Chapter 4: Tissue: The Living Fabric

Question 1

tissues

Answer 1

groups of cells that are similar in structure and perform a common or related function
four major types: epithelial, connective, muscle, nervous

Question 2

histology

Answer 2

study of tissues

Question 3

epithelial tissue (epithelium)

Answer 3

sheet of cells that covers a body surface or lines a body cavity
two kinds: covering and lining epithelium, and glandular epithelium
boundaries between different environments
functions: protection, absorption, filtration, excretion, secretion, sensory reception
have no blood vessels but are supplied by nerve fibers
has high regenerative capacity

Question 4

covering and lining epithelium

Answer 4

forms the outer layer of skin
dips into and lines open cavities of urogenital, digestive and respiratory systems
covers walls and organs of closed ventral body cavity

Question 5

glandular epithelium

Answer 5

fashions glands of the body

Question 6

apical surface

Answer 6

upper free surface of the epithelium exposed to the body exterior or the cavity of an internal organ

Question 7

basal surface

Answer 7

lower attached surface of the epithelium

Question 8

microvilli

Answer 8

fingerlike extensions of the plasma membrane on apical surfaces
increase exposed surface are to absorb or secrete substances more effectively
ex: lining of kidney tubules

Question 9

cilia

Answer 9

motile tiny hairlike projections that propel substances along free surface
ex: lining of the trachea

Question 10

basal lamina

Answer 10

thin supporting sheet
noncellular, adhesive sheet consisting of glycoproteins secreted by the epithelial cells with some fine collagen fibers
selective filter that determines which molecules diffuse to the underlying connective tissue
acts as a scaffolding which epithelial cells can migrate to repair a wound

Question 11

reticular lamina

Answer 11

layer of extracellular material containing a fine network of collagen protein fibers that belong to the underlying connective tissue

Question 12

bassement membrane

Answer 12

made up of the basal lamina and the reticular lamina
reinforces the epithelial sheet
helps resist stretching and tearing
defines the epithelial boundary

Question 13

avascular

Answer 13

contains no blood vessels

Question 14

innervated

Answer 14

supplied by nerve fibers

Question 15

simple epithelia

Answer 15

consists of a single cell layer

found where absorption, secretion and filtration occur and a thin epithelial barrier is desirable

Question 16

stratified epithelia

Answer 16

two or more cell layers stacked on top of each other
common in high abrasion areas where protection is important
ex: skin surface and lining of the mouth

Question 17

squamous cells

Answer 17

common epithelial cell
flattened and scale-like
nucleus is a flattened disc

Question 18

cuboidal cells

Answer 18

common epithelial cell
boxlike, about as tall as they are wide
spherical nucleus

Question 19

columnar cells

Answer 19

common epithelial cell
tall and column shaped
elongated nucleus from top to bottom and is located closer to the cell base

Question 20

simple squamous epithelium

Answer 20

flattened laterally
sparse cytoplasm
thin and often permeable
found where filtration or exchange of substances by rapid diffusion is necessary
two kinds: endothelium, mesothelium

Question 21

endothelium

Answer 21

provides a slick, friction-reducing lining in lymphatic vessels and hollow organs in the cardiovascular system
capillaries of endothelium
thinness encourages exchange of nutrients and wastes between bloodstream and surrounding tissue cells

Question 22

mesothelium

Answer 22

epithelium found in serous membranes

membrane lining the ventral body cavity and covering its organs

Question 23

simple cuboidal epithelium

Answer 23

single layer of cells as tall as they are wide
function: secretion and absorption
forms walls of smallest ducts of glands and many kidney tubules

Question 24

simple columnar epithelium

Answer 24

single layer of tall, closely packed cells
lines digestive tract from stomach to rectum
associated with absorption and secretion
digestive tract lining has dense microvilli on the apical surface of absorptive cells and tubular glands made of cells hat secrete mucus-containing intestinal juice
have cilia on free surfaces to help move substances along

Question 25

psuedostratified columnar epithelium

Answer 25

cells vary in height and rest on basement membrane nucleus lies low in cell giving impression of many layers of cells short cells re relatively unspecialized and give rise to taller cells secretes or absorbs substances

Question 26

stratified squamous epithelium

Answer 26

most widespread of stratified epithelia has many layers, thick free surface cells are squamous (replaced by basal cells after wear and tear) and keratinized, deeper layers are cuboidal or columnar protects body forms external part of skin and extends a short distance into every body opening that is continuous with skin

Question 27

stratified cuboidal epithelium

Answer 27

rare in the body, found mostly in the ducts of some larger glands has two layers of cuboidal cells

Question 28

stratified columnar epithelium

Answer 28

rare in body, found in the pharynx, male urethra, lining of some glandular ducts, transition areas or junctions between different kinds of epithelia only apical layer is columnar

Question 29

transitional epithelium

Answer 29

forms lining of hollow urinary organs that stretch when filling with urine basal layer is made of cuboidal or columnar cells apical cells vary depending on stretching when full, layer stretches from six cell layers to three and cells become flattened

Question 30

gland

Answer 30

consists of one or more cells that make or secrete a particular product classified by where they release their product and the number of cells

Question 31

secretion

Answer 31

product of a gland | aqueous fluid containing proteins, lipids or steroids

Question 32

unicellular epithelial glands

Answer 32

scattered within epithelial sheets

Question 33

multicellular epithelial glands

Answer 33

formed by invagination of an epithelial sheet into the underlying connective tissue

Question 34

endocrine glands

Answer 34

lose their ducts (called ductless glands) produce hormones structurally diverse, most are compact multicellular organs secretions include modified amino acids, peptides, gylcoproteins and steroids

Question 35

hormones

Answer 35

messenger chemicals secreted by exocytosis into the extracellular space by endocrine glands

Question 36

exocrine glands

Answer 36

secrete products onto body surfaces or into body cavities unicellular glands secrete directly using exocytosis multicellular glands secrete via epithelium-walled duct that transport to the epithelial surface secretions include mucous, sweat, oil ex: salivary glands, liver, pancreas

Question 37

unicellular exocrine glands

Answer 37

mucous cells and goblet cells sprinkled in epithelial linings of intestinal and respiratory tract produce mucin

Question 38

mucin

Answer 38

complex glycoprotein that dissolves in water when secreted | forms mucus once dissolve

Question 39

goblet cells

Answer 39

cuplike accumulations of mucin distends the top of the cell that looks like a stem on a glass

Question 40

multicellular exocrine glands

Answer 40

structurally more diverse two basic parts: epithelium-serviced duct and a secretory unit (acinus) have supportive connective tissue surrounding the secretory unit that supples it with blood vessels and nerve fibers classified by structure and type of secretion

Question 41

simple multicellular exocrine glands

Answer 41

have an unbranded duct

Question 42

compound multicellular exocrine glands

Answer 42

have a branched duct

Question 43

tubular multicellular exocrine glands

Answer 43

secretory cells in secretory units form tubes

Question 44

alveolar multicellular exocrine glands

Answer 44

secretory cells form small, flask-like sacs

Question 45

tubuloalveolar multicellular exocrine glands

Answer 45

have secretory cells that form tubes and form small sacs

Question 46

merocrine multicellular exocrine glands

Answer 46

secrete products by exocytosis as they are produced secretory cells are not altered ex: pancreas, sweat glands, salivary glands

Question 47

holocrine multicellular exocrine glands

Answer 47

secretory cells accumulate products within them until they rupture secretion includes synthesized product and dead cell material ex: sebaceous (oil) glands of skin

Question 48

connective tissue

Answer 48

has four main kinds: connective tissue proper, cartilage, bone and blood functions: connects body parts, binds and supports, protection, insulation, storing reserve fuel and transporting substances through the body all connective tissues rise from the mesenchyme largely composed of nonliving extracellular matrix (can bear weight, withstand tension, endure physical trauma)

Question 49

ground substance

Answer 49

unstructured material that fills the space between cells and contains fibers made of interstitial fluid, CAMs, and proteoglycans has a high fluid content functions as a molecular medium for nutrients and dissolved substances to diffuse between blood capillaries and cells

Question 50

cell adhesion proteins (CAMs)

Answer 50

serve as connective tissue glue that attaches connective tissue cells to the matrix ex: fibronectin, laminin etc.

Question 51

proteoglycans

Answer 51

protein core which glycosaminoglycans (GAGs) are attached | form huge aggregates and trap water to form a fluidy-gel

Question 52

glycosaminoglycans (GAGs)

Answer 52

strandlike large, negatively charged polysaccharides ex: chondroitin sulfate, hyaluronic acid higher GAG content in proteoglycans more viscous the ground substance

Question 53

collagen fibers

Answer 53

strongest and most abundant connective tissue fiber secreted into extracellular space where they spontaneously assemble into cross-linked fibrils that bundle together into think collagen fibers

Question 54

elastic fibers

Answer 54

long and thin form branching network in extracellular matrix contain rubberlike protein elastin that allow them to stretch and recoil found where elasticity is needed (i.e. skin, lungs and blood vessel walls)

Question 55

reticular fibers

Answer 55

short, fine, collagenous fibers continuous with collagen fibers, brand extensively to form networks that surround small blood vessels and support soft tissue of organs abundant where connective tissue meets other kinds of tissue (i.e. basement membranes)

Question 56

connective tissue cells

Answer 56

``` immature = -blast, synthesize matrix by secreting ground substances and fibers or particular matrix kind mature = -cyte, maintain health of matrix, can never back to immature state to repair and regenerate matrix if damaged also includes fat cells, white blood cells, mast class and macrophages ```

Question 57

fibroblast

Answer 57

immature cells of connective tissue proper flat branching cells that appear spindle shaped predominate areolar connective tissue

Question 58

chondroblast

Answer 58

immature cells of cartilage produce new matrix until skeleton stops growing at end of adolescence chondrocytes are found in small groups in cavities called lacunae

Question 59

osteoblast

Answer 59

immature cells of bone produce organic portion of bone matrix where bone salts are deposited on mature bone cells = osteocytes, live in lacunae in matrix

Question 60

hematopoietic stem cell

Answer 60

undifferentiated blast cell that produces blood cells

Question 61

fat cells

Answer 61

connective tissue cells | store nutrients

Question 62

white blood cells

Answer 62

connective tissue cells tissue response to injury ex: neutrophils, eosinophils, lymphocytes

Question 63

mast cells

Answer 63

connective tissue cells cluster along blood vessels, detect foreign microorganisms and initiate local inflammatory response contain secretory granolas with chemicals that mediate inflammation (i.e. heparin, histamine, proteases, other enzymes)

Question 64

macrophages

Answer 64

connective tissue cells large, irregularly shaped cells consume foreign materials, dispose of dead tissue cells, participate in the immune system

Question 65

mesenchyme

Answer 65

common embryonic tissue that mature connective tissue arises from has a fluid ground substance containing fine sparse fibers and star-shaped mesenchymal cells

Question 66

connective tissue proper

Answer 66

all mature connective tissues except bone, cartilage and blood two subclasses: loose connective tissue and dense connective tissue

Question 67

areolar connective tissue

Answer 67

loose connective tissue functions: support and bind other tissues, holds body fluids, defends agains infection, stores nutrients as fat in adipocytes contains fibroblasts mainly, some macrophages and fat cells, occasionally mast cells has a loose arrangement of fibers provides reservoir for water and salts surrounding body tissues (nutrients and wastes) high content of hyaluronic acid makes ground substance viscous, hinders movement of cells through it most widely distributed connective tissue in the body

Question 68

adipose (fat) tissue

Answer 68

similar to areolar tissue in structure and function higher nutrient-storing ability 90% adipocytes closely packed cells with little matrix richly vascularized 18% of human body weight accumulates in subcutaneous tissue functions as a shock absorber, insulator, energy storage site serves as general nutrition for entire body

Question 69

white adipose tissue

Answer 69

aka white fat | stores nutrients for other cells

Question 70

brown adipose tissue

Answer 70

``` aka brown fat contains abundant mitochondria use lipids as fuel to heat bloodstream to warm the body richly vascularized common in babies, rarer in adults ```

Question 71

reticular connective tissue

Answer 71

resembles areolar connective tissues but only has reticular fibers that form a network of scattered fibroblasts called reticular cells limited to stroma (internal framework) to support free blood cells in lymph nodes, spleen and bone marrow

Question 72

dense connective tissue

Answer 72

connective tissue proper three kinds: dense regular, dense irregular, elastic often called fibrous connective tissue because they are predominantly fibers

Question 73

dense regular connective tissue

Answer 73

contain closely packed bundles of collagen fibers funning parallel to direction of pull white, flexible structures with great resistance to tension in a single direction form tendons including aponeuroses, ligaments and fascia

Question 74

aponeuroses

Answer 74

type of tendon flat, sheetlike attach muscle to other muscle or bone

Question 75

ligaments

Answer 75

type of tendon bind bones together at joints contain more elastic fibers than tendons, more stretchy

Question 76

fascia

Answer 76

fibrous membrane that wraps around muscles, groups of muscles, blood vessels and nerves and binds them together

Question 77

dense irregular connective tissue

Answer 77

same structural elements as regular but with thicker bundles of collagen fibers that are irregularly arranged (run in more than one direction) forms sheets where tendons are exerted in different directions found in skin as the dermis, fibrous join capsules and fibrous coverings of some organs

Question 78

elastic connective tissue

Answer 78

very elastic ligaments dense regular connective tissue ex: ligaments that connect adjacent vertebrae, in walls of larger arteries

Question 79

cartilage

Answer 79

stands up to tension and compression has qualities of dense connective tissue and bone (tough and flexible) lacks nerves, avascular receives nutrients through diffusion of blood vessels in connective tissue layer around it has firm ground tissue up to 80% water three kinds: hyaline, elastic and fibro

Question 80

hyaline cartilage

Answer 80

aka grisle most abundant cartilage type contains large amounts of collagen, has a transparent matrix 1-10% chondrocytes provides firm support with some pliability covers ends of long bones (articular cartilage), supports tip of nose, connects ribs to sternum, supports respiratory passages

Question 81

elastic cartilage

Answer 81

nearly identical to hyaline cartilage, has more elastic fibers found external ear and epiglottis

Question 82

fibrocartilage

Answer 82

has rows of chondrocytes that alternate with rows of thick collagen fibers compressible, resists tension found in intravertebral discs and spongy cartilages of knee

Question 83

bone (osseous tissue)

Answer 83

supports and protects body features provide activities for storing fat and synthesizing blood cells bone matrix is similar to cartilage but has more collagen and contains inorganic calcium salts making it harder

Question 84

blood

Answer 84

fluid in blood vessels develops form mesenchyme, doesn't connect things or give mechanical support, consists of blood cells surrounded by nonliving fluid matrix (blood plasma) majority are erythrocytes (RBCs) fibers are soluble protein molecules that protein molecules that precipitate during clotting

Question 85

muscle tissue

Answer 85

highly cellular, well vascularized tissue responsible for most types of body movement contain myofilaments three kinds: skeletal, cardiac, and smooth

Question 86

myofilaments

Answer 86

in muscle cells | elaborate networks of actin and myosin filaments that bring about movement or contraction in all muscle cell types

Question 87

skeletal muscle

Answer 87

aka voluntary muscle tissue is packaged by connective tissues sheets into organs that are attached to bones form flesh of body pull on bones or skin when they contract creating body movements cells are called muscle fibers

Question 88

muscle fibers

Answer 88

skeletal muscle cells long, cylindrical cells with many peripherally located nuclei banded or striated reflecting alignment of myofilaments

Question 89

cardiac muscle

Answer 89

involuntary muscle found only in walls of heart contractions propel blood through blood vessels throughout the body cardiac cells are generally uninucleate with a centrally located nucleus and are branched allowing them to fit tightly together at junctions called intercalated discs

Question 90

intercalated discs

Answer 90

junctions where branched cardiac muscle cells fit tightly together

Question 91

smooth muscle

Answer 91

involuntary muscle cells have no visible striations spindle shaped cells with one centrally located nucleus found mostly in walls of hollow organs other than the heart squeezes substances through organs by contracting and relaxing

Question 92

nervous tissue

Answer 92

main component of the nervous system (brain, spinal cord and nerves) regulates and controls body functions two major cells types: neurons and supporting cells

Question 93

neurons

Answer 93

highly specialized nerve cells that generate and conduct nerve impulses typically branching cells with cytoplasmic extensions that allow them to respond to stimuli (dendrites) and transmit electrical impulses (axons)

Question 94

supporting cells

Answer 94

non-conducting cells that support, insulate and protect neurons ex: glial cells or neuroglia

Question 95

cutaneous membrane

Answer 95

skin organ system of keratinized stratified squamous epithelium (epidermis) attached to a thick layer of connective tissue (dermis) exposed to air, dry membrane

Question 96

mucous membranes (mucosae)

Answer 96

line all body cavities open to the outside of the body wet membranes (bathed in secretions) cell composition varies (either stratified squamous or simple columnar epithelia) epithelial sheet lies directly over layer of loose connective tissue called lamina propria which can rest on a layer of smooth muscle tissue adapted for absorption and secretion

Question 97

serous membranes (serosae)

Answer 97

moist membranes found in closed ventral body cavities consists of simple squamous epithelium (mesothelium) on a layer of loose connective (areolar) tissue thin, clear serous fluid lubricates facing surfaces of the parietal and visceral layers so they can slide past one another named for location in body

Question 98

regeneration

Answer 98

replaces destroyed tissue with same kind of tissue

Question 99

fibrosis

Answer 99

replaces destroyed tissue with dense connective tissue that proliferates to form scar tissue