Chapter 3: Compartmentalization - Cells and Tissues

Question 1

separates cell from environment

Answer 1

cell membrane

Question 2

what are the functions of the cell membrane?

Answer 2

1. physical isolation, separates ICF from ECF
2. Regulation of exchange with the environment, entry of ions and nutrients, elimination of cellular waste and release of cell products
3. Communication between the cell and its environment, contains proteins that allow the cell to respond to external changes
4. Structural support, create the cells cytoskeleton, form cellular junctions, and connect to the extracellular matrix. These cell-cell and cell-matrix junctions help to stabilize the structure of tissues

Question 3

what does the fluid mosaic model entail?

Answer 3

• Phospholipids
• Sphingolipids-phospholipids or glycolipid heads with longer fatty acid tails.
• Cholesterol
• carbohydrates
• integral proteins
• peripheral proteins

Question 4

help to decrease permeability of the cell to small water-soluble molecules and helps to keep the membrane flexible or fluid with changing temperatures.

Answer 4

cholesterol

Question 5

• form bilayers, micelles, or liposomes

* arrange themselves so that their nonpolar tails are not in contact with aqueous solutions such as extracellulalr fluid

Answer 5

membrane phospholipids

Question 6

forms a sheet

Answer 6

phospholipid bilayer

Question 7

• droplets of phospholipid

* important in lipid digestion

Answer 7

micelles

Question 8

have an aqueous center

Answer 8

liposomes

Question 9

embedded within the lipid bilayer, so they can be dissociated from the membrane only by disrupting the bilayer

Answer 9

integral proteins

Question 10

what are the different types of integral proteins?

Answer 10

1. enzymatic proteins
2. transmembrane proteins
3. lipid-anchored proteins

Question 11

what are examples of integral proteins with enzymatic function?

Answer 11

1. G proteins

2. Receptor molecules

Question 12

span the lipid bilayer, with surfaces exposed to both the ICF and ECF

Answer 12

transmembrane proteins

Question 13

what are examples of transmembrane proteins?

Answer 13

1. ion channels

2. carrier proteins

Question 14

can be attached to lipid tails (sphingolipids) that insert into the bilayer (play a role in lipid rafts)

Answer 14

lipid-anchored proteins

Question 15

• are loosely bound to the membrane by associations with integral membrane proteins or phospholipids.
• attached to cytoskeleton
• some enzymatic function

Answer 15

peripheral proteins

Question 16

primarily on the extracellular surface of the membrane

Answer 16

carbohydrates

Question 17

what are the two main functions of carbohydrates in the membrane?

Answer 17

1. form the glycocalyx

2. function in cell recognition, labeling the cell as part of the body or as a distinct type of cell

Question 18

• *a protective layer that also functions in holding cells together
• *formed by carbohydrates

Answer 18

glycocalyx

Question 19

carbohydrates attached to proteins

Answer 19

glycoproteins

Question 20

carbohydrates attached to lipids

Answer 20

glycolipids

Question 21

synthesized and secreted by cells and its composition varies from tissue to tissue

Answer 21

extracellular matrix

Question 22

what are the 2 basic components of extracellular matrix?

Answer 22

1. proteoglycans

2. insoluble protein fibers

Question 23

provide strength and anchor cells to matrix

Answer 23

insoluble protein fibers

Question 24

what is a subset of proteoglycans?

Answer 24

glycoproteins

Question 25

what do insoluble fibers include in the extracellular matrix?

Answer 25

1. collagen 2. fibronectin 3. elastin 4. laminin

Question 26

what are the three major types of cell junctions?

Answer 26

1. gap junctions 2. tight junctions 3. anchoring junctions

Question 27

* form small channels that enable ions and small molecules to move between two cells * communicating junctions

Answer 27

gap junctions

Question 28

membrane proteins composed of smaller proteins called connexins

Answer 28

connexons

Question 29

what are examples of gap junctions?

Answer 29

smooth muscle | cardiac muscle

Question 30

* integral membrane proteins called claudins and occludins fuse adjacent cells together to form a nearly impermeable barrier to the movement of substances between cells * occluding junctions

Answer 30

tight junctions

Question 31

what does the barrier of tight junctions result in?

Answer 31

causes solutes to cross epithelial cell layer (transepithelial transport), rather than going around (paracellular movement)

Question 32

what are examples of tight junctions?

Answer 32

epithelial cells that line hollow structures of the kidneys, or gastrointestinal tract

Question 33

attach cells to each other or to the ECM.

Answer 33

anchoring junctions

Question 34

what are cell-cell junctions created by?

Answer 34

created by cadherins which connect across the intercellular space

Question 35

link actin fibers in adjacent cells

Answer 35

adheren junctions

Question 36

* the strongest | * link intermediate filaments of the cytoskeleton

Answer 36

desmosomes

Question 37

use integrins which are membrane proteins that can be receptors

Answer 37

cell-matrix junctions (anchoring)

Question 38

what is used in cell-matrix junctions?

Answer 38

1. hemidesmosomes | 2. focal adhesions

Question 39

anchor intermediate fibers of the cytoskeleton to matrix proteins such as laminin

Answer 39

hemidesmosomes

Question 40

tie intracellular actin fibers to matrix proteins such as fibronectin

Answer 40

focal adhesions

Question 41

what are the 4 major classes of tissues?

Answer 41

1. connective 2. neural 3. muscle 4. epithelial

Question 42

provides structural support, but also encompasses fluids such as the blood and lymph, which serve to “connect” the various parts of the body together by providing avenues of communication

Answer 42

connective tissue

Question 43

excitable cells carrying information in the form of electrical and chemical signals

Answer 43

neural tissue

Question 44

excitable cells with the ability to contract and produce force

Answer 44

muscle tissue

Question 45

play a role in both protection of the internal environment and regulation of the exchange of materials between the ICF and ECF

Answer 45

epithelial tissue

Question 46

what is the structure of epithelia?

Answer 46

* one or more layers of cells * Separated from underlying tissue by the basal lamina or basement membrane (extra cellular layer composed of collagen and laminin in proteoglycans)

Question 47

How is epithelia structurally divided into two types?

Answer 47

1. sheets of cells lining the body surfaces of internal and external surfaces 2. secretory epithelia (glands)

Question 48

what do most epithelia attach to?

Answer 48

basal lamina or basement membrane

Question 49

how do epithelial cells attach to the basal lamina?

Answer 49

using cell adhesion molecules

Question 50

acellular matrix layer that is secreted by the epithelial cells

Answer 50

basal lamina

Question 51

what are the histological classifications of epithelial tissue?

Answer 51

1. layering (simple or stratified) 2. shape (squamous, cuboidal, columnar) 3. function (exchange, transport, ciliated, protective, secretory)

Question 52

* allows for rapid gas exchange * simple squamous epithelium (very thin) * endothelium lines the circulatory system

Answer 52

exchange epithelia

Question 53

* cuboidal or columnar in shape * have membrane modifications * tight junctions force materials to cross the cell * many mitochondria that provide energy for transport

Answer 53

transporting epithelia

Question 54

what are the membrane modifications of transporting epithelia?

Answer 54

* apical membrane faces lumen and has microvilli | * basolateral membrane faces ECM and may also have fold

Question 55

moves fluid and particles in respiratory system and female reproductive tract

Answer 55

ciliated epithelium

Question 56

* are found in areas of mechanical and chemical stress. * stratified tissue * may be strengthened by secretion of keratin

Answer 56

protective epithelia

Question 57

* scattered among other epithelial tissue | * grouped into glands

Answer 57

secretory epithelium

Question 58

what are the glands of secretory epithelium?

Answer 58

1. exocrine glands | 2. endocrine glands

Question 59

* release products to external environment (mostly through ducts) * serous secretions * mucous secretions

Answer 59

exocrine glands

Question 60

watery (digestive,tears, and sweat)

Answer 60

serous secretions

Question 61

produced by goblet cells

Answer 61

mucous secretions

Question 62

release hormones into extracellular compartments (ECF or blood)

Answer 62

endocrine glands

Question 63

how many layers do exchange epithelium have and what is its cell shape?

Answer 63

one cell layer | flattened shape

Question 64

has pores between cells that permit east passage of molecules

Answer 64

exchange epithelium

Question 65

where are exchange epithelium found?

Answer 65

lungs lining of blood vessels

Question 66

how many cell layers do transporting epithelium have and what is the shape?

Answer 66

one layer | columnar or cuboidal

Question 67

* tight junctions prevent movement between cells | * surface area increased by folding of cell membrane into fingerlike microvili

Answer 67

transporting epithelium

Question 68

where are transporting epithelium found?

Answer 68

intestine kidney some exocrine glands

Question 69

how many cell layers do ciliated epithelium have and what is the shape?

Answer 69

one cell layer | columnar or cuboidal

Question 70

one side covered with cilia to move fluid across surface

Answer 70

ciliated epithelium

Question 71

where are ciliated epithelium found?

Answer 71

nose, trachea, upper airways; female reproductive tract

Question 72

how many cell layers do protective epithelium have?

Answer 72

many

Question 73

what is the cell shape of protective epithelium?

Answer 73

flattened in surface layers; polygonal in deeper layers

Question 74

cells tightly connected by desmosomes

Answer 74

protective epithelium

Question 75

where are protective epithelium found?

Answer 75

skin and lining of cavities that open to the environment

Question 76

how many cell layers do secretory epithelium have and what is the shape?

Answer 76

one to many layers | columnar or polygonal

Question 77

* protein secreting cells filled with membrane bound secretory granules and extensive RER * steroid secreting cells contain lipid droplets and extensive SER

Answer 77

secretory epithelium

Question 78

where are secretory epithelium found?

Answer 78

* exocrine glands: pancreas, sweat glands, salivary glands | * endocrine glands: thyroid and gonads

Question 79

* minimal matrix * basal lamina matrix * no direct blood supply * has microvilli, cilia * covers body surface, lines cavities and hollow organs and tubes; secretory glands

Answer 79

epithelial tissue

Question 80

* extensive matrix * varied matrix * cartilage has no blood supply * supports skin and other organs; cartilage, bone, blood * cells not in layers

Answer 80

connective tissue

Question 81

* minimal matrix * external lamina matrix * can generate electrical signals, force, and movement * makes up skeletal muscles, hollow organs, and tubes * cells linked in sheets or elongated bundles

Answer 81

muscle tissue

Question 82

* minimal matrix * external lamina matrix * can generate electrical signals * throughout the body, but mainly in brain and spinal cord * cells isolated or networked

Answer 82

nerve tissue