The Human Body's four basic tissue types Flashcards
1
Q
What are the major functions of Epithelial cells/tissue?
A
Protection; filtration; secretion; absorption; excretion (F.A.P.E.S)
2
Q
What does the epithelial cells/tissue do?
A
they cover the body’s surfaces, lines hollow organs, tubes, cavities, ducts and forms glands.
3
Q
The cells of the epithelium are held together by what and in what formation?
A
The cells are held together by a variety of cell junctions and are arranged in single or multiple layers of continuous sheets.
4
Q
What are these cell junctions which hold the epithelial cells together?
A
Tight Junction, Adherens Junctions, Gap junctions, Desmosomes and Hemidesmosomes
5
Q
What cell junctions are found on the Lateral?
A
Tight junction, Adherens junctions, Gap junction, Desmosomes
6
Q
What cell junction is found on the basal junction?
A
Hemidesmosomes
7
Q
What is the apical / free surface?
A
the top, its may be open to the outside world or the lumen inside the gut.
8
Q
What is the lateral surface?
A
where two cells are adjacent to each other.
9
Q
What is the basal or attached surface?
A
attaches the cell to the basement membrane
10
Q
What is the protein skeleton of cells called?
A
Cytoskeleton
11
Q
What are two key proteins that make up the cytoskeleton?
A
Microfilaments and Intermediate filaments
12
Q
What protein are microfilaments primarily made up of?
A
ACTIN
13
Q
Where are microfilaments in the cell and what do they do?
A
They are bundles under the cell membrane and cytoplasm. Microfilaments provide strength and give the shape to the cell, causes movement within the cell, links the cytoplasm to the membrane, tie cells together and muscles contractions.
14
Q
What protein are Intermediate filaments primarily made up of?
A
KERATIN
15
Q
What does the intermediate filament do within the cell?
A
it provides strength and moves materials through the cells’ cytoplasm
16
Q
Where about is the tight junction located and how would you describe the tight junctions?
A
Near the apical surface of the cell, the tight junction has a knitted like appearance
17
Q
In the tight junctions how are adjacent membranes held together?
A
transmembrane proteins pass back and forth around the two adjacent cell membrane holding and fusing them together. Tight junctions removes the gap between the two cell membranes.
18
Q
When tight junctions removes the gap between the two cell membranes, what is this called and why is it called that?
A
It makes the cells electrically tight. This means that ions and other proteins can’t pass easily down between the cells. This means the environment lower down can be different from what is above the apical surface thereby keeping cell polarity.
19
Q
What are the two key proteins that make up the knitting (transmembrane proteins) together in tight membrane is called?
A
Claudins and occludins
20
Q
What do the protein claudin and occludin do to membrane and in what cell junction?
A
They bind into the membrane. They are the two key proteins for tight junctions.
21
Q
What would increase the tightness of the tight jucntion?
A
more strands
22
Q
Where are a large quantity of Tight junctions found? And what do tight junctions prevent?
A
stomach, intestines and bladder. stops the passage of substances between cells and prevents the contents within the organ from leaking out (into blood or surrounding tissue)
23
Q
Where about is the adherens junction? and how would you describe the Adherens junction?
A
Generally near the apical surface but more basal that tight junctions. Plaque-like structure with a Belt-like appearance which encompasses the cell.
24
Q
Why is there a gap in the Adherens junction?
A
This gap is extended by a transmembrane glycoprotein called cadherin.
25
What happens to cadherin in the Adheren junctions?
The cadherin extends across the from one membrane and then through the other cells membrane and interacts with another protein called Catenins. Catenins helps the cadherin bind to the microfilaments of the cytosketeons of the two cells (ACTIN). This links the cells at a skeleton level.
26
What are the two proteins in the adheren Junctions
Cadherin and catenin
27
What is the advantage of Adheren junctions linking cells together in the skeleton level?
It stops cells from moving around, and so that the cells can move in unison. This is beneficial when epithelial surfaces are contracting as it prevent the cells separating.
28
Where about is the Desmosome junctions? and how would you describe them?
Found in the lateral wall, and has a button-like appearance.
29
Why is there a gap in the desmosome junctions?
The gap is held open by transmembrane glycoprotein called cadherin.
30
What two junctions having the same spanning protein cadherin?
Adheren junction and desmosome junction.
31
What does the Desmosomes help to do between the cells?
it helps the link the intermediate filaments between the different cells.
32
How does the Desmosomes junction interact with the intermediate filaments and cadherin?
The keratin protein which are intermediate filaments become attached to the desmosome plaque and those attach to the keratin protein in the other cell.
33
Where is desmosomes junctions common in? and what are the benefits
Muscle cells. it increases the structural integrity of the cells.
34
How are the Gap junctions held together? How are the proteins in Gap junctions arranged in?
They are held together by proteins. Gap jucntions are formed by 2 six proteined cells called connexOn or Hemichannel.
35
How are ConnexOn or Hemichannel formed?
They are formed when ConnexIn proteins molecules are together.
36
What does a ConnexOn look like?
a donut
37
What does the ConnexOn look like and do when its first made?
When it is first made it has no hole in the middle. It enters and moves around in the cell membrane until it find a donut in the adjacent cell.
38
What happens to the ConnexOn when two ConnexOns of adjacent cells in Gap junctions find each other?
The two donuts dock together and then the channel between them opens (the donut hole - conformation change ). This forms a tunnel from the cytosol of one cell to another.
39
How big can the molecules flowing through the tunnel in Gap Junctions be?
The molecules can be up to
| approximately 1kDa.
40
What kind of molecules can travel through the tunnel in Gap junctions?
ATP, Calcium and ions.
41
What is it called when several gap junction come together?
to form large communication plaques.
42
What kind of appearance does Hemidesmosome have, and where are they located?
Button-like appearance, found in the basal surface
43
What are the advantages of Gap junctions?
enables nerve and muscle impulses to spread rapidly among cells, it also allows cells to communicate with each other and allows the transfer of nutrients and sometimes waste.
44
Hemidesmosomes are similar to Desmosomes in what way?
Both junctions binds the intermediate filaments (Keratin)
45
Where does the Hemidesmosome junctions bind the cell to and what is the advantage of this?
it binds the cell down to the basement membrane, this prevents the cells from sliding all over the place.
46
Since Hemidesmosomes don't join to another cell but rather the basement membrane, what is its linking transmembrane glycoprotein? and what protein does the transmembrane glycoprotein bind into?
INTEGRIN, binds to LAMININ in the basement membrane.
47
Describe the relationship belween Keratin, Integrin and Laminin in Hemidesosome junctions.
The keratin protein in the cytoplasm of the cell is linked to the Laminin protein via the Integrin.
48
What is the combination of Tight junction, adheren junction and desmosome called?
Junctional complex
49
Where is the Epithelia always located? and why?
It always overlays a basement membrane. so that the epithelia cells can anchor themselves to.
50
what are the two parts of the basement membrane.
Basal Lamina and Reticular Lamina
51
Where is the basement membrane found between?
it is found between the epithelium and connective tissue.
52
What is the basal lamina made up of, and where is those proteins from? give examples of the proteins.
Made by proteins which are largely secreted by the epithelial cells above. Proteins such as collagen, Laminin, glycoproteins.
53
What is the reticular Lamina made up of? and where are those proteins from? give examples of the proteins.
Made up of proteins which are largely secreted by the the connective tissue called fibroblasts below. Proteins such as fibronectin and collagen.
54
Epithelia contains nerves but does not contain what? And what does that mean for the epithelia cells?
Epithelia cells are avascular, so the Epithelia cells cant get nutrition. In response to this by nutrients being diffused into the epithelial cells through the basement membrane from the connective tissue. similarly waste material is diffused out of the epithelial cells into the basement membrane into the connective tissue.
55
what does avascular mean?
contain no blood vessels
56
What are the functions of the basement membrane?
supports the overlying epithelium cells (especially in the cases of wounds). it also acts as a physical barrier. As well as helps out in the filtration of substances in the kidneys.
57
How does the basement membrane aid in the cases of wounds?
when cut, the epithelium and basement membrane are both divided. The process to heal includes reform the basement membrane so that the cells can migrate in from the sides so that the epithelial cells can migrate over the basement cells and reform.
58
Basement Membrane in relation to Malignant melanoma
The basement membrane acts as a barrier from the invasion of tumors such as melanoma, if the tumor depth is above the basement membrane the chances of survival are high but as the depth increases and penetrates the basement membrane the chances of spread increases significantly and therefore survival decreases.
59
What are the ABCD of melanoma warning signs?
A - asymmetry - if the half of the mole doesn't match the other half.
B - Border irregularity - the edges of the mole is ragged, notched or blurred
C - Colour - mix of brown, black, red, white or blue
D - Diameter - if the mole has a greater that 6mm diameter.
60
What are the two major types of Epithelial tissue?
Covering and lining Epithelia. Glandular Epithelia
61
Where is the Covering a lining Epithelia found?
they line either the outer covering (skin and some internal organs) or the inner lining (blood vessels, ducts and body cavities and interiors of systems)
62
Where is the glandular epithelia found?
Is the whole secretory portion of glands ( thyroid gland, adrenal gland and sweat glands)
63
What are the two types of Glandular epithelia?
Exocrine and Endocrine
64
What are the two aspects used to classify Covering and lining Epithelia?
The arrangement of cells and the shapes of the cell.
65
What are the three arrangements for Covering and lining epithelia?
Simple, Stratified and Pseudostratified
66
What does the simple arrangement for covering and lining epithelial look like? and what is its purpose?
it is a single layer, its functions are diffusion, osmosis, secretion, absorption and filtration
67
What does the stratified arrangement for covering and lining epithelial look like? and what is its purpose?
it is two or more layers, its function is protection in areas where there is alot of wear and tear.
68
What does the Pseudostratified arrangement for covering and lining epithelial look like? and what is its purpose?
looks like it has multiple layers by where the nuclei positions, but all cells in this arrangement are in contact with the basement membrane, while not all cells reach the apical membrane. It therefore is actually simple epithelial and have the function of secretion.
69
What are the four shapes in classifying covering and lining epithelial?
Squamous, Cuboidal, Columnar and Transitional.
70
What does the shape Squamous for covering and lining epithelial look like? and what is its function?
it is flat and thin, its function is to allow rapid passage by diffusion.
71
What does the shape Cuboidal for covering and lining epithelial look like? and what is its function?
It is has the same height and width (cube-like or hexagon-like shape). They might also have microvilli at their apical surface. Its function is secretion; absorption.
72
What does the shape Columnar for covering and lining epithelial look like? and what is its function?
it's height is greater than width, (column-like or rectangular shape). more elongated nuclei, their apical surfaces may have microvilli and cilla. primary functions secretion and absorption.
73
What does the shape Transitional for covering and lining epithelial look like? and what is its function?
it changes shape between cuboidal and flat depending on the tension in the wall.
74
What is the only organ structure that needs to be known for transitional shape for covering and lining epithelia? what shape do they have in a relaxed state?
Urinary bladder, it has a scalloped shape (round and uneven)
75
What are the 3 types of Simple layer covering and lining epithelial tissues?
Simple Squamous, Simple Cuboidal, Simple Columnar (ciliated and non-ciliated).
76
What are the 4 types of Stratified layer covering and lining epithelial tissues?
Stratified squamous (keratinized and non-keratinized), Stratified cuboidal, Stratified columnar, Transitional
77
What are the 1 type of Pseudostratified layer covering and lining epithelial tissues?
Pseudostratified columnar (Ciliated or non-ciliated)
78
Describe Simple Squamous Epithelium's appearance?
is a single layered thing flat cells which are somewhat irregular in overall shape. Cells which look like paving stones. That have centrally located flattened spherical or oval nuclei. Most delicate epithelium.
79
What are the two specialised subsets of the simple squamous epithelium?
Mesothelium and Endothelium.
80
Where does the subset Endothelium of Simple Squamous Epithelium line in the body?
lines the inside of cardiovascular and lymphatic systems - heart, blood vessels and lymphatic vessels.
81
Where does the subset Mesothelium of Simple Squamous Epithelium line in the body?
lines the serous membranes - pericardial, pleural, peritoneal cavities.
82
What is the function of simple squamous Epithelium?
Present at sites where there is filtration (kidney); diffusion (lung); secretion where slippery surface is required (outer layer of serous membrane)
83
Where is the Simple squamous Epithelium not found?
Where there is stress (wear and tear)
84
Where is the Simple Squamous Epithelium found?
In Bowman's capsule of kidney, lines cardiovascular and lymphatic systems, inside eye, alveoli of lungs, visceral cavity linings, inside blood vessels, inside heart and inner surface of tympanic membrane (eardrum)
85
Describe the Simple Cuboidal Epithelium's appearance?
single layer of cube-shaped or hexagonal cells, with a round centrally located nucleus. The distance between the adjacent nuclei is approx. the height of the cell.
86
Where is the simple cuboidal epithelium not lining?
cannot line small tubes, because the cells are too big (height=width)
87
Does the Simple Cuboidal Epithelium have any special subsets?
no
88
What is the function of simple cuboidal epithelium?
It is found where secretion and absorption is required
89
Where is the simple cuboidal Epithelium found?
Pancreas ducts; parts of kidneys tubules, smaller ducts of many glands; secretory chambers of thyroid; anterior surfaces of lens; pigmented epithelium at posterior of retina; secretory part of some glands like thyroid.
90
What a membrane modifications?
are changes or adaptations that have occurred in the membrane of different cells.
91
What are examples of membrane modifications?
Microvilli and cillia
92
What is Microvilli and why is there a modification?
fingerlike cytoplasmic projections which increases surface area of plasma membrane.
93
What is another name for Microvilli?
Brush boarder (from appearance)
94
What is a cilia and why is there a modification?
motile (move around) fingerlike membranes, to move material along the surface of the cell
95
What is an example of cilia?
found in the lungs, when sick the cilla helps move phlegm up.
96
What are the two major subsets of simple columnar Epithelium?
Non-ciliated simple columnar Epithelium and Ciliated simple columnar epithelium.
97
What is the difference between non-ciliated and ciliated simple columnar epithelium?
Non-ciliated has microvilli,
| ciliated has cilla
98
Describe the appearance of simple columnar epithelium?
Rectangular, taller and slender than cuboidal, the nuclei is often elongated. They also have more cytoplasm therefore more organelles are found
99
Why is single columnar epithelium more metabolically active than simple squamous cells and simple cuboidal cells?
The single columnar epithelium cells are bigger and therefore it is more metabolically active.
100
Describe non-ciliated simple columnar epithelium?
single layer column-like cells with oval nucleus near the base of the cell, microvilli on apical surface and goblet cells spread throughout.
101
What are goblet cells? and why are they called goblet cells?
are modified columnar cells, called goblet cell because it is filled with mucous and it looks like a goblet.
102
What is the goblet cell's fucntion?
secretes out mucous onto the surface of the membrane.
103
What is the function of non-ciliated columnar epithelium?
secretion, lubrication and absorption, (large cells contain more organelle - greater secretion and absorption capabilities.)
104
Where are non-ciliated columnar epithelium found?
lines gastrointestinal tract (stomach to anus), ducts to many glands and gall bladder.
105
describe ciliated simple columnar epithelium?
single layer of ciliated column-like cells with oval nucleus near base of cells. Goblet cells spaced throughout.
106
What is the function of ciliated simple columnar epithelium?
the cillia beat in unison, pushing mucous and foreign molecules towards the throat where it can be coughed up, they can also help expel oocytes form ovaries through the uterine tubes into the uterus.
107
Where are ciliated simple columnar epithelium found?
lines the bronchioles (small tubes) of respiratory tract, uterine tubes, uterus, paranasal sinuses, central canal of spinal cord and ventricles of brain.
108
Describe stratified Squamous Epithelium?
2 or more layered flat, thin cells. lower layers can have the shape cuboidal or columnar. The layers closer to the apical surface have fewer nutrients and become less active and thinner as they move away from the blood supply in the connective tissue
109
where are stratified squamous epithelium found? and why in those locations?
where there is trauma (wear and tear) as there is many layers and can be afford to lose some with compromising barrier function of cell.
110
What are the two subtypes of stratified squamous epithelium? and why?
Keratinised and non-keratinised.
There is keratin in the outer layers (near apical surface) where there is alot of wear from mechanical stress and dehydration, the keratin makes the surface tough and waterproof.
111
Why does the relative amount of keratin in the stratified squamous epithelium increase in the cells as it moves up towards the apical surface?
because the cells move away from the nutritive blood supple and the organelles die.
112
Where is Keratinised stratified squamous epithelium found?
superficial layer of skin
113
Where is non keratinised stratified squamous epithelium found?
lines wet surfaces - mouth, throat, tongue, oesophagus, anus and vagina
114
What happens when the keratinised stratified squamous epithelium die? and what happens with huge quantities of water?
When the cell dies, they leave the keratin on the surface of the membrane, when showering for long periods or in water for long time the slimy feeling is the keratin due to it becoming full of water.
115
describe stratified cuboidal epithelium?
2 or more layered cells, cells in apical surface is cube-shaped.
116
where is stratified cuboidal epithelium found?
ducts of adult sweat glands, oesophageal glands, part of the male. urethra.
117
Function of stratified cuboidal epithelium?
protection, also has limited secretion and absorption.
118
Describe stratified columnar epithelium?
basal layers consist of shortened irregular shaped cells, the cells in apical layer has columnar shape.
119
Where is stratified columnar epithelium found?
lines parts of urethra, large excretory ducts in glands (eg; oesophageal glands), small areas in anal mucous membrane; part of conjunctiva of eye.
120
Function of stratified columnar epithelium?
protection and secretion
121
how common is stratified columnar epitheliums?
uncommon
122
how common is stratified cuboidal epithelium?
fairly rare
123
Describe Transitional epithelium?
2 or more layer cell. its appearance changes depending on tension of the cells.
124
What is the appearance of transitional epithelium in relaxed or unstretched state?
looks like stratified cuboidal epithelium, but the apical layer tend to be large and rounded.
125
What is the appearance of the transitional epithelium in stretched state?
the cells become flatter appearing like stratified squamous epithelium.
126
Where is transitional epithelium found?
lines urinary bladder, urethra
127
Function of transitional epithelium?
allows urinary organs to stretch and maintain protective lining while holding different amounts of fluids without rupturing.
128
Describe Psuedo-stratified Columnar Epithelium.
Nuclei at different levels therefore appears to have multiple layers, but is single layer as all cells have contact with basement membrane therefore a single epithelium.
129
Which epithelium cells classifications are dependent on the shape of the cells in the apical layer?
Stratified squamous
Stratified cuboidal
Stratified columnar
130
What are the subtypes of Psuedo-stratified columnar epithelium?
Psuedo-stratified ciliated columnar epithelium.
| Psuedo-stratified non-ciliated columnar epithelium
131
Describe Psuedo-stratified ciliated columnar epithelium?
it has cilia on some cells, secrets mucus from goblet cells
132
Describe Psuedo-stratified non-ciliated columnar epithelium?
has no cilia and no goblet cells
133
location of Psuedo-stratified ciliated columnar epithelium?
most of upper airways - trachea
134
location of Psuedo-stratified non-ciliated columnar epithelium?
Larger ducts of glands, epididymis, part of male urethra.
135
Function of Psuedo-stratified ciliated columnar epithelium?
secrete mucus and move it
136
Function of Psuedo-stratified non-ciliated columnar epithelium?
absorption and protection
137
what are glands?
a single cell of a group of cells that secrete substances into ducts, onto surfaces or into blood.
138
How are glandular epithelia classified?
according to where they secrete their substances
139
What is the function of all glandular epithelia?
secretion
140
what are the two types of glandular epithelia?
endocrine glands and exocrine glands.
141
What is the secretion pathway?
this is where the substance is secreted to
142
What is the secretion pathway for endocrine glands?
Secrete directly into blood via traversing interstitial fluid and get diffused into the bloodstream (no duct)
143
what is the secretion pathway for exocrine glands?
secrete into ducts that empty onto the surface of a covering or lining epithelium.
144
Locations of endocrine glands?
pituitary, pineal, thyroid, parathyroid. always has blood vessels nearby.
145
Locations of exocrine glands?
sweat and salivary glands; oil glands; wax glands and pancreas
146
Function of Endocrine glands?
the hormones secreted regulate many metabolic and physiological activities to maintain homeostasis
147
Function of Exocrine glands?
to produce substances such as sweat to lower body temperature, oil, earwax, saliva or digestive enzymes.
148
What are the two types of exocrine glands?
Single cell and multicellular
149
What type of cells are single cell exocrine glands? describe and function?
mucous cells, the apical cytoplasm is filled with large secretory vesicles. The function is to secrete mucin.
150
Example of single cell exocrine glands?
goblet cells
151
What is the classification of multicellular exocrine glands?
nature of duct - Simple or compound
the stucture of secretory area - coiled, branched
the arrangement of glandular tissues - tubular, alveolar, tubuloalveolar
152
What is a simple muticellular exocrine gland?
has a single duct
153
What is a compound multicellular exocrine gland?
Has branched ducts - multiple ducts
154
What is a tubular multicellular exocrine gland?
long hollow tube like shaped secretory parts
155
What is a alveolar multicellular exocrine gland?
rounded secretory parts
156
What is a tubuloalveolar multicellular exocrine gland?
With both rounded and long and tubular secretory parts
157
What are the five types of Simple multicellular exocrine glands?
```
Simple tubular,
Simple coiled tubular,
simple branched tubular,
simple alveolar (acinar),
Simple branched alveolar (acinar)
```
158
What are the three types of compound multicellular exocrine glands?
Compound tubular,
Compound alveolar,
Compound tubuloalveolar
159
What does it mean when the secretory area is coiled in multicellular exocrine glands?
The secretory part is coiled
160
What does it mean when the secretory area is branched in multicellular exocrine glands?
secretory part is branched but attaches to a single unbranched duct
161
Examples of Simple tubular?
Intestinal glands
162
Examples of simple coiled tubular?
merocrine sweat glands
163
Simple branched tubular examples?
gastric glands, mucous glands of oesophagus, tongue and duodenum
164
Examples of simple alveolar (Acinar)
a stage in the embryonic development of simple branched glands
165
Examples of simple branched alveolar
Sebaceous (oil) glands
166
Examples of Compound tubular?
mucous glands (in mouth), Bulbo-urethral glands (in male reproductive system), Seminiferous tubules of testes.
167
Examples of Compound Alveolar?
mammary glands
168
Compound tubuloalveolar examples?
Salivary glands, glands of respiratory passages, pancreas
169
What is another name for alveolar gland
acinar gland
170
What are the three functional classifications of exocrine glands?
Merocrine glands, Apocrine glands and Holocrine glands.
171
How is functional classification of exocrine glands determined?
Depends on how the exocrine gland secretions are released
172
where do all three classifications of exocrine glands. secretory processes begin at?
the secretory process begins with the combination of the Golgi complex and endoplasmic reticulum working together to form intercellular secretory vesicles.
173
What do the intercellular secretory vesicles contain?
the secretory product of the gland.
