Exam 1 Flashcards
(172 cards)
1
Q
What 2 interacting components are tissues made of?
A
Cells and extracellular matrix (ECM)
2
Q
Describe light microscopy.
A
Light beam is transmitted through a tissue.
3
Q
T/F: Bright field microscopy is a type of light microscopy.
A
True
4
Q
What does a bright field microscope require?
A
Staining
5
Q
What is the difference between phase contrast and fluorescence microscopy?
A
Phase contrast: light changes its speed when passing through structures with different refractive indices and observe living non-stained structures.
Fluorescence: affinity of fluorescent compounds for specific cell components.
6
Q
What are some advantages of light microscopy?
A
Inexpensive, rapid diagnosis, observe living specimens
7
Q
What are some disadvantages of light microscopy?
A
2-D image, limited resolving power due to wavelength of light, needs maintenance, requires quality analysis and control
8
Q
What are some advantages of using a dissecting scope?
A
Inexpensive, practical, 3-D image, microsurgery
9
Q
What are some disadvantages of using a dissecting scope?
A
Low resolving power, needs maintenance
10
Q
Which type of electron microscopy is based on the interaction of electrons and tissue components?
A
Transmission electron microscopy (TEM)
11
Q
What can the viewer see on a SEM?
A
Only external structures (scans the surface)
12
Q
What conditions have to be met in order to see a specimen under the microscope?
A
Specimen must…
- Be well preserved (fixation)
- Thin to allow transmission of light (microtome)
- Enough contrast to observe details (staining)
13
Q
What is the most common survey routine staining method?
A
Hematoxylin- Eosin (H + E)
14
Q
What is histochemical staining method used to demonstrate?
A
Chemical constituients DNA, RNA, lipids, glycogen, carbohydrates and elements such as Ca
15
Q
What color is DNA stained?
A
Basophilic = Blue
16
Q
In a Hematoxylin - Eosin stain what are the possible colors and what do they indicate?
A
Red/ pink = Acidophilic or Eosinophilic
Blue/ purple = Basophilic
17
Q
T/F: Basic dyes like Hematoxylin stain acidic structures: DNA, RNA, acid proteins; and Acid dyes like Eosin stain basic structures: collagen, hemoglobin, protein amines.
A
True
18
Q
What are 2 examples of special stains discussed?
A
Silver stain and elastic fiber’s stain
19
Q
What is silver stain used for?
A
Reticular fibers, nerve fibers
20
Q
What does the periodic acid Schiff (PAS) stain for?
A
- Basement membrane and localize carbohydrates
- Goblet cells stain magenta
- Mucus in respiratory tract
21
Q
What can histochemistry be used to demonstrate?
A
Rapidly dividing chromosomes of DNA, carbohydrates like glycogen in the liver, lipids in tissues, spinal cord gray matter with myelin lipid
22
Q
Describe fluorescence microscopy.
A
– Blue fluorescence binding to nuclear DNA.
– Green fluorescent dye binds to actin filaments.
23
Q
What is the difference between immunohistochemistry and immunocytochemistry?
A
Histo= tissue Cyto= cell
24
Q
What are the basic constituents of a cell?
A
- cytosol (hyaloplasm)
- organelles (cell organelles)
- cell inclusions (paraplasm)
25
Hyaloplasm
Basic structureless cytoplasm
26
Paraplasm
Cell inclusions: secretory granules, glycogen, lipid droplets, lipofuscin, melanin
27
Nucleus
Contains genetic info, double envelope for eukaryotes
28
Examples of multi-nucleated cells?
Skeletal muscle cells, osteoclasts, precursors of platelets
29
What are the two types of chromatin?
Heterochromatin (inactive) vs. Euchromatin (active)
30
T/F: Chromatin is eosinophilic.
False, basophilic
31
In a liver cell, for example, would the chromatin be heterochromatin or euchromatin?
Euchromatin, it is active
32
The most euchromatic cells are?
* Neurons
* Hepatocytes (liver cells)
* Pancreatic acinar cells
* Sertoli cells
33
What are 4 functions of the cell membrane?
1. Communication
2. Intercellular connection
3. Physical barrier
4. Selective permeability
34
Describe the basic structure and function of mitochondria.
Self-replicating, circular DNA, double membrane with cristae, produce ATP, inherited from mother
35
Roles of mitochondria?
ATP generation, cell death necrosis, cell death apoptosis
36
What is the endoplasmic reticulum?
Network of intercommunicating channels
37
What does the region on the ER that is rough contain?
Polyribosomes
38
Functions of smooth ER?
- Lipid biosynthesis
- Detoxification
- Sequestration of calcium ions
39
Functions of rough ER?
* Segregate proteins not destined to the cytoplasm
* Glycosylation of glycoproteins
* Synthesis of phospholipids
* Assembly of multichain proteins
40
Describe the golgi apparatus.
Collection of membrane- bound flattened sacs ‘cisternae’, modifies and packages proteins
41
Describe lysosomes.
- Secretory vesicles/ granules, membrane bound
- Have hydrolytic enzymes
- Pinocytosis, phagocytosis
- Intracellular digestion
42
If material remains permanently, is known as?
Lipofuscin
| Ex. cardiac cells, neuron
43
Why are lysosomes commonly seen in neutrophils?
Fight against bacterial agents
44
What are proteasomes?
Small enzymatic complexes for intracellular digestion that requires ubiquitin protein
45
Ubiquitin
Small globular protein present in all eukaryotic cells.
46
What is the primary function of proteasomes?
Recycling amino acids from endogenous proteins
47
What are peroxisomes?
Contain the enzyme ‘catalase’ which can degrade intracellular hydrogen peroxide
48
What are the different types of secretory vesicles/ granules?
Lysosomes, proteasomes, peroxisomes
49
What are the 3 constituents of cytoskeleton?
Microfilaments, intermediate filaments, microtubules
50
Describe the microfilaments.
Actin: thin, 5-7 nm diameter
Myosin: thick, 15 nm diameter
51
How big are intermediate filaments?
6-12 nm diameter
52
Tonofilaments (cytokeratins)
Keratinizing and non-keratinizing epithelia
53
Vimentin
- Mesenchymal cells
| - Fibroblasts, chondroblasts, osteoblasts, macrophages, endothelial cells, vascular smooth muscle cells
54
Desmin
- Muscle
| - Striated and smooth
55
Neurofilaments
-Neurons
56
Glial filaments
- Glial cells
| - Astrocytes
57
In microtubules, how are doublets linked?
Dynein arms
58
What are some inclusions discussed?
Pigments, Glycogen, Lipid droplets
59
What are the different types of pigments?
Melanin, lipofuscin, lutein, hemosiderin
60
T/F: Glycogen is present in highly energetic types of tissues, like the liver and muscle.
True
61
What are some surface projections discussed?
Microvilli, cilia, stereocilia
62
Microvilli
Small, absorptive, form a brush boarder
Digestive tract, kidney
Increase surface area -> more absorption
63
Cilia
Motile projections (they move!), longer, less dense, easier to observe under LM, come from basal bodies
64
Stereocilia
Nonmotile projections, absorptive
65
Cell shapes
Squamous, cuboidal, columnar, spindle, cylindrical, multipolar, round
66
Nuclear shape
Round, elongated, polymorphonuclear
67
Nuclear position
Central, eccentric/hypolemmal, apical vs. basal
68
Epithelial cells have...
* Apical (free) surface
* Lateral surfaces
* Basal surface
69
Tissue
An aggregation of cells and extracellular substances.
70
Epithelium
A tissue composed of closely aggregated cells with very little extracellular substance.
71
What are the 4 basic types of tissue?
o Epithelial tissue
o Connective tissue
o Muscular tissue
o Nervous tissue
72
What are the 3 categories of epithelia?
Surface or lining, glandular, and special
73
Where is surface epithelia found?
Lining luminal organs, tubular structures and body cavities
74
What is the function of glandular epithelia?
Synthesize, store and release their product -> secretion
75
What are the functions of epithelial tissue?
- Protection
- Secretion
- Absorption
- Diffusion
- Friction Reduction
- Cleaning
- Sensation
76
Which type of epithelium promotes diffusion of gases, liquids and nutrients?
Simple squamous epithelium
77
What are the 3 germ layers in a developing embryo that contribute to formation of epithelia?
1. Ectoderm
2. Mesoderm
3. Endoderm
78
List some characteristics of epithelium.
Covers surfaces and lines lumens, high cell density, little intercellular space, basement membrane present, avascular lining epithelium, few nerve endings
79
What is the difference between epithelial cells and mesenchymal cells?
Epithelial cells: High cell density, little intercellular matrix
Mesenchymal cells: Few cells, lots of intercellular matrix
80
Where does the basal lamina lie?
Lies at the interface of epithelial and connective tissue.
81
T/F: Small blood capillaries always enter an epithelium across a basal lamina.
False, they never do
82
Basement membrane
When components of a basal lamina are distinguishable under light microscopy
83
What are the roles of the basal lamina?
Provide structural support, act as selective barrier for epithelial layer
84
T/F: Basement membrane is a semi-permeable barrier.
True
85
Which type of stain is used for basement membrane?
PAS (Periodic Acid Schiff) for carbohydrates
86
What causes epithelial cells to be cohesive?
- Transmembrane glycoproteins
- Cadherins
- Folds of PM b/w adjacent cells form intercellular adhesions
87
What are 3 types of intercellular junctions?
Tight junctions, desmosomes, gap junctions
88
Which type of intercellular junction forms a continuous
| hermetic seal around the cell, and prevents leakage?
Tight junctions
89
What is another name for anchoring junctions?
Desmosomes
90
What type of junction adheres epithelial skin cells?
Desmosomes
91
What is another name for gap junctions?
Communicating junctions
92
What do gap junctions provide from one cell to the next?
Cytoplasmic channels or tunnels
93
Describe simple squamous epithelium.
Composed of flat, elongated cells, round nucleus centrally located
94
Where is simple squamous epithelium located?
Lining moist internal surfaces, alveolar walls, lumen of blood vessels, capsule of renal glomeruli
95
Where is simple cuboidal epithelium found?
Lining ducts of glands, choroid plexus in brain, lining follicles of thyroid gland, lens of eye
96
Describe simple columnar epithelium.
Tall, narrow cells with ovoid nucleus near base of cell
97
Where is simple columnar epithelium found?
– Lining the luminal surface of stomach, small and
large intestine, gall bladder
– Lining the uterus and uterine tube
98
What is pseudostratified epithelium composed of?
A single layer of irregularly shaped and sized cells
99
How are cells arranged in pseudostratified epithelium?
All cells contact the underlying basement membrane, but not all reach the surface
100
Where can one find pseudostratified epithelium?
Nasal cavity, upper respiratory tract, male repro
101
What is stratified squamous epithelium?
Epithelium composed of several layers of cells
102
What are the 2 types of squamous epithelium?
Keratinized and non-keratinized
103
T/F: There are nuclei present in keratinized epithelium.
False
104
What is another name used to describe transitional epithelium?
Urothelium
105
Where is transitional epithelium found?
Lines urinary passages
106
How can glandular epithelium be classified?
```
1. Classification according to the number of cells in the gland
unicellular or multicellular
2. Shape of Duct
3. Shape of Adenomere
4. Type of Product
5. Mode of Secretion
```
107
What are unicellular glands and give an example.
Found in epithelial lining and glands of intestine and respiratory tract. Ex Goblet cells (mucinogen granules) in the colon
108
Adenomere
Cluster of epithelial cells and the functional unit
109
What do ducts do?
Convey products to needed locations
110
What are the 2 types of ducts?
```
Simple= one opening draining the gland
Compound= many branches
```
111
What are the 3 shapes of adenomeres?
Tubular- straight or coiled
Acinar- pie shaped, small lumen
Alveolar- large lumen
112
What are the 4 types of products?
Serous- watery
Mucous- viscous
Mixed- both
Sebaceous- oily
113
Serous gland
- cells have round nuclei
- cytoplasm is basophilic in basal portion and acidophilic in the apical part
- zymogen granules
- sweat
114
Mucous gland
- cells have flat, heterochromatic nuclei at the base of each cell
- vacuolated cytoplasm (frothy) and pale
- mucinogen granules are not detectable with routine staining
115
Mixed gland
- mucous and serous cells sharing a common duct system
| - saliva
116
Sebaceous gland
- centrally located nucleus
- cytoplasm is pale and foamy
- skin
117
4 Modes of secretion?
Merocrine, apocrine, holocrine, endocrine
118
Merocrine
- smooth lumen
| - no cytoplasm lost producing secretion
119
Apocrine
- apex bulges, some cytoplasm lost producing secretion
| - predominant sweat gland, prostate gland, mammary gland
120
Holocrine
entire cell is the product
121
Endocrine
secreted product is directed toward vasculature
122
Myoepithelial cells
Contractile, associated with salivary, mammary and sweat glands
123
Functions of connective tissue
* Connect
* Suspend, give form, subdivide
* Insulation and storage
* Defend
* Provide nutrition
* Repair and regeneration
124
What are the 2 components of connective tissue?
Cells and matrix
125
2 Cells of connective tissue
1. Embryonic mesenchyme cells: Resident cells
| 2. Hematopoietic stem cells: Transient cells
126
What are some examples of resident cells?
Fibroblasts, reticular cells, adipocytes, mesenchymal cells, macrophages, mast cells
-Always there
127
What are some examples of transient cells?
Plasma cells, leukocytes
128
What do fibroblasts form?
Collagenous, elastic and reticular fibers of the matrix
129
What is an inactive fibroblast known as?
Fibrocyte
130
Describe the role of macrophages in CT.
- Resident phagocytic cell of CT
- Originates from monocytes in blood, enters CT, termed macrophage
- Can proliferate locally
- Survive in tissue for months
- May be named by location
131
What are 3 components in the matrix?
Fibers, ground substance, tissue fluid
132
3 types of fibers in matrix?
Collagen, elastic, reticular
133
What is ground substance?
Amorphous, formed by principal cells of tissue, contain GAGs, Proteoglycans, Glycoproteins
134
Describe tissue fluid
A solution that bathes and surrounds the cells and fibers, comes from plasma of blood
135
Differentiate between collagen and elastic fibers.
C: white, tensile, strong, no stretch
E: yellow, weak, stretch and recoil
136
Which are the most numerous fibers in CT and bone?
Collagen fibers
137
Collagen type 1
found in bone, dentin, dermis, tendons
| (fibrocartilage); resists tensile forces
138
Collagen type 2
forms fibrils found in cartilage, resists
| compression
139
Collagen type 3
reticular fibers found in stroma of expandable organs- spleen, LN, liver, CVS, lymphatics
140
Collagen type 4
basement membranes
141
What is an important cofactor in synthesizing collagen?
Vitamin C
142
Where are elastic fibers found?
Aorta, lungs, vocal cords, dermis, pinna of ear, epiglottis
143
Which stain is used for reticular fibers?
Silver stain
144
Where are reticular fibers found?
Form a network of cells in lymph node, spleen, and bone marrow
145
Properties of ground substance allows for what?
- Binding of water
- Resisting compressive forces
- Cell adhesion to fibers
- Cell migration
- Barrier to bacterial/ venom penetration
146
What are some common macromolecules of ground substance?
GAGs: HA sulfate, chondroitin sulfate, keratan sulfate, dermatan sulfate, heparan sulfate
Glycoproteins: Fibronectin, Laminin
147
How are proteoglycans formed?
By covalently linking GAGs to protein core
| -Regulate passage of molecules and cells in intercellular space
148
What do structural glycoproteins do?
Proteins with attached carbohydrates, help to attach cells to each other and to ECM
149
What is CT fluid composed of and what is its function?
- Nutrients, dissolved gases, derived from plasma
- Bathes matrix and cells, aids in removing waste
- Fluid movement and prevention of edema
150
What are the types of proper CT?
1. Loose CT (areolar)
2. Dense CT
3. Reticular CT
4. Adipose CT
151
Differentiate between loose CT and dense CT.
L: Ubiquitous, loosely arranged fibers, cell constituents vary with location
D: Irregular and regularly arranged, densely packed fibers, strong
152
Function of bone
Rigid protective and supporting framework for soft tissues
153
Function of cartilage
Semi-rigid support to specific sites: respiratory tract, external ear, joints
154
Functions of joints
Composite structures which unite bones and can provide varying degrees of movement
155
What do ligaments provide?
Stability of joints
156
What do tendons provide?
Strong, flexible connections b/w muscles and bones
157
Describe cartilage
-Avascular, semi-rigid form of CT characterized by
absence of blood vessels, lymphatic vessels and nerves.
-Supports soft tissues, important in bone growth.
-Composed of cells embedded in ground substance
and CT fibers
158
Cartilage arises from what?
Mesenchymal cells- stem cells of bone and cartilage
159
Perichondrium
Cells have cartilage forming potential; precursors of chondrocytes. Resembles mature fibroblasts
160
T/F: The inner layer of perichondrium is cellular and it is present in all hyaline cartilages except on articular surfaces.
True
161
What is ground substance composed of?
Sulfated polysaccharide units GAGs (ex. chondroitin sulfate, keratan sulfate)
162
What is responsible for the strong and flexible
| property of cartilage?
Proteoglycans
163
Within normal articular cartilage,
there is only one type of highly
specialized cell?
The chondrocyte
164
What is the ECM that surrounds each chondrocyte?
Territorial matrix
165
Why is the cartilage matrix more basophilic?
Due to high concentrations of GAGs
166
Growth of cartilage occurs in 2 manners?
1. Interstitial growth from within the cartilage
| 2. Appositional growth at the periphery
167
The classification of cartilage is based on what?
Based mainly in the amount of collagen or elastic fibers present within the extracellular matrix.
168
What are the 3 types of cartilage?
1. Hyaline cartilage
2. Elastic cartilage
3. Fibrocartilage
169
What is the most common type of cartilage?
Hyaline cartilage
170
How is mature hyaline cartilage characterized by?
Small aggregation of chondrocytes embedded in an amorphous matrix of ground substance reinforced by collagen type II fibers.
171
Where is hyaline cartilage found?
```
Fetal axial and appendicular skeleton.
Growth plates – physis.
Articular cartilage.
Costo-chondral junctions.
Nasal septum, larynx, tracheal rings, bronchi.
```
172
T/F: Articular cartilage has perichondrium.
False, it does not. Therefore healing capability is reduced
