Chapter 4 - The Tissue Level of Organization

Flashcards on the topic of tissues

Epithelial Tissue

Sheets of cells that cover exterior surfaces of the body, line internal cavities and passageways, and form certain glands.

Connective Tissue

Binds the cells and organs of the body together and functions in the protection, support, and integration of all parts of the body.

Muscle Tissue

Responding to stimulation and contracting to provide movement; skeletal (voluntary) muscle, smooth muscle, and cardiac muscle in the heart.

Nervous Tissue

Allowing the propagation of electrochemical signals in the form of nerve impulses that communicate between different regions of the body.

Zygote

A single cell formed by the fusion of an egg and sperm.

Totipotent

Each has the capacity to divide, differentiate, and develop into a new organism.

Ectoderm

Outer germ layer.

Mesoderm

Middle germ layer.

Endoderm

Inner germ layer.

Tissue Membrane

A thin layer or sheet of cells that covers the outside of the body, the organs, internal passageways that lead to the exterior of the body, and the lining of the moveable joint cavities.

Synovial Membrane

A type of connective tissue membrane that lines the cavity of a freely movable joint.

Mucous Membrane

Epithelial membranes that line the body cavities and hollow passageways that open to the external environment, and include the digestive, respiratory, excretory, and reproductive tracts.

Serous Membrane

Epithelial membrane composed of mesodermally derived epithelium called the mesothelium that is supported by connective tissue; lines the coelomic cavities of the body.

Cutaneous Membrane

Epithelial membrane also called the cutaneous membrane or skin.

Cell Junction

Specialized intercellular connection between their cell membranes.

Basal Lamina

A mixture of glycoproteins and collagen, provides an attachment site for the epithelium, separating it from underlying connective tissue.

Reticular Lamina

Secreted by the underlying connective tissue, forming a basement membrane that helps hold it all together.

Cilia

Microscopic extensions of the apical cell membrane that are supported by microtubules.

Tight Junction

Separates the cells into apical and basal compartments; there is no extracellular space between them and the movement of substances through the extracellular space between the cells is blocked.

Anchoring Junction

Help stabilize epithelial tissues and are common on the lateral and basal surfaces of cells where they provide strong and flexible connections.

Gap Junction

Forms an intercellular passageway between the membranes of adjacent cells to facilitate the movement of small molecules and ions between the cytoplasm of adjacent cells.

Squamous

Flattened and thin epithelial cell shape.

Cuboidal

Boxy, as wide as it is tall epithelial cell shape.

Columnar

Rectangular, taller than it is wide epithelial cell shape.

Simple Epithelium

Every cell rests on the basal lamina.

Stratified Epithelium

More than one cell layer and only the basal layer of cells rests on the basal lamina.

Pseudostratified

Tissue with a single layer of irregularly shaped cells that give the appearance of more than one layer.

Transitional

Form of specialized stratified epithelium in which the shape of the cells can vary.

Endothelium

Lining vessels of the lymphatic and cardiovascular system, and it is made up of a single layer of squamous cells.

Mesothelium

Forms the surface layer of the serous membrane that lines body cavities and internal organs.

Goblet Cell

A Mmucous-secreting unicellular gland interspersed between the columnar epithelial cells of mucous membranes.

Gland

A structure made up of one or more cells modified to synthesize and secrete chemical substances.

Endocrine Gland

A ductless gland that releases secretions directly into surrounding tissues and fluids.

Exocrine Gland

A gland whose secretions leave through a duct that opens directly, or indirectly, to the external environment.

Hormones

The secretions of endocrine glands.

Merocrine Secretion

The most common type of exocrine secretion where the secretions are enclosed in vesicles that move to the apical surface of the cell where the contents are released by exocytosis.

Apocrine Secretion

Secretion that accumulates near the apical portion of the cell, then that portion of the cell and its secretory contents pinch off from the cell and are released.

Holocrine Secretion

Secretion that involves the rupture and destruction of the entire gland cell.

Serous Gland

Tissue that produces watery, blood-plasma-like secretions rich in enzymes such as alpha amylase.

Mucous Gland

Tissue that releases watery to viscous products rich in the glycoprotein mucin.

Dense Connective Tissue

Contains bundles of fibers that provide tensile strength, elasticity, and protection.

Loose Connective Tissue

The fibers are loosely organized, leaving large spaces in between.

Supportive Connective Tissue

Tissue that provide structure and strength to the body and protect soft tissues.

Fluid Connective Tissue

Various specialized cells circulate in a watery fluid containing salts, nutrients, and dissolved proteins.

Mesenchyme

The stem cell line from which all connective tissues are later derived.

Mucous Connective Tissue

Tissue that forms in the umbilical cord, also called Wharton’s jelly.

Fibroblast

Most abundant cell in connective tissue proper which secrete polysaccharides and proteins that combine with extra-cellular fluids to produce a viscous ground substance.

Adipocytes

Cells that store lipids as droplets that fill most of the cytoplasm.

Mesenchymal Cell

A multipotent adult stem cell that can differentiate into any type of connective tissue cells needed for repair and healing of damaged tissue.

Macrophage Cell

A large cell derived from a monocyte and an essential component of the immune system.

Mast Cell

Found in connective tissue proper, has many cytoplasmic granules which contain the chemical signals histamine and heparin.

Collagen Fiber

Made from fibrous protein subunits linked together to form a long and straight fiber with great tensile strength which resists stretching.

Elastic Fiber

Contains the protein elastin along with lesser amounts of other proteins and glycoproteins; after being stretched or compressed, it will return to its original shape.

Reticular Fiber

Also formed from the same protein subunits as collagen fibers; remain narrow and are arrayed in a branching network.

Reticular Tissue

A mesh-like, supportive framework for soft organs such as lymphatic tissue, the spleen, and the liver.

Dense Connective Tissue

Type of connective tissue that contains more collagen fibers than does loose connective tissue and displays greater resistance to stretching.

Tendinitis

The inflammation of a tendon, the thick band of fibrous connective tissue that attaches a muscle to a bone.

Supportive Connective Tissues

Allows the body to maintain its posture and protect internal organs; two major forms are cartilage and bone.

Cartilage

The polysaccharides called chondroitin sulfates, which bind with ground substance proteins to form proteoglycans.

Chondrocytes

Cartilage cells.

Lacunae

The space that chondrocytes occupy.

Perichondrium

A layer of dense irregular connective tissue that encapsulates the cartilage.

Hyaline Cartilage

The most common type of cartilage in the body and consists of short and dispersed collagen fibers and contains large amounts of proteoglycans.

Fibrocartilage

Tough type of cartilage because it has thick bundles of collagen fibers dispersed through its matrix.

Elastic Cartilage

Type of cartilage that contains elastic fibers as well as collagen and proteoglycans and gives rigid support as well as elasticity.

Bone

Provides protection to internal organs and supports the body due to its rigid extracellular matrix that contains mostly collagen fibers embedded in a mineralized ground substance containing hydroxyapatite, a form of calcium phosphate.

Osteocytes

Bone cells like chondrocytes that are located within lacunae.

Cancellous Bone

Looks like a sponge under the microscope and contains empty spaces between trabeculae, or arches of bone proper; lighter than compact bone and found in the interior of some bones and at the end of long bones.

Compact Bone

Solid and has greater structural strength.

Erythrocytes

Red blood cells that transport oxygen and some carbon dioxide.

Leukocytes

White blood cells that are responsible for defending against potentially harmful microorganisms or molecules.

Platelets

Cell fragments involved in blood clotting.

Muscle Tissue

Properties that allow movement; muscle cells are excitable and contractile.

Skeletal Muscle

Attached to bones and its contraction makes possible locomotion, facial expressions, posture, and other voluntary movements of the body.

Cardiac Muscle

Forms the contractile walls of the heart.

Smooth Muscle Tissue

Contraction are responsible for involuntary movements in the internal organs and forms the contractile component of the digestive, urinary, and reproductive systems as well as the airways and arteries.

Nervous Tissue

Being excitable and capable of sending and receiving electrochemical signals that provide the body with information.

Neurons

Propagate information via electrochemical impulses, called action potentials, which are biochemically linked to the release of chemical signals.

Neuroglia

Play an essential role in supporting neurons and modulating their information propagation.

Cell Body

Includes most of the cytoplasm, the organelles, and the nucleus.

Dendrites

Branch off the cell body and appear as thin extensions.

Axon

A long “tail” that extends from the neuron body and can be wrapped in an insulating layer known as myelin, which is formed by accessory cells.

Synapse

The gap between nerve cells, or between a nerve cell and its target, for example, a muscle or a gland, across which the impulse is transmitted by chemical compounds known as neurotransmitters.

Oligodendrocyte cells

Produce myelin in the central nervous system (brain and spinal cord).

Schwann cell

Produces myelin in the peripheral nervous system

Inflammation

The standard, initial response of the body to injury; limits the extent of injury, partially or fully eliminates the cause of injury, and initiates repair and regeneration of damaged tissue.

Necrosis

Accidental cell death, causing inflammation.

Apoptosis

Programmed cell death, a normal step-by- step process that destroys cells no longer needed by the body; does not initiate the inflammatory response.

Vasodilation

The widening of the blood vessels.

Edema

Excess liquid in tissue causing swelling.

Angiogenesis

The growth of new blood vessels.

Regeneration

The addition of new cells of the same type as the ones that were injured.

Senescence

The surest poison is time; many functions of the body decline with age and All the cells, tissues, and organs are affected by.

Atrophy

Loss of mass through the tissues, including those in muscles

Cancer

The term referring to many diseases in which cells escape regulatory signals.

Mutation

A permanent change in the DNA of a cell.

Tumor

A mass of cells displaying abnormal architecture.