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CTB cards 2
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01/30/2009

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Term
4 basic types of tissue
Definition
1.connective tissue
2.nervous tissue
3.muscular tissue
4.epithelial tissue
Term
Epithelial Tissue (ET) develops from what germ layers
Definition
all 3
Term
Function of ET
Definition
1.Surface covering-ET forms selective barriers between body cavities and surfaces
2.Absorption-ET functions in absorption
3.ET cells are secretory-ie glands
Term
Characteristics of ET
Definition
1.Polarized-ie basal, apical and lateral surfaces
2. avascular-nutrients reach by diffusion
3.Basal Lamina-ET cells rest on this basement membrane
Term
ET to ECM ratio
Definition
many ET cells to little ECM
Term
Ways of organization of ET
Definition
1.Number of cellular layers
2.Shape of epithelial
3.Cell Membrane Specializations
Term
Number of Cellular Layers
Definition
1.Simple Epithelium
2.Stratified Epithelium
3.Transitional
Term
Simple Epithelium
Definition
contains only one layer of cells
Term
Stratified epithelium
Definition
contains more than one layer
Term
pseudostratified
Definition
All cells touch basement membrane so simple epithelium even though it looks like stratified
Term
Transitional epithelium
Definition
stratified epithelium that stretches causing the appearance of fewer cellular strata than when organ is contracted
Term
Location of transitional epithelium example
Definition
bladder
Term
Shape of epithelial cells
Definition
1.squamous
2.cuboid
3.columnar
Term
Squamous epithelium
Definition
cells are flat
Term
cuboid cells are
Definition
cube-shaped
Term
columnar cells are
Definition
rhomboid shaped
Term
Naming convention in simple epithelium
Definition
if cells are cuboid than it is simple cuboidal
Term
Naming convention in stratified epithelium
Definition
cells in most superficial layer dictates name of epithelium
Term
what kind of surface is the Apical cell surface
Definition
apical surface is a free surface
Term
lateral and basal surface specializations
Definition
are characterized by one or more of
1.occluding junctions
2.anchoring junctions
3.communicating junctions
Term
Apical cell membrane specializations function
Definition
interface with adjacent non-cellular environments to:
1.propel substances along
2.absorbs nutrients from
3.secretes factors
4.protects
Term
Apical cell membrane specialization types
Definition
1.cilia
2.microvilli
3.glycocalyx
Term
Cilia
Definition
motile structures commonly found in the respiratory tract and oviduct where there is a need to propel extracellular material through a tube
Term
Cilium anchor
Definition
basal body or centriole that contains 9 triplets of microtubules and is situated just beneath cell membrane
Term
Axoneme
Definition
made of 9 doublets of peripheral microtubules w/ dynein ATPase arms plus two central MT
Term
Flagellum
Definition
single highly elaborated cilium used for cellular locomotion
Term
Microvilli function
Definition
increase surface area and help in absorption
Term
Microvilli are commonly found in the
Definition
intestinal tract
Term
Microvilli contain
Definition
actin MF that connect a terminal web of actin MF that runs under the cell membrane
Term
Glycocalyx
Definition
carbohydrate rich complex on extracellular surface of epithelial cells
Term
Glycocalyx function
Definition
protection and recognition
Term
What does the glycocalyx use for cell recognition
Definition
lectins
Term
Lateral cell membrane specializations general function
Definition
1.maintain coherence
2.provide communication
3.distribute stress
Term
Lateral cell membrane specializations types
Definition
1.Zonula Occludens
2.Zonula Adherens
3.Macula adherens
4.Gaps junctions
Term
Zonula occludens
Definition
tight or occludens junction near the apical cell surface that forms a selectively permeable barrier that surrounds the entire cell
Term
What can pass through the Zonula Occludins
Definition
water and small solutes
Term
Zonula occludins coerce
Definition
transcellular transport across polarized cell
Term
EM structure of Zonula occludins
Definition
pentalaminar appearance which is caused by fusion of the outer members of the lipid bilayers of the two adjacent cells.
Term
Tight junction proteins
Definition
specialized integral membrane proteins that regulate passage of solute molecules
Term
Types of tight-junction proteins
Definition
occludins and claudins
Term
Tight junction proteins interact with
Definition
ZOs
Term
ZOs proteins 1-3
Definition
specialized proteins in sub-plasmalemmal plaque that bind to tight junction proteins
Term
Zonula adherens
Definition
anchoring junction located beneath zonula occludins that completely surrounds the cell
Term
Three components of of Zonula Adherens
Definition
1. transmembrane linker protein
2. sub-plasmalemmal plaque
3. cytoskeletal filaments
Term
Transmembrane linker protein of zonula adherens
Definition
cadherin
Term
cadherin
Definition
calcium dependent protein in the CAM (cell adhesion molecule family) located in the extracellular space
Term
Sub-plasmalemmal plaque of zonula adherens
Definition
plaque containing actinin, vinculin and other proteins
Term
cytoskeletal filaments of zonula adherens
Definition
actin MF ie terminal web
Term
Macula adherens
Definition
or desmosome is another anchoring junction that does not encircle the cell (think of spot weld)
Term
Macula adherens transmembrane linker protein
Definition
type of cadherin (ie cadherin-like) termed desmoglein
Term
Macula adherens plaque
Definition
contains desmoplakin
Term
Macula Adherens cytoskeletal filament
Definition
keratin IF
Term
Gap junction
Definition
communicating junction that provides electrical and metabolic communication channels
Term
Gap junction structure
Definition
each is made up of two connexons one from each of the adjoining cells
Term
Connexon structure
Definition
each is made up of six identical subunits composed of connexin proteins
Term
Diameter of gap junction
Definition
1.5 nm which allows small molecules in the 1500 dalton range to pass through
Term
Gap junction location
Definition
particularly important in cardiac and smooth muscle myocytes
Term
Transmembrane linker protein in Gap junctions
Definition
connexin
Term
Plaque in gap junctions
Definition
none
Term
cytoskeletal filaments in gap junction
Definition
none
Term
Junctional complex
Definition
the group of cell membrane specializations along the lateral surface which can contain all or just 3 of the types
Term
Basal membrane specializations function
Definition
mechanical attachment to the basal lamina ecm so they are considered anchoring junctions
Term
Hemidesmosome difference from desmosomes
Definition
transmembrane linker protein is integrin not desmoglein but both use IF
Term
integrin
Definition
transmembrane linker protein found in hemidesmosomes that attaches to the major ecm component of fibronectin rather than an adjacent cell
Term
integrin attaches to
Definition
fibronectin
Term
Cell to cell adhesion is
Definition
calcium dependent
Term
Cadherins are
Definition
calcium dependent proteins mediating adhesion in homotypic fashion
Term
hemidesmosomes demonstrate what kind of protein interaction
Definition
heterotypic btwn integrin and fibronectin
Term
E cadherin is found
Definition
in epithelium
Term
N cadherin is found
Definition
in nerve, muscle and lens
Term
P cadherin is found
Definition
in placenta and epidermis
Term
Cell-cell adhesion is
Definition
tissue specific and is mediated by lectins
Term
Epithelial cell replacement
Definition
self replacing in adults but rate varies
Term
Metaplasia
Definition
refers to a change in epithelial cells to a biochemically different cell type
Term
carcinomas
Definition
malignant tumors of epithelial cells
Term
adenocarcinomas
Definition
tumors of epithelial glandular cells
Term
Carcinomas and adenocarcinomas comprise
Definition
85% of all cancers perhaps due to mitotic activity or their position as barriers to an insulting environment
Term
Metastasis
Definition
malignant spread of cancer that can occur through basement membranes so mechs that prevent loss of epithelial adhesiveness are important
Term
Technique to diagnose origin of cancer
Definition
immunostain IFs to find type expressed by tumor ie basis behind PSA
Term
Tumors of epithelium express
Definition
keratin
Term
tumors of glia express
Definition
GFAP
Term
Muscle tumors express
Definition
desmin
Term
connective tissue tumors express
Definition
vimentin
Term
Stomach cells normally stain positive for
Definition
cytokeratin but tumor cells do not
Term
Epithelial tissue components of the integumentary system
Definition
epidermis, glands, nails, and hair
Term
Muscle tissue components of the integumentary system
Definition
arrector pili
Term
Muscle tissue components of the integumentary system
Definition
arrector pili
Term
Nervous tissue components of the integumentary system
Definition
sensory nerve endings
Term
Connective tissue components of the integumentary system
Definition
dermis
Term
Epidermis is what type of epithelium
Definition
stratified squamous epithelium
Term
Epidermal layers
Definition
1.Stratum corneum
2.Stratum Granulosum
3.Stratum Spinosum
4.Stratum Basale
Term
Stratum corneum
Definition
flattened dead stratified squamous full of keratin IF
Term
Stratum granulosum
Definition
in this layer cells begin to extrude their organelles and there are keratohyaline granules
Term
Keratohyaline granules
Definition
found in S. Granulosum and represents the protein filigrin which is a like a cement for Keratin IF that helps them aggregate and stick together
Term
Stratum Spinosum
Definition
very thick layer made up of keratinocytes linked by numerous desmosomes
Term
Where will we find prominent S. spinosum
Definition
on soles of feet and palms so areas where lots of abrasion can occur
Term
Stratum Basale
Definition
mitotic layer that generates all other layers and is the source of the continual renewal that is the primary source of protection from abrasion
Term
How does stratum basale stain
Definition
basophilic b/c of synth of keratin IF
Term
Is the dermis epithelium
Definition
no
Term
Types of skin
Definition
thick and thin
Term
thick skin
Definition
stratum corneum >50 cells thick
Term
thick skin location
Definition
palms, flexor surfaces of digits and soles of feet
Term
thin skin classification
Definition
stratum corneum <50 cells thick
Term
thick skin features
Definition
lacks hair, arrector pili muscles, sebaceous glands but it does have sweat glands
Term
thin skin contents
Definition
has hair arrector pili muscles, sebacious and sweat glands
Term
Psoriasis
Definition
a hyperproliferation of keratinocytes such that the epidermis is twice as thick as normal
Term
traits of psoriasis
Definition
1.silvery scaly plaques cover elbows, knees and other areas
2.abnormally rapid turnover of cells in epidermis due to rapid cell cycle
Term
treatment of psoriasis
Definition
treat with UV radiation and meds
Term
Epithelial keratinocytes are linked by
Definition
desmosomes that couple the IF cytoskeleton to intercellular junctions
Term
Desmosome components Plaque proteins
Definition
1.desmoplakin 1 and 2
2.plakoglobin
3.plakophilin 1
Term
Desmosome components: plaque cytoskeletal role
Definition
IFs loop through electron dense plaques just deep to the PM
Term
Desmosome components core-distance of cell separation
Definition
30 nm
Term
desmosome components core glycoproteins
Definition
desmogleins and desmocollins
Term
Bullous skin diseases
Definition
acquired autoimmune diseases in which there are autoantibodies against cell-cell attachment proteins or cell matrix attachment proteins
Term
Example of bullous skin diseases
Definition
Bullous Pemphigoid, Pemphigus foliaceus and vulgaris
Term
Pemphigus foliaceus antibody is directed against
Definition
desmoglein 1 which leads to intra epidermal blister formation
Term
Pemphigus vulgaris antibody is directed against
Definition
desmogleins 1 and 3 which leads to intra epidermal blister formation
Term
The epidermis is anchored to its basement membrane via ... and interdigitates with the ...
Definition
hemidesmosomes, dermis
Term
Layers of the dermis
Definition
papillary and reticular layer
Term
papillary layer
Definition
superficial layer of the dermis with loose connective tissue
Term
reticular layer
Definition
deep layer of dermis with dense irregular connective tissue
Term
lamina lucida
Definition
electron lucent zone making up the superficial part of the basement membrane (closer to the epithelium)
Term
Lamina densa
Definition
electron dense portion making up the deep layer of the basement membrane
Term
Hemidesmosome components
Definition
1.plaque
2.lamina lucida
3.lamina densa
Term
Hemidesmosome plaque make up
Definition
1.BP230Ag
2.Plectin
3.Transmembrane molecules which are BP180Ag and a6B2 integrin
Term
Lamina Lucida contents
Definition
laminin and proteoglycans
Term
Lamina Densa collagen types
Definition
type IV and VII collagen
Term
Bullous Pemphigoid
Definition
bullous skin disease in which the antibody is directed against BP180 forming sub epidermal blisters
Term
Melanocyte function
Definition
protect the organism from UV radiation
Term
UV radiation effects
Definition
1.carcinogenic
2.collagen and elastin damage
3.sebaceous gland enlargement
Term
Melanocyte location
Definition
s. basale
Term
melanocytes origin
Definition
derived from neural crest cells
Term
Melanocytes function
Definition
synthesize melanin which is packaged into melanosomes which are then transferred by dendritic processes to keratinocytes where they provide photoprotection
Term
Malignant melanoma
Definition
a neoplasm composed of atypical melanocytes which may invade the dermis
Term
Malignant melanoma cause
Definition
major factor is exposure to natural sunlight
Term
Malignant melanoma typical patient
Definition
caucasian female aged 30-50 w/ lesion on the leg
Term
what to look for in a potential malignant melanoma
Definition
1. assymetry
2.border irregularity
3.color variation
4. diameter
Term
The skin is a barrier to
Definition
microorganisms
Term
Langerhans cells
Definition
dendritic cells that make up 3-4% of the epidermal population
Term
Langerhans cell location
Definition
more superficial levels of the epidermis
Term
Langerhans cell origin
Definition
derived from bone marrow precursors that migrate to the skin
Term
Langerhans cell function
Definition
take up cutaneous antigens and process them then they migrate via lymphatic vessels to lymph nodes where they stimulate t cells
Term
Other cells in the epidermis
Definition
lymphocytes, leukocytes, monocytes, macrophages
Term
Contact allergic dermatitis
Definition
delayed (1-4 days) immunological rxn of the skin to an exogenous antigen mediated by langerhans cells
Term
Contact allergic dermatitis-common allergens
Definition
poison ivy/oak, nickel, rubber compounds, cosmetics
Term
Contact allergic Dermatitis histology
Definition
intercellular edema, lymphocyte infiltration, epidermal thickening and scaling
Term
Contact Allergic Dermatitis therapy
Definition
avoidance of allergen and topical steroids
Term
The skin function in
Definition
thermoregulation
Term
skin heat loss is minimized by
Definition
vasoconstriction of dermal capillaries and subcutaneous fat
Term
skin heat loss is facilitated by
Definition
vasodilation of dermal capillaries and evaporation of sweat
Term
Eccrine sweat glands location
Definition
found in most areas of the body especially in thick skin but not in the skin of genitalia
Term
Eccrine sweat gland product
Definition
sweat=ultrafiltrate of blood plasma that includes water, NaCl, urea, NH3, uric acid and some protein
Term
Eccrine sweat gland structure
Definition
simple coiled tubular with two parts
Secretory part and Duct part
Term
The secretory part of eccrine sweat glands is made up of
Definition
simple cuboidal epithelium
Term
The duct part of eccrine sweat glands is made up of
Definition
stratified cuboidal epithelium and opens to the skin surface as well as stains dark
Term
Eccrine sweat gland innervation
Definition
sympathetic and cholinergic
Term
Eccrine sweat gland mode of secretion
Definition
merocrine(eccrine)-exocytosis
Term
Eccrine sweat glands additional functino
Definition
removal of wastes
Term
Hair location
Definition
thin skin
Term
Hair follicle
Definition
cylindrical downgrowth of epithelial cells
Term
hair bulb
Definition
terminal expansion of the hair follicle that encloses a dermal papilla
Term
dermal papilla
Definition
highly vascular tissue which projects into the hair bulb
Term
Hair function
Definition
heat loss is minimized by hair erection which traps warm air above the skin surface
Term
Arrector pili muscles location
Definition
thin skin
Term
Arrector pili muscle structure
Definition
obliquely-oriented bundles of smooth m. which insert into connective tissue
Term
Arrector pili m. innervation
Definition
sympathetic
Term
arrector pili m. action
Definition
contraction pulls hair upright
Term
Skin prevents
Definition
dehydration
Term
Sebaceous glands associated w/ and location
Definition
associated w/ hairs but not in thick skin
Term
seb. gland secretory product
Definition
sebum waxy product whose secretion begins at puberty and may have antibacterial and antifungal properties
Term
Seb. gland structure
Definition
branched simple, acinar (grape like cluster) with a short duct that opens onto upper portion of hair or directly onto skin surface
Term
Seb gland mode of secretion
Definition
holocrine-entire cell is shed
Term
Sebaceous gland function
Definition
may waterproof and moisturize hair and skin surface
Term
Acne vulgaris
Definition
results from increase in sebum production which blocks hair follicle orifice then bacteria and yeast within cysts break down sebum causing inflammation
Term
Burns
Definition
30-40% of skin destroyed->life threatening
if 75% of skin destroyed->almost always fatal
Term
Membrane-coating granules
Definition
secrete extracellularily and are a form of waterproof barrier
Term
The skin also functions in
Definition
communication
Term
Sensory receptors in skin
Definition
1.free nerve endings
2.pacinian corpuscles
3.meissner's corpuscles
4. ruffini endings
Term
Mitochondria evolved from
Definition
purple bacteria
Term
2 major functions of mito
Definition
1.complete oxidative metabolism of carbs, aa, and FA
2.coupling of e- transport and oxidative phosphorylation for the generation of ATP
Term
4 compartments of the mito
Definition
OMM, IMS, IMM, matrix
Term
OMM contents
Definition
1. Porin or VDAC-voltage dependent anion channel
2.Receptors
3.TOMs-translocases of OMM
Term
IMS contents
Definition
cytochrome C
Term
IMM contents
Definition
1.Cardiolipin
2.Respiratory chain enzymes
3.Transport proteins like ATP-ADP translocase (ANT) and TIM (translocases of IMM)
Term
Respiratory chain enzymes found in IMM
Definition
1.Complex 1-NADH-CoQ reductase or NADH DH
2. Complex 2 Succinate DH
3.Complex 3 CoQH2-cytochrome c reductase
4.Complex 4 cytochrome c oxidase
5. complex 5 ATP synthetase ie F0 F1 ATPase
Term
Mito matrix contents
Definition
1.krebs cycle enzymes
2. peptidases
3. mtDNA
4. ribosomes
5. calcium
Term
Electrical gradient of mito
Definition
- inside which is the basis for membrane potential and proton gradient
Term
Mitochondria multiply by
Definition
binary fission of existing mito which is why you can trace mtDNA back
Term
mtDNA bp and general
Definition
16,569 bp, double stranded, closed circular DNA, compact with no introns
Term
mtDNA encodes for
Definition
1. 2 RNAs
2. 13 polypeptides- 7 units of complex 1, 1 sub unit of complex III, 3 subunits of complex IV, and 2 subunits of complex V
3. 22 tRNAs
Term
D loop of mtDNA
Definition
contains the origin of replication for the heavy strand, promoters for the heavy and light strands, 3 conserved sequence blocks and termination associated sequences
Term
mtDNA replication
Definition
bidirectional and asynchronous
Term
mtDNA txn
Definition
occurs symmetrically from the 2 promoters in D-loop and rRNA transcripts outnumber other transcripts
Term
mtDNA unique codons
Definition
1.AGA, AGG normally arg in mito are stop
2.AUA normally Ile are now met
3.UGA normally stop are now trp
Term
mtDNA replication is
Definition
semiautonomous b/c not dependent on cellular division
Term
Inheritance of mtDNA
Definition
maternal
Term
During mitosis and meiosis, mtDNA undergoes
Definition
replicative segregation
Term
Mutation rate of mt DNA
Definition
10-20x higher than that of nuclear DNA
Term
Threshold expression in mitochondria
Definition
mito can only be expressed to a threshold number in different organs until they die off-this threshold varies from organ to organ
Term
Roles of nuclear genome in mito biogenesis and nuclear mito interactions
Definition
1.specifies all enzymes of mito matrix
2. cooperates with mito genome in assembly of multisubunit enzyme complexes of oxidative phosphorylation
3. encodes all components of protein (and RNA) import machinery
4. encodes txn factors for mtDNA txn and replication as well as for proteins that target mito
5. controls the translation of specific mito mRNAs
6. controls the processing of specific mito RNA precursors
Term
What percentage of mito proteins have to be imported
Definition
>90%
Term
Targeting sequence for protein import into mito
Definition
1.20-70aa
2.rich in basic and hydroxylated aa usually at n-terminus
3.can form amphipathic structures
4.usually cleaved by specific peptidases in the mitochondria
Term
Cytosolic chaperones
Definition
ex hsp70 - does unfolding and requires ATP
Term
types of Import receptors on OMM
Definition
1.receptor proteins (TOM complex)
2.SAM complex-sorting and assembly machinery which is necessary for assembling complex OMM proteins like porin
Term
Insertion site on OMM
Definition
GIP (general insertion pore) or channels match up with channels in IMM (like TIMs)
Term
MIA pathway proteins
Definition
machinery for protein import and assembly
Term
Tims
Definition
small IMS proteins
Term
MIA and Tims function
Definition
assist in the sorting and assembly of proteins in the IMS and IMM
Term
What force is needed to transport protein across the IMM
Definition
proton motive force
Term
What mediates crossing of IMM in addition to proton motive force
Definition
translocation motors like mtHsp70 which uses ATP
Term
Mech of protein import into the mito 9 steps
Definition
1.targeting sequence
2.cytosolic chaperones-ie unfolding
3.Import receptors on OMM
4.Insertion site on OMM
5.Sorting and assembly in the IMS and IMM
6.proton motive force to cross IMM
7.translocation motors
8.proteolytic processing of target signals
9.refolding, assembly, and intramitochondrial sorting
Term
What mediates intramitochondrial folding and assembly of imported proteins
Definition
chaperonins like Hsp60 which uses ATP
Term
Three possible sources of mutations responsible for mito pathology
Definition
1.Nuclear DNA
2.cytoplasmic DNA ie mtDNA
3.X-linked
Term
Why mtDNA mutations occur more frequently
Definition
1. mtDNA is attached to IMM, the source of oxygen radicals
2. mtDNA lacks protective histones
3. mtDNA has limited repair system
Term
mito diseases resulting from missense mutations
Definition
LHON
Term
LHON
Definition
Leber's hereditary optic neuropathy which causes blindness and occurs more in males
Term
Biogenesis mutations are
Definition
tRNA point mutations that affect protein synth
Term
diseases caused by mito biogenesis mutations are
Definition
MERRF and MELAS
Term
MERRF
Definition
Myoclonus Epilepsy and Ragged Red Fibers
Term
MELAS
Definition
mitochondrial encephalomyopathy, lactic acidosis, and stroke-like symptoms
Term
diseases caused by insertion deletion mutations in mito
Definition
KSS and PEO
Term
KSS
Definition
Kearns Sayre Syndrome
Term
PEO
Definition
progressive external ophthalmoplegia
Term
Diseases of aging in which mito dysfunctions are implicated
Definition
1.normal aging
2.parkinson's
3.alzheimer's
Term
Normal aging is characterized by
Definition
mtDNA damage caused mainly by reactive oxygen species which as damage accumulates causes a decline in oxidative phosphorylation over time
Term
Release of cytochrome c is
Definition
an early event in many cases of apoptosis
Term
Bcl-2 and Bcl-XL are
Definition
anti-apoptotic agents which promote cell survival by residing on the OMM and block the release of cytochrome c from mito
Term
Apoptosis cascade
Definition
Cyt C binds to APAF-1 which then activates Caspace 9 which in turn activates Caspase 3 triggering apoptosis
Term
Bad and Bax
Definition
pro-apoptotic
Term
ECM
Definition
composed of a hydrated gel-like ground substance with fibers embedded in it
Term
Function of ground substance
Definition
resists compression
Term
Fibers of ECM function
Definition
withstand tensile forces
Term
Function of tissue fluid associated with ground substance
Definition
forms the medium for passage of metabolites and waste products
Term
Ground substance is composed of
Definition
glycosaminoglycans and proteoglycans
Term
GAGs
Definition
are unbranced polysaccharide chains consisting of repeating disaccharide units
Term
Proteoglycans
Definition
consist of a core protein linked to GAGs
Term
ECM consists of two types of fibers
Definition
collagen and elastin
Term
Collagens are
Definition
a family of proteins that consist of a triple helix of alpha chains
Term
Elastin molecules
Definition
are cross-linked and form elastic fibers that are coated with fibrillin and have the properties of being able to stretch and recoil
Term
what coats elastin fibers
Definition
fibrillin
Term
Function of adhesive glycoproteins
Definition
link cell to the ECM by binding integrins located in the cell membrane and comprise the third constituent of ECM
Term
Examples of adhesive glycoproteins
Definition
laminin and fibronectin
Term
basal lamina function
Definition
provides stability and interfaces with the ecm as well as helping to control cell behavior
Term
What is considered the beginning of the ecm?
Definition
basal lamina
Term
Repeating sugars in GAG
Definition
always N-acetyl glu or gal paired with uronic acid (glucoronic or iduronic)
Term
Charge of gags
Definition
very negative due to sulfated sugars and the sugars also have carboxyl groups
Term
Role of negative charges in gags
Definition
bind Na+ which osmotically attracts water to the matrix so that it swells up which creates a gel that cushions and disperses compressive loads
Term
4 main types of GAGs
Definition
1.hyaluronate
2.chondroitin and dermatan sulfate
3.heparan sulfate and heparin
4.keratan sulfate
Term
Hyaluronate
Definition
non sulfated, single disaccharide unit, consisting of long chains of greater than 300 units up to 25000 units
Term
what is the predominant GAG in loose supporting tissues
Definition
hyaluronate
Term
Hyaluronate does not
Definition
form covalent links to protein molecules
Term
sulfated gag chains other than hyaluronate form
Definition
covalent links with a protein core to form proteoglycans
Term
Aggregan proteoglycans are
Definition
bound by link proteins to a hyaluronate backbone to form large multimeric complexes that assemble in cartilage and connective tissue
Term
Proteoglycan functions
Definition
1.form molecular filters of variable pore size and charge density that screen and retard macromolecules as they pass through them
2.Proteoglycans contain binding sites for secreted growth factors like FGF and TGF beta as well as proteases and protease inhibitors this can activate the factors or concentrate them in a specific location
Term
ex of molecular filter function of proteoglycan
Definition
kidney heparan sulfate proteoglycan in the glomerular basal lamina
Term
Syndecan
Definition
proteoglycan that is not released but stays attached to cell membrane to bind FGF and present FGF to its cell membrane receptors in the vicinity
Term
ex Proteoglycan genetic disease
Definition
progeria is caused by galactosyltransferase thermolability in fibroblasts results in failure of dermatan sulfate chain addition to proteoglycan
Term
Members of this family of fibrous proteins constitute the largest percentage of protein mass in mammals
Definition
collagens
Term
connective tissue fibroblasts
Definition
synthesize and secrete collagen
Term
Collagen is secreted into the ECM as
Definition
tropocollagen
Term
tropocollagen
Definition
triple helix of three alpha chains that polymerize to form collagen in ecm
Term
alpha chain sequence of collagen is usually
Definition
a repeat of Gly-X-Y where proline is commonly X and hydroxypro is commonly y
Term
Type 1 collagen
Definition
forms fibril found in bone, skin, tendon, ligaments, cornea, and organs
Term
type 2 collagen
Definition
forms fibril found in cartilage, IV discs, vitreous humor
Term
Type III collagen
Definition
forms fibril found in skin, blood vessels, and visceral organs
Term
Type 9 collagen
Definition
forms lateral association found in cartilage
Term
type 12 collagen
Definition
forms lateral association found in tendon and ligaments
Term
type 5 collagen
Definition
forms sheet-like network in basal laminae
Term
type VII collagen
Definition
forms anchoring fibrils in skin
Term
Collagen is synthesized on the ... as individual ...
Definition
rER, preprocollagen chains
Term
preprocollagen chain
Definition
alpha chains containing additional aa sequences known as propeptides at the n and c termini ends
Term
procollagen triple helix
Definition
made when three preprocollagen molecules are aligned and assembled and then secreted into the extracellular space
Term
Tropocollagen formation
Definition
formed when the newly excreted procollagen triple helix is cleaved removing the propeptides
Term
Tropocollagen to collagen fibril
Definition
tropocollagen molecules are spontaneously assembled in a head to tail fashion which is augmented by covalent bonds formed between lys and lys-OH of neighboring tropocollagen molecules to form collagen fibril
Term
Collagen hierarchy
Definition
preprocollagen->procollagen triple helix->tropocollagen->collagen fibrils->collagen fibers
Term
Collagen fibril
Definition
aggregation of tropocollagen
Term
Collagen fibers
Definition
aggregations of collagen fibrils and is mediated by type IX and XII fibril associated collagens
Term
Fibroblasts function
Definition
regulate the orientation and size of collagen fibrils
Term
Clinical conditions involving collagens
Definition
1.scurvy
2.keloid
3.osteogenesis imperfecta
4.chondrodysplasias
5.ehlers-danlos syndrome
Term
Scurvy
Definition
deficiency of vitamin c, which required for hydroxylation of proline residues, lack of hydrox destabilizes the alpha chain helices so can't get collagen fibrils
Term
Scurvy clinical symptoms
Definition
blood vessels are fragile, wound healing poor, and teeth loosen in their sockets
Term
keloid
Definition
elevated scar due to excessive accumulation of collagen during wound healing
Term
Osteogenesis imperfecta
Definition
defect in type 1 collagen yielding easily fracturing bones
Term
Chrondrodysplasias
Definition
result from defect in type 2 collagen resulting in cartilage joint deformities
Term
Ehlers-Danlos syndrome
Definition
type III collagen mutation and is characterized by weak skin, fragile blood vessels and hypermobile.
Term
defective type vii collagen
Definition
produces blistering disease of skin and dystrophic necrosis of skeletal muscle
Term
elastic fibers are composed of the proteins
Definition
elastin and fibrillin
Term
elastin is rich in
Definition
gly, lys, and pro
Term
Chains of elastin are covalently linked by
Definition
lysine residues
Term
Elastin is synthesized by ... and assembled in the ....into...
Definition
fibroblasts, ECM into elastic fibers consisting of an elastin core surrounded by a sheath of microfibrils composed of fibrillin, an elastin glycoprotein
Term
Marfan mutation
Definition
in fibrillin leads to aortic aneurysms
Term
Integrins
Definition
cell transmembrane receptors that bind adhesive proteins to link the cell to ecm
Term
Integrin structure
Definition
heterodimers composed of a and b subunits in which the carboxyl ends of the a/b chains are linked to actin filaments in the ECM mediating the cell matrix interactions
Term
What determines the ligand-binding specificity of the various integrins
Definition
the isoforms of the a and b chains
Term
What do integrins bind to
Definition
fibronectin, laminin, collagen and other matrix proteins
Term
how do you modulate attachment of cells to matrix components
Definition
regulate the number of integrins on the cell surface
Term
fibronectin
Definition
large glycoprotein heterodimer (disulfide-linked) containing collagen, heparin, and integrin binding domains separated by flexible hinge peptides
Term
Integrin or cell binding site composition on fibronectin
Definition
RGD-arg, gly, asp
Term
fibronectin binds to what (besides integrins)
Definition
collagen and heparin sulfate in the ecm to establish structural continuity
Term
Laminin
Definition
major component of the basal lamina that forms links btwn cell membranes and other constituients of the basal lamina
Term
laminin
Definition
large glycoprotein composed of 3 polypeptide chains a, b1, b2
Term
b chain function of laminin
Definition
warp around the alpha chain to form a cross like pattern of 1 long and 3 short chains held together by disulfide bonds
Term
basal lamina composition
Definition
composed primarily of type 4 collagen, proteoglycan perlecan heparan sulfate, and the adhesive glycoproteins laminin and entactin joined by covalent and non covalent linkages
Term
Functions of basal lamina
Definition
1. molecular filter
2. selective barrier to cells
3. scaffolding for regeneration like skeletal muscle regeneration
Term
ECM components are degraded by
Definition
extracellular proteases secreted locally by cells
Term
Macrophages lymphocytes and nerve fibers can penetrate the basal lamina through the release of
Definition
matrix metaloproteinases and serine proteases which collectively degrade collagen, laminin and fibronectin
Term
plasminogen
Definition
serine protease proenzyme is distributed in the matrix and is activated by plasminogen activator to plasmin
Term
Proteolysis of matrix proteins contributes to cell migration in several ways
Definition
1. clearing a path through the matrix
2. exposing cryptic sites on the cleaved proteins that promote cell binding, migration or both
3.promoting cell detachment so that a cell can move onward
4. releasing extracellular signal proteins that stimulate cell migration
Term
Matrix degradation is regulated by
Definition
TIMPs (peptide tissue inhibitors of metalloproteases) and serine protease inhibitors (serpins)
Term
ECM degradation and WBC
Definition
allow them to migrate through basal lamina of blood vessel into tissue in response to infection
Term
metastasis and ecm
Definition
metastasis of malignant melanoma involves proteolytically breaking through the basal lamina and entering blood stream
Term
Angiogenesis and ecm degradation
Definition
sprouting endothelial cells penetrate the ecm by secreting hyaluronidase and plasminogen activator
Term
Fixed cells
Definition
are relatively stable populations of long-lived cells that develop form the mesenchyme
Term
Fixed cells regeneration
Definition
their regeneration capabilities suggests there is a population of stem cells
Term
Two examples of fixed cells
Definition
fibroblasts-form ecm and adipocytes-store fat
Term
Free or wandering cells
Definition
changing populations of specific defense cells (WBC) that are short lived and enter connective tissue from the blood vessels
Term
Types of free or wandering cell types
Definition
eosinophils, monocytes, macrophages, lymphocytes, plasma cells, mast cells, and neutrophils
Term
Connective tissue types
Definition
1.Embryonic CT
2. General CT
3. Specialized CT
Term
Embryonic CT
Definition
found only in the developing embryo
Term
Types of embryonic connective tissue
Definition
mesenchymal CT and mucous ct
Term
mesenchymal ct
Definition
give rise to most cells of loose ct
Term
mucous ct
Definition
found in the umbilical cord
Term
General connective tissue types
Definition
1. loose
2. dense
3. reticular
4. adipose tissue
Term
loose ct
Definition
also known as areolar is distributed within and btwn tissue layers in most organs
Term
dense ct
Definition
forms tendons and ligs
Term
reticular ct
Definition
supports the parenchyma of lymphoid organs
Term
adipose tissue
Definition
functions in synth, storage, and release of fat
Term
Cartilage and bone
Definition
provide rigid framework for body that permits its movement
Term
Specialized connective tissue types
Definition
Cartilage/bone and blood
Term
blood born cells
Definition
provide metabolic support, distribution of oxygen, and defense of the body against pathogens and injury
Term
Normal functions of CT
Definition
1.mechanical support
2.exchange of metabolites
3.storage of energy
4.protection against infection
5.repair
Term
CT function mechanical support
Definition
bundles cells of the same tissue together, anchors tissues to each other to organs, and binds organs together
Term
CT function exchange of metabolites
Definition
btwn blood and tissues-ground substance of ECM provides hydrated medium for diffusion
Term
CT function storage of energy
Definition
reserves-storage of lipids in fat cells and proteins in the ecm and the blood
Term
CT function protectin against infection
Definition
phagocytosis by macrophages, neutrophils, and eosinophils and mast cell degranulations during inflammation
Term
CT function repair
Definition
repair following injury-fibroblast proliferation and secretion in wound healing
Term
These are responsible for the synthesis of almost all of the ECM of connective tissue
Definition
fibroblasts
Term
Fibroblasts often reside in close association with
Definition
collagen bundles
Term
fibroblasts lie in what orientation to collagen fibers
Definition
parallel to the long axis so their shape and orientation reflects the composition and stress (tension) of the surrounding environment.
Term
Fibroblasts lack
Definition
a basal lamina
Term
Myofibroblasts
Definition
modified fibroblasts that demonstrate characteristics of both fibroblasts and smooth muscle cells
Term
myofibroblasts have little or no
Definition
basal lamina
Term
myofibroblasts are abundant in areas undergoing
Definition
wound healing b/c like smooth muscle they have bundles of actin filaments and dense bodies which allow them to cause the contraction of an shrinkage of scar tissue
Term
Myofibroblasts are also found (besides wound healing)
Definition
periodontal ligament where they assist in tooth eruption
Term
Dupuytren's fibromatosis
Definition
disease characterized by hypercontraction and thickening of the palmar fascia
Term
Adipose cells store lipid in the form of
Definition
triglyceride droplets
Term
Triglyceride in triglyceride droplets come from three sources
Definition
1. chylomicrons
2. liver synthesis
3. synthesized in adipocytes from glu
Term
Adipocytes have receptors for
Definition
insulin, glucocorticoids, growth hormone and NE which modulate fat uptake and release
Term
Adipocytes secrete
Definition
leptin
Term
leptin
Definition
hormone secreted by adipocytes that helps regulate hunger
Term
Insulin in adipocytes
Definition
glucose to fat conversion
Term
NE in adipocytes
Definition
stimulates lipase activity
Term
2 types of adipose tissue
Definition
white and brown
Term
White adipose tissue comprises
Definition
upto 20% of body weight in normal males and 25% in females
Term
Functions of white adipose tissue
Definition
energy store, thermal insulator, and structural support
Term
White adipose cells are characterized by
Definition
single large lipid droplet (unilocular) surrounded by a thin rim of cytoplasm, thin basal lamina, and highly vascularized
Term
Brown adipose tissue
Definition
specialized form of adipose tissue found in newborn mammals and some hibernating animals
Term
Brown adipose cells structure
Definition
contain multiple small lipid droplets (multilocular)
Term
why is brown adipose tissue brown
Definition
reddish in color b/c of abundant capillaries and mitochondria
Term
brown fat function
Definition
nonshivering thermogenesis due to uncoupling protein thermogenin which causes the mitos to be leaky and dissipate the proton gradient thus requiring more energy to maintain it
Term
hypertrophic obesity
Definition
results from accumulation and storage of fat in white adipose cells which can increase in size by 4x
Term
hypercellular obesity
Definition
more severe and results from overabundance of adipocytes
Term
What regulates adipose mass
Definition
leptin
Term
Leptin binds to
Definition
leptin receptors in the appetite center of the hypothalamus and activates the symp nervous system to release NE which mobilizes fat from adipocytes
Term
shortage of leptin
Definition
means voracious appetite and uncontrollabe weight gain
Term
leukocytes
Definition
WBC that circulate in the blood stream and migrate through capillary walls during inflammation
Term
types of leukocytes
Definition
1. monocytes
2.neutrophils
3.eosinophils
4.lymphocytes
5.plasma cells
6.mast cells
Term
Monocytes
Definition
can be free or fixed macrophages
Term
Macrophages belong to the ... and are subdivided into two groups of cells..
Definition
mononuclear phagocytic system, phagocytes, and antigen presenting cells
Term
macrophages in the ct, lymphoid organs and bone marrows
Definition
histiocytes
Term
macrophages in the lungs
Definition
alveolar phagocytes
Term
macrophages in the liver
Definition
kupffer cells
Term
macrophages in the CNS
Definition
microglia
Term
macrophages of the bone
Definition
osteoclasts
Term
Macrophage function
Definition
1. phagocytosis so first line defense against bacteria
2.processing and presenting antigens to lymphocytes for antibody generation
Term
Macrophages are characterized by
Definition
kidney shaped indented nucleus, abundant lysosomes, and a large juxtanuclear gogi
Term
Macrophages contain complement protein which is
Definition
liver secreted proteins that bind immunoglobulins to the surface of the bacteria making them more susceptible to phagocytosis in process called opsinization
Term
opsinization
Definition
process by which complement proteins make bacteria more susceptible to phagocytosis by binding to immunoglobulins on the bacteria surface
Term
Neutrophils characterized by a
Definition
multilobulated nucleus and non-specific cytoplasmic granules (primary lysosomes)
Term
Neutrophils are attracted by
Definition
injured tissue through cleavage products of complement, cytokines, and bacterial lipopolysaccharide liberated in the inflammatory response
Term
neutrophils function
Definition
phagocytose and digest bacteria in areas of acute inflammation resulting in the formation of pus
Term
What makes pus
Definition
neutrophils
Term
Eosinophils are characterized by
Definition
multilobed nucleus that is partially obscured by cell type defining eosinophilic specific granules
Term
eosinophils are attracted to
Definition
areas of inflammation through chemotaxic factors like neutrophils are
Term
Eosinophil function
Definition
attack parasitic organisms by releasing cytotoxins which degrade cell membranes
Term
eosinophils and allergies
Definition
they are attracted to sites of allergic inflammation where they phagocytose antibody-antigen complexes and degrade histamines moderating the allergic reactions
Term
eosinophils occur in regions associated with allergic rxns like
Definition
nasal mucosa, lung, skin, and lamina propia of gut
Term
lymphocytes
Definition
small dark cells containing a dark round nucleus and a thin rim of cytoplasm
Term
lymphocytes are the principle cells of
Definition
the immune system so are prevalent in lymphoid tissue and areas of chronic inflammation
Term
Plasma cells
Definition
are derived from B lymphocytes that have interacted with antigen and secrete antibodies
Term
plasma cells are characterized by
Definition
being large cells with a round nucleus and a clock face pattern of heterochromatin and an extensive basophilic cytoplasm of rER
Term
Mast cells arise from
Definition
bone marrow
Term
mast cell function
Definition
mediate the inflammatory process and immediate hypersensitivity reactions
Term
mast cells appear as
Definition
large cells filled w/ basophilic granules which obscure the small round nucleus
Term
Mast cell granules contain
Definition
heparin, histamine, neutral proteases, neutrophil and eosinophil chemotactic factors and leukotrienes
Term
Mast cells are prevalent in the
Definition
connective tissue surrounding small blood vessels
Term
Mast cells possess surface receptors for
Definition
immunoglobulins ig
Term
Mast cell receptor binding to igE triggers
Definition
degranulation resulting in histamine release which increases capillary and venule permeabilty resulting in mucosal edema
Term
Victims of hay fever attacks suffer from the effects of
Definition
histamine released by mast cells of the nasal mucosa, which causes localized edema from increased permeability of vessels which hinders breathing and gives stuffed up feeling
Term
in asthmatics the release of
Definition
leukotrienes in the lungs initiates bronchial smooth muscle contractions and difficulty breathing
Term
Mucous connective tissue exhibits a
Definition
jelly like matrix of hyaluronic acid and small amounts of fibrillar collagens
Term
loose ct
Definition
composed of a loose arrangement of fibers and dispersed cells imbedded in a gel like substance
Term
dispersed cells in loose ct
Definition
fibroblasts, macrophages, mast cells and WBC
Term
loose ct found where
Definition
under the epithelia of the body where it packages organs and surrounds capillaries
Term
loose ct functions to
Definition
wrap and cushion organs as well as hold tissues together
Term
two types of dense ct
Definition
regular and irregular
Term
irregular dense ct is composed primarily of
Definition
irregularly arranged collagen fibers and contains few cells
Term
Irregular dense ct is able to withstand
Definition
tension exerted in multiple directions and provides structural strength
Term
Irregular dense ct location
Definition
reticular layer of the dermis of the skin, submucosa of the digestive tract, and fibrous capsules of visceral organs and joint
Term
Regular dense connective tissue is composed primarily of
Definition
coarse collage bundles densely packed and oriented into parallel cylinders or sheets that resist tensile forces
Term
regular dense ct can withstand great tensile strength when
Definition
pulling force is applied in one direction
Term
regular dense ct location
Definition
tendons, most ligaments, and aponeurosis where it functions to attach muscles to bones or muscles and bones to bones
Term
Reticular connective tissue consists of a network of
Definition
reticular fibers composed from collagen type III in loose ground substance
Term
Reticular ct function
Definition
supports the parenchyma of organs
Term
Reticular ct location
Definition
lymphoid organs such as lymph nodes, bone marrow and spleen
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