Connective Tissue Flashcards
The cells of connective tissue are quite ___ and can be either fixed in place or ___ throughout the tissue
Varied
Wonder
In connective tissue, the ___ ____ plays a more prominent role than other types of tissues
Extra cellular matrix
The connective tissue functions are:
Support, connection, and protection
Connective tissue can provide ____ support to cells that do not have blood flow
Metabolic
Connective tissue ____ supports the functional paranchyma of most organs
Stroma
___ = cells + extracellular matrix
Tissue
The extra cellular matrix is composed of three different fibers:
Collagen, reticular, and elastic
The extracellular matrix is also composed of a ground substance containing:
Proteoglycans, adhesive glycoproteins, and glycosaminoglycans (GAG)
Connective tissue proper is divided into ___ connective tissue or ____ connective tissue
Dense
Loose
Dense, connective tissue can be ___ or ____
Regular
Irregular
Loose connective tissue can be ____, ____, or ___
Reticular
Adipose
Areolar
Embryonic connective tissue is called ____. ___ ____ ___ is found in the umbilical cord.
Mesenchyme
Mucus connective tissue
Specialized connective tissue include:
(Focused on in later lectures)
Cartilage, bone, blood
This shows:
Dense regular connective tissue
____ ____ shows the elastic fibers in connective tissue
Verhoeff’s stain
Dense connective tissue is found in ___ and ___
Ligaments
Tendons
This is showing:
Dense, irregular connective tissue
The cells in dense irregular connective tissue are mostly ____. Locations of this tissue are the ___ of the skin, ____ of organs, and _____ layer of digestive tract
Fibroblasts
Dermis
Capsules
Submucosal
The cells of dense regular connective tissue are mostly ___ , similar to dense, irregular connective tissue
Fibroblasts
This shows:
Areolar connective tissue
It is loose containing a lot of “empty space”
Ground substance is interspersed with:
Adipocytes, blood vessels, and nerves
Areolar connective tissue is found in underlying ____ ____, and ___ ___ of the digestive tract to allow for movements of nutrients and waste
Epithelial tissue
Lamina propria
This shows:
Reticular tissue
___ ___ is a network of reticular fibers visible with ___ stain. It is located in the ___, ___, and ___
Reticular tissue
Silver
Bone marrow
Liver
Lymph nodes
In lymphoid organs/tissues, reticular fibers are produced and enveloped by ___ ___
Reticular cells
___ ____ contains large aggregates of the fat cells and are held together by reticular fibers. Most of this tissue is lost during fixation when staining.
Adipose tissue
Adipose tissue functions in:
Energy storage
Hormone secretion
Thermal regulation
Cushioning
Take home
_____ fibers have a very high tensile strength.
It is thread like ____ that assemble into larger collagen bundles. Individual fibrils display a 67nm ___ ___.
Collagen
fibrils
Banding patterns
Collagen fibrils are very rich in protein, therefore they stain ____ with H&E
Red
67 nm banding pattern is unique to ___ fibers.
Collagen
Collagen fibers are a good way to navigate yourself around a cell:
Collagen alpha chains have repeating triplets of amino acids. Every third amino acid is ____, followed by X and Y. X is usually ____. Y is usually ___ or ___
Glycine
Proline
Hydroxyproline
Hydroxylysine
A collagen ____ is three alpha chains wound around one another to form a rope like super helix. They can be ____ with three identical alpha chains or ____ with two or three different alpha chains
Molecule (monomer)
Homotrimeric
Hetero trimeric
Collagen synthesis:
Procollagen alpha chains with propeptides at both ends. _____ of specific proline and lysine residues in the ER. Assembly of ___ triple helix with non-helical propeptides at each end. Then formation of ___ and ___ bonds. The packing of ___ pro collagen molecules into secretory vesicles
Hydroxylation
Procollagen
Hydrogen
Disulfide
Soluble
____ ____ in the extracellular space, cleaves the propeptides transforming soluble procollagen into insoluble collagen molecules. Insoluble, collagen, molecules, spontaneously, assemble head to tail into overlapping staggered arrays to form ___ ___
Procollagen peptidases
Collagen fibrils
The highest order of collagen fibrils are ____ ___ and ___
Collagen fibers
Bundles
____ is necessary for collagen synthesis. _____ are dependent on vitamin C. Leads to ____ disease
Vitamin C
Hydroxylase
Scurvy
____ ____ forms cross links in collagen fibrils that help stabilize it. Defects in this enzyme result in weakened collagen fibers leading to ____ of joints and ___ ___
Lysyl oxidase
Hyperextension
Arterial aneurysms
90% of collagen is __ __.
_____ ___ form networks
Type I
Non-fibrillar collagens
Collagen ___ is sheet like layers that are found in basement membranes, external lamina, and Lens capsule
IV
Collagen ___ is small, banded, collagen, fibers that are found in blood vessels, bone marrow lymphoid, tissues, nerves, lungs
III
Collagen ___ are small, banded, collagen, fibers found in hyaline and elastic cartilage, vertebral discs
II
Collagen ___ are short striated fibroids found in anchoring fibrils in basement membrane of skin
VII
Collagen ___ are large bounded collagen, fibers, found in skin, tendons, bonds, ligaments, facia fibers, cartilage, cornea, and loose fibrous tissue
I
Type ___ collagen give rise to reticular fibers. Reticular fibers form branching networks rather than thick bundles, reticular fibers stain poorly with ____ they stain well with ___. Reticular fibers are abundant in laminar reticularis, the liver, endocrine glands.
III
H&E
PAS
___ ___ allows tissues to stretch and recoil. They are often interwoven with collagen fibers. They form a linear fibers, networks, and sheets.
Elastic fibers
Elastic fibers are composed of the proteins ___ and ____
Elastin
Fibrillin-1
Elastin is highly ___ folded into unstructured, random coil confirmation
Hydrophobic
Fibrillin-1 are ____ that form a scaffold for fiber assembly. Mutations lead to ___ ___ characterized by aortic aneurysms, and weakened ligaments and weakened heart valves
Microfibrils
Marfan syndrome
Two amino acids unique to elastin ___ and ___ form covalent bonds between elastin molecules.
Desmosine
Isodesmosine
Elastic fibers under tension:
Fibers are all embedded in ___ ___
Ground substance
____ ____ is a highly hydrated, viscous space filler. It functions to resist compression it binds and organizes ECM fibers it regulates cellular movement it allows diffusion of nutrients oxygen and waste.
Ground substance
______ are a component of ground substance. They are unbranched polysaccharide chains, composed of repeating disaccharide units.
Glycosaminoglycans (GAGs)
One sugar of GAGs is always a ___ ___ sugar and the second sugar is usually a ___ sugar
Sulfated amino
Uronic
GAG’s carry a very high ___ charge that repel and cause GAGs to be stiff and straight
Negative
Types of glycosaminoglycans:
Be able to recognize them
Sulfonated GAG chains are covalently linked to a core protein to form _____
Proteoglycans
Proteoglycans bind positively charged ions, and thus attract ____ . This allows rapid diffusion an exchange of nutrients and allows the ground substance to resist compression.
Water
Proteoglycans ____ in the types and number of associated GAGs
Vary
Proteoglycans can regulate the activity and distribution of ___ proteins. They bind to molecules and regulate their ____ through the ____ which affects their range of action and lifespan
Secreted
Diffusion
ECM
Proteoglycans that are anchored in the plasma membrane can act as ____ by binding molecules, and presenting them to sell surface receptors on the same cell
Co-receptors
_____ (hyaluronic acid) is a unique GAG. It is extremely large. It has no sulfate and sugars. It is not linked to a core protein. It is synthesized at the plasma membrane. it serves as the basis for ____ ___
Hyaluronan
Proteoglycans and aggregates
_____ ____ attached to a core of hyaluronan. They are interwoven with fibers.
Some bacteria and cancer cells secrete _____ and ____ to allow movement through connective tissues
Proteoglycan aggregates
Hyaluronidase
Collagenase
_____ ____ ____ contain multiple binding domains each specific for other matrix molecules or cell service receptors. They organize the matrix and guide movement of cells.
Multi-domain adhesive glycoproteins
____ is the most abundant glycoprotein in connective tissue. They contain a series of a functionally, distinct binding domains.
Fibronectin
Adhesive glycoproteins
(be able to recognize them)
____ can self assemble in vitro into a net work. it is found in the basal lamina
Laminin
Resident connective tissue cells include:
Fibroblasts, macrophages, adipocytes, mast cells, and mesenchymal cells
Transient connective tissue cells include:
Plasma cells, lymphocytes, granulocytes
_____ ____ ____ give rise to adipocytes and fibroblasts
_____ ___ ____ give rise to macrophages, lymphocytes, granulocytes, plasma cells, mast cells
Undifferentiated mesenchymal cells
Hematopoietic stem cells
____ is embryonic connective tissue that gives rise to most adult connective tissue. It is composed of spindle-shaped ___ ___ embedded in a viscous ground substances with a few fibers
Mesenchyme
Mesenchymal cells
_____ are capable of synthesizing all of the components of the ECM. And dense connective tissue, fibroblasts are located within bundles of ____ ____
Fibroblasts
Collagen fibers
The nucleus of fibroblasts are only visible via ____ ___
Light microscope
Fibroblasts help organize ___ ___
Collagen fibers
If fibroblasts are active they have a lot of ____ in nucleus. If they are less active there, chromosomes will be more condensed.
Euchromatin
Inactive fibroblasts are known as ____
Fibrocytes
Fibroblasts are not bound by intracellular or matrix junctions, making them free to ____ through connective tissue
Migrate
Fibroblasts are recruited to sites of ___ from at least three pools
1.
2.
3.
Injury
Local fibroblasts
Bone marrow derived fibrocytes
Epithelial mesenchymal transition
_____ cells function to store energy. They also secrete a number of hormones. Mature, adipocytes do not ____
Adipocyte
Divide
There are two classes of adipocyte cells. ____ are white fat and ____ are brown fat
Unilocular
Multilocular
White adipocytes display a single centrally located ___ ___ composed, primarily of ____ that fills most of the cell volume
Lipid droplet
Triglycerides
White adipocytes function in the storage of _____. Circulating ____ from the diet are lipids coded with proteins and _____ transport triglycerides. ____ ____ is secreted by adipocytes, which breaks down triglycerides.
Triglycerides
Chylomicrons
VLDLs
Lipoprotein lipase
____ ____ ___ inside of the adipocyte breaks down triglycerides, and the free fatty acids diffuse into the capillary where they are bound by ____ and transported through the body
Hormone sensitive lipase
Albumin
_____ increases the amount of Lipoproteins lipase and uptake of glucose. ____ inhibits hormone sensitive lipase.
Insulin
Insulin
Adipocytes secrete ____ which functions as an energy thermostat. It regulates the amount of stored fat and adjust energy expenditures and the sensation of hunger. Making it a ___ factor
Leptin
Satiety
Leptin targets the hypothalamus and other organs, causing a ____ in appetite. In obese people, adequate levels of Leptin are produced, but target cells do not respond making them ____ ___
Decrease
Leptin resistant
Brown Adipocytes are present in ___ but are greatly reduced by adulthood. They display many mitochondria. They are more vascularized than white fat, giving them their color
Newborns
Brown adipose tissue have multiple smaller, lipid droplets making them ____
Multilocular
Brown adipocytes function in ____. Under nerve stimulation, they metabolize triglycerides to produce ___. _____ ____ in the mitochondria use protons to generate heat rather than the protons participating in the electron transport chain
Thermogenesis
Heat
uncoupling proteins (UCP-1)
_____ remove cellular debris and attack foreign invaders. They ingest bacteria, dead cells and foreign materials, which are degraded in the lysosome net work. Macrophages and dendritic cells are referred to as ____
Macrophage
Histocytes
This shows
Macrophage via transition electron microscope
___ ___ on the surface of macrophages recognize antibodies coating the surface of target antigens. This triggers, the process of _____. The targets are ingested by a large endocytic vesicle is called ____
Fc receptors
Phagocytosis
Phagosomes
___ ____ are formed from B lymphocytes in response to foreign antigens. They are part of the adaptive immune system. They are short-lived only 10 to 20 days.
Plasma cells
___ ___ pattern of peripheral, alternating heterochromatin and euchromatin are found in plasma cells
Clock-face
___ ___ synthesize and secrete circulating antibodies. They are present in high numbers and loose connective tissues of the intestinal and respiratory tracks.
Plasma cells
___ ____ secrete factors that promote inflammation. They are derived from the bone marrow and transported via blood to connective tissue.
Mast cells
Mast cell granules contain mediators of inflammation, including ___ and ____. The presence of heparin causes mast cells to display _____ with toluidine blue
Heparin
Histamine
Metachromasia
___ ____ are involved in allergic reactions. They have receptors for ___ antibodies. These antibodies bind to ___ ____ on mast cells. In the second exposure, aggregation of Fc receptors and activation of the mast cell results. Massive release of granules called _____ causes allergy symptoms
Mast cells
IgE
Fc receptors
Degranulation
Systemic mast cell degranulation can cause ____ ___
Anaphylactic shock
