Trans 2 Epithelium Flashcards
1
Q
What are the characteristics of an epithelium?
A
- Avascular tissue
- Covers internal closed cavities and body tubes that communicate with the exterior
- lining or surface epithelium
- Self-renewing
- With functional and morphological polarity
- Can form glands
2
Q
What are the functions of an epithelium
A
Selective barrier Absorption Secretion Protection Others (sensation, contractility, transport of nutrients and other elements, waterproofing)
3
Q
Classification of epithelium based on morphological characteristics
A
Simple
Compound
4
Q
Classifications of epithelium based on cell shape
A
Squamous
Cuboidal
Columnar
5
Q
Type of squamous epithelium
Single later of flattened cells
A
Simple squamous epithelium
6
Q
Function of simple squamous epithelium
A
exchange and barrier
7
Q
The endothelium and mesothelium are examples of what kind of epithelium
A
Simple squamous
8
Q
Type of simple epithelium in wc the height and width of the cells are almost equal
A
Simple cuboidal
9
Q
Function of simple cuboidal cell
A
Secretion and absorption
10
Q
The kidney tubule is an example of what epithelium
A
Simple cuboidal
11
Q
Type of simple epithelium with the width smaller than the height of the cell
A
Simple columnar
12
Q
What is the function of simple columnar cells
A
Secretion and absorption
13
Q
The lining of the gallbladder is an example of what epithelium
A
Simple columnar
14
Q
Type of epithelium consisting of a single layer which appears to be stratified due to different levels of the nuclei
A
Pseudostratified
15
Q
Where can you find pseudostratified epithelium?
A
respiratory (lining of trachea, bronchi and nasal cavity)
Male reproductive tract (epididymis)
16
Q
True or false
For compound epithelium, you describe the epithelium based on which type of cell is present in larger amounts
A
False, you described based on the MOST SUPERFICIAL layer
17
Q
Several layers of flattened cells
A
Stratified squamous epithelium
Can be keratinized or non-keratinized
18
Q
Function of keratinized stratified squamous epithelium
A
Waterproofing layer (skin)
19
Q
Where to find non-keratinizing stratified squamous epithelium
A
Mucus-rich regions with glandular tissue underneath
20
Q
Function of stratified squamous epithelium
A
Barrier and protection
21
Q
Consists of 2-3 layers of cuboidal cells
A
Stratified cuboidal
22
Q
Function of stratified cuboidal cells
A
barrier and conduit
23
Q
The large excretory duct of salivary glands are made up of what kind of epithelium?
A
Stratified cuboidal
24
Q
Usually consists of 2-3 layers of columnar cells
A
Stratified columnar cells
25
Function of stratified columnar cells
Barrier and conduit
26
The large excretory ducts of exocrine are made up of what type of compound epithelial cells?
Stratified columnar
27
Other name of transitional epithelium
Uroepithelium
28
Surface cells of transitional epithelium
Dome cells or umbrella cells
29
Cells in the transitional epithelium that allow changes in the volume without changes in the pressure of the organ
Dome cells / umbrella cells
30
Match the following (Transitional epithelium)
1. Dome shaped
2. Flattened
A. Contracted
B. Distended
Dome-shaped (contracted) -> flattened (distended)
31
Function of the uroepithelium
Barrier with a distensible property
32
True or false:
| The height of the cells often reflects the level of secretory or absorptive activity
True
33
Three domains/surfaces of an epithelial cell
Apical
Lateral
Basal
34
What are the surface modifications of the apical part of the epithelial cell
Microvilli
Cilia
Stereocilia
35
What are the surface modifications in the lateral domain of the epithelial cell?
Tight junction
Intermediate junction
Desmosomes
Gap junctions
36
Surface modification of the basal domain
Hemidesmosomes
37
Functions of the apical cell
Increase the surface area for absorption
| Move substances along the epithelial surface
38
Domain of epithelial cells that face the organs lumen and often have specialized projecting structures
Apical domain
39
Shortest non-motile projection, closely packed with upright array of fingerlike evaginations from the plasma membrane of the cell
Microvilli
40
Microvilli are composed of what kind of filaments
ACTIN filaments
41
Horizontal network of filaments which lies just below the base of microvilli, where the actin filaments are attached for RIGIDITY
Terminal web
42
Microvilli have this on their surfaces which serves as surface for adsorption and release of digestive enzymes
Glycocalyx
43
What are the functions of microvilli
Increases absorptive surface of a cell
| Facilitates movement of materials
44
Motile surface modifications used to move mucus/ovum across surface (respiratory tract/oviduct)
Cilia
45
The cilia has a core of microtubules called what? And where is it attached?
Axoneme, attached to the basal body
46
How many peripheral doubles and central singlets does an axoneme have?
9 peripheral doubles, 2 central singlets (9:2)
47
How many peripheral doubles and central singlets does a basal body have?
9 peripheral doubles, 0 singlets (9:0)
48
Where does the cilia come from?
Centriole
49
What causes cilia to move?
Adjacent axoneme interaction via DYNEIN links
50
What are the functions of non-motile cilia
Detection of light, odors, motion and flow of liquid
51
Only found in cuboidal or columnar epithelia, type of cilia with rapid beating patterns of movement that propel a current of fluid and suspended matter in one direction over the epithelium
Motile cilia
52
Movement of motile cilia
Metachronous
53
Non-motile, bigger and more elevated microvili which is long, thin and clumped at the ends
Stereocilia
54
Functions of stereocilia
absorption for ductus deferens and epididymis in male repro tract
Sensory hearing for Organ of Corti
55
Epithelial cells that strongly adhere to neighboring cells
Lateral
56
Collective term used to refer to the specific structural components that make up the barrier and attachment devices between adjacent cells
Junctional complex
57
Transmembrane proteins present in anchoring junctions
Cell adhesion molecules
58
CAMs for cell to cell adhesion
Cadherins
Immunoglobulin superfamilies
Selectins
59
Ca 2+ dependent, for same cell types
Cadherins
60
CAMs for same cell types
Immunoglobulin superfamilies
61
CAM attaching different cell types
Selectins
62
Found at the most apicolateral portion, most adhesive portion, fused plasma membrane of adjacent cells
Tight junction (Zonula Occludens)
63
Fusion of the tight junction (sealing intercellular space and maintaining polarity) was brought about by what transmembrane protein?
occludins
64
Junction that is medial in position with a wider intercellular space
Intermediate Junction (Zonula Adherens)
65
Plasma membrane of adjacent cells are linked by what complexes
E-cadherin and catenin complexes
66
Why is the intermediate junction not present in squamous cells
Squamous cells are too thin and flat
67
Lowermost junctional complex
Desmosomes (Macula adherens)
68
Major transmembrane link proteins
Desmocollin and desmoglein
69
Part of the cytplasm which counters wear and tear and holds the shape of the skin
Cytoplasmic attachment plaque
70
Allows faster communication
Gap Junctions (Nexus)
71
Gap junctions are made up of what
Connexons
72
Functions of connexons
Allows the transmission of ions, basically transmembrane channels
73
Differentiate connexon from connexin
Connexon: channels
Connexin: transmembrane proteins that surrounds the connexons
74
Found in actively transporting epithelia of smooth muscle, cardiac muscle and nerves
Gap junctions
75
TRUE OR FALSE: epithelial cells strongly adhere to basal lamina esp those subject to friction and other mechanical forces
True
76
Specialized structure located next to the basal domain of epithelial cells and the underlying connective tissue stroma
Basement membrane
77
Increase cell surface area and facilitate interactions between adjacent cells and ECM proteins
Basal cell membrane infoldings
78
Main cell adhesion molecules
Integrins
79
The basement membrane is made up of what
Basal lamina + reticular lamina
80
Single later, one of the main characteristics of epithelium
Basal lamina
81
Basal lamina collagen type
Type IV collagen
82
The basal lamina [collagen] is coated with what and why
PROTEOGLYCANS with negatively charged SULFATE groups, allowing it to become an electrostatic barrier
83
Two layers of the basal lamina
Lamina lucida
| Lamina densa
84
Thinner portion of the basal lamina, with laminin only
Lamina lucida
85
Made up of laminin, type IV collagen, sulfated proteoglycans, glycoproteins (Fibronectin)
Lamina densa
NOTE: laminin makes up the backbone/scaffold
86
Functions of the basal lamina
Attachment, selective barrier, polarity, tissue-scaffolding for would healing and repair
87
Made up of reticular fibers of underlying connective tissue
Reticular lamina
88
Reticular fibers collagen type
Type III
89
Anchoring fibrils collagen type
Type VII collagen
90
Why is reticular lamina thickened in the trachea
To support airway from collapsing
91
Type of cell-ecm junction, one half of the desmosome
Hemidesmosome
92
Where is the hemidesmosome connected
To the basal lamina
93
Desmosome vs hemidesmosome
Clustered transmembrane proteins that link to cytokeratin intermediate filaments are integrins in hemidesmosome, cadherins in desmosome
94
Where can you find hemidesmosomes
Abrasive and shearing forces
95
Group of epithelial cells specialized for sevretion
Glands
96
Types of glands depending on method of delivery
Exocrine gland
| Endocrine gland
97
Has a ductal system, decretes products onto a surface directly or through epithelial ducts or tubes connected to a surface
Exocrine glands
98
Classification of exocrine glands based on number of cells
Unicellular
| Multicellular
99
Classification of exocrine glands based on branching
Simple
| Compound
100
Classification of exocrine glands based on secretory portion
Tubular
Acinar
Tubulo-acinar
101
Classification of exocrine glands based on secretion
Mucous
Serous
Mexed seromucous acini called SEROUS DEMILUNE
102
Classification of exocrine glands based on method of secretion
Merocrine
Holocrine
Apocrine
103
Tubular vs acinar vs tubulo-acinar
Elongated - rounded - mixed
104
[exocrine gland based on type of secretion] produces mucin, have a pale cytoplasm and a flat nucleus
Mucous
105
[exocrine gland based on type of secretion] with watery, enzyme rich secretion
Serous
106
[exocrine gland based on type of secretion] with a half moon appearance
Serous demilune
107
Merocrine vs holocrine vs apocrine
Cell is intact - Suicidal secretion - Part of cell is destroyed
108
Components of exocrine glands
Stroma
| Parenchyma
109
Supportive portion of exocrine glands
Stroma
110
Secretory portion of exocrine gland, epithelial component
Parenchyma
111
[stroma] condensation of connective tissue
Capsule
112
[stroma] extemds omward from the capsule to divide the gland into lobes and lobules
Septa (thinner septa to divide into lobules)
113
[stroma] delicate network which surrounds acini
Reticular fibers
114
Ductal system arrangement:
Intercalated duct -> striated duct -> intralobular duct -> interlobular duct -> lobar duct -> main duct
115
Gland that lacks a duct system, they decrete their products into the connective tissue to the blood stream tor each their target cells
Endocrine glands
116
What do you call the products of endocrine glands
Hormone
117
How are cells in endocrine gland arranged
Cords and columns
Except thyroid gland, cells are in rounded units
118
True or false: endocrine glands are avascular
False, they are HIGHLY VASCULAR
