Saladin Chapter 5 Review: Tissues

This set of flashcards covers the vocabulary and essential concepts from Saladin Chapter 5 on Tissues, including epithelial, connective, nervous, and muscular tissues, as well as gland types, cell junctions, and tissue growth and repair.

Tissue

A group of similar cells and cell products that arise from the same region of the embryo and work together to perform a specific structural or physiological role in an organ.

Matrix (ECM)

The extracellular material that surrounds the cells, composed of fibrous proteins and ground substance.

Ground substance

A clear, featureless gel (also known as tissue fluid, ECF, or interstitial fluid) that occupies the space between cells and fibers in a tissue.

Ectoderm

The outer germ layer that gives rise to the epidermis and nervous system.

Endoderm

The inner germ layer that gives rise to the mucous membranes of the digestive and respiratory tracts and to the digestive glands.

Mesoderm

The middle germ layer that turns into a gelatinous tissue called mesenchyme, eventually giving rise to muscle, bone, and blood.

Longitudinal section

A tissue cut on its long axis.

Cross (transverse) section

A tissue cut perpendicular to its long axis.

Oblique section

A tissue cut at an angle between a longitudinal and cross section.

Basement membrane

A thin layer of glycans and proteins between an epithelium and the underlying connective tissue that anchors the epithelium.

Basal surface

The surface of an epithelial cell that faces the basement membrane.

Apical surface

The surface of an epithelial cell that faces away from the basement membrane, toward the body surface or internal cavity (lumen) of an organ.

Simple epithelium

An epithelial arrangement in which every cell touches the basement membrane and there is only one layer of cells.

Stratified epithelium

An epithelial arrangement where some cells rest on top of others and do not touch the basement membrane.

Squamous

A cell shape that is thin and flat; often compared to the shape of a fried egg or a floor tile.

Cuboidal

A cell shape that is squarish or round in profile, roughly equal in height and width.

Columnar

A cell shape that is significantly taller than it is wide.

Connective tissue

A type of tissue in which cells usually occupy less space than the extracellular matrix, serving to bind, support, and protect organs.

Fibroblast

Large, flat cells that produce the fibers and ground substance that form the matrix of connective tissue.

Macrophage

Large phagocytic cells that wander through connective tissues, engulfing and destroying bacteria, foreign particles, and dead cells.

Leukocyte

White blood cells that spend most of their time in connective tissues to provide defense against infection and disease.

Erythrocyte

Red blood cells, which are the most abundant cells in blood and transport oxygen and carbon dioxide.

Mast cells

Cells found alongside blood vessels that secrete heparin to inhibit clotting and histamine to increase blood flow.

Adipocyte

Fat cells that appear in small clusters in some connective tissues; they are the dominant cell type in adipose tissue.

Collagen fibers

Tough, flexible, white fibers made of protein that are the most abundant fibers in the body's connective tissues.

Elastic fibers

Fibers made of the protein elastin that allow tissues to stretch and then recoil when tension is released.

Reticular fibers

Thin collagen fibers coated with glycoprotein that form a spongelike framework for organs like the spleen and lymph nodes.

Compact bone

Denser, calcified osseous tissue with no spaces visible to the naked eye; it forms the external surfaces of all bones.

Spongy bone

Osseous tissue that fills the heads of long bones and forms the middle layer of flat bones; it has a delicate, sliver-like structure.

Osteon

The structural unit of compact bone consisting of a central canal surrounded by concentric lamellae.

Osteocyte

A mature bone cell located within a lacuna.

Canaliculi

Delicate channels that radiate from each lacuna to its neighbors, allowing osteocytes to contact each other.

Periosteum

A tough, fibrous sheath that covers the bone as a whole.

Neuron

Nerve cells that detect stimuli, respond quickly, and transmit coded information rapidly to other cells.

Neuroglia

Glial cells that protect and assist neurons.

Neurosoma

The cell body of a neuron, which houses the nucleus and most other organelles.

Dendrite

Short, branched processes of a neuron that receive signals from other cells and conduct messages to the neurosoma.

Axon

A single long nerve fiber (nerve fiber) that sends outgoing signals to other cells.

Tight junction

A region in which adjacent cells are bound together by fusion of the outer phospholipid layer of their plasma membranes, making it difficult for substances to pass between cells.

Desmosome

A patch that holds cells together like a snap, resisting mechanical stress but not preventing substances from passing through.

Hemidesmosome

A half-desmosome used to anchor basal cells of an epithelium to the underlying basement membrane.

Gap junction

A junction formed by a ringlike connexon which creates a water-filled channel, allowing small solutes to pass directly from the cytoplasm of one cell to the next.

Endocrine gland

A gland that loses contact with the surface and has no ducts; it secretes hormones directly into the blood.

Exocrine gland

A gland that maintains contact with the surface by way of a duct.

Secretion

A product produced by a gland that is useful to the body, such as an enzyme or hormone.

Excretion

The process of eliminating waste products from the body, such as urine or bile.

Stroma

The connective tissue framework of an exocrine gland, which supports and organizes the glandular tissue.

Parenchyma

The cells of a gland that perform the tasks of synthesis and secretion.

Eccrine (merocrine) gland

Glands that release their secretion by means of exocytosis; examples include tear glands and pancreas.

Apocrine gland

Glands where lipids coalesce from the cytosol into a droplet that buds from the cell surface with a thin film of cytoplasm.

Holocrine gland

Glands in which cells accumulate a product and then the entire cell disintegrates to become the secretion.

Serous glands

Glands that produce relatively thin, watery fluids such as perspiration, milk, and tears.

Mucous glands

Glands that secrete a glycoprotein called mucin, which absorbs water to form the sticky substance mucus.

Hyperplasia

Tissue growth through cell multiplication.

Hypertrophy

Tissue growth through the enlargement of preexisting cells.

Neoplasia

The development of a tumor (benign or malignant) composed of abnormal, nonfunctional tissue.

Differentiation

The development of a more specialized form and function from unspecialized embryonic tissue.

Metaplasia

A change from one type of mature tissue to another.

Stem cell

Undifferentiated cells that are not yet performing any specialized function but have the potential to differentiate into one or more types of functional cells.

Regeneration

The replacement of dead or damaged cells by the same type of cells as before, restoring normal function.

Fibrosis

The replacement of damaged tissue with scar tissue, composed mainly of collagen.

Atrophy

The shrinkage of a tissue through a loss in cell size or number.

Necrosis

Premature, pathological tissue death due to trauma, toxins, or infection.

Apoptosis

Programmed cell death; the normal death of cells that have completed their function.