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Definition
| (immotile- like long microvilli) facilitate absorption and are found in the male reproductive tract -epididymis. Actin core. |
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Basement Membrane function |
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Definition
| provides structural support, acts as a filter, establishes polarity and controls epithelial growth and differentiation. |
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Term
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Definition
Proteins within: collagen type IV heparan sulfate proteoglycan laminin entactin fibronectin Made of: lamina lucida(LL), lamina densa(LD), lamina reticularis (made by underlying connective cells)
basal lamina: LL, LD - madeby epithelial cells
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Definition
| PM folds in, occur to allow for more surface, so more transport and so more mitochondria can provide energy for active transport. Found in kidney. |
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Unicellular glands examples |
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Definition
- Goblet Cells- lg. light granules fills the apical portion, nucleus at the base, synthesize and secrete mucins, in the intestine and respiratory systems
- Enteroendocrine cells- sm. dense granules at the basal portion, nucleus at the base, synthesize and secrete hormones into blood (op. the path of Goblet cells secretion), intestine and respiratory systems.
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Term
| Compare and contrast the developmental pattern of exocrine and endocrine glands |
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Definition
After the mesenchymal cells induce a bud, exocrine glands will maintain their connection w/ surface epithelia. Endocrine glands break free from parent epithelial glands ( disappearance of duct cells) and are surrounded by capillaries |
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| examples of exocrine glands |
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Definition
| Sweat glands are simple tubular. Sebaceous glands are branched acinar. |
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Term
Multicellular exocrine glands 2 types of ducts Organization of secretory portion Architecture of gland |
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Definition
- 2 types of ducts –
- Organization of secretory portion
- Acinar- grapes (5-7 cells)
- Architecture of gland
- Parenchyma- functional –secretory component + the duct system (secretion cells)
- Stroma-supportive – surrounding connective tissue + capsules (connective tissue)
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Definition
- Exocrine – through duct (apical release)
- Endocrine- w/o duct – into bloodstream (basal release)
- Autocrine – secretory product stimulates receptors on the same cell
- Paracrine – secretion affects neighboring cells – growth factors
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Term
| Mechanisms of Secretion by Glands |
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Definition
- Merocrine – conservation of membrane – exocytosis – most glands are
- Apocrine – secretion includes apical part of the cell – sweat glands are an ex.
- Holocrine – Cell secretes “whole” self w/ secretory product- it dies– sebaceous glands are an ex.
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Term
serous cells mucous cells |
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Definition
serous cells – enzymatic glandular secretion mucous cells – mucins glandular secretion |
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Term
Lamina lucida composed of: |
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Definition
| composed primarily of laminin – asymmetrical structure cross structure, with 2 shorter arms, it has globular proteins on the ends |
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Term
Lamina lucida three components |
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Definition
- alpha
- contains center peptide with the terminal singular globular end on the long arm
- the globular end contains a binding site for Heparan sulfate –
- beta
- integrin (cell- surface receptors) binding site in long arm
- proteoglycan binding site
- Heparan Sulfate binding site
- gamma
- has a proteoglycan binding site- -the protein core
- on the short arm - a binding site for entactin-imp binding site for type IV collagen
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Term
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Definition
- binds the 2 networks(lamina lucida and lamina densa) together – not the only connection – laminin can also bind to IV collagen
- 2 domains – laminin domain and a collagen domain
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Term
| Other ways Lamina Rara is connected |
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Definition
- integrin (cell- surface receptors) binding site in long arm
- integrins can bind to laminin to adhere epithelium to lamina rara
- integrins cross the cell membrane – and adhere to actin cytoskeleton
- Laminin can also bind to itself – to form a laminin network to form the lamina lucida
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Term
Lamina densa What's in it and how is it connected |
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Definition
- Primarily type 4 collagen molecule
- All collagens have a collagenous domains - triple helix
- The N-terminal end- non collagenous domain called the NC1 domain
- non collagenous globular domain called the 7S domain
- In most collagen, these non collagenous ends are cleave off, but these remain in type 4 collagen. They allow for an interaction b/w one another.
- They interact in a anti- parallel via the 7S domain and extend the globular domain away from the center
- They can also interact via the NC1 domain also in anti-parallel fashion (head to head) extending the 7S domain away from the site of interaction
- Forms a sheet- looks like chicken wire
- Sites of interaction b/w the triple-helix domains to stabilize the structure
- Furthermore, multiple type 4 collagen sheets layer on top of one another to form the lamina densa
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Term
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Definition
- Fibronectin
- Dimer formed by disulfide bonds at the C-terminal end
- Permits interaction of cells with collagen (usually not IV collagen, instead I or III)
- Not synthesized by epithelium – instead by resident connective cells that make up the lamina reticularis
- Found in the basement membrane and also found in lamina reticularis
- Proteoglycan
- A large core protein to which glycosaminoglycan (GAG) side chains are attached
- heparin sulfate or chondrotin sulfate – types in BM
- can be very long, they are sulfated, so they have a high amount of neg. charge
- functions for filtration and sequestered growth factors (the growth factors and receptors would not interact w/o)
- growth factors are found in abundance in the BM
- epithelial cells have receptors for growth factors
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Term
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Definition
- Not in the basal lamina
- Synthesized by fibroblasts
- Can see where in starts on a EM but not where it stops
- Attaches to underlying connective tissue
- High abundance of type 3 collagen fibers ( reticular fibers) made by specialized fibroblasts called reticulacytes
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Term
| Glomerular Basement membrane (GBM) |
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Definition
specialized BM - In the kidney, part of filtration barrier
- Fusion of 2 basal lamina – doubly thick membrane- lamina densas face each other
- 1 synthesized by specialized epithelial cell called potocytes
- 1 synthesized by endothelial cells that line the capillarys of the glomeruli tuft
- no lamina reticularis
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Definition
Advanced glycation end products diabetes complication they are created from the interaction of excess glucose and AA that create reactive oxygen species they lead to a thickening of the GBM and more |
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Term
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Definition
poly-pro helix, collagenous helix - has 3 linear peptide subunits (the collagenous domain)
- A glycine is every 3rd AA to produce a liner peptide. It also has proline and hydroxyproline which stabilize the structure.
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Term
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Definition
- synthesized with non-collagenous domains
- All initially resemble IV collagen, then the globular domains are cleaved so that the collagenous domains can assemble fibrils
- The individual subunits with the 7s domain and the other domains are called procollagen
- Procollagen contains registration peptides that allow the chains to assemble into a triple helix – lines them up exactly
- Procollagen molecules – in a triple helix- are secreted into the extracellular space (the procollagen molecule is created in the cell by resident connective cells- all the subunits and the triple helix is made)
- in the extracellular space, procollagen peptidases cleave the non-helical region peptides (including the registration peptides) creating tropocollagen which is now insoluble (it was soluble)
- Tropcollagen- aggregates to form collagen fibrils, driven because they are insoluble. The tropocollagen molecules are also covalently crosslinked to reinforce the fibril structure.
- The overlap of tropocollagen molecules give the collagen fibrils a characteristic banding pattern
- Collagen fibrils then can associate to form collagen fibers.
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Term
| 4 major types of collagen: |
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Definition
- Type I – most abundant in the body, it forms fibers, found in high amounts in skin and bone, but found everywhere, it’s ubiquitous
- Type II – networks of fibrils – it does not form fibers, found only in cartilage, in abundance in hyaline cartilage and elastic cartilage
- Type III- forms fibers, but specialized ones called reticular fibers – found in lamina reticularus, spleen and liver – looks very different than type 1 collagen fibers
- Type IV – forms networks, no fibers, only in BMs
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Term
Elastic fibers where found synthesis |
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Definition
- Found in the nose and ear, but also found in other tissues
- They are cross-linked which allows stretching to occur
- Synthesized similar to collagen
- Composed of: tropoelastin, Fibrillin I, Fibrillin II, and microfibril associated glycoprotein (MAGP)
- Synthesized by resident connective tissue cells, fibroblasts, or by smooth muscle cell (a resident connective cell in this case)
- Synthesized in the cell and assembled in extracellular
- Synthesized as proelastin (inside) and then processed to tropoelastin (outside) and it assembles with Fibrillin I, Fibrillin II, and MAGP to form immature elastic fibers
- Assemble to form mature elastin fibers
- Can be found as individual fibers or as sheets ( in the large heart vessels – aoeta- to allow the vessels to dilate and contract rapidly)
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Term
| matrix metalloproteinases |
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Definition
MMP degrading extracellular matrix proteins depends on metal ions for catalytic activity - MMPS are involved in:
- Embryonic development (normal)
- Tissue morphogenesis (normal)
- Wound repair (normal)
- Inflammatory disease (pathology)
- Cancer (pathology)
Tumor cells will express activated MMPs allowing the degradation of BM and structural proteins in the connective tissue so they can move into the connective tissue |
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Term
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Definition
- Must be regulated, transcriptional, translational and post-translationaly
- Proteolytic activation – MMPs are synthesized in an inactive form, and must be activated
- Proteolytic processing and inactivation – can be inactivated after being activated
- Protein inhibitions (TIMPs) – proteins that bind to activated MMPS and prevent it’s activity
- Localized to extracellular matix – activity is restricted
- Cell surface localization - activity is restricted
- Endocytosis and intracellular degradation
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Term
Fibroblasts Purpose and 4 derivatives |
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Definition
- synthesize proteoglycans, collagen, and elastin, tendon and skin (type I collagen – always in fibers)
- Chondroblasts –(cartilage) type II collagen- fibrils (hyaline and elastic cartilage)
- Osteoblast (bone) type I collagen
- Odontoblast (teeth - dentin) type I collagen
- Reticular Cells (bone marrow, lymphoid organs, spleen, liver, lamina ret.) – type III collagen (fibers)
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Term
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Definition
precursor cell (differentiation) to all fibroblasts, and smooth muscle cell, and adipocytes. - Umbilical cord called Wharton’s jelly (connective tissue- composed of ground substance with no fibers – mainly proteoglycans)
- There are mesenchymal cells in Wharton's Jelly that have large oval nuclei – seen in early development structures
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Term
| Resident Connective Tissue Cells |
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Definition
Fibroblasts Adipocyte Smooth Muscle Cell Mesenchymal Cell |
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Term
| Transient Cells in Connective Tissue |
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Definition
Mast Cells Macrophages Plasma Cells Lymphocytes Eosinophils |
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Term
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Definition
| how circulating transient cells move into the connective tissue |
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Term
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Definition
| Proteins expressed on endothelial cells membranes, bind to carbohydrates on the transient cells, binds with low affinity allowing them to roll on the surface, then the integrins bind tightly so to pass between |
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Term
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Definition
filled with granules that contain many diff. molecules such as Histamine, Heparin, proteases, proteoglycans, and cytokines allergic response: they have IgE immunoglobulins on their surface that when crosslinked with an antigen results in the activation of the cell that releases intracellular Ca2+ and then release of granule molecules |
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Term
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Definition
| manufacture and secrete antibodies, lots of RER, oblong cells with “cartwheel” distribution of heterochromatin (heavily involved in gene expression), extensive golgi – found in abundance in GI where exposure to foreign substances |
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Term
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Definition
| huge nucleus, B-lymphocytes can differentiate into plasma cells |
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Term
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Definition
they have granules that pick up the eosin stain, a crystalline center - 1st line of defense in parasitic infection
- Contents of granules include:
- Eosinophil perxidase: binds to microorganisms facilitating their killing by macrophages
- Major Basic Protein (MBP): component of crystalline center, binds and disrupts the membrane of parasites.
- Eosinophil cationic protein: with MBP causes fragmentation of parasites
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Term
Wound Healing Normal vs. Diabetic |
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Definition
- Normal:
- En-RAGE (ligand for RAGE) –expressed in clots (usually type III collagen) at the site of a wound. This draws macrophages and fibroblasts.
- The MMPs clear the way for macrophages and fibroblasts
- then these two degrade the MMPS and synthesize collagen to heal the wound.
- Diabetic:
- The presence of AGE competes with EN-RAGE for binding to RAGE
- Connective tissues becomes like a glue preventing macrophages and fibroblasts from getting to the wound
- The clot cells continue to synthesize MMPs which break down new collagen and the wound doesn’t heal
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