basement membrane associated with it. The same statement is valid for free surface. Example: some endocrine glands (secrete directly into circulation) do not have free surface and basement membrane) and lymphatic capillaries do not have basement membrane.

Fluid Connective Tissue: Hemopoietic Tissue

•Forms blood cells •Found in bone marrow •Types of bone marrow -Red: hemopoietic tissue surrounded by a framework of reticular fibers. Produces red and white cells -Yellow: yellow adipose tissue •As children grow, yellow marrow replaces much of red marrow •Bone marrow transplant: commonly done in flat bones of the axial skeleton

Hyaline Cartilage

•Found in joints for strong support and some flexibility (e.g., rib cage and cartilage in trachea and bronchi, articulating joints) •Forms most of skeleton, before replaced by bone, in embryo •Involved in growth that increases bone length •Small collagen (type II) fibers evenly distributed in matrix (transparent aspect)

Elastic Cartilage

•Hard connective tissue composed of living cells (osteocytes (maintain bone), osteoblasts (build/form bones), osteoclasts (breakdown bone) and mineralized matrix (collagen and hydroxyapatite) • •Osteocytes located in lacunae • •Types: Cancellous (Spongy) and Compact bone

Tissue Damage and Inflammation

•Inflammation characteristics -Redness, heat, swelling, pain, disturbed function •How does it happen? -Chemical mediators: histamine, kinins, prostaglandins, leukotrienes Stimulate pain receptor and increase blood vessel permeability as well movement of WBCs to affected area

Blood

•Matrix (= plasma) is liquid, lack fibers •Matrix formed by other tissues, unlike other types of connective tissue •Moves through vessels, but both fluid and cells can move in/out of the vessels •Functions: Transports oxygen, carbon dioxide, hormones, nutrients, waste products, and other substances; protects the body from infections and is involved in temperature regulation

Compact Bone

•Outer portions of all bones, the shafts of long bones

Epithelial Tissue functions

•Protection of underlying structures (e.g., mouth - mucosa) •Barrier (e.g., skin) •Permits passage of substances (e.g., nephron of kidneys) •Secretion of substances (e.g., pancreas) •Absorption of substances (e.g., small intestine)

Fibrocartilage

•Slightly compressible and very tough •Found in areas of body where a great deal of pressure is applied to joints (e.g., knee, jaw, between vertebrae) •Collagen fibers similar to those in hyaline, but more numerous and arranged in thick bundles

Cardiac muscle- structure and function

•Structure: Cardiac muscle cells are cylindrical and striated and have a single, centrally located nucleus; they are branched and connected to one another by intercalated disks, which contain gap junctions • Function: Pumps the blood; is under involuntary (unconscious) control

Pseudo-unipolar Neuron structure, function and location

•Structure: Consists of a cell body with one axon • Function: Conducts action potentials from the periphery to the brain or spinal cord • Location: In ganglia outside the brain and spinal cord

Multipolar Neuron structure, function and location

•Structure: Dendrites, cell body, and long axon; neuroglia, surround the neurons • Function: Transmit information (action potentials), store "information," and integrate and evaluate data; neuroglia support, protect, and form specialized sheaths around axons • Location: brain, spinal cord, ganglia

Skeletal Muscle structure and function

•Structure: Skeletal muscle cells or fibers appear striated (banded); cells are large, long, and cylindrical, with many nuclei located at the periphery • Function: Moves the body; is under voluntary (conscious) control

Smooth Muscle structure and function

•Structure: Smooth muscle cells are tapered at each end, are not striated, and have a single nucleus • Function: Regulates the size of organs*, forces fluid through tubes*, controls the amount of light entering the eye, and produces "goose flesh" in the skin, etc. It is under involuntary (unconscious) control!

Cancellous Bone

•interior of the bones of the skull, vertebrae, sternum, and pelvis; in the ends of the long bones