Epithelial Flashcards
(109 cards)
1
Q
Lining of surface or body cavities; glandular secretion
A
Epithelial
2
Q
Support and protection of tissues/ organs
A
Connective
3
Q
Strong contraction; body movements
A
Muscle
4
Q
Transmission of nerve impulses
A
Nervous
5
Q
Shapes and dimensions of epithelial cells are
A
variable, ranging from tall columnar cells to
cuboidal to low squamous cells.
6
Q
Function is generally delegated by shape and size
A
epithelial
7
Q
cell nuclei also vary in shape and may be elliptic (oval), spherical, or flattened, roughly
corresponding to cell shape.
A
Epithelial
8
Q
Epithelial cell nuclei
generally have elongated nuclei
A
Columnar cells
9
Q
Epithelial cell nuclei
have flattened nuclei
A
Squamous cells
10
Q
Epithelial cell nuclei
have more spherical nuclei
A
Cuboidal or Pyramidal cells
11
Q
Epithelial cells generally show
A
polarity
12
Q
Region of the cell contacting the ECM and connective tissue
A
Basal Pole / Surface
13
Q
The opposite end, usually facing a space
A
Apical Pole / Surface
14
Q
Regions of __ or __ cells that adjoin neighboring cells comprise the cells’ lateral surfaces
A
cuboidal and columnar
15
Q
Thin extracellular sheet on which the basal surface of epithelia rests
A
Basement Membrane
16
Q
Basement Membrane Divided into:
A
Basal lamina and Reticular lamina
17
Q
Entire structure beneath the epithelial cells visible with the light microscope
A
Basement membrane
18
Q
Fine extracellular layer seen ultrasonically; not seen under light microscope
A
Basal Lamina
19
Q
Most apical of the junctions and seals two adjacent cells
A
Tight Junctions (Zonula Occludens)
20
Q
Area of strong cell adhesion and stabilizes neighboring tight junctions
A
Adherens (Anchoring) Junctions (Zonula Adherens)
21
Q
Spot-like structures between cells
A
Desmosomes (Macula Adherens)
22
Q
Provides medium for communication
between cells
A
Gap Junctions (Nexus)
23
Q
Allows intercellular exchange of small molecules
A
Gap Junctions (Nexus)
24
Q
Attaches cytoskeleton to the basal lamina
A
Hemidesmosomes
25
Basal anchoring junction found in cells that are moving during epithelial repair or reorganization
Focal Adhesion
26
(+) Actin Filaments
● Visible as brush (striated) borders in cells lining the small intestine
Microvilli
27
Increases cell surface area to facilitate absorption
Microvilli
28
(+) Microfilaments and actin-binding proteins
● Increases the surface area of the cells to facilitate absorption of molecules
Stereocilia
29
Much longer and less motile than microvilli
Stereocilia
30
Found in the lining of the male reproductive tract (epididymis, vas deferens) and hair cells of the inner ear
Stereocilia
31
(+) Microtubules
● Long highly motile apical structures that
are abundant on cuboidal or columnar
cells of many epithelia
Cilia
32
Single layer of flattened cells with flat nuclei
Simple Squamous Epithelium
33
Distribution:
Lines luminal surfaces of the heart and blood vessels
Endothelium
34
Distribution:
Lines serous cavities
Mesothelium
35
Functions: Facilitates movement of the viscera
Simple Squamous Epithelium
36
Functions: Secretion of biologically active molecules
Simple Squamous Epithelium
37
Functions: Active transport by pinocytosis
Simple Squamous Epithelium
38
Functions: Gas exchange
Simple Squamous Epithelium
39
Single layer of squared-shaped cells with spherical nuclei
Simple Cuboidal Epithelium
40
Distribution:
Epithelium of ovaries, Thyroid follicles, Collecting tubules (kidney), Some ducts of salivary glands and pancreas
Simple Cuboidal Epithelium
41
42
Functions: Covering, Secretion
Simple Cuboidal Epithelium
43
Single layer of cells that are taller than wide with elongated nuclei
Simple Columnar Epithelium
44
Often with specialized structures on apical surface (cilia, microvilli)
Simple Columnar Epithelium
45
Distribution:
○ Colon (with goblet cell) and small intestine (with microvilli and
goblet cells)
○ Fallopian tubes (with surface cilia)
○ Respiratory tract (with pseudostratification)
○ Vas deferens (with stereocilia)
○ Gallbladder
Simple Columnar Epithelium
46
Functions:
○ Protection, lubrication, absorption, secretion
Simple Columnar Epithelium
47
Two or more layers of flattened cells
Stratified Squamous Epithelium
48
Two layers of Stratified Squamous Epithelium
Keratinized stratified squamous (dry)
Non-Keratinized Stratified Squamous (moist)
49
Keratinized stratified squamous (dry)
○ Surface cells with no nucleus and are
metabolically inactive
50
Packed with keratin filaments, Seen in epidermis, Prevents water loss, protection
Keratinized stratified squamous (dry)
51
Non-Keratinized Stratified Squamous (moist)
○ Surface cells with nucleus and are more
metabolically active
52
Seen in moist internal cavities like outer covering of the cornea, mouth, esophagus, larynx, vagina, and anal canal
○ Functions for protection, secretion, and prevention of water loss
Non-Keratinized Stratified Squamous (moist)
53
Relatively rare histologic types of epithelia
Stratified Cuboidal and Columnar Epithelium
54
Distribution: Lines the excretory ducts of
salivary and sweat glands and ovarian follicles
Stratified Cuboidal Epithelium
55
Distribution: Lines the conjunctiva
Stratified Cuboidal and Columnar Epithelium
56
Functions: Protection and secretion
Stratified Cuboidal and Columnar Epithelium
57
Stratified with round dome-shaped superficial cells called umbrella cells
Transitional Epithelium (Urothelium)
58
Distribution: most of the urinary tract, from the kidneys to the
proximal part of the urethra
Transitional Epithelium (Urothelium)
59
Function: Specialized for distensibility
Transitional Epithelium (Urothelium)
60
Irregular cells that are all attached to the basement membrane but give a stratified appearance due to their nuclei are at different levels and not all reach the free surface
Pseudostratified Columnar Epithelium
61
Distribution: Respiratory tract (trachea, bronchi, nasal cavities)
Pseudostratified Columnar Epithelium
62
Function: Heavily ciliated to transport mucus-trapped particles
Pseudostratified Columnar Epithelium
63
Specialized form of epithelia otherwise known as “glands”
Glandular Epithelia
64
Has a variety of functions: Synthesis, storage, and release of substances such as lipids, proteins, and complexes of carbohydrate-protein
Glandular Epithelia
65
• Lipids (__ glands, __ glands)
• Proteins (_, __ glands)
• Complexes of carbohydrate-protein (__ glands)
L: adrenal, sebaceous
P: pancreas, mammary
C: salivary
66
Sweat glands mostly secrete water and electrolytes from the blood
Glandular Epithelia
67
Glandular Epithelia Divided into
endocrine and exocrine glands
68
Ductless and has no connection with its original epithelium
Endocrine gland
69
Releases substances like hormones towards target areas for specific hormones
Endocrine gland
70
Consist of irregular chords and rounded follicles for temporary storage of products to be secreted
Endocrine gland
71
Endocrine gland example
Pituitary, Adrenal, Thyroid Gland
72
Connected to the surface epithelium, transports substances over short distance
Exocrine gland
73
Secretes substances via the duct system
Exocrine gland
74
Consist of small secretory portions and ducts
Exocrine gland
75
Consist of tubular ducts that are lined with epithelia
Exocrine gland
76
Exocrine gland examples
Sweat, Mammary, Intestinal, Salivary gland
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78
Simple gland (ducts do not branch) (5)
Simple tubular, Branched tubular, Coiled tubular, Acinar/Alveolar, Branched acinar
79
Simple glands FEATURES
Elongated secretory portion; duct usually short and absent
Simple tubular
80
Simple glands FEATURES
Several long secretory parts joining to drain into 1 duct
Branched tubular
81
82
Simple glands FEATURES
Secretory portion is very long and coiled
Coiled tubular
83
Simple glands FEATURES
Rounded, saclike secretory portion
Acinar/Alveolar
84
Simple glands FEATURES
Multiple saclike secretory parts entering the same duct
Branched tubular
85
Simple glands EXAMPLES
Mucous gland of colon; intestinal glands or crypts of Lieberkuhn
Simple tubular
86
Simple glands EXAMPLES
Glands in the uterus and stomach
Branched tubular
87
Simple glands EXAMPLES
Sweat glands
Coiled tubular
88
Simple glands EXAMPLES
Small mucous glands along the urethra
Acinar/Alveolar
89
Simple glands EXAMPLES
Sebaceous glands of the skin
Branched acinar
90
Compound glands (3)
Tubular, Acinar/Alveolar, Tubuloacinar
91
Compound glands
Several elongated coiled secretory units and their ducts converge to form larger ducts
Example: Submucosal mucousgland of brunner in the duodenum
Tubular
92
Compound glands
Several saclike secretory units with small ducts converge at larger duct
Example: Exocrine pancreas
Acinar/Alveolar
93
Compound glands
Ducts of both tubular and acinar secretory units converge at larger ducts
Example: Salivary gland
Tubuloacinar
94
Secrets substances
via exocytosis from
membrane-bound
vesicles or secretory
granules
Merocrine Glands
95
Most
common
method of protein or
glycoprotein
secretion
Merocrine Glands
96
Most exocrine glands
are merocrine (e.g.
Salivary glands)
Merocrine Glands
97
Merocrine Gland Based on
Secretory Products
Synthesizes nonglycosylated proteins (digestive enzymes)
Serous
98
Merocrine Gland Based on Secretory Products
Cells have well-developed RER and Golgi complexes and are filled apically with secretory granules in different stages of maturation.
Serous
99
Merocrine Gland Based on Secretory Products
Stain intensely
● Examples: Acini of the pancreas, parotid
Serous
100
Merocrine Gland Based on Secretory Products
Synthesizes heavily glycosylated proteins called
mucins
Mucous
101
Merocrine Gland Based on Secretory Products
Also have RER and Golgi complexes and are filled
apically with secretory granules
Mucous
102
Merocrine Gland Based on Secretory Products
When mucins are released
from the cell, they become
hydrated and form a layer of
mucus
Mucous
103
Merocrine Gland Based on Secretory Products
Stain poorly due to washed hydrophilic mucous
● Example: Goblet cells
Mucous
104
Merocrine Gland Based on Secretory Products
Some salivary glands are
mixed seromucous glands,
having both serous acini and
mucous tubules with clustered serous cells
Mixed (Sero-mucous)
105
Merocrine Gland Based on Secretory Products
The product of such glands is a mixture of digestive enzymes and watery mucus
● Example: Submandibular gland
Mixed (Sero-mucous)
106
Cells accumulate substances resulting to
their enlargement and undergo terminal
differentiation
Holocrine Glands
107
Secretes substances via complete cell
destruction where products and cell debris
are released into the lumen
Example: Sebaceous glands of hair follicles
Holocrine Glands
108
Substances accumulate at the apical end of
the cell
Apocrine Glands
109
Secretes substances by loss of membrane enclosed, apical cytoplasm, usually containing one or more lipid droplets
● Example: Mammary gland, ceruminous
glands
Apocrine Glands
