Connective Tissue Week 3 Flashcards
What is connective tissue?
A diverse group of cells within a tissue-specific ECM.
The ground substance is __________.
gelatinous material that fills spaces between fibers and cells
What are the functions of connective tissue?
Support
Defense
Nutrition
Describe connective tissue support.
Tendons and ligaments can provide support and connection.
Describe connective tissue defense.
Site of inflammatory and immune reactions as well as serves as a physical barrier
Describe nutrition provided by connective tissue
Reservoir for water and electrolytes and hormone growth factors
Stores energy as adipocytes (triglycerides)
Support blood vessels
Passageway for nutrients and gases
What are examples of embryonic CT?
umbilical cord
There are 3 classes of connective tissue. What are they?
Embryonic CT
CT Proper
Specialized CT
CT Proper can be further be divided into categories. What are they ?
Loose CT and Dense CT
Dense CT can be further divided into regular and irregular
What is an example of loose CT
Lamina propria
What are examples of specialized CT ?
Bone, Cartilage , Adipose tissue
Loose/areolar CT is a ____________. It is made up of loosely arranged ________ and ________ and ________. There are more __________ than __________.
CT proper
Cells, Ground Substance, Fibers
Cells, Ground Substance > Fibers
Loose/areolar CT function to __________(5).
Support epithelial Tissue
Surround blood vessels
Fill spaces between muscles
Diffusion of O2/Co2 and nutrients and wastes
Inflammatory and immune reactions
Dense CT is a type of _____________ that has more ______ and little ________.
Regular Dense CT has fibers arranged ________
Irregular Dense CT has fibers arranged _________.
CT Proper
Fibers, Ground Substance
in parallel bundles
randomly
What are examples of dense regular connective tissue?
Dense regular tissue function to ____________(3).
Tendons, ligaments, cornea
Transmit force of muscle contraction
Attach muscles to bones
Protection
What are examples of dense irregular connective tissue?
Irregular connective tissue function to ___________(2)
Skin, GI tract
Provide tensile strength
Protection
How does loose CT stain compared to dense CT?
Loose CT will stain less red because it has less fibers
What are the two types of fiber systems in CT?
Which fibers do NOT stain well in H&E?
Collagen fiber system made of collagen fibers and reticular fibers.
Elastic fiber system made of elastic fiber.
Reticular Fibers and Elastic Fibers
Reticular Fibers are a Type _____ .
Type III Collagen
Collagen fibers stain ________ in trichrome and ___________ in H&E because they are _______.
Blue/green
Red, Acidophilic
Collagen fibers are _______ yet high in _______. They are _______ structures with ______width.
flexible, tensile strength
wavy, variable
How is collagen synthesized? Where is it synthesized?
Fibroblast cells and cartilage cells synthesize collagen via 5 steps
- The nucleus produces the genetic code for the collagen
- The RER produces the pro-collagen precursor to collagen.
- Post translational modifications are made
- Pro-collagen leaves the cell to process into Tropocollagen
- Collagen fibers or networks are built extracellularly
What is the post-translational modification of collagen synthesis dependent on?
Vitamin C allows post translational modifications of adding hydroxyl groups to proline and lysine residues.
Procollagen synthesis happens ______ while other steps are ________.
Intracellular, Extracellular
What is scurvy?
Water-soluble vitamin C deficiency resulting in an inability to produce collagen.
What is scurvy characterized by?
Bone disease in growing children
Hemorrhages and healing defects in children and adults.
What is the dental application to scurvy?
Type 1 collagen forms ligaments that hold tooth to bone. Patients with scurvy may have their teeth fall out.
Type ____ collagen forms ______ that hold tooth to bone.
1 , ligaments
What are scorbutic gums?
Scurvy gums that present a symmetrical appearance without infection
What are pinpoint hemorrhages? What are they an indication of?
Small red spots on skin indicating spontaneous internal region
Scurvy
Several collagen _____ create a collagen ____ which can be bundled together to create a _____.
fibril , fiber bundle of collagen fibers
Reticular fibers are a very _________ Type ____ collagen that forms a ______ rather than a _________ for _______.
fine Type III collagen that forms a 3D network rather than a thick bundle for support
Reticular fibers support __________ and _______ organs except the __________. They are produced by _________.
Hematopoietic (stem cells in bone marrow) and lymphoid organs except the thymus
Reticular cells
Why are reticular fibers stained with silver salts?
High sugar content
What are reticular fibers stained with?
Silver salts due to high content of sugar chains
Type I Collagen
Function:
Examples:
Structure:
Resistance to tension
Dermis, Tendon, Bone, Fibrocartilage
Fibril Forming
Type II Collagen
Function:
Examples:
Structure:
Resistance to pressure
Hyaline Cartilage, intervertebral disc
Fibril Forming
Type III Collagen
Function:
Examples:
Structure:
Maintenance of expansible organs
Reticular Connective Tissue
Fibril Forming
Type IV Collagen
Function:
Examples:
Structure:
Support delicate structures and filtration
Basal lamina, basement membrane
Network Forming
Elastic fibers are responsible for ____________. Tissues can respond to _________ and ________.
Elasticity, resilience and shape control
Stretch and Distension
Elastic fibers are thinner than collagen fibers. True or false?
True
How are elastic fibers synthesized?
fibroblasts - skin and tendons
chondroblast - elastic cartilage
Smooth Muscle cells - Large blood vessels
The aorta is made of ______ by __________ in ________.
Elastic fibers by smooth muscle cells in large blood vessels.
Blood pressure changes a lot so the elastic fiber allows the aorta to stretch and recover.
What is the structure of elastic fibers?
Branching pattern of fibers to form a 3D network that are interwoven with collagen fibers
What makes up an elastic fiber?
- Core of elastin protein, (fibrillin glycoprotein acts as template for elastin deposititon)
- Desmosine and Isodesmosine which covalently link elastin monomers together
What two unique amino acids are associated with elastic fibers and what is their function?
Desmosine and Isodesmosine, link elastin monomers together to make an elastic fiber
Osteogenesis Imperfecta is caused by _________________ and characterized by ____________.
defective synthesis of Type I collagen usually
Brittle bones, blue sclera
What collagen is often associated with osteogenesis imperfecta?
Type I
Ehlers-Danlos Syndrome is a _____________. Clinical features include _______________.
defect in collagen synthesis or assembly
fragile, hyperextensible skin vulnerable to trauma, hypermobile joints, wound healing is poor
Marfan Syndrome is caused by a __________ resulting in a _____________. Clinical features include__________.
Mutation in the FBN1 gene encoding fibrillin resulting in a lack of resistance in tissues rich in elastic fibers.
Tall stature, long fingers, bilateral subluxation of lens, mitral valve prolapse, aortic aneursym, aortic dissection
What are the 4 structures of ground substance?
Glycosaminoglycans (GAG)
Proteoglycans
Structural Glycoproteins
Water
What is ground substance?
Ground substances fills the space between cells and fibers. It is colorless and hydrated (high water content)
What are the functions of ground substance?
Lubricant (due to viscosity)
Diffusion of water-soluble molecules
Anchors cells through cell-ECM adhesion via integrin
Provides path for cell migration
Binds and retains growth factors
Via cell adhesion molecules, information is transmitted across the plasma membrane
Dermatan Sulfate is a _________. Its function is to _________.
GAG
Mediate wound repair, fibrosis
Keratan Sulfate is a _________. Its function is to _________.
GAG
Cell motility, axonal guidance, embryo implantation
Hyaluronic acid is a _______. Its function is _______.
GAG
to serve as the major component of mucous connective tissue found in the umbilical cord.
it is a major component of cartilage and immobilizing molecules like growth factors.
An effective insulator preventing diffusion through the dense network.
Hyaluronic acid is present as a ______________. It is ___________ bound to a ________.
Proteoglycans ____________ bind to HA by _________ thereby forming ______ that are ________.
free carbohydrate chain , not covalently bound to a protein
indirectly linker proteins giant aggregates that are extremely hydrophobic.
Aggrecan is a ________. Its function is ________-
Proteoglycan
Hydration of ECM
Syndecan is a ________. Its function is_________.
Proteoglycan
interaction between proteins of ECM and the actin cytoskeleton
Integrin is a _________. It’s function is to ___________.
glycoprotein
binds cells to ECM
Fibronectin is _________.It’s function is to __________.
glycoprotein
bind many ECM components, attach to integrin
Laminin is a ___________. It’s function is to __________.
Glycoprotein
mediating attachment to basement membrane
What are glycosaminoglycans? (GAGs)
Unbranched polysaccharide
What are proteoglycans ?
Large macromolecules with protein core
What are glycoproteins?
Multiadhesive glycoproteins stabalize ECM and link it to cell surfaces.
Multiadhesive glycoproteins facilitate the attachment between __________ element or _________.
Cell-CT element
CT-CT element
Hyluronidases play a role in _________. Enzymes that degrade ________ lowers the _________ of the connective tissue thus _______ drug permeability. ____ can release hyluronidases to______.
Metastatic potential of _______
drug delivery
hyaluronic acid , viscosity, increasing
Bacteria , infiltrate
tumors
MMPS (matrix metallloproteinases) play a role in _______________ and ____________.
___________, __________,__________ require the participation of MMPs whose expression ___________ association with tumorigenesis.
tissue remodeling and degradation of the extracellular matrix
Tumor invasion, metastasis, and tumor angiogenesis , increases in
Fibroblasts are at a _______________. They are the ________ common cell type.
They ______ divide but _________ in response to ___________. They are activated when ____________
CT resident cell
most
rarely
capable
injury and inflammation
more collagen fiber is needed
What is a specialized fibroblast?
Myofibroblast
Active fibroblasts have _______, ____________ while inactive fibroblasts are ___________ with ________.
large, euchromatic nuclei
smaller
heterochromatic nuclei
Macrophages _______________ and _____________.
initiate immune responses and secrete hydrolytic enzymes
How do macrophages initiate immune responses?
Release cytokines, present antigens to lymphocytes
What hydrolytic enzymes are secreted by macrophages?
Collagenase
Macrophages originate from the __________ as a _________, turn into a _________ and then a ____________ in the ______. Then, in the _______, it develops into a ___________. The macrophage will either go through _______ or ___________.
bone marrow, stem cell
monoblast
monocyte, blood
tissue, macrophage
activation or differentiation to tissue macrophages
Macrophages are __________ because they contain ________ and ____________. They have a _______ or _______ shaped nucleus.
phagocytic, lysosomes and residual bodies
oval, kidney
Macrophages have ____________ for the breakdown of phagocytic material. There are numerous _________ for storage of ________.
lysosomes
phagocytic vesicles , ingest material.
Mast Cells are a ______________.
CT resident cell
Mast cells arise from ______________ in the ____________. They have __________ cells with ______. The _________ is centrally located and the surface expresses ____________.
The cytoplasm is filled with ____________ containing ______, ______-, _________, ________.
multipotent hematopoetic stem cells, bone marrow
oval to round , microvilli
nucleus, IgE receptors
dense secretory granules , heparin, histamine, vasoactive mediators and chemotactic factors
Adipose tissue is a ____________.
Specialized Connective Tissue
Functions of adipose tissue include a _________ for _________ as _________. _________ body against _________.
____________ as ___________
Fills _______ between _________ behaving as _________. For example ________
Secretes __________ and __________substances such as _________.
depot for triglycerides , main energy stores
Insulates body against heat lost
Fat stored triglycerides
space, tissues, shock absorbers
paracrine and endocrine, leptin (hunger)
You can see lots of _________ on __________.
blood vessels, adipose
Adipocytes are _________.
Resident cells in CT
There are _______ of adipocytes.
___________ adipocytes are responsible for __________.
____________ adipocytes are responsible for ___________-
two
Unilocular/white, metabolic energy storage, insulation, cushioning, hormone production
Multilocular/brown , heat production/thermogensis
Unilocular (White) Adipocytes contain _________- surrounded by a ________ of ________. The nucleus is ___________ and located on the ___________.
It secretes ____________ that surround the _________.
one large lipid droplet, ring of cytoplasm
flattened, periphery
reticular fibers, adipocyte
Multilocular (Brown) Adipocytes are found during ___________ and _________ after birth because _______________. They look like _____ with an _________ nucleus. They have _________ mitochondria.
fetal life and first decade, heat regulation system is not developed during the time period.
multiple lipid droplets, eccentric
numerous
Wandering cells in connective tissue include _________.
Eosinophil, Basophil, Neutrophil, Lymphocyte, Monocyte
Plasma cells are _________ that produce _______. They have an __________ cell with an ________ nucleus shaped like __________.
The golgi body appears _____- in TEM.
lymphocyte-derived , antibodies
oval, eccentric, clock face/wheel
ghost
Where does collagen synthesis occur?
Fibroblast and cartilage cells
Diapedesis
How WBC enter Connective tissue; they migrate between epithelial lining of capillaries to enter CT ; increases during inflammation.
