Chapter 1 Flashcards
1
Q
General functions of epithelium
A
- Absorption (bile duct)
- Secretion (stomach cells, HCL)
- Provide a barrier (all types of epithelium do this)
2
Q
Specialized functions of Epithelium
A
- Transportmoleculesacrossepi.
- Preventtransportofmaterialsacrossepi.=selectivepermeability
- Sensory(ex.Tastebuds,retinaineye)
3
Q
Cells are ____________ to each other
A
adjacent
4
Q
Associated with __________ or __________ basement membrane
A
Complete or Partial
5
Q
Parts of Complete Basement Membrane
A
A. Basal Lamina- produced by epithelial cells
B. Reticular Lamina- produced by fibroblasts in CT
6
Q
Part(s) of Partial Basement Membrane
A
Basal Lamina Only
7
Q
Functions of a basement membrane
A
a. provides a surface for epithelial attachment
b. molecular filter- limited
c. limit stretch- protects
8
Q
Epithelium is ___________. Cells obtain nutrition by __________.
A
avascular
diffusion
9
Q
Functions of CT
A
- provides nutrition for associated epithelium
2. source of defensive cells
10
Q
Cells are held together by ____________
A
cell junctions
11
Q
Zonula Occludens (name)
A
Tight Junctions
12
Q
Zonula Occludens (tight junctions) involve the sharing of intrinsic membrane proteins between ________ _______.
A
adjacent cells
13
Q
Zonula Occludens (tight junctions) functions
A
- provides strong attachment
2. prevents the passage of material between cells
14
Q
Zonula Adherens (name)
A
Adhesion Belt
15
Q
Zonula Adherens (Adhesion Belt) consist of ________ (________) between cells & _______ (________) which attach the cytoskeleton to the cell membrane at these areas
A
cadherins (linkage proteins)
Marginal bands (microfilaments)
16
Q
Zonula Adherins (Adhesion Belt) functions
A
- provides strong attachment
2. provide cell structural stability
17
Q
Macula Adherens (name)
A
Desmosomes
18
Q
Macula Adherens (Desmosomes) function
A
Provides strong attachment
19
Q
Gap Junctions are six ______ (______) arranged in a cylinder.
A
connexins (proteins)
20
Q
The size of the openings in gap junctions can be controlled _______________.
A
by the cell
21
Q
Gap Junctions function
A
- provides strong attachment
2. Transport materials (purpose: communication) [Primary Function]
22
Q
Junctional complex = 3 junctions beginning with free cell surface
A
- Zonula Occludens
- Adhesion Belt- Zonula Adherens
- Macula Adherens
23
Q
What junction type is NOT included in the junctional complex
A
Gap Junctions
24
Q
Helps to connect epithelial cells to the basal lamina.
A
Hemidesmosomes
essentially half a desmosome
25
Integrin (a transmembrane protein of the cell membrane) binds to structural CT glycoproteins and also connects to cytoskeleton.
Focal Point Contacts
26
Single Epithelium
epithelium that is a single cell thick
27
Simple squamous- example locations
lung, parietal layer of the Bowman's capsule in the kidney, serosa on the outside of organs
28
Simple squamous cells are...
a single layer of flattened cells
29
Simple squamous cells- functions
1. provide a barrier
| 2. living filter
30
Simple cuboidal- example locations
exocrine ducts, thyroid follicular cells, kidney tubules
31
Simple cuboidal cells are...
a single layer of cube shaped cells; nucleus occupies much of the cell cytoplasm; typically looks like a square when sectioned for a slide
32
Simple cuboidal cells- functions
1. Provide a barrier
2. Secretion
3. Absorption
33
Simple columnar- example locations
stomach, small intestines, gallbladder, larger exocrine ducts
34
Simple columnar cells are...
a single layer of cells that have height; more cell cytoplasm than simple cuboidal; typically look rectangular when sectioned for a slide
35
Simple columnar cells function
1. provide a barrier
2. secretion
3. absorption
36
Ciliated Pseudostratified Columnar Epithelium Example Locations
trachea, respieratory region of nasal cavity, bronchi
37
Ciliated Pseudostratified Columnar Epithelium is...
three cell types of various heights so it can have the appearance of a stratified epithelium.
38
Ciliated Pseudostratified Columnar Epithelium cell types:
1. Goblet cells
2. Ciliated Columnar cells
3. Basal Cells
39
Goblet cells are...
| Function
modified columnar cell
| function: to produce mucus
40
Ciliated columnar cells are...
| Function
columnar cells that contain cilia. Cilia are anchored in the apex of the cell by basal bodies.
function: to move mucus over the surface
41
Basal cells are...
| Function
short pyramidal shaped cell that does not reach the surface
| function: to be the stem cell for this type of epithelium
42
Microvilli are...
finger-like projections at the apical surface on some epithelial cells.
43
Microvilli are also called:
a brushborder or a striated border
44
Microvilli function
to increase surface area so as to increase absorption function
45
Microvilli example locations
kidney tubule cells, small intestines
46
Stereocilia are...
extremely long microvilli; usually fewer present than in microvilli
47
Are stereocilia related to true cilia
NO
48
Stereocilia function
usually to increase surface area
49
Stereocilia example locations
epididymis, cochlear hair cells
50
Cilia are...
thin apical hair-like extensions of the cytoskeleton
51
Cilia function
to move something over a surface
52
Cells with Cilia have...
1. many mitochondria
| 2. basal bodies that block the free surface so there is NO secretion or absorption
53
Cilia example locations
trachea, fallopian tubes
54
Glycocalyx is...
surface layer of glycoproteins and carbohydrates that covers some epithelium
55
Glycocalyx is produced by:
epithelial cells
56
Glycocalyx functions:
1. protective function (particularly in digestive system)
| 2. cell recognition
57
Glycocalyx example locations
stomach and small intestines
58
Stratified epithelium is...
Epithelium that is two or more cell layers thick. Named for the shape of its superficial cells.
All have a protective function
59
Stratified squamous example locations
esophagus, oral cavity, tongue, vagina
60
Stratified squamous are...
multiple layers of cells that tend to flatten out from basal layer to superficial layer; superficial layer of cells are flat and alive.
61
Stratified squamous function
protection from abrasion
62
Stratified squamous problems/limitations
1. no protection from drying
| 2. limited thickness so protection is limited.
63
Keratinized Stratified Squamous example location
skin
64
Keratinized Stratified Squamous are...
multiple layers of cells that also tend to flatten from basal layer to superficial layer of cells; superficial cell layer is covered by an added nonliving layer of keratin.
65
Keratinized Stratified Squamous function
protection in a dry environment
66
Keratinized Stratified Squamous layers in epithelium of skin
```
Stratum Basale (germinativum)
Stratum Spinosum
Stratum Granulosum
Stratum Lucidum
Stratum Corneum
```
67
Stratum Basale (Germinativum)
1-2 layers of keratinocytes which are mitotic and closest to the dermis
68
Stratum Spinosum
multiple layers of "spiny shaped" keratinocytes that produce lipids and keratohyaline vacuoles. Kertinocytes have cytokeratin tonofilaments that radiate outwards from the nuclear region. Thickness of this layer can vary.
69
Stratum Granulosum
uppermost 2-5 layers of flattened living keratinocytes that contain flattened, condensed keratohyaline granules. Exocytosis of lipid-filled lamellar granules will occur from these cells.
70
Stratum Lucidum
thin layer of recently dead or dying keratinocytes present ONLY IN THICK SKIN. This layer is not easy to see. Nucleus & organelles are not present.
71
Stratum Corneum
Layer of dead cells, keratin and lipids. Thickness of this layer varies.
72
Stratum Corneum functions
a. Prevents water loss
b. Provides a barrier to microbes
c. Protects against abrasion/friction
73
Epidermal pegs (rete ridges) and dermal papillae contribute strength to this epithelium by __________
increasing surface area for attachment of the epithelium to the CT below
74
Keratinized stratified squamous cells have a ____ life cycle
~28 day
75
Melanocytes (function)
protect against UV radiation
76
Melanocytes are found in what layer
stratum basale
77
How do melanocytes function
Keratinocytes phagocytize the cytoplasmic tips of the melanocytes containing the melanosomes with the melanin
78
Skin color is generally influenced by
A. environmental factors
B. Genetics
C. Number of blood vessels in dermis
79
Environmental (melanocyte) influences are:
increased UV light exposure: increase melanocytes numbers and increase melanin
80
Genetic (melanocyte) influences are:
Eumelanin or Pheomelanin
Placement of melanin
Destruction rate of melanin by lysosomes
81
Langerhans cells (function)
recognize forein antigens
82
Langerhans cells found in:
Stratum Spinosum
83
Merkel Cells (function)
provide touch receptors
84
Merkel Cells found in:
Stratum Basale
85
Merkel Cells are assoicated with
free nerve endings
86
Melanocyte numbers _______ when exposed to UV light repeatedly
increase
87
Langerhans cells ________ with repeated UV exposure
decrease
88
Stratified Cuboidal example locations
larger ducts in sweat glands and salivary glands
89
Stratified cuboidal are...
Two layers of cells.
Basal layer is typically flattened.
Superficial layer of cells is cuboid in shape.
Not common.
90
Stratified cuboidal function
to increase protection
91
Stratified columnar example locations
large ducts in pancreas, parts of the male urethra, conjunctiva of the eye.
92
Stratified columnar are...
Two layers of cells.
Basal layer is flattened to cuboid in shape.
Superficial layer is columnar in shape.
Very rare.
93
Stratified columnar function...
1. to increase protection
| 2. to provide a transition between epithelial types
94
Transitional (urinary) [name]
Urothelium
95
Transitional (urinary) example locations
most of urinary tract
96
Transitional (urinary) are...
multiple layers of cells.
97
Transitional (urinary) function
protection to stretch
98
Specializations of Transitional (Urinary) epithelium
1. Thin, fenestrated basement membrane
2. Large, rounded superficial cells
3. Well-developed zonula occludens (tight junctions)
99
Why are well developed zonula occludens important in Transitional (urinary) epithelium?
1. Need due to fenestrated basement membrane
| 2. Prevents wastes from seeping between epithelium cells.
100
Unusual Superficial Cell features in Transitional (urinary) epithelium:
some bi-nucleate cells
101
Urothelium cells obtain more oxygen because:
1. Fenestrated basement membrane
| 2. when stretched, the diffusion distance is decreased
102
Psoriasis Vulgaris appearance
patchy skin lesions
103
```
Psoriasis Vulgaris
______________ life cycle ~ 1 week
Cells accumulate in ____________
Inflammation in _______________
______ and _______ is unknown
```
Accelerated kertinocyte
stratum corneum
dermal papillae
cyclic and etiology
104
Freckles are due to:
an increase in melanin without an increase in melanocyte numbers
105
Vitiligo appearance
patches which lack melanocytes
106
Vitiligo cause:
unknown. Often associated with systemic diseases
| i. e. hypothyroidism, hyperthyroidism, diabetes, Addison's disease, pernicious anemia, leprosy
107
Moles (naevi) appearance and cause
discoloration due to a proliferation of melanocytes
108
Malignant Melanoma: description and treatment
Melanocytes become mitotically active and invade dermis, very invasive and metastatic
treatment: surgery and chemotherapy
109
Albinism: cause
melanocytes fail to produce melanin
110
Albinism: most common form
Tyrosinase (enzyme) is missing form melanocytes. Tyrosinase is a catalyst in the conversion of tyrosine to melanin.
111
2 subcategories of epithelial glands
Endocrine & Exocrine
112
Exocrine secretion: definition
method of secretion by which the product is released into a duct or directly onto an epithelial surface
113
What is parenchyma?
components directly involved with a primary function
114
What is stroma?
components providing mechanical/metabolic support
115
Morphology: methodology
This method classifies the gland according to the shape of secretory units and the ducts arrangements
116
Morphology: example
compound branched tubular gland
secretory units: tubular vs acinar (alveolar)
duct arrangment: unbranched vs branched
117
Method of Secretion:
| Merocrine (eccrine): examples
goblet cell, salivary glands, pancreas, all sweat glands in children, many adult sweat glands.
118
Method of Secretion:
Merocrine (eccrine):
_________ method of secretion
Secretion by exocytosis therefore:
Most common
| No cell damage, no cell cytoplasm or membranes in the secretory product, no odor associated
119
Method of Secretion:
| Holocrine: examples
sebaceous glands, tarsal (meibomian) glands of eyelid
120
```
Method of Secretion:
Holocrine:
Cell matures and _______
Secretory product = ________
Associated with _______
```
cell matures and dies
secretory product = some cytoplasm & membrane + intact vacuoles
associated with odor
121
Product secreted:
| Acinus
smallest division of a gland; a group of cells surrounding a cavity
122
Product secreted:
| Serous Demilune
a small group of serous cells attached to a mucus acinus
123
Product secreted:
| Myoepithelial Cells
contractile cells with epithelial origin. These cells warp around the acini and sometimes the ducts in some exocrine glands.
124
Product secreted:
Myoepithelial cells
Found in:
Salivary glands and sweat glands
lacrimal glands
Lactating mammary glands
125
Product secreted:
Myoepithelial Cells
Function:
Assist secretion
126
Serous Glands
Produce:
Examples:
produce proteins
| ex. pancreas, parotid gland, chief cells in stomach
127
Serous Glands
| Characteristics:
cell is trapezoid shaped
Nucleus is typically round and noticeable
cells pick up stain
128
Mucus Glands
Produce:
Examples:
produce mucus
| Examples. Goblet cells, mucus cells in stomach, minor salivary glands in tongue and palate
129
Mucus Glands
| Characteristics:
Cells typically stain light
| Nucleus is often flat and peripheral
130
Mixed Glands
Produce:
Example:
produce serous & mucus
| Sublingual and submandibular salivary glands
131
Mixed Glands
| Characteristics:
Serous demilunes are possible
132
Exocrine Regulation: how
Myoepithelial cells
Hormones
Blood Supply
