Histology Lecture 1 And 2

Front 1

4 main tissue types

Back 1

epithelium
connective
muscle
nervous

Front 2

group of cells with the same function

Back 2

tissue

Front 3

smallest structural and functional units

Back 3

cells

Front 4

what do all cells consist of EXCEPT RBCs?

Back 4

nucleus and cytoplasm and carry out basic metabolic activities

Front 5

tissues

Back 5

groups of cells performing specialized functions

Front 6

organs

Back 6

associations of several different tissues that together perform a specialized function

usually one type of tissue dominates the organ according to function

Front 7

organ systems

Back 7

higher level organizations of several organs that together perform more complex functions of the body

Front 8

tissue prep for light microscopy

Back 8

use formaldehyde to fix the specimen then dehydrate so that all lipids are extracted and place in paraffin

it is then placed on microtome in sections, slides are prepared, paraffin is removed

(remember that lipids and small molecules look like spaces bc they were removed during dehydration?

Front 9

light microscopy

Back 9

photons pass through the lens then through the specimen to form an image

Front 10

electron microscopy

Back 10

electrons pass through electromagnetic beams onto specimen

the image is passed to a viewing screen

the specimen is stained with hvy metals so some parts of cell is darker than others

Front 11

what is electron dense

Back 11

dense areas where that are heavily coated in metal so the electrons cannot pass through so they are seen as dark areas on TEM

Front 12

scanning electron microscopy

Back 12

electrons hit the 3D image coated in gold so the e- bounce off and give a 3D image

Front 13

what does appearance of structures depend on?

Back 13

orientation within the plane of the section

Front 14

what are tissue fixed with in electron microscopy?

Back 14

formaldehyde
gluteraldehyde
osmium tetroxide

Front 15

prep for e- microscopy

Back 15

fix with formaldehyde,gluteraldehyde, or osmium tetroxide

dehydrate with ethanol

section block on ultramicrotome

section put on Cu grid and stained with hvy metal

grids are put on electron microscope and e- beams are sent through tissue secctions

Front 16

what has higher resolution light or e- microscopy?

Back 16

electron

Front 17

what hvy metals are used to stain specimens in e- microscopy?

Back 17

uranyl acetate and lead citrate

Front 18

e- dense areas

Back 18

areas which stain heavily w/metal salt. these areas scatter e- well and produce black areas on screen below specimen

Front 19

e- lucent areas

Back 19

areas where little scattering of e- occurs bc less staining by hvy metals. areas appear lt gray or white

Front 20

what is important factor in staining for lt microscopy?

Back 20

postive and negative charges

positive charge of amino groups in muslce

neg charge on phosphate like in nucleus due to DNA/RNA

Front 21

what are most tissues stained with?

Back 21

hematoxylin and eosin

known as H & E staining

Front 22

hematoxylin

Back 22

a basic die

hematoxylin has a positive charge so it binds to negatively charged tissue through electrostatic interactions. Hematoxylin is blue so the nucleus with DNA/RNA is blue

Front 23

Basophillic

Back 23

acidic substances are basophillic bc the like to bind to the basic dye hematoxylin. Nucleic acids and cartilage matrix are negative so they bind to hematoxylin.

Front 24

what substances are basophillic?

Back 24

acidic cell components

Front 25

Eosin

Back 25

is a red acidic dye with a negative charge so it binds to positively charged tissue like amino groups in protiens

Front 26

acidophillic

Back 26

basic cell components that will bind to the acidic dye eosin like amino groups on proteins

Front 27

describe epthelial tissue

Back 27

it lines tubes and covers SURFACES

specialized for absorption,secretion, transporation, and protection

forms barriers that control passage of substances

Front 28

what tissue makes up most surfaces?

Back 28

epithelium

Front 29

describe connective tissue

Back 29

mostly in ECM with few cells

they support, compartmentalize, and provide protection of tissues

Front 30

how is connective tissue categorized?

Back 30

based on morphology

Front 31

what tissue provides structural and metabolic support for other tissue?

Back 31

connective tissue

Front 32

describe muscular tissue

Back 32

its cells are structurally and functionally specialized for contraction to produce movemnt of body wi body

Front 33

categories of muscular tissue

Back 33

cardiac
smooth
skeletal

Front 34

describe nervous tissue

Back 34

its cells are specialized to respond to internal and external stimuli and conduct signas from one pt to another

the cells integrate singals and determine reponse and stimulate muscle and glands to effet responses

Front 35

what tissue coordinates the activity of other tissues?

Back 35

nervous tissue

Front 36

what determines the boundaries of the cell?

Back 36

the plasma membrane

Front 37

what composes the plasma membrane?

Back 37

lipids
phospholipids
cholesterol
glycoproteins

membrane proteins
integral protein
peripheral proteins

the plasma membrane mass is 50% proteins and 50% lipids

Front 38

2 types of integral membrane proteins

Back 38

transmembraine proteins

membrane surface proteins

Front 39

role of cholesterol is bilayer

Back 39

determine rigidity of membrane

the more cholesterol the more rigid the bilayer

Front 40

types of cell junctions

Back 40

zonula occludens
zonula adherens
macula adherens
hemidesmosomes
gap junctions

Front 41

apical surface of cel

Back 41

in contact with lumen

top of cell

Front 42

basal layer of cell

Back 42

bottom of cell which is in contact with the basement membrane

Front 43

what forms a barrier between cytoplasm of cell and ECM?

Back 43

plasma membrane

Front 44

how thick is plasma membrane?

Back 44

5 nm thick

Front 45

role of integral proteins in plasma membrane

Back 45

receptors for external signal

act as structural links that connect plasma membrane to cytoskeleton or to ECM

Front 46

most abundant type of proteins in plasma membrane

Back 46

phospholipids

they have hydrophillic end and hydrphobic ends

Front 47

glycoproteins in plasma membrane

Back 47

sugar contain lipids whre carbs are on the non cytoplasmic surface of the membrane. the function of the carbs on the surface of the plasma membrane:

1.insulation (myelin)
2.cell recognition (receptor)
3.protection from lo pH and
enzymes (glycolcalyx)
4.binding to ECM

Front 48

glycolcalyx

Back 48

region of highly exaggerated glycolsylation found in intestinal lining

serves as protective barrier

provides region for metabolic
activity

functions as receptor

Front 49

what provides structural component of plasma membrane? how about specfic function?

Back 49

lipid bilayer provides basic structure and the membrane proteins carry out specific functions

Front 50

transmembrane proteins

Back 50

covalently anchored to bilayer via lipid side chain and have portions of proteins which pass through the lipid bilayer. these proteins form channels or pores and can act as receptors

Front 51

membrane surface proteins

Back 51

not imbedded wi bilayer like the transmembrane proteins but are still covalently bound via lipid side chains

these proteins are only associatedwith the internal or external surface of the plasma membrane

Front 52

peripheral membrane proteins

Back 52

bound non covalently to lipid bliayer by interaction with integral membrane proteins

Front 53

cell junctions in plasma membrane

Back 53

plasma membrane contains proteins that provide adhesion to other cells orto connective tissues (ECM)

Front 54

how are most epithelial cells joined?

Back 54

by combination of junctions called junctional complex

Front 55

components of junctional complex

Back 55

zonula occludens
zonula adherens
macula adherens
hemidesmosome
gapjunction

Front 56

zonula occludens (tight junctions)

Back 56

forms tight seal between lateral membranes of epithelial cells

prevents materials from passing between 2 epithelial cells

Front 57

where are zonula occludens located?

Back 57

most abundant in epithelium

located just basolateral to apical membrane

Front 58

zonula adherens
(adhesion belts or belt desmosome)

Back 58

provies mechanical adhesion between cells

a web of actin all the way around the cell. provides mechanical attachment between adjacent cells. Strands of actin filaments comlex w/proteins just below the plams membrane called cadherin allowing structural attachement between cells

Front 59

cadherins vs integrins

Back 59

cadherins attach cell to cell

integrins attact cell to matrix

both are transmembrane linkers and depend on extracellular cations to function

Front 60

where are zonula adherens generally found?

Back 60

as part of junctional complex of polarized epithelial cells

located basolateral to tight junction

Front 61

macula adherens (desmosome)

Back 61

plaque like adhersions restricted to epithelial cells

provides mechanical attachement between cells but dont go all the way aroundthe cell like adhesion belts

desmosomes are spots of proteins wi plasma membrane w/cadherins projecting out to join other cells. cytoplasmic plaques attach to the cadherin. on the opposite side of the plaques are intermediate filaments called keratin filaments which project out of plaque and attach to plaques on other cells

Front 62

hemidesmosome

Back 62

have asymmetric morphology like desmosomes but attaches basal membrane of epithelial
cell to underlying ECM

half of desmosome at basal surface. no cadherins here. has intefrin molecules that allow attachment of basal surface of ep cell to ECM

Front 63

Gap junction

Back 63

hexagonal arrays of 6 integral membrane proteins called connexins that come together to form connexons. connexons line up to form channels to allow small molecules to pass through. the opening of the pores are regulated by Ca and phosphorylation of the connexins

Front 64

where are gap junctions mainly found?

Back 64

epithelium, smooth, and cardiac muscle, nerve cells and osteocytes

Front 65

network of filamentous proteins in the cytoplasm in eukaryotic cells which interatcs w/oraganelles and membrane to allow movement and compartmentalization

Back 65

cytoskeleton

Front 66

what does cytoskelton depend on?

Back 66

netwok of protein filament to provide structural integrity and carry out intracellur movemnt

Front 67

what is cytoskelton composed of?

Back 67

1. intermediate filaments- ropelike and provide structure

2. microtubules-hollow cylinders of tubulin for intracellular trasport. larger that int. filaments. have + and - end so can change lenghth

3. microfilaments-"actin" double stranded helix of actin monomers. maintinas cell structure and shape and provides movement of cells especially near cell surface

Front 68

four main groups of intermediate filaments based on protein compostion and cellular localization

Back 68

1.cytokeratin
2. neurofilaments
3.heterogenous filaments (vimentin)
4.nuclear lamins

Front 69

where is vimentin found?

Back 69

type of intermediate filament found in conncecitve tissue, muscle cells, and neural glial cells

Front 70

where are neurofilament found?

Back 70

type of intermedeate filament found in nerve cells

Front 71

what component of cytoskelton is important in diagnosis for cell types?

Back 71

intermediate filaments

Front 72

four main groups of intermediate filaments

Back 72

1.cytokeratin filaments
2.neurofilaments
3.heterogenous filament
4.nuclear lamins

Front 73

what are the four main groups of intermediate filaments based on?

Back 73

protein composition and cellular localization

Front 74

where is keratin found?

Back 74

in epithelial cells only

Front 75

where is vimentin found?

Back 75

in connective tissue, muscle cells, and neural glial cells

Front 76

where are neurofilaments found?

Back 76

in nerve cells

Front 77

types of intermediate heterogenous filaments

Back 77

vimentin
desmin
neurofilaments
lamins

Front 78

what type of protein filament is specific for cell types and diagnostic?

Back 78

intermediate filaments is diagnostic for cancers bc they are specific to certain cell types and provide clues to tissue orgin of tumor

Front 79

2 categories of intermediate filaments

Back 79

1.cytoplasmic
keratins
vimentin
neurofilaments

2.nuclear
nuclear lamins

Front 80

microtubules

Back 80

hollow cylinder composed of tubulin that assembles and disassembles

at + and - end

Front 81

where does - end of microtube attach?

Back 81

to microtubule organizing center aka centrosome

Front 82

what is centrosome

Back 82

where - end of microtubule attaches in center of cell near the nucleus

contains pair of cylindrical centrioles with a 9+0 triplet

Front 83

what type of protein filament are cilia and flagella?

Back 83

microtubules

Front 84

where are + and - end of microtubule?

Back 84

+ end at periphery

- end in center

Front 85

point of attachment of microtubules and spindle fibers. also where chromosomes attach during cell division

Back 85

centrioles

Front 86

microtubules function

Back 86

provides structural rigidity to cell

control movement of transport vesicles and other organelles wi cell

framework of miotic spindle during cell division

provide forces needed for ceiliary and flagellar beating

Front 87

microtubule motor proteins

Back 87

bind to microtubule and vessicles/organelles

2 kinds
1.dynein
2.kinesin

Front 88

dynein

Back 88

microtubule motor protein that moves molecules from plus to minus end moving transport vesicles toward the centrosome in prescence of ATP

Front 89

kinesin

Back 89

type of microtubule motor proteins that move carbon molecules toward the plus end at the periphery

effects vesicular and organelle transport toward plus end

Front 90

what are cilia made of?

Back 90

basal body with similiar structure to centrioles except that cilia has 9+2 arrangement: 9 doublets and 2 single microtubules in the center surrounded by plasma membrane.

Front 91

what allow movement of cilia?

Back 91

interaction of dyenin arms w/adjacent microtubules in sliding motion of cilia

Front 92

difference in size of cillia and microvilli

Back 92

cillia are 10-12 microns, same size as nucleus

microvilli are like 1 micron

Front 93

Kartageners syndrome (immotile cilia)

Back 93

rare congenital disorder where dynein arms (common),spokes,nexin links or other ciliar components are absent. this causes male and femal infertility,chronic bronchitis, and sinusitis

Front 94

microfilaments

Back 94

flexible DS helical polymers of actin

Front 95

how are microfilaments aka actin attached to plasma membrane and other cytoskelton cmpds?

Back 95

via accessory proteins

Front 96

function of microfilaments

Back 96

maintain cell sape

form core of micro villi

locomotion

cytokinesis

endo/exocytosis

growth of axons

capping

Front 97

what does cell locomotion require?

Back 97

actin-myosin motor protein system and actin binding protein

Front 98

where are actin filaments located?

Back 98

within the cytoplasm below the plasma membrane through proteins that bind w/membrane proteins,such as integrins, which then interact w/proteins in EXM like fibronectin and aminin

this helps make supporting framework

Front 99

what bridges cytoskeleton to Extracellular support framework?

Back 99

integrins

Front 100

microvilli

Back 100

non motile

comrprised of actin microfilaments

1mm

increase SA/absorptive

Front 101

stereocillia

Back 101

basically long microvilli
with absorptive function seen in epididymis of male repro tract