Chapter 4 - Tissues Flashcards
four main types of tissues
epithelial, connective, muscle, and nervous
epithelial tissue
tissue that forms sheets that cover or line the body
connective tissue
tissue that provides structural and functional support
muscle tissue
tissue that contracts to produce movement
nervous tissue
tissue that senses, conducts, and processes information
extracellular matrix (ECM)
also called matrix; the non-cellular portion of a tissue produced and secreted by cells and used mainly for providing support; it is like jelly and made up of mostly water with various interlocking fibers that thicken it
plasma
the thin watery matrix of blood; it is best understood as the liquid part of blood
collagen
a protein that forms microscopic twisted ropes within the matrix of many tissues
elastin
a protein forming the main constituent of elastic connective tissue, found especially in the dermis of the skin
proteoglycans
any of a class of glycoproteins of high molecular weight that are found especially in the extracellular matrix of connective tissue
glycoprotein
a type of protein molecule that has had a carbohydrate attached to it
four shapes of epithelial cells
squamous (flat), cuboidal (cube-shaped), columnar (like a column), and transitional (varying shapes that can stretch)
two arrangements of epithelial tissue
epithelial tissue can be classified as simple (arranged in a single layer) or stratified (arranged in many layers)
simple squamous epithelium
A single layer of very thin and irregularly shaped epithelial cells. Because of the thin structure of simple squamous epithelium, substances can readily pass through its cells, making transport its special function. Absorption of oxygen into the blood, for example, takes place through the simple squamous epithelium that forms the tiny air sacs in the lungs
stratified squamous epithelium
Epithelial tissue that consists of several layers of closely packed cells, an arrangement that makes this tissue especially adept at protection. Most microbes cannot work their way through a barrier of stratified squamous tissue such as that which composes the surface of skin and of mucous membranes.
simple cuboidal epithelium
a single layer of epithelial cells that are, on average, about as high as they are wide—thus exhibiting a cube shape. This tissue does not form protective coverings but instead forms tubules or other groupings adapted for secretory activity. These secretory cuboidal cells usually function in tubes or clusters of secretory cells commonly called glands.
exocrine vs endocrine glands
Glands of the body may be classified as exocrine if they release their secretion through a duct or as endocrine if they release their secretion directly by diffusion into the bloodstream.
gland
An organ which produces and releases substances that perform a specific function in the body. Examples of such substances include saliva, sweat, and digestive juices
stratified cuboidal epithelium
a rare type of epithelial tissue composed of cuboidally shaped cells arranged in multiple layers. They protect areas such as ducts of sweat glands, mammary glands, and salivary glands.
simple columnar epithelium
epithelial tissue that can be found lining the inner surface of the stomach, intestines, and some areas of the respiratory and reproductive tracts
goblet cells
specialized epithelial cells that line multiple mucosal surfaces and have a well-appreciated role in barrier maintenance through the secretion of mucus; typically found in the respiratory, reproductive and gastrointestinal tracts
pseudostratified epithelium
an epithelial tissue typical of that which lines the trachea or windpipe; it is called pseudo- because even though it appears to be stratified, it is not
basement membrane
a thin, pliable sheet-like type of extracellular matrix that provides cell and tissue support; it sits between the epithelial and connective tissues
stratified transitional epithelium
epithelial tissue that is typically found in body areas subjected to stress and that must be able to stretch. In many instances, up to 10 layers of differently shaped cells of varying sizes are present in the absence of stretching. When stretching occurs, the epithelial sheet expands, the number of cell layers decreases, and cell shape changes from roughly cuboidal to nearly squamous (flat) in appearance. (One example of this type of tissue is the wall of the urinary bladder.)
electron microscopes
microscopes that use electron beams instead of light to produce images of very high magnification
cytology
the study of cells
histology
the study of tissues
loose fibrous connective tissue
also called areolar tissue; is the most widely distributed of all connective tissue types. It is the “glue” that helps keep the organs of the body together. It consists of webs of fibers and of a variety of cells embedded in a loose matrix of soft, sticky gel.
fascia
the fibrous material that helps bind the skin, muscles, bones, and other organs of the body together; it is mainly made up of areolar tissue
adipose tissue
also called fat tissue; it is areolar tissue that stores lipids
reticular tissue
A type of connective tissue that forms thin, delicate webs of collagen fibers called reticular fibers. It is found in bone marrow. It is also found in the spleen and lymph nodes, where it supports developing cells of the immune system
dense fibrous connective tissue
Connective tissue that consists mainly of thick bundles of strong, white collagen fibers that are packed closely together. A few fiber-producing cells are scattered among the bundles.
regular dense fibrous connective tissue
a type of dense fibrous connective tissue; it has collagen fiber bundles arranged in roughly parallel rows; it is seen in tendons
irregular dense fibrous connective tissue
a type of dense fibrous connective tissue; it has collagen arranged in a chaotic swirl of tangled bundles. This type of tissue forms the tough sheets in the deepest layer of the skin. It forms a tough, flexible support to the epithelial superficial layer of the skin. Although the swirled pattern of fiber bundles allows the skin to stretch a little, overstretching the skin often causes tears in the irregular fibrous tissue called stretch marks.
compact bone
the solid form of bone that makes up the outer walls of bones in the skeleton
osteon
also called Haversian systems; they are the chief structural unit of compact bone
cancellous bone
also called spongy bone; it is the internal tissue of the skeletal bone. The spaces within cancellous bone are filled with blood-forming hematopoietic tissue or adipose tissue. It is almost as hard as compact bone. (The term cancellous refers to something that is made up of a lattice.)
lattice
a structure consisting of strips of wood or metal crossed and fastened together with square or diamond-shaped spaces left between, used as a screen or fence or as a support for climbing plants; can also refer to something that looks like a lattice
chondrocytes
the only cells found in healthy cartilage; also called cartilage cells
hyaline cartilage
Cartilage that has a moderate amount of collagen in its gel matrix, giving it a translucent, glasslike appearance. This is the most common type of cartilage in the body. It is found in the support rings of the respiratory tubes and covering the ends of bones that form joints.
elastic cartilage
Cartilage that contains few collagen fibers but large numbers of very fine elastic fibers that give the matrix material a high degree of flexibility. This type of cartilage is found in the external ear and in the voice box, or larynx.
fibrocartilage
The strongest and most durable type of cartilage. The matrix is rigid and filled with a dense packing of strong collagen fibers. Fibrocartilage disks serve as shock absorbers between adjacent vertebrae and in the knee joint.
hematopoietic tissue
the bloodlike connective tissue found in the red marrow cavities of bones and in organs such as the spleen, tonsils, and lymph nodes. This type of tissue is responsible for the formation of blood cells and lymphatic system cells important in our defense against disease
contractility
the ability to shorten or contract
susceptibility of muscle tissue
a reference to the fact that injured muscle cells are often slow to heal and often are replaced by fibrous scar tissue if injured
skeletal muscle tissue
a type of muscle tissue that is attached to bones and, when contracted, produces voluntary and controlled body movements
cardiac muscle tissue
a type of muscle tissue that forms the walls of the heart; the regular but involuntary contractions of cardiac muscle tissue produce the heartbeat
smooth muscle tissue
a type of muscle tissue that helps form the walls of blood vessels and hollow organs such as the intestines and other tube-shaped structures in the body. Involuntary contractions of smooth muscle tissue propel material through the digestive tract and help regulate the diameter of blood vessels.
striated muscle tissue
a muscle tissue that features repeating functional units called sarcomeres; there are two types: cardiac muscle tissue and skeletal muscle tissue
sacromere
the smallest functional unit of striated muscle tissue
neuron
also called a nerve cell; a cell that that communicates with other cells via specialized connections called synapses
axon
the part of the neuron which transmits a nerve impulse away from the neuron’s cell body
dendrite
the part of the neuron which transmits a nerve impulse toward the neuron’s cell body
glial cells
also call neuroglia; nerve cells that maintain homeostasis, form myelin in the peripheral nervous system, and provide support and protection for neurons
synapse
a structure that permits a neuron to pass an electrical or chemical signal to another neuron or to the target effector cell
effector cell
any of various types of cell that actively responds to a stimulus and effects some change
brown fat
also called brown adipose tissue; a special kind of adipose tissue that burns its fuel when the body is cold in order to produce heat
