The Tissue Level of Organization Flashcards
1
Q
What is a tissue?
A
a group of cells that usually have a common embryonic origin and function together to carry out specialized activities
2
Q
how many basic types of cells are there?
A
Epithelial
connective
muscular
nervous
3
Q
what are cell junctions?
A
hold cells together
4
Q
what are tight junctions?
A
consist of weblike strands of transmembrane proteins that fuse together the outer surfaces of adjacent plasma membranes to seal off passageways between adjacent cells
5
Q
what cells have tight junctions?
A
Cells of epithelial tissue that lines the stomach, intestines, and urinary bladder have many tight junctions
6
Q
what do tight junctions do?
A
They inhibit the passage of substances between cells and prevent the contents of these organs from leaking into the blood or surrounding tissues.
7
Q
what are Adherens Junctions?
A
contain plaque,a dense layer of proteins on the inside of the plasma membrane that attaches both to membrane proteins and to microfilaments of the cytoskeleton
8
Q
what are cadherins?
A
Transmembrane glycoproteins
9
Q
what do cadherins do?
A
join the cells. Each cadherin inserts into the plaque from the opposite side of the plasma membrane, partially crosses the intercellular space and connects to cadherins of an adjacent cell.
10
Q
what do adherents junctions often form?
A
adhesion belts
11
Q
what are the structures of the adherent junction?
A
Adjacent plasma membranes
microfilaments
plaque
transmembrane glycoprotein
intercellular space
12
Q
What are desmosomes?
A
contain plaque and have transmembrane glycoproteins (cadherins) that extend into the intercellular space between adjacent cell membranes and attach cells to one another
13
Q
what is the difference between adheren junctions and desmosomes?
A
the plaque of desmosomes does not attach to microfilaments
14
Q
what does the plaque do in desmosomes?
A
attaches to elements of the cytoskeleton known as intermediate filaments, which consist of the protein keratin.
15
Q
where are desmosomes commonly found?
A
These spot weld–like junctions are common among the cells that make up the epidermis and the cardiac muscles
16
Q
what is the function of desmosomes?
A
prevent epidermal cells from separating under tension and cardiac muscle cells from pulling apart during contraction.
17
Q
what are the structures of desmosomes?
A
Adjacent plasma membranes
intercellular space
plaque
cadherin
keratin
18
Q
what are the types of cell junctions
A
Tight
Adheren
Desomosomes
Hemmidesmosomes
Gap
19
Q
What is the difference between hemidesmosomes and desmosomes?
A
hemidesmosomes don’t link to adjacent cells
20
Q
what happens on the inside of hemidesmosomes?
A
On the inside of the plasma membrane, integrins attach to intermediate filaments made of the protein keratin.
21
Q
what happens on the outside of the hemidesmosomes?
A
On the outside of the plasma membrane, the integrins attach to the protein laminin, which is present in the basement membrane
22
Q
where do hemidesmosomes attach?
A
the basement membrane
23
Q
what are the structures of hemidesmosomes?
A
Keratin
plaque
Integrin
Plasma membrane
Basement membrane
24
Q
what happens at gap junctions?
A
membrane proteins called connexins form tiny fluid-filled tunnels called connexons that connect neighboring cells
25
what does the connexons allow in gap junctions?
ions and small molecules can diffuse from the cytosol of one cell to another, but the passage of large molecules such as vital intracellular proteins is prevented.
26
what junction allowshe cells in a tissue to communicate with one another?
gap junctions
27
what junction allows nerve impulses to be transferred quickly?
Gap junctions
28
what are the structures of gap junctions?
adjacent plasm membranes
connexions
gap between cells
29
what is the difference between connective tissue and epithelial tissue?
Connective = large amount of extracellular matrix and few cells
Epithelial = little to no extracellular matrix and cells packed together
30
where do epithelial cells attach?
basement membrane
31
is epithelial tissue vascular?
no but does have nerve supply
32
how is epithelial tissue arranged?
in sheets and densely packed
33
what are the different arrangements epithelial cells can have?
simple
Pseudostratified
Stratified
34
what are the cells shapes epithelial cells can have?
squamous
cuboidal
columnar
35
what are the 2 types of epithelial tissue?
surface
glandular
36
define surface epithelium
forms the outer covering of the skin and some internal organs and the inner lining of structures such as blood vessels, ducts, body cavities, and the lining of the respiratory, digestive, urinary, and genital systems. In other words, it covers or lines a surface.
37
define glandular epithelium
makes up the secreting portion of glands, such as the thyroid gland, suprarenal (adrenal) glands, sweat glands, and digestive glands.
38
what is the unicellular cell of glandular epithelium?
goblet cells
39
What are the multicellular cells of glandular epithelium?
sweat glands
oil glands
salivary galnd
40
what are the surfaces of epithelial tissue?
apical
basal
lateral
41
what are apical surfaces
faces the body surface, a body cavity, the lumen (interior space) of an internal organ, or a tubular duct that receives cell secretions
42
what are lateral surfaces?
face the adjacent cells on either side, may contain tight junctions, adhering junctions, desmosomes, and/or gap junctions.
43
what are basal surfaces?
is opposite the apical surface. The basal surfaces of the deepest layer of epithelial cells adhere to extracellular materials such as the basement membrane.
44
what are the 2 layers of the basement membrane
the basal lamina and reticular lamina.
45
what is the basal lamina?
thin layer,is closer to and secreted by the epithelial cells. It contains proteins such as laminin and collagen, as well as glycoproteins and proteoglycans
46
what is the reticular lamina?
thin layer,is closer to the underlying connective tissue and contains proteins such as collagen produced by connective tissue cells called fibroblasts
47
what is simple epithelium?
single layer of cells that function in diffusion, osmosis, filtration, secretion and absorption
48
what is Pseudostratified epithelium?
multiple layers of cells with their nuclei in different levels of each others
49
what is stratified epithelium?
consists of 2 or more layers if cells that protect underlying tissues in locations where there is considerable wear and tear
50
what are squamous cells?
thin, which allows rapid passage of substances thru them
51
what are cuboidal cells?
are as tall as they are wide and are shaped like cubes or hexagons. They may have microvilli at their apical surface and function in either secretion or absorption.
52
what are columnar cells?
taller than they are wide, like columns, and protect underlying tissues. Their apical surfaces may have cilia or microvilli, and they often are specialized for secretion and absorption.
53
what are transitional cells?
hange shape, from squamous to cuboidal and back, as organs of the urinary system such as the urinary bladder stretch
54
what are the 2 characteristics of epithelial tissues?
Simple
Stratified
55
what is endothelium?
Type of simple epithelium
lines heart blood vessels lymphatic vessels
56
what is mesothelium?
type of simple epithelium
forms layer of serous membranes
57
what is the function of Simple squamous epithelium?
filteration (blood in kidneys, diffusion of O2 in blood vessels of lungs) secretion in serous membranes
58
function of simple cuboidal epithelium?
secretion and absorption
59
what do adheren junctions do?
help epithelial surfaces resist separation during various contractile activities, as when food moves through the intestines.
59
what are the structures of tight junctions?
Adjacent plasma
intercellular space
stands of transmembrane proteins
59
where is simple cuboidal epithelium located?
ovary, anterior surface of lens of eyes, kidney tubules, thyroid gland
60
where is nonciliated simple columnar epithelium found
digestive canal ducts of many glands, gallbladder
61
function ofnonciliated simple columnar epithelium
secretion of absorptionecreted mucus lubricates linings of digestive, respiratory, and genital tracts, and most of urinary tract;
62
where is ciliated simple columnar epithelium found?
Lines some bronchioles (small tubes) of respiratory tract, uterine tubes, uterus, some paranasal sinuses, central canal of spinal cord, and ventricles of brain.
63
what is the function of ciliated simple columnar epithelium?
moves mucus up toward throat, coughing, sneezing, over oocytes
64
Location of Nonciliated Pseudostratified Columnar Epithelium
Lines epididymis, larger ducts of many glands, and parts of male urethra.
65
function of Nonciliated Pseudostratified Columnar Epithelium
absorption and secretion
66
location of Ciliated Pseudostratified Columnar Epithelium
Lines airways of most of upper respiratory tract
67
function of Ciliated Pseudostratified Columnar Epithelium
Secretes mucus that traps foreign particles, and cilia sweep away mucus for elimination from body.
68
location of Stratified Squamous Epithelium
Keratinized variety forms superficial layer of skin; nonkeratinized variety lines wet surfaces (lining of mouth, esophagus, part of epiglottis, part of pharynx, and vagina) and covers tongue.
69
function of stratified squamous epithelium
Protection against abrasion, water loss, ultraviolet radiation, and foreign invasion. Both types form first line of defense against microbes.
70
location of Stratified Columnar Epithelium
Lines part of urethra; large excretory ducts of some glands, such as esophageal glands; small areas in anal mucous membrane; part of conjunctiva of eye.
71
function of Stratified Columnar Epithelium
Protection and secretion
72
location of Urothelium (Transitional Epithelium)
Lines urinary bladder, ureters, and portions of urethra.
73
function of Urothelium (Transitional Epithelium)
Allows urinary organs to stretch and maintain protective lining while holding variable amounts of fluid without rupturing.
74
what is a compound gland
if the duct brnaches
75
what are tubular glands
glands with tubular secretory parts
76
what are acing glands
rounded secretory portions
77
what are tubuloacinar glands
have both tubular and more rounded secretory parts
78
what is simple tubular?
Tubular secretory part is straight and attaches to a single unbranched duct
Example: glands in the large intestine.
79
what is simple branched tubular
Tubular secretory part is branched and attaches to a single unbranched duct Example: gastric glands.
80
what is simple coiled tubular?
Tubular secretory part is coiled and attaches to a single unbranched duct Example: sweat glands.
81
what is simple acinar?
Secretory portion is rounded, attaches to single unbranched duct
Example: glands of spongy urethra.
82
what is simple branched acinar?
Rounded secretory part is branched and attaches to a single unbranched duct Example: sebaceous glands.
83
what is compound tubular?
Secretory portion is tubular and attaches to a branched duct Example: bulbourethral glands.
84
what is compound acinar
Secretory portion is rounded and attaches to a branched duct Example: mammary glands.
85
what is compound tubuloacinar
Secretory portion is both tubular and rounded and attaches to a branched duct Example: acinar glands of the pancreas.
86
what is connective tissue
the most abundant and widely distributed tissues in the body. In its various forms, connective tissue has a variety of functions.
87
function of connective tissue
It binds together, supports, and strengthens other body tissues; protects and insulates internal organs; compartmentalizes structures such as skeletal muscles; serves as the major transport system within the body
88
what does connective tissue contain?
contains and distributes almost all the blood vessels in the body; is the primary location of stored energy reserves (adipose, or fat, tissue); and is the main source of immune responses.
89
what are the 2 basic elements of connective tissue?
cells and extracellular matrix
90
what do mesenchymal cells do?
give rise to the cells of connective tissue.
91
what are fibroblasts?
are large, flat cells with branching processes. They are present in all the general connective tissues
92
what cells are usually most numerous in connective tissue?
fibroblasts
93
what are microphages?
are phagocytes that develop from monocytes, a type of white blood cell.
Large cell eaters
94
what are plasmocytes?
plasma cells
95
where are plasmocytes found?
in many places in the body, but most plasmocytes reside in connective tissue, especially in the digestive canal and respiratory tracts.
96
what are mast cells
re involved in the inflammatory response, the body’s reaction to injury or infection, and can also bind to, ingest, and kill bacteria.
97
what are adipocytes?
fat cells that store triglycerides
98
where are adipocytes located?
deep to the skin and around organs such as the heart and kidneys.
99
what are the 2 major components of extracellular matrix?
ground substance and the fibers
100
what is the ground substance?
is the component of a connective tissue between the cells and fibers.
101
function of the ground substance?
supports cells, binds them together, stores water, and provides a medium for exchange of substances between the blood and cells
102
what is hyaluronic acid
is a viscous, slippery substance that binds cells together, lubricates joints, and helps maintain the shape of the eyeballs.
103
what is chondroitin sulfate?
provides support and adhesiveness in cartilage, bone, skin, and blood vessels.
104
what are adhesion proteins?
responsible for linking components of the ground substance to one another and to the surfaces of cells.
105
what is the main adhesion protein of connective tissues
fibronectin
106
what are the 3 fibres in extracellular matrix?
collagen fibers
elastic fibers
reticular fibers
107
what is included in Embryonic Connective Tissue?
Mesenchyme
Mucoid
108
what is included in Mature Connective Tissue?
Connective tissue proper
supporting connective tissue
liquid connective tissue
109
what is dense regular connective tissue
forms shiny white extracellular matrix; mainly collagen fibers regularly arranged in bundles with fibroblasts in rows between them
110
location of dense regular connective tissue
Forms tendons (attach muscle to bone), most ligaments (attach bone to bone), and aponeuroses (sheetlike tendons that attach muscle to muscle or muscle to bone)
111
location of dense irregular connective tissue
Often occurs in sheets, such as fasciae, reticular (deeper) dermis of skin, fibrous pericardium of heart, periosteum of bone, perichondrium of cartilage, articular capsules, membrane capsules around various organs (kidneys, liver, testes, lymph nodes); also in heart valves
112
function of dense irregular connective tissue
Provides tensile (pulling) strength in many directions.
113
what is elastic connective tissue
contains predominantly elastic fibers with fibroblasts between them; unstained tissue is yellowish.
114
location of elastic connective tissue
Walls of elastic arteries and trachea, bronchial tubes within the lungs, true vocal cords, suspensory ligaments of penis, some ligaments between vertebrae.
115
function of elastic connective tissue
Allows stretching of various organs
116
what are mature cartilage cells called?
chondrocytes
117
what is the space chondrocytes occupy?
Cartilage Lacunae
