Chapter 4

Question 1

are collections of specialized cells and the extracellular substances surrounding them. Body tissues are classified into four types, based on the structure of the cells, the composition of the noncellular substances surrounding the cells (called the extracellular matrix)

Answer 1

Tissues

Question 2

is the microscopic study of tissues. Much information about a person’s health can be gained by examining tissues.

Answer 2

Histology

Question 3

is the process of removing tissue samples from patients surgically or with a needle for diagnostic purposes. Examining tissue samples can distinguish various disorders.

Answer 3

biopsy

Question 4

is an examination of the organs of a dead body to determine the cause of death or to study the changes caused by a disease. Microscopic examination of tissue is often part of an autopsy.

Answer 4

autopsy

Question 5

the inner layer, forms the lining of the digestive tract and its derivatives.

Answer 5

endoderm

Question 6

the middle layer, forms tissues such as muscle, bone, and blood vessels.

Answer 6

mesoderm

Question 7

the outer layer, forms the skin

Answer 7

ectoderm

Question 8

becomes the nervous system

Answer 8

neuroectoderm

Question 9

give rise to parts of the peripheral nerves, skin pigment, the medulla of the adrenal gland, and many tissues of the face.

Answer 9

neural crest cells

Question 10

covers and protects surfaces, both outside and inside the body.

Answer 10

Epithelial tissue

Question 11

consists of a single layer of cells, with each cell extending from the basement membrane to the free surface.

Answer 11

Simple epithelium

Question 12

consists of more than one layer of cells, but only the basal layer attaches the deepest layer to the basement membrane.

Answer 12

Stratified epithelium

Question 13

is a special type of simple epithelium. The prefix pseudo- means false, so this type of epithelium appears to be stratified but is not. It consists of one layer of cells, with all the cells attached to the basement membrane. There appear to be two or more layers of cells because some of the cells are tall and extend to the free surface, whereas others are shorter and do not extend to the free surface.

Answer 13

Pseudostratified columnar epithelium

Question 14

cells are flat or scalelike.

Answer 14

Squamous

Question 15

cells are cube-shaped—about as wide as they are tall.

Answer 15

Cuboidal

Question 16

(tall and thin, similar to a column) cells tend to be taller than they are wide

Answer 16

Columnar

Question 17

Found in areas such as the mouth, esophagus, rectum, and vagina, consists of living cells in the deepest and outermost layers. A layer of fluid covers the outermost layers of cells, which makes them moist.

Answer 17

Nonkeratinized (moist) stratified squamous epithelium

Question 18

found in the skin, consists of living cells in the deepest layers, and the outer layers are composed of dead cells containing the protein keratin. The dead, keratinized cells give the tissue a dry, durable, moisture-resistant character. In addition to the skin, keratinized stratified squamous epithelium is also found in the gums and hard palate of the mouth.

Answer 18

keratinized stratified squamous epithelium

Question 19

lines the urinary bladder, ureters, pelvis of the kidney, and superior part of the urethra

Answer 19

transitional epithelium

Question 20

which are specialized columnar epithelial cells. The goblet cells are responsible for synthesizing and secreting mucus

Answer 20

goblet cells

Question 21

consist of adhesive glycoproteins that bind cells together and intracellular proteins attached to intermediate filaments that extend into the cytoplasm of the cells

Answer 21

desmosomes

Question 22

similar to one-half of a desmosome, attach epithelial cells to the basement membrane.

Answer 22

Hemidesmosomes

Question 23

hold cells together and form a permeability barrier. Tight junctions are formed by proteins in the plasma membranes of adjacent cells that join one another to make a very tight seal.

Answer 23

Tight junctions

Question 24

of glycoproteins is found just below the tight junction. It is located between the plasma membranes of adjacent cells and acts as a weak glue that holds cells together

Answer 24

adhesion belt

Question 25

is a small, specialized contact region between cells containing protein channels that aid intercellular communication by allowing ions and small molecules to pass from one cell to another

Answer 25

gap junction

Question 26

are secretory organs. Glands are composed primarily of epithelium, with a supporting network of connective tissue. These glands develop from an infolding or outfolding of epithelium in the embryo.

Answer 26

Glands

Question 27

Glands with ducts, Both the glands and their ducts are lined with epithelium.

Answer 27

exocrine glands

Question 28

Alternatively, some glands become separated from the epithelium of their origin and have no ducts, have extensive blood vessels.

Answer 28

endocrine glands

Question 29

The cellular products of endocrine glands, are secreted into the bloodstream and carried throughout the body.

Answer 29

hormones

Question 30

have a single, nonbranched duct. If there are multiple secretory regions that branch off the duct, then the gland is called branched.

Answer 30

Simple glands

Question 31

have multiple, branched ducts. For both simple and compound glands, the shape of the secretory regions further defines the gland.

Answer 31

Compound glands

Question 32

Glands with secretory regions shaped as tubules (small tubes)

Answer 32

tubular

Question 33

whereas those shaped in saclike structures

Answer 33

acinar or alveolar

Question 34

involves the release of secretory products by exocytosis, is used by water-producing sweat glands and the exocrine portion of the pancreas.

Answer 34

Merocrine secretion

Question 35

involves the release of secretory products as pinched-off fragments of the gland cells. The milk-producing mammary glands release milk by a combination of apocrine and mostly merocrine secretion.

Answer 35

Apocrine secretion

Question 36

involves the shedding of entire cells. Products accumulate in the cytoplasm of each epithelial cell, the cell ruptures and dies, and the entire cell becomes part of the secretion.

Answer 36

Holocrine secretion

Question 37

create the matrix

Answer 37

Blasts

Question 38

maintain it

Answer 38

cytes

Question 39

break it down for remodeling

Answer 39

clasts

Question 40

are cells that form fibrous connective tissue

Answer 40

Fibroblasts

Question 41

maintain it.

Answer 41

fibrocytes

Question 42

form cartilage; maintain it

Answer 42

Chondroblasts; chondrocytes

Question 43

also called adipose (fat) cells, contain large amounts of lipid. The lipid pushes the rest of the cell contents to the periphery, so that each cell appears to contain a large, centrally located lipid droplet with a thin layer of cytoplasm around it.

Answer 43

Adipocytes

Question 44

play important roles in inflammation. They contain chemicals, such as heparin, histamine, and proteolytic enzymes, that are released in response to injury, such as trauma and infection.

Answer 44

Mast cells

Question 45

continuously move from blood vessels into connective tissues. The rate of movement increases dramatically in response to injury or infection.

Answer 45

White blood cells, or leukocytes

Question 46

are large, phagocytic cells found in some connective tissue types. They are derived from monocytes, a type of white blood cell.

Answer 46

Macrophages

Question 47

are fragments of hemopoetic cells containing enzymes and special proteins that function in the clotting process to reduce bleeding from a wound.

Answer 47

Platelets

Question 48

are a type of adult stem cell, that persist in connective tissue. They have the potential to form multiple cell types, such as fibroblasts or smooth muscle cells, in response to injury.

Answer 48

Undifferentiated mesenchymal cells

Question 49

consist the protein of collagen. Collagen is the most abundant protein in the body. It accounts for one-fourth to one-third of total body protein and 6% of total body weight. Collagen is synthesized within fibroblasts and secreted into the extracellular space.

Answer 49

Collagen (kol′a-jen) fibers

Question 50

are very fine collagen fibers and therefore not a chemically distinct category of fibers. However, reticular fibers are very different from collagen fibers.

Answer 50

Reticular fibers

Question 51

consist of the protein elastin (e-las′tin). As the name suggests, this protein has the ability to return to its original shape after being stretched or compressed, giving tissue an elastic quality.

Answer 51

Elastic fibers

Question 52

consists of nonfibrous molecules. It is the “shapeless” background against which the collagen fibers are seen through the microscope. The two major components are hyaluronic acid and proteoglycans.

Answer 52

ground substance

Question 53

is a long, unbranched polysaccharide chain composed of repeating disaccharide units. It gives a very slippery quality to the fluids that contain it; for that reason, it is a good lubricant for joint cavities

Answer 53

Hyaluronic (glassy appearance) acid

Question 54

Elastic fibers consist of

Answer 54

the protein elastin (e-las′tin). As the name suggests, this protein has the ability to return to its original shape after being stretched or compressed, giving tissue an elastic quality.

Question 55

The ground substance consists of

Answer 55

nonfibrous molecules. It is the “shapeless” background against which the collagen fibers are seen through the microscope. The two major components are hyaluronic acid and proteoglycans.

Question 56

Two major categories of connective tissue are embryonic and adult. Embryonic connective tissue is called

Answer 56

mesenchyme (mez′en-kīm). It forms in the embryo during the third and fourth weeks of development from mesoderm and neural crest cells (see chapter 29), and all adult connective tissue types develop from it. By 8weeks of development,

Question 57

Adipose tissue

Answer 57

Adipose tissue functions as an insulator, a protective tissue, and a site of energy storage. Lipids take up less space per calorie than either carbohydrates or proteins and therefore are well adapted for energy storage.