Chapter 4 Vocab

a group of cells that have a common embryonic origin and function together.

Tissue

covers body surfaces and lines spaces and ducts it also forms glands.

Epithelial tissue

protects and supports the body, binds organs together, stores energy reserves, or provides immunity.

Connective tissue (C.T.)

produces movement and generates force.

Muscle tissue

detects changes and helps coordinate body activities through action potentials

Nervous tissue

forms a fluid-tight seal between cells.

Tight junction

fastens cells to other cells or nearby materials by dense layers of protein called

Adherens junction

permits electrical or chemical signals to go from cell to cell. Ions and small molecules

Gap junction

are like adherens but have intermediate filaments that extend from one side of the cell

Desmosomes

are like half a desmosome and are especially important in anchoring one type of

Hemidesmosomes

consists of closely packed cells arranged in continuous sheets, and are securely attached to each other. \n- Cells have an apical (free) surface exposed to a space and a basal surface attached to a basement membrane. \n- avascular (no blood vessels) but h

Epithelium

one layer of cells.

Simple epithelium

two or more layers.

Stratified

one layer of a mixture of cell shapes so that it appears stratified.

Pseudostratified

flat, thin cells.

Squamous

height, length and width are all about the same.

Cuboidal

much taller than wide, many are ciliated (short appendages).

Columnar

cells change shape.

Transitional

one or more cells that secrete(s) substances into ducts, blood, or onto a surface.

Gland

secretions are passed through a duct to the lumen (cavity) of an organ or the skin surface (not into the blood)(e.g. sweat glands)

Exocrine glands

secretions enter blood without passing through a duct. (E.g. thyroid gland)

Endocrine glands

secretory vesicles release secretions by exocytosis.

Merocrine glands

apical portion of cell pinches off and releases secretions.

Apocrine glands

cell ruptures to release secretions

Holocrine glands

is a very abundant and widely distributed tissue.\n- distinguished by the presence of cells surrounded by a noncellular matrix. \n- does not usually occur on a free surface. \n- typically has a nerve supply and is highly vascular. \n- matrix is usually se

Connective Tissue (C.T.) type of tissue

are larger, flat cells with branching processes (fibers). These secrete matrix

Fibroblasts

cells that produce matrix in cartilage.

Chondroblasts

cells that produce matrix in bone.

Osteoblasts

are cells that help fight foreign invaders.

Macrophages, plasma cells, mast cells

cells that store triglycerides (fat)

Adipocytes

along with fibers this makes up the matrix. It is the background material of C.T. and contains many different types of large molecules. \n-supports cells, holds tissues together and provides a medium for exchange of chemicals between blood and cells. \n-

Ground substance

enzymes produced by white blood cells to break hyaluronic acid apart so that they can penetrate C.T.

hyaluronidase

are very tough and resistant to pulling but give some flexibility since they are not pulled tight. They are straight and often occur as bundles.

Collagen Fibers

provide strength but can be stretched considerably without breaking. \n-They are branching

Elastic Fibers

are relatively thin and branching, provide support and strength but do not stretch much

Reticular fibers

is embryonic C.T. It gives rise to the other C.T.s.

Mesenchyme

has a semifluid ground substance (hyaluronic acid). -gives a strong but elastic support to skin, mucous membranes, blood vessels, and body organs.

Areolar C.T type of connective tissue

contains cells (adipocytes) that store triglycerides in a large space. \n- serves as an insulator and stores energy reserves.

Adipose Tissue

has a network of interlacing fibers and forms the stroma (framework) of many organs

Reticular C.T.

consists mainly of parallel collagen fiber bundles. \n- forms tendons and ligaments, and resists pulling in one direction

Dense Regular C.T.

contains collagen fibers that are randomly arranged. \n- occurs in sheets where there is tension exerted in various directions.

Dense Irregular C.T

consists mainly of freely branching elastic fibers and can stretch. \n- occurs in lung tissue, arteries and respiratory tubes

Elastic C.T.

consist of cells (chondrocytes) within spaces called lacunae surrounded by a rubbery ground substance. \n- avascular so it heals slowly

Cartilage

a membrane that surrounds most cartilage. \n- can help repair damage

perichondrium

consists of cells (osteocytes) in lacunae, surrounded by protein fibers and a hard ground substance composed mainly of calcium salts.

Bone (osseous) tissue

consists of cells and cell fragments surrounded by a liquid matrix (plasma).

Blood (vascular) tissue

consists of excess tissue fluid, drained from tissues and cells, in vessels. \n- Also contains dietary lipids absorbed from intestines

Lymph

a thin, flexible sheet of tissue that covers or line part of the body and is composed of epithelium and C.T. layers, or of C.T. only.

Membrane

Location:\n- lines body cavities that open to the outside\nFunction:\n- Serves as a barrier to entry of pathogens.\n- Prevents desiccation\n- Traps and removes particles in the respiratory pathway\n- Provides lubrication in various tubes\n- Secretes diges

Mucous Membrane (mucosa)

Location:\n- lines body cavities that do not open to the outside and covers organs w/in these cavities.\nFunction:\n- secretes a watery fluid that allows organs to glide over nearby structures reducing friction).

Serous Membrane (serosa)

Location:\n- covers the surface of the body

Cutaneous Membrane (skin)

Location:\n- lines cavities of freely movable joints. Is composed of discontinuous layer of synoviocytes and areolar C.T. (no epithelium).\nFunction:\n- secrets fluid that lubricates and nourishes cartilage that covers bones

Synovial Membrane

Location: Usually attached to bones\nMode of control: Voluntary\nStructure: Striated, parallel fibers, each with many nuclei located peripherally.

Skeletal muscle

Location: Wall of the heart\nMode of control: Involuntary\nStructure: Striated, branching fibers each w/ 1or 2 nuclei located centrally. It also has intercalated disks where fibers attach end to end

Cardiac muscle

Location: Walls of organs, blood vessels, and airways to the lungs\nMode of control: Usually involuntary.\nStructure: Unstriated, nonbranching, spindle-shaped fibers each w/ one centrally located nucleus.

Smooth muscle

Function:\n- to detect stimuli (changes) and send information in the form of action potentials to other cells for processing or for a response.\nStructure (3 basic parts):\n- Cell body\n- Dendrites\n- Axons

Neurons

these cells do not carry nerve impulses but they service the neurons

Neuroglia- contains the nucleus and other organelles. Cell body

branched fibers that are the input part of that cell.

Dendrites

a single fiber on each cell that carries its output to other cells (typically away from the\ncell body).

Axons

the ability of some cells to respond to certain stimuli (changes) by producing an electrical signal, often called an action potential.

Electrical excitability

may occur if cells from the parenchyma (functioning part) divide in repair,

tissue regeneration

The top surface or free surface of epithelium

Apical surface

The bottom surface of epithelial tissue that joins with the connective tissue

Basal surface

The sides of epithelial tissue where they meet

Lateral surface