Connective tissue and Blood part 1 Flashcards
What is the function of connective tissue? What are the three components that make up MT?
- ) Provides and maintains form in the body ( ex: binds/ connects cells and organs)
- ) structurally formed by cells, fibers, and ground substance
What are the general categories of connective tissue proper? Distinguish the specific types of categories.
- ) Loose CT (areoloar, reticular)
- ) dense CT ( regular, irregular)
Describe specialized CT and what are the types of specialized CT?
Semirigid to rigid tissue consisting of.
- )cartilage (hyaline, elastic, fibrous)
- )bone (spongy, compact)
- ) adipose tissue
- ) blood cells
What are the differences in CT to epithelium?
CT: 1.) highly vascular 2.)variable cellularity, intercellular, extracellular material 3.) surface is surrounded by tissue 4.) cells lack basement membrane 5.) cell membranes nonpolar
Epithelium: 1.) avascular 2.)highly cellular 3. small amount of intercellular material 4. Almost no extracellular material 5. free surface 6.basement membrane subjacent to cells 7.polar
what are the two types of CT?
fixed and mobile (RBCs)
What is connective tissue derived from?
mesoderm (mesenchyme)
What are the 2 components of extracellular CT?
- )Fibers (collagen, reticular, elastic)
- )ground substance (jello-like)
What is the most abundant protein in human body?
Collagen.
- more than 25 different types
- glycoprotein
What is collagen?
- main fiber of CT
- It is a glycoprotein
What are the types of fibril-forming collagen types?
types 1,2,3
What are the non fibril forming collagen types?
type 4-5
Know the biosynthesis of collagen (List the main points)
- ) synthesis of preprogollagen
- ) Hydroxlyation of proline and lysine residues. Vitamin C (cofactor) is required
- ) “glycosylation”
- ) pro-collagen: H-bond, disulfide bond to form 3 alpha chain collagen (triple helical group)
- ) secreted to trans golgi and then sent to Extracelluar space
- )transform procollagen into insoluble TROPOCOLLAGEN by cleaving the procollagen side chains. These troporcollagen aggregate to form collagen fibrils. These aggregates turn into aggregate fibers.
What is the cofactor for proline hydroxdase? What happens if it was absent?
- vitamin c
- defective collage would be made scurvy
What is the location and function of type 1 collagen?
- most abundant type of collage type in our body. (accounts for 90% of collagen function
location: connective tissue of skin, bone, tendon, ligament, dentin, sclera (eye),fascia, organ capsules
: provides resistance to force, tension and stretch one is “strongest”
What is the location and function of type 2 collagen?
location: cartilage (hyaline and elastic), notochord, and intervertebral discs
function: provides resistance to pressure
“CarTwolage”
What is the location and function of type 3 collagen?
location: connective tissue of organs (uterus liver), smooth muscle, endoneurium, blood vessels, and fetal skin
function: provides structural support and elasticity
Can think of it as more delicate like a fetus that lives in the uterus and is developing organs, fetal skin, smooth muscle, endoneurium,blood vessels
Type 4 location and function of collagen.
L: Basal lamina of epithelial and endothelial cells,kidney, glomeruli and lens capsules
F: provides support and filtration.
What is the location and of type 5 collagen?
L: distributed uniformly throughout connective tissue stroma (CT for any organ)
What produces reticular fibers?
smooth muscles, fibroblasts, schwann cells.
How are reticular fibers similar to collagen fibers?
reticular fibers are composed of collagen fibrils
How are reticular fibers different from collagen?
- type 3 collagen fibrils
- Fibers are thin (.5-2 micrometers)
- reticular fibers stain with silver stains -more glycoproteins attached to reticular fibers compared to collagen fibers; stain with periodic acid schiff (PAS)
- It is least stretchy -for structural integrity while allowing volume change
Collagen fibers: collagen is made up if type 1
-flexible support -multiple type one 70 nm in diameter
What are collagen fibers? what is the size? what is its function?
- Multiple fibers tend to be type 1 collagen (20 nm diameter
- Most abundant protein in the body
- many types of cells produce collagen fibers
- function: strong inelastic yet flexible support
What is the size of reticular fibers and describe its features?
.5-2 micrometers
-small diameter and loose disposition helps create a network in organs that are subjected to change in volume of form (uterus, arteries, intestinal muscle layer, spleen)
What is collagenopathesis?
disorders and diseases abnormalities/deficits caused by specific changes in collagen (see page 167)
What are the characteristics of elastic fibers?
- Non collagen
- 110 Angstroms diameter (thinner than collagen fibers)
- produced by fibroblasts, smooth muscle cells, and chondrocytes.
What are the component that make up elastic fibers?
Elastin, microfibrils
What does elastin contain?
-gly and pro (like collagen) - small amount of OH-pro or OH- Lys (unlike collagen)
What are the characteristics of microfibrils?
(not like microfilaments)
- high in fibrillin (a glycoprotein)
- form a sheath around the elastin
What is the function of elastic fibers?
Elasticity: facilitate to return to original shape after mechanical distortion
What is Marfan’s Syndrome?
type of elastin disease -Autosomal dominant -defective fibrillin gene -Patient may have abnormally long bones, eye lens not in proper place, abnormal joints, weakened blood vessels-> aortic dissection is a common life threatening problem
What is ground substance?
- amorphous-found between cells and fibers
- colloid of variable visocity
- binds varying amounts of water
- made up of GAGs,Proteoglycans, and glycoproteins
What is water’s role in ground substance?
water serves as a medium for diffusion of gases, nutrient, material, and metabolic products from blood vessels to tissue and vice versa
ground substance is relevant to fluid accumulation within CT at sites of injury (edema), in which part that does it help facilitate?
facilitates invasion of lymphoid (immune) cells.
What is ground substance soluble in?
reagents used in tissue processing and is not seen in ordinary preparations.
What are Glycoaminoglycans (GAGs)?
- very long (70+ saccharides) unbranched polysaccharide chain (series of disaccharides)
- very negative charge-> attraction of + ions like sodium -hydrophillic
What are the 2 types of GAG?
- ) Nonsulfated GAG
- hyaluronic acid: major component of CT proper ground substance
- very rigid - ) sulfated GAG: gel-like compound- provides rigidity
What are the properties of hyaluronic acid in nonsulfated GAG?
- 1 KDa in size
- It defines physical characteristics
- serves as a lubricant of joint fluid -protects from compression “larger collects more water”
What is the size of nonsulfated GAG in comparison to sulfated GAG?
- sulfated GAG is smaller than hyaluromic acid (10-40 dalton in size)
- nonsulfated GAG: 1KDa
What are the six types of sulfated GAG?
- ) Chondroitin-4-sulfate
- )Chondroitin- 6-sulfate
- ) Dermatan sulfate
- ) KERATAN sulfate
- ) Heparan sulfate
- ) Heparin (mast cell product)
What does proteoglycan consist of?
- GAG and core protein
- 3D structure that can be pictured as resembling a testtube brush
What are the 4 main GAGs?
- dermatan sulfate
- chrondroitin sulfate
- keratan sulfate
- heparan sulfate
What is proteoglycan aggregate?
Proteoglycan + HYALURONIC ACID CORE
How many types of lysosomal enzymes degrade proteoglycan? What happens if one or more of these enzymes block or limit degradation?
- several types
- proteoglycan accumulate in tissues.
- some of these lysosomal diseases can occur: hurler syndrome, hunter syndrome and samfilipo syndrome
What are the 2 stages of activity in fibroblast?
- ) actively producing-> fibers, cellular products (fibroblast)
- ) quiescent-> fibrocyte
What is the function of a fibroblast? What does the nucleus, cytoplasm, cell form look like?
- actively synthesizing extracellular material (collagen, reticular fibers)
- nucleus: oval, light basophila- abundant euchromatin, distinct
- cytoplasm: basophilic- due to ribosomes and RER, golgi complex is well developed, many mitochondria
- cell form: oval or starshaped, many processes
What is a fibrocyte? What are the features of a nucleus, cytoplasm, cell form?
- inactive fibroblast
- synthetically inactive
- nucleus: small,spindle shaped, dark staining-abundant heterochromatin, difficult to visualize
- cytoplasm: pale staining due to few ribosomes and RER , golgi complex poorly developed with few vesicles, few mitochondria
- cell form: elongate, spindle shaped, few cell processes
What is myofibroblast?
displays properties of both fibroblasts and smooth muscle cells
What are myofibroblast characterized by?
bundles of ACTIN filaments
- usually exist as isolated cells (not linked up with others usually)
- some synthetic properties of fibroblasts usually
- implicated in WOUND contraction
What are thoughts on scar formation?
When tissue is destroyed by inflammation or trauma, these sites of destruction are not replaced with native cells. (native cells don’t divide and make new tissue)
What is Keloid formation?
formed from local swelling caused by abnormal amounts of collagen
tx: excision usually mininmally helpful; steroid injection may help
- most common person of african descent
What are the 2 types of loose connective tissue?
- ) areolar (“space”)
- )Reticular
What are the characteristics of Areolar loose CT?
- has a random placement of cells in CT
- more ground substance than cells by volume
- gel-like consistency
What is the importance or areolar loose connective tissue?
- diffusion of O2 and nutrients from small vessels.
- site of inflammatory response an edema (allergic or immune reactions)
- initial sited of bacteria or virus breach from blood vessels
- immune cells (e.g. mast cells, plasma cells, t and b cells etc. patrol this tissue)
Where can Loose areolar CT be found?
-found beneath epithelia that cover the body surface and lines the body cavity and makes up the lamina propria of digestive trac
t -surround small vessels
What is loose Reticular connective tissue?
It is a scaffolding for organs-lots of reticular fibers
What is the reticular connective tissue made of?
- Stroma:
- parenchyma
- reticular cells
What is stroma?
connective tissue that supports reticular and parenchyma cells
What is parenchyma?
cells that provide a actual function of tissue, specific organ
What are reticular cells?
found in most organs
- create the scaffolding for organ specific cells (liver cells)
What are the 2 types of dense connective tissue?
Irregular and regular
What are the characteristics of irregular dense connective tissues?
- they are abundant in fibers and few in cells
- found in skin, capsules of organs
- consist of fibroBLASTS, collagen fibers-> mostly type 1 fibers, elastic fibers, blood borne cells (relatively little ground substance)
- collagen bundles in no particular direction, but provides good deal of strength
What are the characteristics of regular dense connective tissue?
- orderly of densely packed arrays of fiber cells (parallel fibers).
- found in tendon and ligaments -consists of fibroCYTES, collagen fibers, elastic fibers, blood borne cells.
Adipocytes: fats get store here in form of what?
lipid droplet
What are the main function of multilocular adipose (brown fat)?
thermogenesis (found in many hibernating animals)
Where can multilocular fat found?
- present mostly in fetus and newborns
- newborns have high surface to mass ratio with significant loss
- brown fat gradually decreases with age. (mostly lost over 1st decade)
- can be bound in the perirenal or axilla neck region in adults
What are the cell features of multilocular adipose?
- nucleus: eccentric, spherical -multiple inclusion, not membrane bound
- many mitochondria- lack respiratory assembly on inner membrane-unique to brown fat —mitochondria- make heat, not ATP
- highly vascular -reticular and collagen fibers
- lipid-multiple inclusions per adipocyte
What is the unilocular adipose and its characteristics?
(white fat)
- highly vascular -reticular and collagen fibers
- normal mitochondria -flattened eccentric nucleus
- lipid: SINGLE giant inclusion, not membrane bound.
- inclusion can be used up to 100 micrometers and larger
What is the function of unilocular adipose?
-Caloric energy storage
It is 9 Kcal/g fat
4 Kcal/g carbs/ proteins
What are mobile CT cells?
-leukocytes, macrophages, plasma cells, mast cells
What are leukocytes and where are they originated from?
White Blood cells, transient visitors of CT proper
- originate from blood and lymph
What are the different types of leukocytes?
Lymphocytes, Neurtophils, Eosinophils
What are lymphoctes?
It is primarily involved in immune responses.
- natural killer cells (B and T cells)
- found on the extracellular portion of plasma membrane (CD proteins–> name tags)
What are neutrophils?
- 1st to arrive at site of injury
- phagocytize bacteria, foreign organisms, damaged tissue and cellular debris. (these form pus)
What are Eosinophils?
- Produce antihistamines,
- modulate inflammatory response
- found in response to paracytic invasion
What is the characteristic of macrophages?
- leading edge
- active phagocyte
- cytoplasmic inclusions (2ndary lysosome) -nucleus
- well developed RER, Golgi, complex, mitochondria, lysosomes.
What is the function of macrophages?
- phagocytosis and secretion of the following:
1. ) pyrogen-increase heat, fever
2. )certain interferons-work on viruses
3. )elastases
4. )collagenases
5. )proteases
What are plasma cells?
-Not numerous under normal conditions
–can be found in some numbers in alimentary mucous
What forms plasma cells?
B cell lymphocyte
What are the morphologic characteristics of plasma cell?
- Nucleus: heterochromatic cartwheel shape
- basophilic due to RER -golgi: clear area in plasma
What is the function of plasma cells?
secrete antibodies
What are mast cells found?
Widely distributed cells of connective tissue, often abundant along small blood vessels
What are the morphologic characteristics of mast cells?
- very basophilic
- has many cytoplasmic granules
- contains histamine and heparin
What is the function of mast cells?
- Release histamine
- increase permeability of blood vessels, allowing antibodies to move.
- releases heparin
- anticoagulant
- undergoe degranulation in response to allergic stimulus and/or injury
Name a specialized type of peripheral connective tissue?
(circulating) blood
What is the avg quantity of blood in adults?
- b/w 5-6 L (2.3-2.8 L are formed elements, remainder is plasma)
- 7-8% of body weight
What are the layers of blood when centrifuged?
plasma, WBC &platelets, RBCs
What are the formed elements? (44-45%)
leukocytes, erthrocytes, thrombocytes (platelets)
What is plasma (fluid) portion consist of?(44-45%)
-water (90%) -electrolytes (Na+, Cl-) -lipids -carbohydrates -vitamins, hormones, minerals -proteins
What is Albumin?
33-55g/L -made in liver-major factor in regulating osmotic pressure in vascular system-transports some metabolites- smallest protein in blood. -one of the most abundant protein in body
What are the proteins that make up blood?
albumin, globulin, fibrinogen (clotting protein), complement proteins
What happens when you lose Albumin?
loss of Albumin lowers osmotic pressure-> lead to tissue swelling
What are the types of globulins in plasma?
alpha globulins: 10-21 g/L
beta globulins: 9-18 g/L
gamma globulins: 9-18 g/L
What is serum?
plasma that lacks coagulation factors.
-blood in test tube from clotting by addition of citrate heparin
What is the function of blood?
- transport: nutrients, O2, CO2, metabolic wastes
- ph regulation
- termperature regulation
- immunity defense (WBCs)
What is the morphology of erythrocytes?
- anuclueate, biconcave disc 7-8 micrometer in diameter
- cytoplasm: due to presence of hemoglobin (which makes up 33% of cell weight) there are no visible organelles
What are the physical properties of RBCs
- Biconcave shape favor flexbility-spectrin
- sialic acid residues on membrane impart a strong negative charge
- RBCs repel each other ~120 day life on RBCs
What is spectrin?
intermediate filament in RBC
-keeps RBC shape
What are the three basic fibers?
collagen, reticular, elastic
What is scruvy?
Degeneration of collagen.
-more pronounced in tissue where collagen turnover/ renewal takes place at a faster rate (ex gum–> teeth loosening/loss bleeding)
what is stroma?
CT for any organ
How are collagen fibers similar to reticular fibers?
Both composed of collagen fibils
How is elastin different from collagen? How are they similar?
-small amount of OH-Pro or OH-Lys -contains Pro and Gly
What produces elastin ?
Fibroblasts, Smooth muscle cells, chondrocytes
How are macrophages made?
Derived from monocytes circulating in blood. Leave bloodstream and differentiate
What is the function of histamine?
Increases permability of blood vessels, allowing antibodies to move
What is heparin?
An anticoagulant
