Epithelial Tissue

Question 1

A simple epithelium has how many cell layers?

Answer 1

one

Question 2

Which of the following structures is not commonly found on the apical surface of epithelial cells?

a. Microvilli
b. Cilia
c. Stereocilia
d. Desmosomes

Answer 2

d. Desmosomes

Question 3

Epithelial cells that function mainly to produce and secrete various macromolecules may occur in epithelia with other major functions or comprise specialized organs called?

Answer 3

Glands

Question 4

This is the connective tissue that underlies the epithelia lining the organs of the digestive, respiratory, and urinary systems.

Answer 4

Lamina propria

Question 5

What does “keratinized” mean in stratified squamous cells?

Answer 5

Dry

Question 6

Where do stratified columnar cells line?

Answer 6

Conjunctiva

Question 7

How much sodium ions should be present inside the cell compared to potassium ions?

Answer 7

more potassium ions inside, more sodium ions outside

Question 8

These are the shapes of Epithelial Cells, except:

a. Cuboidal
b. Squamous
c. Spherical
d. Columnar

Answer 8

c. Spherical

Question 9

Scattered secretory cells, sometimes called as ______.

Answer 9

Unicellular glands

Question 10

These are the Apical Structures of Epithelial Cells, except:

a. Cilia
b. Celiac
c. Microvilli
d. Stereocilia

Answer 10

b. Celiac

Question 11

______ tissue is a type of tissue that covers body surfaces, lines cavities, and forms glands.

Answer 11

Epithelial

Question 12

It serves as a protective barrier, involved in absorption, secretion, and sensation.

Answer 12

Epithelial tissue

Question 13

The cells in Epithelial tissue are tightly packed, forming layers that can be ______ (one layer) or ______ (multiple layers), and vary in shape, including ______ (flat), ______, and ______ (tall) forms.

Answer 13

simple, stratified, squamous, cuboidal, columnar

Question 14

______ tissue is crucial for protecting the body and supporting essential functions.

Answer 14

Epithelial

Question 15

______ (Gr. epi, upon + thele, nipple) line all external and internal surfaces of the body and all substances that enter or leave an organ must cross this type of tissue.

Answer 15

Epithelia

Question 16

Epithelial tissues are composed of ______ adhering strongly to one another and to a thin layer of ECM, forming cellular sheets that line the cavities of organs and cover the body surface.

Answer 16

closely aggregated polyhedral cells

Question 17

Shapes of Epithelial cells

Answer 17

columnar
Cuboidal
squamous

Question 18

Shapes of Epithelial cell nuclei

Answer 18

elliptic (oval)
spherical
flattened

Question 19

Functions of epithelial tissues

Answer 19

Covering, lining, and protecting surfaces (eg, epidermis)
Absorption (eg, the intestinal lining)
Secretion (eg, parenchymal cells of glands)

Question 20

This is the connective tissue that underlies the epithelia lining the organs of the digestive, respiratory, and urinary systems.

Answer 20

lamina propria

Question 21

These are Small evaginations that increases the area of contact between the epithelial and connective tissues.

Answer 21

Papillae

Question 22

______ occur most frequently in epithelial tissues
subject to friction, such as the covering of the skin or tongue.

Answer 22

Papillae

Question 23

Most epithelia are adjacent to ______ tissue containing blood vessels from which the epithelial
cells receive nutrients and O2. Even thick epithelia do not themselves normally contain blood vessels.

Answer 23

connective

Question 24

Epithelial cells generally show ______, with organelles and membrane proteins distributed unevenly within the cell.

Answer 24

polarity

Question 25

The region of the cell contacting the ECM and connective tissue is called the ______ and the opposite end usually facing a space is the ______.

Answer 25

basal pole, apical pole

Question 26

The two poles differing significantly in both structure and function. Regions of cuboidal or columnar cells that adjoin neighboring cells comprise the cells’ ______; ______ here often have numerous folds which increase the area and functional capacity of that surface.

Answer 26

lateral surfaces, cell membranes

Question 27

This is a thin extracellular, felt-like sheet of macromolecules where the basal surface of all epithelia rests on.

Answer 27

Basement Membranes

Question 28

This is a semipermeable filter for sub stances reaching epithelial cells from below.

Answer 28

Basement Membranes

Question 29

This always lies at the interface of epithelial cells and connective tissue.

Answer 29

Basement Membranes

Question 30

Nutrients for epithelial cells must diffuse across the ______.

Answer 30

basement membrane

Question 31

Glycoproteins and other components in the ______ can often be stained and visualized with the light microscope.

Answer 31

basement membrane

Question 32

It is Nearest the epithelial cells.

Answer 32

Basal lamina

Question 33

It is a thin, electron-dense, sheet-like layer of fine fibrils.

Answer 33

Basal lamina

Question 34

It is Beneath the basal lamina and More diffused and fibrous.

Answer 34

Reticular lamina

Question 35

The terms “basement membrane” and “basal lamina” are sometimes used interchangeably, but “______” usually denotes the fine extracellular layer seen ultra-structurally and “______” the entire structure beneath the epithelial cells visible with the light microscope.

Answer 35

basal lamina, basement membrane

Question 36

ECM components of the Basal lamina:

Answer 36

Type IV collagen
Laminin
Nidogen and perlecan

Question 37

Monomers of ______ self assemble into a two-dimensional network of evenly spaced subunits resembling the mesh of a window screen.

Answer 37

type IV collagen

Question 38

These are large glycoproteins that attach to transmembrane integrin proteins in the basal cell membrane and project through the mesh formed by the type IV collagen.

Answer 38

Laminin

Question 39

Respectively a short, rod-like protein and a proteoglycan, both of these cross-link laminins to the type IV collagen network, helping to provide the basal lamina’s three-dimensional structure, to bind the epithelium to that structure, and to determine its porosity and the size of molecules able to filter through it.

Answer 39

Nidogen and perlecan

Question 40

The ______ helps to provide structural support for epithelial cells and attach epithelia to underlying connective tissue.

Answer 40

Basement Membrane

Question 41

______ components help organize integrins and other proteins in the plasma membrane of epithelial cells, maintaining cell polarity and helping to localize endocytosis, signal transduction, and other activities.

Answer 41

Basal lamina

Question 42

______ proteins also mediate many cell-to-cell interactions involving epithelia and mark routes for certain cell migrations along epithelia.

Answer 42

Basement membrane

Question 43

The ______ also serves as a scaffold that allows rapid epithelial repair and regeneration.

Answer 43

basement membrane

Question 44

Intercellular Adhesion and Other Junctions

Answer 44

Tight or occluding junctions
adherent or anchoring junctions
gap junctions

Question 45

lateral surfaces of epithelial cells have complexes of several specialized intercellular junctions with different functions:

______ junctions form a seal between adjacent cells.

Answer 45

Tight or occluding

Question 46

lateral surfaces of epithelial cells have complexes of several specialized intercellular junctions with different functions:

______ junctions are sites of strong cell adhesion.

Answer 46

Adherent or anchoring

Question 47

lateral surfaces of epithelial cells have complexes of several specialized intercellular junctions with different functions:

______ junctions are channels for communication between adjacent cells.

Answer 47

Gap

Question 48

In many epithelia, these junctions are present in a definite order at the ______ end of the cells.

Answer 48

apical

Question 49

Tight junctions, also known as ______, are located at the ______ end of epithelial cells.

Answer 49

zonulae occludens, apical

Question 50

The term “______” indicates that these junctions form a continuous band around each cell.

Answer 50

zonula

Question 51

In transmission electron microscopy (TEM), ______ junctions appear as fused or tightly apposed adjacent membranes.

The seal between cell membranes is created by interactions between transmembrane proteins, specifically ______ and ______.

Answer 51

tight, claudin, occludin

Question 52

______ junctions are clearly visible after cryofracture of epithelia, appearing as a band of branching strands around each cell’s apical end.

Answer 52

Tight

Question 53

______ junctions ensure that molecules crossing an epithelium do so through the cells (______ path) rather than between them (______ pathway).

Answer 53

Tight, transcellular, paracellular

Question 54

Permeability (Tight Junctions)

Epithelia with fewer fused sealing strands (e.g., proximal renal tubule) are ______ permeable to water and solutes.

Answer 54

more

Question 55

Permeability (Tight Junctions)

Epithelia with many fused strands (e.g., lining of the urinary bladder) are ______ permeable.

Answer 55

less

Question 56

______ junctions also serve a related purpose: these continuous zones within cell membranes serve as fences restricting movements of membrane lipids and proteins at the apical cell surface into the lateral and basal sur faces, and vice versa.

Answer 56

Epithelial tight

Question 57

The tight junctions thus maintain two distinct membrane domains (______ and ______) with different sets of components, which allows these two sides of the epithelium to display different receptors and other proteins and to function differently.

Answer 57

apical, basolateral

Question 58

______ cell membranes of epithelia are part of the luminal compartment of a tissue or organ, while the ______ domains are part of a basal compartment that also encompasses the underlying connective tissue.

Answer 58

Apical, basolateral

Question 59

Proteins of tight junctions provide the targets for certain common bacteria of medical importance. The ______ secreted by Clostridium perfringens, which causes “food poisoning,” binds claudin molecules of intestinal cells, prevents insertion of these proteins during maintenance of tight junctions, and causes loss of tissue fluid into the intestinal lumen via the paracellular pathway. Similarly, ______, which is important in the etiology of gastric ulcers, binds the extracellular domains of tight-junction proteins in cells of the stomach and inserts a protein into these cells, which targets ZO-1 and disrupts signaling from the junction.

Answer 59

enterotoxin, Helicobacter pylori

Question 60

The ______ Junction (______) Encircles the epithelial cell, usually just below the tight junction. It Anchors a cell to its neighbors.

Answer 60

Adherens, Zonula Adherens

Question 61

Adherens Junction (Zonula Adherens)

Cell adhesion is mediated by ______, transmembrane glycoproteins of each cell that bind each other in the presence of Ca2+.

Answer 61

cadherins

Question 62

Adherens Junction (Zonula Adherens)

At their ______ ends, cadherins bind catenins that link to actin filaments with actin-binding proteins.

Answer 62

cytoplasmic

Question 63

The actin filaments linked to the adherens junctions form part of the “______,” a cytoskeletal feature at the apical pole in many epithelial cells.

Answer 63

terminal web

Question 64

Together, the ______ and ______ junctions encircling the apical ends of epithelial cells function like the plastic bands that hold a six-pack of canned drinks together.

Answer 64

tight, adherent

Question 65

Another anchoring junction is the ______ (Gr., ______, binding and ______, body) or ______ adherens (L. ______, spot).

Answer 65

desmosome, desmos, soma, macula, macula

Question 66

The ______ Resembles a single “spot-weld” and does not form a belt around the cell.

Answer 66

Desmosome

Question 67

______ are disc-shaped structures at the surface of one cell that are matched with identical structures at an adjacent cell surface.

Answer 67

Desmosomes

Question 68

Desmosomes contain larger members of the cadherin family called ______ and ______. The cytoplasmic ends of these clustered transmembrane proteins bind plakoglobins, catenin-like proteins which link to larger proteins called ______ in an electron-dense plaque.

Answer 68

desmogleins, desmocollins, desmoplakins

Question 69

______ in turn bind intermediate filament proteins rather than actins. Epithelial desmosomes attach to cable-like filaments of cytokeratin, sometimes referred to ______. Such intermediate filaments are very strong and desmosomes provide firm cellular adhesion and strength throughout the epithelium.

Answer 69

Desmoplakins, tonofilaments

Question 70

Various ______ (______) diseases, such as ______, involving the epidermis or stratified squamous epithelia of the oral mucosa, are due to abnormal desmosome function caused by autoimmune reactions against specific desmogleins that reduce cell-to-cell adhesion. Similar disorders arise with genetic mutations for various junctional proteins.

Answer 70

blistering, bullous, pemphigus vulgaris

Question 71

______ junctions mediate intercellular communication in many epithelia and most mammalian tissues.

Answer 71

Gap

Question 72

Gap junctions consist of transmembrane protein complexes, called ______, which form circular patches in the plasma membrane.

Answer 72

connexons

Question 73

Each connexon has a central pore about ______ nm wide.

Answer 73

1.5

Question 74

When cells connect, ______ align between adjacent membranes, forming numerous aligned pairs. These junctions allow the exchange of small molecules (<1.5 nm) between cells.

Answer 74

connexons

Question 75

______ are specialized structures that anchor epithelial cells to the basal lamina, ensuring tissue stability.

Answer 75

Hemidesmosomes

Question 76

These resemble half-desmosomes but use integrins instead of cadherins to connect cytokeratin filaments to laminin in the basal lamina.

Answer 76

Hemidesmosomes

Question 77

In ______, integrins link indirectly to cytokeratin intermediate filaments inside the cell and bind primarily to laminin molecules in the basal lamina outside the cell.

Answer 77

hemidesmosomes

Question 78

______ are crucial for maintaining the strong adhesion of epithelial cells to the underlying basal lamina, ensuring the stability and structural integrity of epithelial tissues.

Answer 78

Hemidesmosomes

Question 79

Smaller and more numerous than hemidesmosomes, these junctions connect integrins to actin filaments.

Answer 79

Focal Adhesions

Question 80

These play a key role in cell movement, signaling, and adhesion by initiating intracellular phosphorylation cascades.

Answer 80

Focal Adhesions

Question 81

______ anchor cells to the extracellular matrix (ECM), particularly during cell movement, repair, and reorganization of epithelial tissues.

Answer 81

Focal adhesions

Question 82

Unlike hemidesmosomes, ______ are smaller, more numerous, and link integrins to actin filaments rather than intermediate filaments.

Answer 82

focal adhesions

Question 83

Focal adhesions connect integrins to actin filaments via paxillin and are associated with ______.

Answer 83

focal adhesion kinase (FAK)

Question 84

Upon integrin binding to ECM proteins like laminin, ______ initiates a signaling cascade that affects cell adhesion, mobility, and gene expression. These structures are crucial for cell migration, particularly in nonepithelial cells such as fibroblasts, and play a significant role in tissue repair and cellular responses to the environment.

Answer 84

FAK

Question 85

SPECIALIZATIONS OF THE APICAL CELL SURFACE

Answer 85

Microvilli
Stereocilia
Cilia

Question 86

The ______ ends of many columnar and cuboidal epithelial cells have specialized structures projecting from the cells. These function either to increase the apical surface area for better absorption or to move substances along the epithelial surface.

Answer 86

apical

Question 87

Many cells have ______ projections best seen with the electron microscope. Such extensions usually reflect the movements and activity of actin filaments and are both temporary and variable in their length, shape, and number.

Answer 87

cytoplasmic

Question 88

These are usually of uniform length and are bristle-like protrusions found on cell surfaces.

Answer 88

Microvilli

Question 89

These can be found in epithelia specialized for absorption the apical cell surfaces and are often filled with an array of projecting microvilli.

Answer 89

Microvilli

Question 90

In cells such as those lining the small intestine, densely packed ______ are visible as a brush or striated border projecting into the lumen.

Answer 90

microvilli

Question 91

Each ______ contains bundled actin filaments that are capped and bound to the surrounding plasma membrane by actin-binding proteins.

Answer 91

microvillus

Question 92

Although ______ are relatively stable structures, the microfilament arrays within them are dynamic and undergo various myosin-based movements. These movements help maintain optimal conditions for absorption through the numerous channels, receptors, and other proteins in the plasma membrane.

Answer 92

microvilli

Question 93

The ______ filaments extend into the terminal web of cortical microfilaments located at the base of the microvilli.

Answer 93

actin

Question 94

______ disease, also called ______ or ______, is a disorder of the small intestine in which one of the first pathologic changes is loss of the microvilli brush border of the absorptive cells.

Answer 94

Celiac, gluten-sensitive enteropathy, sprue

Question 95

______ disease is caused by an immune reaction against the wheat protein gluten during its digestion, which produces ______ (intestinal inflammation), changes to the epithelial cells leading to malabsorption, and eventually to pathologic changes in the intestinal wall. The malabsorption problems and structural changes are reversible when gluten is removed from the diet.

Answer 95

Celiac, diffuse enteritis

Question 96

These are finger-like projections that are sometimes branched.

Answer 96

Stereocilia

Question 97

These are longer than microvilli and less motile than microvilli.

Answer 97

Stereocilia

Question 98

These are cylindrical, long structures that have the same characteristics as a cell membrane.

Answer 98

Stereocilia

Question 99

______ are a much less common type of apical process, primarily found on the absorptive epithelial cells lining the male reproductive system.

Answer 99

Stereocilia

Question 100

Like microvilli, ______ increase the cell’s surface area, aiding in absorption. In addition to this, more specialized ______ with a motion-detecting function play a crucial role in the sensory cells of the inner ear.

Answer 100

stereocilia, stereocilia

Question 101

Structurally, ______ resemble microvilli as they contain arrays of microfilaments and actin-binding proteins, sharing similar diameters and connections to the cell’s terminal web.

Answer 101

stereocilia

Question 102

These are short, hair-like structures present on cell
surfaces and can be motile or non-motile.

Answer 102

Cilia

Question 103

______ cilia help in movement and locomotion, such as in Protozoans.

Answer 103

Motile

Question 104

Primary cilia are ______, they are used to sense external cues such as light and odour.

Answer 104

nonmotile

Question 105

Cilia’s core structure consisting of nine peripheral microtubule doublets (in which a few tubulin protofilaments are shared) arrayed around two central microtubules. This 9 + 2 assembly of microtubules is called an ______.

Answer 105

axoneme

Question 106

Cilia

As with other microtubules, ______ and ______ dynein motors move along the peripheral microtubules for the transport of molecular components into and out of these structures.

Answer 106

kinesin, cytoplasmic

Question 107

Cilia

Microtubules of ______ are continuous with those in basal bodies, which are apical cytoplasmic structures located just below the cell membrane. Basal bodies have a structure similar to centrioles, consisting of triplets of microtubules and dynamic tubulin protofilaments that form rootlets anchoring the entire structure to the cytoskeleton.

Answer 107

axonemes

Question 108

______ exhibit rapid beating patterns that move fluid and suspended matter in one direction along the epithelium.

Answer 108

Cilia

Question 109

______ motion occurs through successive changes in the conformation of the axoneme, where various accessory proteins make each cilium relatively stiff yet elastic.

Answer 109

Ciliary

Question 110

Complexes with axonemal dynein bound to one microtubule in each doublet extend as “______” toward a microtubule in the adjacent doublet. Powered by ______, dynein induces the sliding of adjacent doublets relative to each other, bending the axoneme. A rapid series of these sliding movements produces the beating motion of the ______.

Answer 110

arms, ATP, cilium

Question 111

The long ______ that extends from each fully differentiated sperm cell has an axonemal structure similar to that of a cilium and moves through a comparable mechanism.

Answer 111

flagellum

Question 112

Mutations in the proteins of cilia and flagella are associated with immotile cilia syndrome, also known as ______ syndrome.

Answer 112

Kartagener

Question 113

This condition results in chronic respiratory infections due to the impaired cleansing action of cilia in the respiratory tract and male infertility caused by immotile spermatozoa.

Answer 113

Kartagener syndrome

Question 114

______ syndrome is an autosomal recessive genetic condition and a form of primary ciliary dyskinesia (PCD), a disorder in which the cilia do not function properly. These hair-like structures are found on the surface of cells in the lungs, airways, and other areas. They move in a wave-like motion, helping to position organs during fetal development and clearing mucus, bacteria, and debris from the lungs and airways.

Answer 114

Kartagener

Question 115

Types of Epithelia

Answer 115

Covering (lining) epithelia
Secretory (glandular) epithelia

Question 116

There are also lining epithelia that also secrete (ex. ______ lining). There are also glandular cells that are distributed among thw lining cells (ex. ______ cells in small intestine and trachea)

Answer 116

stomach, mucous

Question 117

Cells of covering epithelia are organized into one or more layers that cover the surface or line the cavities of an organ:

One Layer - ______
cell forms: ______, ______, ______

Answer 117

Simple, squamous, cuboidal, columnar

Question 118

Cells of covering epithelia are organized into one or more layers that cover the surface or line the cavities of an organ:

Two or more layers - ______
cell forms: ______ (dry), ______ (moist), ______,
______, ______

Answer 118

Stratified, squamous keratinized, sqamous nonkeratinized, cuboidal, transitional, columnar

Question 119

Cells of covering epithelia are organized into one or more layers that cover the surface or line the cavities of an organ:

Layers of cells with nuclei at different levels - ______

Answer 119

Pseudostratified

Question 120

These are flat and wide cells that facilitate the movement of the viscera (mesothelium), active transport by pinocytosis (mesothelium and endothelium), secretion of biologically active molecules (mesothelium)
Found at: lining of vessels; serous lining of cavities: pericardium, pleura, peritoneum

Answer 120

Squamous

Question 121

Cube-shaped cells that covers and secretes.
Found at: covering of ovary and thyroid

Answer 121

Cuboidal

Question 122

Tall cells that protect, lubricate, absorb, and
secrete
Found at: intestine and gallbladder lining

Answer 122

Columnar

Question 123

These cells are packed with keratin filaments which makes them dry. These cells protects and prevents water loss or dehydration of the tissue. Contains many desmosomes and become more irregular in shape. They then flatten as the keratin accumulates (keratinization). It moves progressively toward the skin surface and becomes thin, metabolically inactive packets (squames) of keratin lacking nuclei.

Answer 123

Squamous Keratinized

Question 124

Only a sparse amount of keratin is found in these cells which makes them moist. They protect structures where dehydration is not a problem, it secretes, and prevents water loss. The flattened cells on the surface layer retain their nuclei and most metabolic functions.
Found at: mouth, esophagus, larynx, vagina, anal canal

Answer 124

Squamous Nonkeratinized

Question 125

These large, dome - like cells (umbrella cells) lines much of the urinary tract, extending from the kidneys to the proximal part of the urethra. These cells protect underlying tissues from the hypertonic and potentially cytotoxic effects of urine. Unique morphological features of the cells allow distension of stransitional epithelium as the urinary bladder fills which allow the cells to adjust their relationship with one another.

Answer 125

Transitional / Urothelium

Question 126

These rare cells occur in the excretory ducts of salivary and sweat glands where the double layer of cells allows additional functions.

Answer 126

Cuboidal

Question 127

These rare cells is seen in the conjunctiva lining the
eyelids, where it is both protective and mucus secreting.

Answer 127

Columnar

Question 128

These are Several layers with nuclei at different levels and Their basal ends all rest on the basement
membrane.

Answer 128

Pseudostratified Covering/ Lining

Question 129

These are Tall, irregular cells are attached to basement mambrane.

Answer 129

Columnar

Question 130

Epithelial cells that function mainly to produce and secrete various macromolecules may occur in epithelia with other major functions or comprise
specialized organs called ______.

Answer 130

GLANDS

Question 131

Secretory cells may synthesize, store, and release ______ (eg, in the pancreas), ______ (eg, adrenal, sebaceous glands), or complexes of ______ and ______ (eg, salivary glands). Epithelia of ______ glands secrete all three substances.

Answer 131

proteins, lipids, carbohydrates, proteins, mammary

Question 132

______ secretory cells, sometimes called unicellular glands, are common in simple cuboidal, simple columnar, and pseudostratified epithelia.

Answer 132

Scattered

Question 133

This is An important, easily seen example that is abundant in the lining of the small intestine and respiratory tract, which secretes lubricating mucus that aids the function of these organs.

Answer 133

Goblet Cell

Question 134

Glands develop from covering epithelia in the fetus by cell proliferation and growth into the underlying connective tissue, followed by further differentiation:

______ glands and ______ Glands

Answer 134

Exocrine, Endocrine

Question 135

______ glands remain connected with the surface epithelium, the connection forming the tubular ducts lined with epithelium that deliver the secreted material where it is used.

Answer 135

Exocrine

Question 136

The epithelia of ______ glands are organized as a continuous system of many small secretory portions and ducts that transport the secretion out of the gland.

Answer 136

exocrine

Question 137

In both exocrine and endocrine glands, the secretory units are supported by a stroma of ______ tissue. In larger glands, layers of ______ tissue also surround the larger ducts, form partitions or ______ separating the gland into lobules, each containing secretory units connected to a small part of the duct system, and enclose the entire gland as its ______.

Answer 137

connective, connective, septa, capsule

Question 138

Glands can be ______ (ducts not branched) or ______ (ducts with two or more branches).

Answer 138

simple, compound

Question 139

Glands

Secretory portions can be ______ (either short or long and coiled) or ______ (rounded and saclike); either type of secretory unit may be branched, even if the duct is not branched.

Answer 139

tubular, acinar

Question 140

Compound glands can have branching ducts and can have multiple ______, ______, or ______ secretory portions.

Answer 140

tubular, acinar, tubuloacinar

Question 141

______ glands lack ducts; secreted substances are hormones carried throughout the body by the interstitial fluid and blood, with specificity produced by the hormone receptors of target cells.

Answer 141

Endocrine

Question 142

Three Basic Mechanisms for releasing the product are commonly used by cells specialized for secretion
and cells engaged in each type of secretion can be
distinguished histologically:

Answer 142

Merocrine Secretion
Holocrine Secretion
Apocrine Secretion

Question 143

This is the most common method of protein or glycoprotein secretion and involves typical exocytosis from membrane-bound vesicles or secretory granules.

Answer 143

Merocrine Secretion

Question 144

Here cells accumulate product continuously as they enlarge and undergo terminal differentiation, culminating in complete cell disruption that releases the product and cell debris into the gland’s lumen. This is best seen in the sebaceous glands producing lipid rich material in skin.

Answer 144

Holocrine Secretion

Question 145

Here product accumulates at the cells’ apical ends, portions of which are then extruded to release the product together with small amounts of cytoplasm and cell membrane. Lipid droplets are secreted in the mammary gland in this manner

Answer 145

Apocrine Secretion

Question 146

Exocrine glands with merocrine secretion can be further categorized as either ______ or ______ according to the nature of their secretory products, which give distinct staining properties to the cells.

Answer 146

serous, mucous

Question 147

______ cells synthesize proteins that are mostly not glycosylated, such as digestive enzymes.

Answer 147

Serous

Question 148

The cells have well-developed RER and Golgi complexes and are filled apically with secretory granules in different stages of maturation. ______ cells therefore stain intensely with basophilic or acidophilic stains. Acini of the pancreas and parotid salivary glands are composed of ______ cells.

Answer 148

Serous, serous

Question 149

______ CELLS such as goblet cells, also have RER and Golgi complexes and are filled apically with secretory granules, but these contain heavily glycosylated proteins called ______.

Answer 149

MUCOUS, mucins

Question 150

When _______ are released from the cell, they become hydrated and form a layer of mucus. The ______ mucins are usually washed from cells during routine histological preparations, causing the secretory granules to stain poorly with eosin. Sufficient oligosaccharides remain in developing mucinogen granules, however, to allow mucous cells to be stained by the PAS method.

Answer 150

mucins, hydrophilic

Question 151

Some salivary glands are mixed ______ glands, having both serous acini and mucous tubules with clustered serous cells. The product of such glands is a mixture of digestive enzymes and watery mucus.

Answer 151

seromucous

Question 152

In addition to secretory cells, epithelia of many exocrine glands contain contractile ______ CELLS at the basal ends of the secretory cells.

Answer 152

MYOEPITHELIAL

Question 153

______ cells are rich in actin filaments and myosins. Strong contractions in these cells serve to
help propel secretory products from acini into the duct system.

Answer 153

Myoepithelial

Question 154

______ glands lack myoepithelial cells and are specialized either for protein or steroid hormone synthesis, with cytoplasmic staining characteristic of RER or SER, respectively.

Answer 154

Endocrine

Question 155

______ signaling involves hormone transport in the blood to target cells throughout the body, often within other endocrine glands. The receptors may also be on cells very close to the hormone-secreting cell or on the secreting cell itself, signaling which is termed paracrine or autocrine, respectively.

Answer 155

Endocrine

Question 156

Important but inconspicuous ______ or ______ cells also occur singly or in small groups in epithelia of the digestive, respiratory, and other organ systems. Hormones are also secreted from some cells specialized for other functions, such as certain cardiac muscle cells or fat cells.

Answer 156

endocrine, paracrine

Question 157

The pancreas contains both ______ and ______ cells. Liver cells exert both functions in the same cells, secreting bile components into a duct system and releasing other products to the bloodstream.

Answer 157

endocrine, exocrine

Question 158

______ have the ability to actively transport certain ions against concentration and electrical potential gradients.

Answer 158

Cells

Question 159

This is The transfer of ions and water via aquaporins in either direction across the epithelium.

Answer 159

Transcellular Transport

Question 160

______ tight junctions prevent paracellular diffusion or backflow between the cells.
The basal membrane of these cells is elaborately folded, with ______ located between the folds to supply ATP for a Na+/K+ pumps.
Lateral membrane folds interdigitating between the cells increase surface area for transport.

Answer 160

Apical, mitochondria

Question 161

Transcytosis

All cells can internalize extracellular molecules and fluid using ______ and formation of cytoplasmic, membrane-bound vesicles.

Answer 161

endocytosis

Question 162

Transcytosis

Examples are simple squamous epithelial cells lining blood and lymphatic capillaries (______) or body cavities (______).

Answer 162

endothelia, mesothelia

Question 163

Transcytosis

Abundant in pinocytotic vesicles, which cross the thin cells in both directions and release their contents on the opposite side by ______.

Answer 163

exocytosis

Question 164

Transcytosis

Occurs between the ______ and ______ membranes domains in cells of simples cuboidal and columnar epithelia.

Answer 164

apical, basolateral

Question 165

______ tissues are labile structures whose cells are renewed continuously by mitotic activity and stem cell populations.
Renewal varies widely.

Answer 165

Epithelial

Question 166

In stratified epithelial tissues, stem cells and mitosis occur only within the ______ layer in contact with the basal lamina.

Answer 166

basal

Question 167

______ cells are located only in restricted niches some distance from the transit amplifying cells and differentiating cells.

Answer 167

Stem

Question 168

Benign and malignant tumors can arise from most types of ______ cells.

Answer 168

epithelial

Question 169

______ - Malignant tumors of epithelial origin.

Answer 169

Carcinomas

Question 170

______ - Malignant tumors from glandular epithelial tissue.

Answer 170

Adenocarcinomas

Question 171

Adenocarcinomas are the most common tumors after age ______.

Answer 171

45

Question 172

An ______ is a tissue in which cells are bound tightly together structurally and functionally to form a sheetlike or tubular structure with little extracellular material between the cells.

Answer 172

epithelium

Question 173

Cells in epithelia each have an ______ side facing the sheet’s free surface and a ______ side facing a basement membrane and underlying connective tissue.

Answer 173

apical, basal

Question 174

Epithelia are often specialized for absorption or transcytosis, pinocytosis of material at the ______ side and exocytosis at the ______ side (or vice versa).

Answer 174

apical, basolateral

Question 175

Cells of most ______ exhibit continuous renewal, with the locations of stem cells and rates of cell turnover variable in various specialized epithelia.

Answer 175

epithelia

Question 176

The ______ of all epithelia is a thin extracellular layer of specialized proteins, usually having two parts: a ______ and a more fibrous ______

Answer 176

basement membrane, basal lamina, reticular lamina

Question 177

The ______ is a thin meshwork of type IV collagen and laminin produced by the epithelial cells.

Answer 177

basal lamina

Question 178

The ______ contains type III collagen and anchoring fibrils of type VII collagen, all secreted by cells of the immediately adjacent connective tissue.

Answer 178

reticular lamina

Question 179

Together, these components attach epithelia to connective tissue, regulate/filter substances passing from connective tissue into epithelia, provide a guide or scaffold during tissue regeneration after injury, and compartmentalize epithelial cells from other tissues.

Answer 179

basal lamina and reticular lamina

Question 180

______ junctions are well developed in epithelia and consist of three major types and functions.

Answer 180

Intercellular

Question 181

______ or ______ junctions are formed by interacting transmembrane proteins such as claudin and occludin; linear arrangements of these linked proteins surround the apical ends of the cells and prevent paracellular passage of substances (between the cells.)

Answer 181

Tight, occluding

Question 182

______ or ______ junctions, formed by interacting proteins of the cadherin family, are points of strong attachment holding together cells of the epithelium.

Answer 182

Adherent, anchoring

Question 183

______ composed of transmembrane integrins attach cells to proteins of the basal lamina.

Answer 183

Hemidesmosomes

Question 184

______ or ______ junctions are points of cell contact where both plasma membranes have numerous hexameric complexes of transmembrane connexons, each forming a channel allowing passage of small molecules from one cell to the other.

Answer 184

Gap, communicating

Question 185

Apical Structures of Epithelial Cells

Answer 185

Microvilli
Stereocilia
Cilia

Question 186

These are small membrane projections with cores of actin filaments that generally function to increase epithelial cells’ apical surface area for absorption.

Answer 186

Microvilli

Question 187

These are long microvilli with specialized mechanosensory function in cells of the inner ear and for absorption in tissues of the male reproductive tract.

Answer 187

Stereocilia

Question 188

These are larger projecting structures with a well-organized core of microtubules (in a 9 + 2 arrangement called the axoneme) in which restricted, dynein-based sliding of microtubules causes ciliary movement that propel material along an epithelial surface.

Answer 188

Cilia

Question 189

This is an epithelium in which the basement membrane has one cell layer.

Answer 189

Simple

Question 190

The cells of different ______ epithelia range widely in height, from very thin or squamous, to roughly cuboidal, to very tall or columnar.

Answer 190

simple

Question 191

These are Epithelia with two or more layers of cells.

Answer 191

Stratified

Question 192

______ glands have epithelial ducts carrying secretions to specific sites; the ducts of simple glands are ______ and those of compound glands are ______.

Answer 192

Exocrine, unbranched, branched

Question 193

The secretory portions of exocrine glands may form round, saclike ______ (also called ______) or elongated tubules; both types of secretory units may themselves branch.

Answer 193

acini, alveoli

Question 194

______ glands lack ducts; secreted substances are hormones carried throughout the body by the interstitial fluid and blood, with specificity produced by the hormone receptors of target cells.

Answer 194

Endocrine

Question 195

Glands have three basic secretory mechanisms: ______, which uses exocytosis; ______, in which terminally differentiated cells filled with lipid product are released; and ______, in which apical, product-filled areas of cells are extruded.

Answer 195

merocrine, holocrine, apocrine

Question 196

Exocrine glands producing mucus, or similar individual cells called goblet cells, are called ______ glands; oligosaccharide components of mucus stain poorly with routine dyes but stain well with PAS stain.

Answer 196

mucous

Question 197

Exocrine glands producing largely enzymes (proteins) are called ______ glands and stain darkly with H&E due to the cells’ content of RER and secretory granules.

Answer 197

serous

Question 198

Which specialization of the apical cell surface has more bristle-like structure and are usually uniform in length?

Answer 198

Microvilli

Question 199

An important, easily seen example that is abundant in the lining of the small intestine and respiratory tract, which secretes lubricating mucus that aids the function of these organs?

Answer 199

Goblet Cells

Question 200

The region of the cell contacting the ECM and connective tissue

Answer 200

basal pole

Question 201

three components of the basal lamina

Answer 201

type IV collagen
Laminin
Nidogen and perlecan

Question 202

Which is an example of transcytosis?

a. simple squamous epithelial cells lining blood
b. Na+/K+ pump
c. stratified epithelial tissues

Answer 202

a. simple squamous epithelial cells lining blood

Question 203

This allows cells to maintain the required low intracellular sodium concentration

Answer 203

Na+/K+ pump

Question 204

synthesize proteins that are mostly not glycosylated, such as digestive enzymes

Answer 204

Serous Cells