Chapter 1- Epithelium Flashcards
(154 cards)
1
Q
what are the four basic types of tissue?
A
epithelial
connective
nervous
muscle
2
Q
what are the three general functions of epithelium?
A
absorption
secretion
provide a barrier
3
Q
what the three specialized functions of epithelium?
A
- transport molecules across epithelium
- prevent transport of material across epithelium= selective permeability
- sensory
4
Q
what are the five basic characteristics of epithelium?
A
- cell are adjacent to each other
- complete or partial basement membrane
- avascular
- associated with vascular connective tissue
- cells held together by cell junctions
5
Q
what are the two parts of the complete basement membrane?
A
- basal lamina
2. reticular lamina
6
Q
what part of the basement membrane is produced by epithelium? fibroblasts in the CT?
A
epithelium- basal lamina
fibroblasts in CT- reticular lamina
7
Q
T/F. a partial basement membrane contains only the reticular lamina.
A
false; only basal lamina
8
Q
what are the four functions of a basement membrane?
A
- provides a surface for epithelial cell attachment
- molecular filter (limited)
- limits stretch
- directs migration of cells (e.g. wound healing)
9
Q
since epithelium is avascular, how do cells obtain nutrition?
A
by diffusion
10
Q
what are the two functions of CT when associated wit epithelium?
A
- provides nutrition
2. source of defensive cells
11
Q
what are the four types of cell junctions?
A
- zonula occludens
- zonula adherens
- macula adherens
- gap junctions
12
Q
what is another name for zonula occludens?
A
tight junctions
13
Q
zonula occludens involve the sharing of ________ membrane proteins ________ adjacent cells.
A
- intrinsic
2. between
14
Q
what are the two functions of zonula occludens/tight junctions?
A
- strong attachment
2. prevent passage of material between cells
15
Q
what is another name for zonula adherens?
A
adhesion belt
16
Q
zonula adherens consists of what two things?
A
- CADHERINS (linkage proteins) between cells
2. MARGINAL BANDS (microfilaments) which attach the cytoskeleton to the cell membrane at these areas
17
Q
what are the two functions of zonula adherens?
A
- strong attachment
2. provide cell structural stability
18
Q
what is another name for macula adherens?
A
desmosome
19
Q
what is the function of macula adherens/desmosomes?
A
provide strong attachment
20
Q
what three structures are associated with macula adherens?
A
transmembrane protein, tonofilaments, protein plaque
21
Q
what is the structure/shape of gap junctions?
A
six connexins (proteins) arranged in a cylinder
22
Q
T/F. the size of the openings of gap junctions cannot be controlled by the cell.
A
false; it can be controlled by the cell
23
Q
what are the two functions of gap junctions?
A
- strong attachment
2. transport material between cells
24
Q
T/F. All types of cell junctions (zonula occludens, zonula adherens, macula adherens, gap junctions) provide strong attachment.
A
true
25
list, in order, the junctional complex beginning with the free cell surface.
1. zonula occludens
2. zonula adherens
3. macula adherens
26
T/F. hemidesmosomes and focal point contacts are junctions that hold the epithelium to the basement membrane and the ct below.
true
27
what is the function of hemidesmosomes?
help connect epithelial cells to the basement membrane
28
what is the function of focal point contacts?
integrin (a transmembrane protein of the cell membrane) binds to structural CT glycoproteins and also connects to cytoskeleton
29
what autoimmune skin disease causes blistering lesions that burst, but do heal?
A. Bullous Pemphigoid
B. Cholera
C. Pemphigus Vulgaris
A. Bullous Pemphigoid
30
what is the cause of Bullous Pemphigoid?
anitbodies bind to particular proteins in hemidesmosomes
31
what autoimmune skin disease causes skin blisters that do not heal as easily, likely to excessively bleed, and can be fatal?
A. Bullous Pemphigoid
B. Cholera
C. Pemphigus Vulgaris
C. Pemphigus Vulgaris
32
will you see Pemphigus Vulgaris more in children or adults?
adults
33
what causes Pemphigus Vulgaris?
antibodies bind to parts of desmosomes
34
what is bacterial infection of the small intestines?
cholera
35
what causes cholera?
toxins disrupt proteins in zonula occludens which permits the loss of water and electrolytes from the CT below the epithelium
36
in regard to cholera, toxins disrupt what part of the junctional complex?
zonula occludens
37
what type of epithelium is a single cell thick?
simple epithelium
38
what are the four types of simple epithelium?
1. simple squamous
2. simple cuboidal
3. simple columnar
4. respiratory epithelium (ciliated pseudostratified columnar epithelium)
39
name the locations of simple squamous.
1. lung
2. parietal layer of Bowman's capsule in kidney
3. serosa on outside of organs
40
what are the 3 functions of simple squamous epithelium?
1. living filter
2. provide a barrier
3. secretion
41
name the locations of simple cuboidal.
1. exocrine ducts
2. thyroid follicular cells
3. kidney tubules
42
what are the 3 functions of simple cuboidal epithelium?
1. absorption
2. provide a barrier
3. secretion
43
name the locations of simple columnar.
1. stomach
2. small intestines
3. gallbladder
4. larger exocrine ducts
44
what are the 3 functions of simple columnar epithelium?
1. absorption
2. provide a barrier
3. secretion
45
matching
1. nucleus occupies much of the cell cytoplasm
2. more cell cytoplasm than nucleus
3. single layer of flattened cells
A. simple columnar
B. simple cuboidal
C. simple squamous
B. simple cuboidal
A. simple columnar
C. simple squamous
46
name the locations of respiratory epithelium.
1. trachea
2. respiratory region of nasal cavity
3. bronchii
47
respiratory epithelium has three cell types of various heights so it can have the appearance of stratified epithelium. name the cell types.
1. goblet cells
2. ciliated columnar cells
3. basal cells
48
T/F. goblet cells are modified cuboidal cells.
false; modified columnar cells
49
ciliated columnar cells contain cilia. where are the cilia anchored? how are they anchored?
in the apex of the cell by basal bodies
50
in basal cells, will you see nuclei along the basement membrane?
yes
51
basal cells are short _______ shaped cells that do not reach the surface.
pyramidal
52
matching
1. produce mucus
2. move mucus over the surface
3. the stem cells for respiratory epithelium
A. basal cells
B. goblet cells
C. ciliated columnar cells
B. goblet cells
C. ciliated columnar cells
A. basal cells
53
what is another name for microvilli?
brush border or striated border
54
what is the function of microvilli?
to increase surface area to increase absorption
55
name the locations of microvilli.
1. kidney tubule cells
| 2. small intestines
56
T/F. stereocilia are related to true cilia.
false
57
what is the functions of stereocilia?
increase surface area
58
name the locations of stereocilia.
1. epididymis
| 2. cochlear hair cells
59
what is the function of cilia?
to move something over a surface
60
what are the two points about cells with cilia?
1. many mitochondria
| 2. basal cells block the free surface so there is NO absorption or secretion
61
name the locations of cilia.
1. trachea
| 2. oviduct
62
what produces a glycocalyx?
epithelial cells
63
what are the functions of glycocalyces?
1. protection
2. cell recognition
3. cells adhesion
4. hold enzymes
64
name the locations of glycocalyces.
1. stomach
| 2. small intestines
65
matching
1. finger-like projections at the apical surface on some epithelial cells
2. extremely long microvilli
3. thin apical hair-like extensions of the cytoskeleton
4. surface layer of glycoproteins and carbohydrates that covers some epithelium
A. cilia
B. glycocalyx
C. microvilli
D. stereocilia
C. microvilli
D. stereocilia
A. cilia
B. glycocalyx
66
what type of epithelium is two or more cell layer thick?
stratified epithelium
67
T/F. all stratified epithelium have a protective function.
true
68
stratified epithelium is named for the shape of its deep or superficial cells?
superficial
69
name the five types of stratified epithelium.
1. stratified squamous
2. keratinized stratified squamous
3. stratified cuboidal
4. stratified columnar
5. transitional (urinary)
70
name the locations of stratified squamous epithelium.
1. esophagus
2. oral cavity
3. tongue
4. vagina
71
what is the function of stratified squamous epithelium?
protection from abrasion in moist environments
72
what are some problems or limitation of stratified squamous epithelium?
1. no protection from drying
| 2. limited thickness so protection is limited
73
name the location of keratinized stratified squamous epithelium.
skin
74
what is the function of keratinized stratified squamous epithelium?
protection in a dry environment
75
name, in order, the layers in epithelium of the skin starting with the layer closest to the dermis.
1. stratum basale
2. stratum spinosum
3. stratum granulosum
4. stratum lucidum
5. stratum corneum
76
what is the typical cell type in epithelium of the skin?
keratinocytes
77
matching
1. 1-2 layers of keratinocytes which are mitotic
2. multiple layers of "spiny shaped" keratinocytes that produce keratin
3. uppermost 2-5 layers of flattened living keratinocytes that contain flattened, condensed keratohyaline granules
4. thin layer of recently dead or dying keratinocytes present only in thick skin
5. layer of dead cells, keratin, and lipids
```
A. stratum spinosum
B. stratum lucidum
C. stratum basale
D. stratum granulosum
E. stratum corneum
```
```
C. stratum basale
A. stratum spinosum
D. stratum granulosum
B. stratum lucidum
E. stratum corneum
```
78
keratinocytes have ______ _______ that radiate outward from the nuclear region.
cytokeratin tonofilaments
79
T/F. thickness of the stratum spinosum cannot vary.
false; it can vary
80
T/F. keratin and lipids are produced in the stratum granulosum.
true
81
why is the stratum lucidum not easily seen?
present only in thick skin, and nucleus and organelles are not present
82
what are the 3 functions of the stratum corneum?
1. prevent water loss
2. provide a barrier to microbes
3. protect against abrasion
83
what two structures contributes strength to keratinized stratified squamous by increasing surface area for attachment of the epithelium to the CT below?
epidermal pegs (rete ridges) and dermal papillae
84
other than keratinocytes, what other cells may be found in keratinzed stratified squamous?
1. melanocytes
2. Langerhans cells
3. Merkel cells
85
what is the general function of melanocytes?
protect against UV radiation
86
what layer in keratinized stratified squamous will you find melanocytes?
stratum basale
87
T/F. melanocytes function by keratinocytes phagocytizing the cytoplasmic tips of melanocytes contianing melanosomes with melanin.
true
88
skin color is greatly influenced by what three factors?
1. environment
2. genetics
3. number of blood vessels in dermis
89
T/F. increased UV light exposure will increase melanocytes and melanin.
true
90
genetically, what will make the skin darker? reddish?
```
darker= eumelanin
reddish= pheomelanin
```
91
what three ways can genetics affect skin color?
1. eumelanin and pheomelanin
2. placement of melanin
3. destruction rate of melanin by lysosomes
92
T/F. melanocyte numbers will vary from person to person.
false; number are about equal in all humans
93
what is the function of Langerhans cells?
recognize and process external foreign antigens; APC
94
what layer will you find Langerhans cells?
stratum spinosum
95
what is another name for Langerhans cells?
epidermal dendritic cell
96
what is the function of Merkel cells?
provide touch receptors
97
what is another name for Merkel cells?
epithelial tactile cells
98
what layer will you find Merkel cells?
stratum basale
99
since Merkel cells provide touch receptors, what are they associated with?
free nerve endings
100
T/F. repeated exposure to UV light will increase both melanocytes and Langerhans cells.
false; increase melanocytes and decrease Langerhans cells
101
name the locations for stratified cuboidal epithelium.
larger ducts in sweat glands and salivary glands (parotid)
102
is stratified cuboidal common or uncommon?
uncommon
103
what are the 2 functions of stratified cuboidal epithelium?
1. increase protection
| 2. provide a barrier
104
name the locations of stratified columnar epithelium.
1. large ducts in pancreas
2. parts of male urethra
3. conjunctiva of eye
105
T/F. stratified columnar epithelium is the most common type of epithelium.
false; most uncommon, very rare
106
what are the 3 functions of stratified columnar epithelium?
1. increase protection
2. provide a barrier
3. provide a transition between epithelial types
107
name the location of transitional epithelium.
most of urinary tract
108
what are the 3 functions of transitional epithelium?
1. provide protection
2. provide barrier
3. stretch
109
what are the 3 specializations of transitional epithelium?
1. thin, fenestrated basement membrane
2. large, rounded superficial cells
3. well developed zonula occludens
110
why is it important to have a well developed zonula occludens in transitional epithelium?
1. needed due to fenestrated basement membrane
| 2. prevent wastes/urine from seeping between epi cells
111
what is an unusual superficial cell feature of transitional epithelium?
bi-nucleate superficial cells
112
why do cells in transitional epithelium obtain more oxygen?
1. fenestrated basement membrane
| 2. when stretched, the diffusion distance is decreased
113
matching
1. superficial layer of cells are flat and alive
2. superficial cell layer is covered by an added nonliving layer of keratin
3. two layers; basal layer is typically flattened and superficial layer is cuboid
4. two layers; basal layer is flattened to cuboid and superficial layer if columnar
5. multiple layers of cells
```
A. stratified columnar
B. stratified squamous
C. transitional
D. keratinized stratified squamous
E. stratified cuboidal
```
```
B. stratified squamous
D. keratinized stratified squamous
E. stratified cuboidal
A. stratified columnar
C. transitional
```
114
matching
1. patchy skin lesions
2. spots with extra pigment; especially in fair skinned
3. patches which lack melanocytes
4. discoloration due to proliferation of melanocytes
5. melanocytes become mitotically active and invade dermis
6. melanocytes fail to produce melanin
```
A. moles (naevi)
B. albinism
C. freckles
D. psoriasis vulgaris
E. malignant melanoma
F. vitiligo
```
```
D. psoriasis vulgaris
C. freckles
F. vitiligo
A. moles (naevi)
E. malignant melanoma
B. albinism
```
115
in psoriasis vulgaris, what layer of keratinized stratified squamous do cells accumulate?
stratum corneum
116
T/F. psoriasis vulgaris has inflammation of epidermal pegs (rete ridges).
false; inflammation of dermal papillae
117
what is the cause of psoriasis vulgaris?
cause is unknown
118
T/F. freckles occur due to an increase in both melanin and melanocytes.
false; increase in melanin within an increase in melanocyte numbers
119
the cause of vitiligo is unknown but is often associated with _____ _______.
systemic diseases (e.g. hypo/hyperthyroidism, diabetes, Addison's disease, pernicious anemia, leprosy
120
what is the treatment for malignant melanoma?
surgery and chemotherapy
121
what is the most common form of albinism?
tyrosinase (catalyst in converting tyrosine to melanin) is missing from melanocytes
122
what are the two subcategories of epithelial glands?
exocrine and endocrine
123
define exocrine secretion.
product is released into a duct or directly onto an epithelial surface
124
what is the difference in parenchyma and stroma regarding exocrine secretion?
parenchyma- components directly involved with the primary function (secreting)
stroma- components providing mechanical/metabolic support
125
what is the morphology of exocrine secretion?
classified according to the shape of the secretory units (tubular v. acinar) and duct arrangement (unbranched v. branched)
126
what are the three methods of exocrine secretion?
1. merocrine/ eccrine
2. holocrine
3. apocrine
127
name the examples of merocrine/eccrine secretion.
1. goblet cell
2. salivary gland
3. pancreas
4. all sweat glands in children
5. many adult sweat glands
128
T/F. merocrine/eccrine is the most common method of exocrine secretion.
true
129
merocrine/eccrine secretion is done by _____ therefore, is there no cell damage.
exocytosis
130
name the examples of holocrine secretion.
1. sebaceous glands
| 2. tarsal (Meibomian) glands of eyelid
131
T/F. in holocrine secretion, the cell matures and dies.
true
132
what is the secretory product of holocrine secretion?
entire cell with in-tact vacuoles
133
name the examples of apocrine secretion.
1. lactating mammary glands
2. some adult sweat glands (pubic and axillary)
3. ceruminous glands in external auditory canal
4. ciliary (Moll's) glands in eyelid
134
in apocrine secretion, is there cell damage?
yes but minimal
135
what is the secretory product of apocrine secretion?
some cytoplasm, membranes, and in-tact vacuoles
136
which two types of exocrine secretion is associated with odor?
holocrine and apocrine
137
matching
1. smallest division of a gland; group of cells surrounding a cavity
2. small group of serous cells attached to a mucus acinus
3. contractile cells with epithelial origin
A. serous demilune
B. myoepithelial cells
C. acinus
C. acinus
A. serous demilune
B. myoepithelial cells
138
where will you find myoepithelial cells?
1. salivary and sweat glands
2. lacrimal glands
3. lactating mammary glands
139
what is the function of myoepithelial cells?
assist secretion
140
what do serous glands produce?
proteins
141
name the examples of serous glands.
1. pancreas
2. parotid gland
3. chief cells in stomach
142
what are three characteristics of serous glands?
1. trapezoid shaped
2. nucelus typically round and noticeable
3. pick up stain
143
what will mucus gland produce?
mucus
144
name the examples of mucus glands.
1. goblet cells
| 2. mucous cells in stomach, minor salivary glands in tongue and palate
145
what are two characteristics of mucus glands?
1. stain light
| 2. nucleus is often flat and peripheral
146
what will mixed glands produce?
serous and muscus
147
name the examples of mixed glands.
1. sublingual
| 2. submandibular
148
how is exocrine secretion regulated?
1. myoepithelial cells
2. hormones
3. blood supply
149
T/F. exocrine secretion regulation is under ANS influence.
true
150
define endocrine secretion.
released into nearby CT for vascular dispersal to target cells/organs
151
what is the secretory product for endocrine secretion often referred to as?
a hormone
152
what are the two types of endocrine secretion?
1. paracrine secretion
| 2. autocrine secretion
153
what is the difference between paracrine and autocrine secretion?
paracrine- signal cell is close to target cell (hormone does not enter blood)
autocrine- signal cell is its own target
154
how is endocrine secretion regulated?
1. hormonal (positive and negative feedback loops)
| 2. ANS
