histology Flashcards
1
Q
histology
A
the study of tissues and how they are arranged
2
Q
tissue
A
a group of similar cells from the same region of the embryo with the same structure and function
3
Q
4 types of tissue in the body
A
epithelial, connective, muscular, neural
4
Q
ectoderm
A
outer layer
5
Q
endoderm
A
inner lay
6
Q
mesoderm
A
middle layer
7
Q
ectoderm tissue
A
nervous tissue and epidermis
8
Q
endoderm tissue
A
digestive system and internal organs
9
Q
mesoderm tissue
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collagen fibers and fibroblasts, connective tissue and most muscle tissue
10
Q
epithelia
A
layers of cells that line hollow organs or cover body surfaces
11
Q
glands
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attached to or derived from epithelia, secret fluid
12
Q
function of epithelial tissue
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physical protection, secretions, sensation, excretion, absorption, filtration
13
Q
characteristics of epithelia
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cellularity, avascularity, regeneration, polarity, attachment
14
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cellularity
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cells bound close together by junctions
15
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avascularity
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lack of blood vessels, cells get nutrients through diffusion
16
Q
regeneration
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higher rate of mitosis that means quick repair
17
Q
polarity
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structural and functional differences between apical (top) and basal surface (bottom)
18
Q
attachment
A
basal surface of epithelium binds to basal lamina
19
Q
basement membrane consists of …
A
basal lamina, reticular lamina
20
Q
basal lamina
A
closer to and secreted by epithelial cells
21
Q
reticular lamina
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closer to underlying connective tissue
22
Q
function of basement membrane
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anchors epithelium to connective tissue, regulates material exchange, binds growth factors, forms surface along epithelial cells and wound healing
23
Q
cell junctions
A
tight junctions, gap junctions, desmosome
24
Q
tight junctions
A
continuous, prevents passage through junction
25
gap junctions
ions and small molecules diffuse through connexin
26
desmosomes
discs on inner side of plasma membrane connect to intermediate fibers in cells, substances can pass through.
27
hemidesomes
half of button desmosome, attaches to cell's basal lamina
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simple epithelium
single layer of cells, all cells touch basement membrane
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stratified epithelium
2 or more layers of cells, some cells rest on top of others and do not touch basement membrane
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squamous cell shape
thin, arranged like floor tiles, allow for fast diffusion and filtration
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cuboidal cell shape
square or round cells, secretion or absorption, my have microvilli at apical surface
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columnar cell shape
tall narrow cells, secretion and absorption, may have microvilli or cilia on apical surface
33
transitional cell shape
change shape from cuboidal to flat and back ( bladder)
34
simple epithelium
simple squamous, simple cuboidal, simple columnar, pseudostratified columnar. (simple columnar and pseudostratified columnar have goblet cells that secret mucous)
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4 stratified epithelium cells
stratified squamous, stratified cuboidal, stratified columnar, transitional
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simple squamous epithelium
single flat layer of cells, function: filtration, diffusion.
endothelium lines heart, blood vessels, lymphatic vessels. mesothelium forms epithelial layer of serous membrane
37
simple cuboidal epithelium
cube shape, nuclei are round and centrally located, function: secretion and absorption.
located: kidney tubules, liver, mammary and salivary glands
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simple columnar epithelium
rectangle shape, nuclei oval and near base of cell, function: absorption and secretion.
location: lining of GI tract, uterus, uterine tubes
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pseudostratified columnar epithelium
single layer of cells but appears as multiple layers, cell nuclei located at different levels, all cells touch basement membrane, not all cells covered by taller ones.
location: respiratory tract, portions of male urethra
40
stratified epithelium
has 2 or more layer of cells, deeper cells may have different shape than the ones on the surface, can produce secretions
41
stratified squamous epithelium
located where mechanical stresses are severe. apical layer flat, loose junction and sloughs off. deeper cells are cuboidal or columnar
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nonkeratinized
remains moist
43
keratinized
contains keratin and protects skin and underlying tissue from heat, and microbes
44
stratified cuboidal epithelium
fairly rare, apical cells are cuboidal in shaper, located in ducts of sweat glands and mammary glands.
protection, secretion, absorption
45
stratified columnar epithelium
rare, apical cells are columnar, basal layer is shortened, irregularly shaped cells, protection, secretion.
location: largest ducts of salivary glands
46
transitional epithelium
cuboidal when relaxed, flat when stretched.
| only in urinary tracts, some cells may contain 2 nuclei, outer plasma membrane thicker than usual and has lipid rafts.
47
endocrine glands
release secretions into bloodstream, can be unicellular or multicellular
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exocrine glands
release secretion into ducts, can be unicellular or multicellular
49
merocrine glands
most common exocrine glands, secretions synthesized by ribosomes
50
apocrine glands
secretory products accumulate at apical surface of cell and then pinch off, cell repairs itself and repeats process
51
holocrine glands
secretions accumulate in cytosol, cell ruptures to release secretions
52
serous glands
secret watery solution
53
mucous gland
secret mucins that hydrate mucus
54
mixed exocrine glands
contain more than one type of gland cell, produce serous and mucous
55
cytogenic glands
release a whole cell (testes and ovaries)
56
connective tissue general features
never exposed to outside environment, highly vascular, may contain sensory receptors.
- cells not usually connected with each other, separated by matrix
- matrix, secreted by connective tissue cells and fill spaces between cells
57
8 functions of connective tissue
binding organs, support framework, protection, immune protections, help in movement, storage, heat production, transport
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cells in connective tissue
fibroblasts, microphages, leukocytes, mast cells, adipocytes
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fibroblasts
large, tapered at both ends, flat, with branching process, secret fibers and ground substance
60
macrophages
arise from monocytes, irregularly shaped with short branches
fixed macrophages, wandering macrophages
function: phagocytosis activate immune system
61
leukocytes
travel briefly in blood, mostly found in CTs
62
mast cells
small and mobile cells, abundant along blood vessels, contain histamine and heparin
63
adipocytes
derived from mesenchymal cells, store triglycerides, nucleus organelles and cytoplasm are squeezed to one side
64
connective tissue matrix consist of:
```
protein fibers: 3 types
- collagen fibers
- elastic fibers
-reticular fibers
ground substances:
- water, glycosaminoglycans, proteoglycans, glycoproteins
```
65
glycosaminoglycan (GAGs)
long polysaccharide, made of amino sugar and uronic acid
66
proteoglycans
gigantic molecule, thick like pudding, slows the spread of pathogenic organisms in tissue, attach to hyaluronic acid
67
glycoproteins
protein-carbohydrate complex, adhesive, bind all tissue components together
68
embryonic connective tissue
mesenchyme: contains abundance of star shaped stem cells separated by matric
MESENCHYME GIVES RISE TO ALL OTHER CONNECTIVE TISSUE
69
3 types of mature connective tissue
1. connective tissue proper
2. supportive connective tissue
3. fluid connective tissue
70
connective tissue proper
1. loose connective tissue has, areolar, adipose, reticular
| 2. dense connective tissue has, dense regular, dense irregular, elastic
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2 supportive connective tissues
cartilage: hyaline, fibrocartilage, elastic. bone: spongy and compact
72
fluid connective tissue
blood tissue and lymph
73
areolar connective tissue
loose fibers, may have empty space
abundant in blood vessels,
ground substance: semifluid
several types of cell: fibroblasts,
macrophages, plasma cells, mast cells, adipocytes.
contain all 3 fibers: collagen, elastic, reticular, randomly arranged
combined with adipose tissue to form subcutaneous layer
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reticular connective tissue
consists of a mesh reticular fibers and fibroblasts, forms stroma, helps bind smooth muscle
75
adipose tissue
white or brown tissue, areolar tissue and fat cells, continuously moving (recycled), protects organs and keeps in heat
76
dense connective tissue
thicker and denser, less open spaces than loose connective tissue
3 types: regular, irregular, elastic
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dense regular connective tissue
densely packed, parallel collagen fibers, fibroblast cells only, slow healing
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dense irregular connective tissue
densely packed, randomly arranged collagen fibers, few visible cells, often found where pulling forces are exerted in multiple directions
79
elastic connective tissue
dense regular connective tissue dominated by elastic fibers, branching, yellowish, large fibroblasts with clear nuclei between fibers
80
cartilage
network of collagen and elastic fibers (strong), chondrocytes are the only cell, slow repair, no blood or nerve supply
81
hyaline cartilage
most abundant, non-visible collagen fibers, reduces friction, absorbs shock, surrounded by perichondrium, except in join cavities and epiphyseal plate
82
elastic cartilage
chondrocytes are located within thread like network of elastic fibers, covered with perichondrium, provide strength and elasticity
83
chondrocytes
cells that produce cartilage
84
perichondrium
connective tissue that envelopes cartilage
85
fibrocartilage
chondrocytes scateres, visible collagen fibers, no perichondrium, strongest cartilage
86
interstitial growth
grows fast, expand from within, brings in early embryo
87
appositional growth
cells in inner perichondrium divide and mature to chondroblasts, matrix formed on outside of cartilage, starts later than interstitial growth and continues through adolescence
88
3 types bone tissue
spongy, compact, periosteum
89
fluid connective tissue
blood: liquid matrix is blood plasma, formed elements: red and white blood cells, platelets
lymph: lymph forms as interstitial fluid that enters lymphatic vessels
90
epithelial membrane
combination of epithelial layer and underlying connective tissue layer
91
connective tissue membrane
synovial membrane (lines joint cavities)
92
mucus membranes
line body cavities that open to outside (mouth, eyes...)
consist of epithelium, lamina propria, sometimes muscularis mucosa
93
serous membrane
line body cavities not open to the outside, covers organ within cavity
2 layers: visceral and parietal layer
94
cutaneous membrane
the skin, covers surface of body, waterproof.
made of stratified squamous epithelium and underlying connective tissue
95
connective tissue membrane
no epithelium
synovial membrane: lines cavities of joints, made of areolar tissue, incomplete layer of fibroblasts separate areolar from joint cavity
secrets synovial fluid for lubrication and nourishment
96
3 types of muscle tissue
1. skeletal
2. cardiac
3. smooth
97
skeletal muscle tissue
usually attached to skeleton, does not divide, voluntary muscles, contains striation; dark and light bands.
muscle cell is long, not branched, cylindrical, many nuclei on peripheral of cell
98
cardiac muscle tissue
striated, involuntary, called "myocytes" or "cardiocytes"
| do not divide, attached to each other by intercalated discs that have desmosomes and gap junctions
99
smooth muscle tissue
located in the wall of the viscera, involuntary, not striated, can divide.
gap junctions connect fibers
100
nervous tissue (2 types of cells)
neurons, neuroglia
neurons: cell body, axons, dendrites
neuroglia: do not generate nerve impulses, have supportive funtion
101
3 types of tissue growth
1. hypertrophy
enlargement of cell
2. hyperplasia
tissue growth through cell multiplication
3.neoplasia
the formation or presence of a new or abnormal growth of tissue
102
2 types of tissue development
differentiation: unspecialized tissue develop into diverse and specialized types of mature tissue, from embryo
metaplasia: change from one type of tissue to another
103
tissue generation and death
atrophy: shrinkage of tissue from lack of usage
apoptosis: (programed cell death) cells complete function then die
necrosis: pathological tissue death
104
stem cells
embryonic stem cells,
| adult stem cells
105
embryonic stem cells
totipotent stem cells: cells have capacity to self-renew by dividing and develop into 3 primary germ cell layers
pluripotent stem cells: develop into any cell type of the embryo
106
multipotent adult stem cell
develop into 2 or more different cell lines sugar as bone marrow stem cells
unipotent: produce only 1 mature cell type such as sperm or egg
107
tissue repair
regeneration: the replacement of damaged cells by the same type of cells, restores normal function to the organ
fibrosis: the replacement of damaged cells with scar tissue, not restore to normal function
108
aging tissue
support maintenance, replace cells and extracellular matrix, tissue repair decreases, epithelia becomes thinner, connective tissue loses resilience and becomes fragile, collagen fibers decline, muscle and nervous tissue being to atrophy, cancer rate increases with age
