epithelium Flashcards
(115 cards)
1
Q
functions of epithelium
A
absorption, secretion and provide barrier
2
Q
what function of epithelium do all types of epithelium posses?
A
provide barrier
3
Q
specialized functions of epithelium
A
transport molecule across epi, prevent transport of material, sensory
4
Q
what are the 2 parts of a basement membrane
A
basal lamina and reticular lamina
5
Q
origin of basal lamina
A
produced by epithelial cells
6
Q
origin of reticular lamina
A
produced by fibroblast in connective tissue
7
Q
partial basement membrane
A
basal lamina only
8
Q
function of basement membrane
A
provide attachment surface for epi. cells, limit stretch (protection), molecular filter
9
Q
epithelium: vascular or avascular
A
avascular
10
Q
what other type of tissue is epi associated with?
A
vascular connective tissue
11
Q
why is epi associated with connective tissue?
A
CT provided nutrition and oxygen; provides defense
12
Q
types of cell junctions in epithelium
A
zonula occludens,, zonula adherens, macula adherens and gap junctions
13
Q
zonula occludens, type of cell junction in epi.
A
aka tight junctions; share intrinsic membrane proteins between cells
14
Q
function of zonula occludens
A
strong attachment and prevent passage of material between cells
15
Q
zonula adherens type of cell junction in epi.
A
aka adhesion belt; linkage proteins and marginal bands
16
Q
linkage proteins
A
weak attachment between 2 cells in the zonula adherens
17
Q
marginal bands
A
part of the cytoskeleton that attach to cell membrane in the zonula adherens
18
Q
functions of zonula adherens
A
weak attachment and structural stability
19
Q
macula adherens type of cell junction in epi.
A
aka desmosome; strong attachment
20
Q
gap junctions type of cell junction in epi.
A
aka connexon
21
Q
function of gap junction
A
strong attachment and transport materials
22
Q
how does macula adherens (desmosome) work
A
protein plaque within adjacent cells link together via transmembrane proteins
23
Q
how does gap junctions (connexon) work
A
cylinders of proteins (connexins) with in adjacent cells like
24
Q
hemidesmosome
A
half of macula adherens
25
location of simple squamous
lung, parietal layer of bowman's capsule (kidney), serosa on the outside of organs
26
function of simple squamous
barrier and living filter
27
location of simple cuboidal
exocrin ducts, thyroid follicular cells, kidney tubules
28
function of simple cuboidal
barrier, secretion, absorption
29
location of simple columnar
stomach, small intestine, gall bladder and LARGE exocrin duct
30
function of simple columnar
barrier, secretion and absorption
31
location of ciliated pseudostratified
trachea, repiratior region of nasal cavity, bronchi
32
other name for ciliated pseudostratified
respiratory epithelium
33
other name for respiratory epithelium
ciliated pseudostratified
34
types of cells in ciliated pseudostratified
ciliated columnar, goblet cells and basal cells
35
how is cilia anchored to ciliated columnar
by basal bodies to the apex of the cell
36
function of the ciliated columnar
to move mucus
37
function of goblet cells
produce mucus
38
basal cells
short pyramidal cells that do not reach surface in respiratory epi
39
function of basal cells
stem cells that divide through mitosis
40
basal cells divide into:
basal cells OR goblet cells OR ciliated columnar
41
microvilli
aka brush border of striated border
42
function of microvilli
increase surface area and increase absorption
43
location of microwilli
kidney tubule cells and small intestine
44
stereocilia
extremely long microvilli
45
function of sterocilia
increase surface area
46
location of sterocillia
epididymis and cochlear hair cells
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function of cilia
to move something over surface
48
cells with cillia...
have many mitochondria and no absorption or secretion due to basal bodies blocking surface
49
location of cilia
trachea and fallopian tube
50
glycocalyx
surface layer of glycoproteins and carbohydrates that cover some epi
51
glycocalyx is produced by...
epithelial cells
52
function of glygocalyx
protection and cell recognition
53
location of glycocalyx
stomach and small intestine
54
location of stratified squamous
esophagus, oral cavity, tongue and vagina
55
function of stratified squamous
protection from abration
56
problems with stratified squamous
no protection from drying, limited thickness (increased thickness will decrease nutrient diffusion and cause cell death)
57
location of keratinized stratified squamous
skin
58
function of keratinized stratified squamous
protection in a dry enviroment
59
layers of keratinized stratified squamous
stratum basale, stratum spinosum, stratum granulosum, stratum lucidum and stratum corneum
60
stratum basale
1-2 layers of keratinocytes; mitotic and close to dermis
61
stratum spinosum
multiple layers of "star" cells; produce lipids and keratohyalin vacuoles; thickness can vary
62
strantum granulosum
upper most 1-2 layers of LIVING keratinocytes; flattened, condensed keratinohyalin vacules
63
stratum lucidum
thin layer of DEAD or DYING keratinocytes; present on ly in thick skin
64
stratum corneum
layer of dead cells, karatin and lipids; variable thickness
65
function of stratum corneum
protection from water loss, abrasion and microorganisms
66
epidermal pegs
aka rete ridges; contribute strength to epi by increasing surface area for attachment to CT below
67
dermal papillae
contribute strength to epi by increasing surface area for attachment to CT belos
68
skin color is influenced by:
number of melanosomes, size of melanosomes and placemnt of pigment/melanosomes within a cell
69
protection from UV increases or decreases with age?
decreases; melanosomes decrease in number and skin lightens
70
langerhans cells
aka antigen presenting cells; recognize external foreign antigens
71
location of langerhans cells
stratum spinosum; and stratified squamous epi in esophagus and vagina
72
merkel cells
provide touch receptors; associated with nerve endings and respond to pressure
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location of merkel cells
stratum basale
74
clinical connection between langerhans cells and melanocytes
melanocytes increase when exposed to UV light while langerhans cells decrease when exposed to UV light
75
location for stratified cuboidal
larger ducts in sweat glands and salivary glands
76
function of stratifed cuboidal
increase protection and structure
77
stratified cuboidal
2 layers: basal layer is flatted and superficial layer is cuboidal
78
location of stratified columnar
large ducts in pancreas, parts of the male urethra, conjuctiva of eye
79
stratified columnar
2 layers; basal layer is flattened to cuboidal shape and superficial layer is columnar
80
location of transitional epi
most of the urinary tract
81
transitional epi
aka urothelium; multiple layers thick
82
function of transitional epi
protection (provides a barrier for urine) and STRETCH
83
specializations for transitional epi
thin, fenestrated basement membrane; large, round superficial cells; well developed zonula occludens
84
what is unusual about transitional epi cells
many are bi-nuclear
85
why do transitional epi cells get more oxygen
due to fenestrated basement membrane and shorter diffusion distance when epi is stretched
86
subcatagories of epi glands
exocrine and endocrine
87
exocrine secretion
product is relased into a duct of directly onto epi surface
88
parenchma
function component; ex. muscle cell
89
stroma
structural component; blood vessles, nerves, CT, tendons
90
classification of exocrine glands
morphology, method of secretion or product secreted
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morphology classification of exocrine glands
secretory units: tubular vs acinar; duct arrangement: branched vs unbranched
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method of secretion classification of exocrin glands
merocrin (eccrine), holocrin or apocrin
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merocrin secretion
method of exocrine secretion that uses exocytosis, does not cause cell damage and relasese only secretory product (generally no odor)
94
holocrine secretion
method of exocrin secretion where mature cells die and release product, vacuole content, lipids, cell membrane, organelles and etc; associated with odor and bacteria
95
apocrin secretion
method of exocrin secretion where vacuoles pinch off from cell; minimal cell damage; secretory products of intack vacules, cytoplasmn and cell membrane; associate with odor and bacteria
96
examples of merocrin glands
goblet cell, salivary glands, pancreas and all sweat glands in children
97
examples of holocrine glands
sebaceous glands, tarsal (meibomian) glands of eyelid
98
examples of apocrine glands
lactating mammary glands, adult sweat glands (pubic/axillary), ceruminous glands in external auditory canal, ciliary (moll's) glands in eyelid
99
acinus
smallest division of a gland; a croup of cells surrounding a cavity
100
serous demilune
small group of serous cells attached to a mucus acinus
101
myoepithelial cells
cells with epithelial origin that are contractile; wrap around the acini and sometimes the ducts in some exocrine glands
102
myoepithelial cells are found in:
salivary & sweat glands, lacrimal glands, lactating mammary glands
103
funcion of myoepithelial cells
assist secretion
104
serous glands produce:
proteins (enzymes)
105
example of serous glands
pancreas parotid gland, chief cells in stomach
106
characteristics of serous glands
cells are trapezoid in shape, nucleus is typically round and noticeable, cells pick up stain
107
examples of mucus glands
goblet cells, mucus cells in stomach, minor salivary glands in tongue and palate
108
characteristics of mucus glands
cells stain light, nucleus is usually flat & peripheral, cells are trapezoid in shape
109
mixed glands produce:
mucus & serous (protein/enzmes) products
110
characteristics of mixed glands
serous demilunes are posible
111
exocrine regulation
myoepithelial cells: influence contraction and secretion of product; hormonal; blood supply: increased oxygen increased activity/secretion
112
endocrine secretion
paracrine secretion and autocrine secretion
113
paracrin secretion
type of endocrine secretion where signaling cell is close to target cell; hormone does not enter blood
114
autocrine secretion
type of endocrine secretion where signaling cell is own target
115
regulation of endocrine secretion
hormonal & ANS
