Exam #1 Prep Flashcards
1
Q
Generally cells with ______ stained nuclei are more active in protein synthesis
A
lightly
p.56
2
Q
Describe the six steps of tissue preparation
A
- Fixation: Tissue placed in solutions that preserve the tissue by cross-linking proteins and inactivating degradative enzymes.
- Dehydration: Tissue transferred through increasingly concentrated alcohol solutions, ending in 100%, thus removing all of the water.
- Clearing: Alcohol is removed in toluene or other agents in which both alcohol AND paraffin are miscible.
- Infiltration: Tissue placed in melted paraffin until it becomes completely infiltrated.
- Embedding: Paraffin-infiltrated tissue placed in a mold with melted paraffin and allowed to harden.
- Trimming: Resulting paraffin block is trimmed to expose the tissue for sectioning (slicing) on a microtome.
3
Q
Hematoxylin binds -ophilic cell components?
Eosin?
A
Hematoxylin binds Basophilic (acidic) cell components – it is a basic/acidophilic dye
Eosin binds acidophilic (basic) cell components
4
Q
What does the objective lens do?
A
enlarges (x4, x10, or x40) and projects illuminated image towards eyepiece.
5
Q
Define resolution
A
Measures how close two objects can be and still appear separate.
6
Q
In freeze fracture, the plane passes through which part of the membrane?
A
Hydrophobic portion.
7
Q
Define cell differentiation. Describe a cells function after differentiation.
A
When cells begin to synthesize increased quantities of specific proteins and become very efficient in specialized functions, often changing their shape accordingly.
Specialized cells have greatly expanded their capacity for one or more functions during differentiation.
p.18
8
Q
Differentiated cells typically _______.
A
Specialize in one or more activities.
9
Q
Cilia are Short, numerous _______ extensions supported by _______.
A
membrane
microtubules
10
Q
Microvilli are numerous thin _______ projecting from the free cell surface; supported by ______. What is their function?
A
Membrane folds
Microfilaments
Increase membrane SA for greater absorption.
11
Q
Describe the structure and function of the glycocalyx
A
Composed of oligosaccharides of glycolipids and glycoproteins.
It provides important antigenic and functional properties to the cell surface. They are important components of proteins acting as receptors, which participate in important interactions such as cell adhesion, cell recognition, and the response to protein hormones.
12
Q
Cytoplasm is defined as…
A
Contents of cells between the plasma membrane and nuclear envelope.
13
Q
Cytosol is defined as…
A
Viscous fluid medium with dissolved solutes (eg, ions, proteins, carbohydrates, lipids).
14
Q
The nuclear envelope is continuous with which organelle?
A
RER
15
Q
What are the fates of proteins synthesized in the RER?
A
Become components of the plasma membrane, or serve as enzymes of lysosomes.
16
Q
What are the functions of SER? (3)
A
- Synthesizes, transports, and stores LIPIDS (eg, steroids); 2. metabolizes carbohydrates; detoxifies drugs, alcohol, and poisons;
- forms vesicles and PEROXISOMES (contain oxidative enzymes related to detoxification).
17
Q
Describe peripheral (extrinsic) membrane proteins. Which surface are they typically associated with?
A
Exhibit a looser association with one of the two membrane surfaces, particularly the inner.
18
Q
What is meant by the concept of membrane asymmetry?
A
The distribution of membrane polypeptides is different in the two surfaces of the cell membrane (i.e. different chemical composition of inner and outer layers).
19
Q
Simple diffusion occurs when small ______ molecules can simply pass through the lipid bilayers.
A
lipophilic (fat-soluble)
20
Q
What allows water to diffuse through the cell membrane and by what process? Describe the general structure.
A
Aquaporins – multipass transmembrane proteins that facilitate the transmembrane diffusion of water molecules (by osmosis).
21
Q
What is the major role of clathrin in endocytosis?
A
It facilitates the invagination of the membrane into pits for endocytosis, i.e. it provides the lattice that helps shape the membrane into vesicles.
22
Q
List the steps of receptor-mediated endocytosis (6)
A
- Receptors on the cell surface for high-affinity ligands such as LDLs and protein hormones bind the ligand, which then associates with cytoplasmic proteins (including CLATHRIN and adaptor proteins).
- The membrane then invaginates (AS A COATED PIT) and pinches off internally as vesicles.
- Invagination begins as a coated pit. Cytoplasmic surface of vesicle is coated with clathrin to form a coated vesicle.
- Clathrin coat is removed and vesicle then undergoes one of three processes.
- Ligands then undergoe one of THREE processes in the endosomal compartment after the clathrin coat is removed:
- ) Degradation: Receptors and ligands may be carried to LATE ENDOSOMES and then to LYSOSOMES for degradation.
- ) Receptor recycling: Ligands may be released internally and the receptors recycled to the cell surface.
- ) Transcyctosis: Vesicles may move to and fuse with another cell surface, where the ligands are released again outside the cell (TRANSCYTOSIS).
23
Q
Give a general definition of endocytosis. What type of process is it?
A
An active process involving FOLDING and FUSION of the MEMBRANE TO FORM VESICLES that enclose the material being transported into the cell.
24
Q
The _____ side of RER membrane will be coated with polyribosomes.
A
cytosolic
25
Cell with few/no RER and many free polyribosomes likely...
Make no protein for secretion.
26
Cells that synthesize, segregate, and STORE various proteins in specific secretory granules or vesicles always have _____, a ______, and a supply of ______; e.g. _______.
RER, a Golgi apparatus, and a supply of granules containing the proteins ready to be secreted; e.g. eosinophilic leukocyte.
27
Describe the two faces of the Golgi apparatus.
Cis face: Faces/is close to the RER. The transport vesicles merge with the Golgi-receiving region, or CIS FACE (faces a CIStern, i.e. RER). On the opposite side of the Golgi network, at its shipping or TRANS FACE, larger saccules or vacuoles accumulate, condense, and generate other vesicles that carry completed protein products to organelles away from the Golgi.
28
Describe the two primary functions of the Golgi apparatus.
1. Enzymes of the Golgi apparatus are important for glycosylation, sulfation, phosphorylation, and limited proteolysis of proteins (i.e POST-TRANSLATIONAL MODIFICATIONS).
2. The Golgi apparatus also initiates packing, concentration, and storage of secretory products.
29
Cells with extensive RER and a well-developed Golgi apparatus show few ______. Why?
Secretory granules. Because the proteins undergo exocytosis immediately after Golgi processing is complete. Many cells, especially those of epithelia, are polarized, meaning that the distribution of RER and secretory vesicles is different in various regions or poles of the cell.
30
Describe the main differences in the cisternae of SER and RER.
The RER consists of saclike as well as PARALLEL STACKS of flattened cisternae (Figure 2–10), each limited by membranes that are continuous with the outer membrane of the nuclear envelope.
SER cisternae are often more tubular and more likely to appear as INTERCONNECTED CHANNELS of various shapes and sizes *than as stacks of flattened cisternae.*
31
The Golgi stains ______ and is identified by ______.
poorly
| pallor (paleness)
32
Synthesis of lysosomal enzymes occurs in the _____, with packaging in the ______.
RER
| Golgi
33
Endocytosis produces vesicles that fuse with ______ before merging with ______.
endosomes
lysosomes
p.38
34
What is lipofuscin?
The accumulated products in long-lived cells (within residual bodies) of indigestible products of lysosomal digestion.
35
Autophagy is a process in which the cell uses ______ to __________________.
lysosomes to dispose of excess or nonfunctioning organelles or membranes.
36
The trans face of the Golgi will typically appear to be (concave or convex)?
Concave.
37
Lysosomes are a heterogeneous collection of ______ vesicles and vacuoles that derive from ______ vesicles.
membrane-bound vesicles
| Golgi complex vesicles
38
Free ribosomes synthesize proteins for _________, but ribosomes attached to RER synthesize proteins for _______.
internal use by the cell (import to the nucleus, mitochondria, and peroxisomes).
incorporated into membranes, stored in lysosomes, or secreted from the cell.
p.29
39
In H&E-stained sections, ribosomes impart cytoplasmic _______ (what type of stain affinity) to cells actively _______. Why do they stain that way?
basophilia to cells actively SYNTHESIZING PROTEIN.
| They are basophilic because of the numerous phosphate groups of RNAs that act as polyANIONs.
40
Collectively, the ______ and ______ form the protoplasm of a cell.
cytoplasm and nucleus
41
_______ are found at the base of cilia and flagella. What are they composed of?
Centrioles; they are composed of microtubules.
42
Synthesis of lysosomal enzymes occurs in the _____, with packaging in the ______.
RER
| Golgi apparatus
43
The mitochondrial matrix contains a small circular chromosome of...(4 things)
DNA, ribosomes, mRNA, and tRNA.
44
Name three important structural proteins made from intermediate filaments, and where they are found.
1. Keratin: Epithelial cells.
2. Lamins: Nuclei of all cells.
3. Desmins: Muscle cells
45
Polymerization of microtubules is directed by ________ (_____), which are predominantly _______ in somatic cells.
Microtubule Organizing Centers (MTOC)
| Centrosomes in somatic cells
46
Growth occurs more rapidly at the ____ end of existing microtubules.
(+) end
47
Kinesins perform _______ transport (i.e. ______ from the nucleus), which is towards the + or – end?
Anterograde, i.e. away from the nucleus, + end.
48
Dyenins perform _______ transport (i.e. ______ from the nucleus), which is towards the + or – end?
Retrograde transport, i.e. towards the nucleus, – end
49
If something exhibits basophilia, how will it stain with H&E?
List SIX basophilic cellular components.
Blue.
Nucleic acids (DNA, RNA)
Heterochromatin (because of ionized phosphate groups in this and nucleic acids)
Nucleolus
GAGs
Cartilage matrix (because of ionized sulfate groups on carbohydrates)
Ground substance
50
If something is eosinohpilic, how will it stain with H&E?
List SEVEN eosinophilic cellular components.
```
Pink.
General cytoplasm
Cytoplasm proteins
Collagen fibers
Mitochondria
Protein granules
Reticular fibers
Extracellular fibers (due to ionized amino groups)
```
51
Describe the general constituents of eukaryotic cell membrane
In eukaryotes, made of phospholipids, cholesterol, proteins, and oligosaccharide chains covalently linked to phospholipid and protein molecules.
52
PAS is used primarily to stain what type of structures?
Carbohydrates.
- Glycocalyx (surface of epithelia and cell membranes)
- Mucin (Goblet cells)
53
Connective tissues originate from ______, a tissue developing mainly from the ___________ ( ______ ).
- embryonic mesenchyme
| - middle layer of the embryo (the mesoderm).
54
What are the two components of extracellular matrix (ECM)?
Fibers and ground substance
55
The terminal web and cytoplasmic cores of microvilli have large numbers of what?
Microfilaments
56
The nucleolus is most directly associated with the synthesis of what?
rRNA
57
Where are ribosomal subunits synthesized?
in the NUCLEOLUS
58
Name three types of intermediate filament associated proteins
Keratins, vimentin, and desmin
59
Karyotypes are usually obtained during which mitotic phase?
metaphase
60
Which cell cycle phase is typically the longest and has the most variability?
G1
61
Which organelle is most likely responsible for the synthesis of intermediate filaments?
Free ribosomes or polyribosomes
62
During which phase of the cell cycle do cells generally double in size?
G1
63
What is the best way to visualize reticular fibers? What is an alternate method?
Silver stains.
| Also PAS positive.
64
What is the general composition of GAGs?
Long, unbranched polysaccharides composed of repeating disaccharide units (HEXOSAMINE and URONIC ACIDS).
65
Name five important GAGs
1. Hyaluronan
2. Chondroitin sulfate
3. Dermatin sulfate
4. Keratan sulfate
5. Heparan sulfate
66
What allows GAGs to resist compression?
Negatively charged GAGs attract osmotically active cations (Na+)
67
What is an important glycoprotein constituent of basement membrane? What does it do?
Laminin: Mediates adhesion of epithelial cells to basement membrane.
68
What is the name of the structure responsible for the covalent cross-linking in elastic fibers?
Desmosine
| -see 5a
69
Proteolytic digestion of a proteoglycan would result in the release of what?
GAGs
70
What is responsible for the banding pattern of collagen on EM?
Staggered arrangement of tropocollagen molecules.
71
What is pyknosis of a nuclei? What does it represent?
Pyknosis is the irreversible condensation of chromatin in the nucleus of a cell undergoing necrosis or apoptosis. It is followed by karyorrhexis, or fragmentation of the nucleus.
72
______ provide a barrier to the lateral diffusion of membrane proteins and lipids between cells.
```
Tight junctions/zonula occludens.
#3 Histo review
```
73
What protein is the principal mediator of membrane ruffling and locomotion in these cultured cells?
```
Actin
#4 Histo review
```
74
Desmin and vimentin are _______ proteins found in ______ cells.
```
intermediate filament proteins found in mesenchymal cells.
#4 Histo review
```
75
What are the nuclear matrix proteins that stabilize the nuclear membrane and organize chromatin?
Lamins
76
Which proteins form the spindle apparatus, regulate INTRAcellular transport, and control the movement of cilia and flagella?
Tubulins
77
Describe holocrine secretion
Loss of plasma due to an initiation programmed cell death in order to release intracellular stores of lipid and wax.
78
It which organ would you expect to find lots of SER and why?
Liver because of its detoxifying role.
79
Mucins within goblet cells are heavily ______ _____proteins that protect the intestinal mucosa and lubricate the luminal contents. Which stain would be best used to visualize these cells?
glycosylated GLYCOproteins.
| PAS.
80
______ are small vesicles filled with catalase and other enzymes that remove reactive oxygen species (e.g., hydrogen peroxide).
Peroxisomes
81
_______ can be used to identify elastic fibers and mast cell secretory granules.
Aldehyde fuchsin
82
What type(s) of cellular materials will stain well with eosin? Give examples.
BASIC materials (eosin is an acidic stain).
- Most proteins in the cytoplasm are basic because they are positively charged due to the arginine and lysine amino acid residues. These form salts with acid dyes containing negative charges, like eosin. Therefore, eosin binds to these amino acids/proteins and stains them pink.
- This includes cytoplasmic filaments in muscle cells, intracellular membranes, and extracellular fibers.
83
The dominant feature of centrioles is the ____ array of _____ ________ with associated proteins.
Cylindrical array of triplet microtubules with associated proteins.
84
Diploid cells have __n amount of DNA after the S-phase.
4n
85
How does a prominent nucleolus stain on H&E? Why?
Intensely BASOPHILIC, because of the dense concentration of rRNA.
86
What are the pale centers of a nucleolus? Describe.
| What is another name for this general location?
Nucleolar organizing regions (NORs): Genes responsible for producing rRNA.
-Fibrillar centers.
87
What is the fibrillar material (pars fibrosa) of a nucleolus?
Where newly synthesized rRNA first appears.
88
What is the pars granulosa?
Granular material of the nucleolus: The region of the nucleolus where ribosomal subunits accumulate.
89
Which types of cells have the longest G1 phase?
Differentiating cells.
90
Describe the G1 phase.
- Typically the longest and most variable phase.
| - A period of active RNA and protein synthesis (including proteins controlling the cell cycle).
91
What is one type of protein NOT synthesized during G1. When is it synthesized?
Histone. S phase.
92
In stratified squamous epithelium, the most common type of intercellular junction is what?
Desmosome (make sure this is right!)
93
Attachment of epithelia to underlying basal lamina is enhanced by what cell junction?
Hemidesmosomes
94
Which type of cell junction is the most efficient barrier preventing diffusion of materials between epithelial cells?
Zonula occludens
95
The cell junction found at the interface of an epithelial cell and a basement membrane is what?
Hemidesmosome.
96
______ are large glycoproteins that self-assemble as a lacelike network immediately below the cells’ basal poles where they are held in place by the transmembrane ______.
Lamins
| Integrins
97
Describe the terminal bar.
Complexes of tight and adherent junctions that are present at the apical ends of cells just beneath apical projections. See p. 85 Junq.
98
Describe the general composition of ground substance.
Ground substance is a complex of anionic, hydrophilic proteoglycans, glycosaminoglycans (GAGs), and multiadhesive glycoproteins (laminin, fibronectin, and others).
99
What molecule associated with elastic tissue provides covalent cross-linking of the elastic fibers and imparts its characteristic rubber-like qualities?
Desmosine.
| p.113 Junq
100
Which family of proteins provides the scaffolding necessary for proper deposition of elastic tissue, and whose mutated gene results in Marfan syndrome?
Fibrillin.
101
What are some of the characteristic symptoms of Marfan Syndrome?
Aortic aneurysm, lens dislocation (eye), rubbery joints, elongated limbs, abnormal height.
102
Which type of collagen is present in all basal and external lamina? What type of collagen is it and what does it do?
What MAG is it often associated with?
Type IV Collagen: Sheet Forming.
- Supports epithelial cells and filters.
- Laminin
103
What type of collagen anchors basal lamina to underlying reticular lamina?
Type VII: Linking/Anchoring Collagen.
| -Figure out what the associated proteins are!
104
Which type of cell junction contains abundant integrins which bind Type IV collagen?
Hemidesmosomes
105
Which type of collagen helps Collagen Type I form bigger bundles? What is it known as?
Type VII Collagen: Linking Collagen.
106
Where are collagen types I, II, and III found? What is their group name?
FIBRILLAR collagen.
Type I: Skin, tendon, ligament.
Type II: Cartilage.
Type III: Reticular fibers
107
Which proteins are commonly associated with stereocilia? What do they do?
Fimbrin and Ezrin: They cross link F-actin present in stereocilia.
108
Which proteins are commonly associated with microvilli? What do they do?
Fimbrin and Villin – VILLin = microVILLi (duh!)
| They cross link F-actin.
109
Which type of enzyme would a bacteria likely have if it could lower the viscosity of, and penetrate connective tissue ground substance?
Because of their high viscosity, HA and proteoglycans tend to form a barrier against bacterial penetration of tissues. Bacteria that produce HYALURONIDASE, an enzyme that hydrolyzes hyaluronic acid and disassembles proteoglycans complexes, reduce the viscosity of the connective tissue ground substance and have greater invasive power.
p.116 Junq
110
What is fibrillin?
A glycoprotein that forms fine microfibrils that serve as the scaffolding for elastin in elastic tissue. Fibrilin is deposited first.
111
What are the agyrophilic elements present in basement membrane?
Type III collagen of reticular fibers
112
How do GAGs stain? Why?
Highly basophilic, because of their (+) sulfated and carboxyl groups.
113
How do GAGs function in protection from bacteria?
They form a viscous medium that makes it difficult for large macromolecules and bacteria to penetrate.
114
How is hyaluronic acid/hyaluronan different from other GAGs?
It is composed of a chain of several thousand sugars (rather than several hundred or fewer in other GAGs). Also, HA is not bound to a core protein to form a proteoglycan. Rather, proteoglycans are indirectly attached to HA by link proteins. The molecule is exceedingly hydrophilic and gives cartilage the ability to compress.
115
In response to body needs, lipids are mobilized rather uniformly in all parts of the body, although adipose tissue in ________ (3 places) resists even long periods of starvation.
the palms, soles, and retro-orbital fat pads
- During starvation, most unilocular adipocytes lose nearly all their fat and become polyhedral or spindle-shaped cells with only very small lipid droplets.
p. 127 Junq
116
It is well established that increased _____ adipose tissue raises the risk of diabetes and cardiovascular disease whereas increased _____ fat does not.
visceral adipose tissue
subcutaneous fat does not
p.127
117
Adipocytes differentiate from _______.
Embryonic mesenchymal cells
118
Although adipocytes can differentiate from mesenchymal stem cells throughout life, adult-onset obesity mainly involves _________________.
increased size of existing adipocytes (hypertrophic obesity).
119
Adult-onset obesity is very often associated with age- related metabolic changes and may involve reduced activity of the ___________, causing less effective fat mobilization out of the cells.
hormone-sensitive lipases of adipocytes
120
Brown adipose tissue constitutes 2% to 5% of the newborn body weight, located mainly in the ______ (3 places), but it is greatly reduced during childhood and adolescence.
back, neck, and shoulders
121
In adults BAT is found only in scattered areas, especially around the _____ (4 places).
kidneys, adrenal glands, aorta, and mediastinum.
| p.128
122
The color of brown adipose tissue or brown fat is due to both the _______ scattered among the lipid droplets of the fat cells and the large number of _______ in this tissue.
- very abundant mitochondria (containing cytochrome pigment).
- blood capillaries
123
Cells of BAT tissue receive direct _____ innervation.
sympathetic
124
In adipose tissue, the neurotransmitter ______ activates the _______ of adipocytes, promoting hydrolysis of triglycerides to fatty acids and glycerol.
- Norepinephrine
| - hormone-sensitive lipase
125
Heat production is increased in these brown-adipose cells because the mitochondria have in their ______ much greater levels of a transmembrane protein called _________.
- Inner membrane
| - thermogenin or uncoupling protein (UCP-1)
126
In adults the amount and activity of brown fat are higher in ______ individuals.
lean individuals
| p.129
127
What are chemotaxic factors and what are they released by?
Chemotaxic factors are important regulators of eosinophil and neutrophil function.
128
Describe anaphylaxis
A life-threatening allergic reaction when IgE antibodies bind with allergins and cause mast cells to release histamine and other molecules stored in these cells.
129
What type(s) of cell junctions might one find present on simple columnar epithelium?
Lateral cell borders have apical TIGHT JUNCTIONS, intermediate ADHERENT JUNCTIONS, and desmosomes.
130
Where is simple columnar epithelium commonly found?
major ducts of glands, convoluted tubules of the kidney, and inner lining of the stomach, small and large intestines, gallbladder, small bronchi of the lungs, and
parts of the male and female (oviducts and uterus) reproductive tracts.
p.34 Netter
131
When _____ are large (1-2 μm high), uniform in size, and closely packed, they form a striated border.
microvilli
| p.34 Netter
132
The parenchyma of most exocrine glands, such as salivary glands and pancreas, consists of _____ and/or ______ epithelial cells in grape-like clusters called ______.
- cuboidal to columnar
- acini
p. 33 Netter
133
- The cytoskeleton of epithelia consists of a network of _______ (______), which are interwoven in each cell.
- Prominent ______-containing _____ filaments (______) and motor proteins allow changes in cell shape and provide pliability.
- intermediate filaments (tonofilaments)
- actin-containing thin filaments (microfilaments)
p. 33 Netter
134
What type(s) of cell junctions anchor adjacent cells together?
Desmosomes and zonula adherens
135
What type of epithelium is typical at sites that make up blood-tissue barriers?
Simple squamous
| p.31 Netter
136
The basal lamina (produced by ______) contains an abundance of Type ____ collagen, which associates with the glycoprotein _______. These two constituents are held together by ________ (an adhesive glycoprotein), and _______ (a proteoglycan).
- Produced by the epithelium
- Type IV collagen, which associates with the glycoprotein LAMININ.
These two constituents are held together by ENTACTIN/NITOGEN (an adhesive glycoprotein), PERLECAN (a proteoglycan).
p.75 Junq
137
Beneath the basal lamina lies the ______ lamina, consisting mostly of a network of _____ fibers (Type _____ collagen).
- Reticular lamina
- Reticular fibers (type III collagen).
p. 41 Netter
138
The basal lamina and the reticular lamina and held together by _______.
Type VII Collagen
139
Blistering-type diseases of epidermis are like relating to a disfunction of what type of epithelial junction?
Desmosomes – thus reducing cell-to-cell adhesion.
140
What is the difference is microtubule structure between cilia and the basal body?
* The cilia has a 9+2 (axoneme) arrangement, i.e. 9 duplets with a central duplet.
* Basal body has a ring of 9 triplets and lacks the central duplet.
141
SER is or is not basophilic?
IS NOT basophilic
142
Describe the staining and chromatin state of fibroblast nuclei
Basophilic, euchromatic.
143
What solution(s) is used to clear a specimen in preparation for LM?
toluene/xylene
144
What is the device used to trim specimens for viewing?
Microtome
145
What is the step after mounting a section on a glass slide?
Deparaffininzed
146
What is silver stain traditionally used to visualize?
Reticular fibers (type III collagen) – Reticular fibers and basement membrane.
147
What is used as a fixative in EM preparations? Why?
Glutaraldehyde, then osmium tetroxide (heavy metal), because glutaraldehyde preserves lipids (e.g. membranes).
148
How are EM preparations mounted?
On copper grids
149
How are EM preparations stained?
With lead citrate and uranyl acetate
150
What is used to trim cryosections? What is the medical application of this?
Cryostat, for onco-surgery and histochemical study
151
What is a benefit of plastic fixation over paraffin?
Plastic embedding avoids the higher temperatures needed for paraffin; helps avoids shrinkage and distortion of tissues.
p.3 Junq
152
Which type(s) of cells release histamine and heparin?
Mast cells and basophils
153
What large molecules are often lost during routine fixation in aqueous fixatives?
Glycogen, Proteoglycans, GAGs, neutral lipids (adipose tissue). p.5 Ross
154
What is Mallory Trichrome typically used to visualize?
Collagen, cytoplasm, RBCs, nuclei
155
What is a special stain for elastic fibers?
Orecein/resorcin
156
What is a special stain for collagen? How does it stain collagen?
Van Gieson Method; pinkish-red
157
What structures/molecules are PAS positive?
Glycogens, glycoproteins, mucins, and glycolipids.
| e.g. Basement membrane, goblet cells, brush border (apical portion of epithelium w/ microvilli).
158
What are fluorescent stains for a.) DNA & RNA, b.) Actin filaments?
a. ) Acridine orange
| b. ) Fluorescein-phalloidin
159
Which type of microscopy produces a 3D image and can also be used to determine the mass of cellular components?
Interference microscopy; a type of phase-contrast.
160
What are the components of ground substance?
Proteoglycans, GAGs, MAGs
161
Fibronectin glycoproteins and heparin sulfate proteoglycans are components of ______ that (do or do not?) show fibrous features when examined by light microscopy.
-components of ground substance
-do NOT
#5
162
Mast cells are typically found in what type of tissue?
Loose connective tissue
163
Give the cause and symptoms of Ehlers-Danlos syndrome (EDS)
Defect in collagen synthesis (typically Types I, III, and V) due to lack of lysyl hydroxylase.
Can cause joint-hypermobilit, stretchy skin, and, in some cases (Type III), arterial rupture.
164
List the cause and symptoms of osteogenesis imperfectica
Type I: Decreased production of alpha-chains = long bone fractures, blue sclerae, hearing loss.
Type II: Replacement of Gly with bulky side-chains. Lethal.
165
Laminins are a family of ______ found in the ______.
- adhesive glycoproteins
| - found in the ECM
166
Macrophages: 1.) Describe the nucleus.
2. ) In what tissues are they present?
3. ) They release what substances that help regulate other immune cells?
1. ) Eccentrically located, oval/kidney-shaped nucleus.
2. ) Present in connective tissue of most organs, after fibroblasts, SECOND MOST NUMEROUS CELL IN LOOSE CT.
3. ) Cytokines
p. 100 Junq
167
Give an approximation of the life-span of macrophages, their lineage, and their immune role.
Long-living (may survive for months), derive from monocytes, they are antigen-presenting cells, and pino- phagocytotic cells.
168
What types of organelles will be prominent in macrophages?
Golgi, lysosomes, RER
169
What striking structural feature of macrophages is a result of their unusual motility?
Extensive cytoskeleton with abundant microtubules, actin filaments, and intermediate filaments (all especially abundant under the plasma membrane).
170
What is a salient feature of the macrophage membrane?
Finger-like extensions (psuedopodia); active in phagocytotic cells.
171
What are epitheloid cells?
Activated macrophages resembling epithelial cells: elongated, with finely granular, pale eosinophilic (pink) cytoplasm and central, ovoid nucleus (oval or elongate), which is less dense than that of a lymphocyte.
172
What are the nuclear characteristics of eosinophils?
Bilobed nucleus, red cytoplasmic granules.
173
List three salient characteristics of plasma cells
-Large, ovoid cells.
-Basophilic nucleus, frequently w/ peripheral clumps of heterochromatin (clock-face appearance).
-Golgi next to nucleus, implying terminal glycosylation of the antibodies (glycoproteins).
Fig. 5-7 Junq.
174
What is the main role of plasma cells?
Production of antibodies.
175
Describe the shape and contents of mast cells
- Oval or irregularly shaped CT cells
| - Cytoplasm filled with BASOPHILIC secretory granules.
176
IgE will bind to the surface of ______ and remember certain antigens in order to elicit and allergic response in the future.
Mast cells
177
What is chemotaxis? Which CT cells cause this process to happen?
- Chemotaxis is the movement of an organism in response to a chemical stimulus.
- Macrophages
178
What the two main secretions of mast cells and what to they do?
Histamine: Vasodilator
Heparin: Anti-coagulant
179
Leukocytes are much _____ than CT mast cells, and have a ______ nucleus.
Much SMALLER than CT mast cells, and have a BILOBED nucleus.
180
Mast cells have a _____ nucleus and are found in _____ and do not enter ______.
Single-lobed nucleus.
| Found in CT and do not enter the blood.
181
Upon ____ stimulation, macrophages secrete ______ that influence the activities of other cells of the immune system.
Upon antigenic stimulation, macrophages secrete CYTOKINES
182
At slightly higher magnification, lymphocytes exhibit little of their _____ and appear in tissue as aggregations of ______ ______.
Exhibit little of their CYTOPLASM, and appear as aggregations of BASOPHILIC NUCLEI.
183
Mast cells are especially numerous near ______ in skin and mesenteries.
small blood vessels.
184
Which unit/subunit of collagen gives the characteristic banding pattern?
Fibrils (staggered arrangement of tropocollagen molecules)
185
What kind of cells are forever stuck in the Go phase? G1?
```
Go = differentiated and permanent cells (hepatocytes, neurons)
G1 = DifferentiaTING cells
```
186
Alteration of which gene can cause retinoblastoma?
Rb gene at the restriction point (G1/S boundary)
187
Which genes code for proteins that control the cell cycle?
Proto-oncogenes
188
_____ is the most commons Type III intermediate filament protein.
Vimentin
189
The class V intermediate filament protein _____ is associated with progeria.
Laminin
190
What are three important proteoglycans and where are they found?
PGs are *SAD*
1. Syndecan: Cell surface PG; a transmembrane core protein that attaches the cell to the EMC.
2. Aggrecan: Lots of chondroitin and keratan sulfate; important in cartilage.
3. Decorin: Binds fibrils in type I collagen.
191
Name and describe two important multiadhesive glycoproteins (MAGs)
1. Laminin: Found in the basement membrane (basal lamina and external lamina); provides adhesion for epithelial and other cells.
2. Fibronectin: Provides binding sites for collagens and certain GAGs in connective tissue.
192
What do integrins do (2) and what are they? Name two important integrins
Integrins are integral membrane proteins that act as matrix receptors MAGs, collagen, and other ECM proteins.
• They mediate connection between ECM outside the cell and the actin cytoskeleton inside of the cell.
• They allow cells to monitor and respond to the physical aspects of their microenvironment, e.g. influencing their orientation.
1. Talin
2. Vinculin (interacts with cytoplasmic elements)
• Both connect actin cytoskeleton to the integrins.
193
Linking collagens help type ___ collagen form bigger _____.
Helps type I collagen form bigger bundles
194
Proteoglycans bind and sequester _______. Why?
Growth factors – So GFs can be released during tissue repair, thereby stimulating new cell growth and ECM synthesis.
195
1. Fibroblasts are derived from which cell lineage?
| 2. What do they do?
1. Embryonic mesenchyme
| 2. Fibroblasts produce essentially all ECM components: collagen, elastin, GAGs, proteoglycans, MAGs.
196
What are fibrocytes?
Quiescent fibroblasts that already synthesized ECM and have scattered in the matrix.
197
1. What is the origin of mast cells?
2. What do their granules contain (4) and how do they stain?
3. What do they possess on their cell surfaces?
1. Mesoderm in origin.
2. The basophilic granules release substances involved in the inflammatory response, e.g. histamine, heparin (anti-coagulant), eosinophilic chemotactic factor (a chemokine; attracts eosiniphils), and prostaglandins.
3. An abundance of IgE on their cell surfaces.
198
Name three types of adult stem cells in CT and what they do.
1. Pericytes: Found in capillaries; can differentiate into different types of cells needed in the case of injury. Have contractile ability to close off capillaries.
2. Undifferentiated mesenchymal cells: Primary source of new cells in the healing process.
3. Fibroblasts: Produce essentially all ECM components.
199
Name the two agranulocytes in CT
Lymphocytes and monocytes
