Test 2 Part 1 Flashcards Preview

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Flashcards in Test 2 Part 1 Deck (112):

CT function

defense and protection
fat depot for cushioning, insulation and energy reserves


cells that turn into CT

mesoderm and ectoderm


fibroblast and fibrocyte

active-larger (blast) and inactive-smaller (cyte)
active =making glycoproteins and CT fibers, euchromatic, rER, May divide if tissue damage but normally no division

inactive - nuleolus not visible, when stimulated durinbg tissue damage can become active, cytoplasm becomes eosinophilic (pink), not a lot of tarnscription, nucleus elongated



reduces state of inflamation, inhibitory effect on fibroblastic activity(production and secretion of CT) long term use=CT damage
bone may also lose some structure


Collagen synthesis

Propepdides keep collagen soluble so doesnt form collagen fibers in the cell!

1) hydroxylation of proline VIT C dependent in ER
2) 3 collagen molecules for triple helix (ER)
3) Delivered to Golgi and exocytosis of propeptides into ECM.
4) ECM propeptidases will cleave off the propeptides = active and forms collagen fibrils and then fibers



resemble fibroblasts and smooth muscle
these are contractile cells (actin and myosin)
become numerous in would healing


Dupuytrens contracture

affects digits 4 and 5 - injury replaces collagen 1 with 3. The actin and myosin connect to the 3 and shorten which bends those fingers


adipocytes (uniocular)

forms white adipose tissue but looks yellow due to what we eat
contain a single lipid droplet that is not bound by membrane - droplet ensheathed in vimentin filaments
nucleus pushed out to periphery = signet shape
energy depot - secrete leptin to DEPRESS appetite


leptin issue

secreted by adipocytes = morbid obesity - no suppression of appetite



loss of body fat disorder - entire body affected - really thin and well defined muscles
can be uniform, or deposited in specific body regions (nech and gut area)


multilocular adipocytes

brown adipocytes - nucleus is centrally located and spherical.
around nucleus are individual droplets of lipids - hence the name multiloculalar - many loci of fat deposit
also surrounded by VIMENTIN fibers
lots of mitochondria! - HEAT GENERATION


mast cell

large and ovoid cell
derived from bone marrow stem cells
filled wtih methachromatic granules (w/ toluidine blue)- diverse sectretory product histamine and heparin,leukotrienes
located in CT proper near blood vesels
not found in nervous tissue


inflammatory response

IgE bound antigens couple to Fc receptor on plasma membrane of mast cell=mast cell releases all of its shit.
histamine = mucus production, swelling, (hay fever)
leukotrienes = bronchospasms (asthma)



professional phagocytes - present antigens to lymphocytes
monocytes emigrate into the CT (from blood) where they differentiate
have lots of lysosomes for degredation (acidophilic)
nucleus is kidney bean shaped and is euchromatic with heterochromatic clumps


chronic inflammatory states

activated macrophages morph into epithelial like (epitheloid) cells. Epitheloid cells fuse and form giant multinucleated cells -- these cells DO NOT Have increased phagocytic levels. their activity is LOW.


plasma cells

MIGRATORY -derived from B-lymphoytes - protein synthsizing cells - antibodies
large oval shape - euchromatic (eccentrically) nucleus with heterochom pushed out to edge in clock face appearance
-intense basophilic - LOT OF rER
-LOTS OF GOLGI - large neg area
constituitive pathway of antibodies - constant = antibodies are not stored - just



monocytes, lymphocytes, neutrophils, eosinophils, and basophils - migrate from blood into CT.
Site of inflammation attract these guys


first wave of response to inflammation=

mainly neutrophils


second wave of response to inflammation

mostly monocytes - morph into macrophages = clean up cell


mesenchymal CT

abundant, gel-like, amorphous with gloycoproteins and glycosaminoglycans; scatters reticular; mesenchymal cells ; embryonic intramembranous bone formation


mucous CT

abundant jelly-like, hyaluronic acid and glycoproteins; collagen I and III; fibroblasts - umbilical cord as whartons jely subdermal in the embryo


Loose CT (areolar)

viscous and amorphous with hyluronic acid, GAGS, proteoglycans and glycoproteins
loose array of collagen, reticular and elastic fibers
Cells: fibroblasts, macrophages, adipose, mast, and undifferentiated
lies immediately deep to epithelium and surrounds bv


dense regular collagenous CT

spare viscous amorphous with hyluronic acid,GAGs, proteoglycans,a nd glycoproteins; densely packed parallel array of type I and scattered elastics; scattered fibroblasts flattened bw colalgen bundles; tendons, ligaments, aponeuroses


dense regular elastic CT

from fibroblasts. spares and visous - amorphous with hyaluronic acid, GAGs, proteoglycans, and glycoproteins
-elastin forms thin sheets of fenestrated membranes.
-elastic fibers branch and run parallel to one another.
-few collagen fibers
-found in lgamenta flava, suspensory ligaments of the penis, vocal ligament and arteries


dense irregular CT

sparse viscous, amorphous with hyaluronic acid, GAGs, proteoglycans, and glycoproteins
-tightly packed, type I, fibers orientated in many axes.
-elastic fibers interspersed
-fibroblasts are scattered
-organ capsules, dermis of skin and sleeve around nerves


reticular CT

Type III collagen
little ground substance
found in red bone marrow, liver, and lymphatic tissues/organs


adipose CT

spare ground substance
reticular fibers are found bw adipocytes
subcutaneous areas and in abdominal cavity


specialized CT

abundant, viscous, amorphous, with hyaluronic acid, GAGS, proteoglycans and glycoproteins
loose array of collagen, reticular and elastic fibers
cells: fibroblasts, macrophages, adipose, mast, and undifferentiated
lies immediately deed to epithelium and surounds bv


cartilage is specialized bc

it is firm and pliable


hyaline cartilage location

in places where it maintains a lumen/space open - -nose, larynx, trachea, bronchi
-articular surfaces of (long) bones - ribs and joints
-at epiphyseal plates of growing bones - grow in length


histogenesis (making) of hyaline cartillage

1) Mesenchyme (embryonic CT) - stellate of star shaped cells - embedded in ECM = condrification centers of cartilage sites
2) Differentiate into chondroblasts - synthesize ECM
3) as chondroblasts deposit more matrix they get stuck in lacunae (bubbes within matrix) and = chondrocytes.
4) chondrocytes may divide to form isogenous groups of 2-4 chondrocytes


isogenous groups

Progeny of a single chondrocyte - groups of 2-4 chondrocytes that are stuck in ECM



membrane that surrounds and protects the cartilage - from mesenchyme (mesenchymal cells that dif into fibroblasts


outer fibrous layer

outside the perichondrium - support and protect inside - dense collagenous CT - type I, fibroblasts, blood vessles and nerves


internal cellular layer - chondrogenic layer

forms cells that will form cartialage - allows for growth


appositional growth

- growing on the surface - adding to the outer layer - needs perichondrium
in most cartilages
occurs throughout lifespan


interstitial rgowth

growing of the tissue from within - only in early stages of cartilage formation
only in articular - does not have perichondrium
occurs at epiphyseal plates


why is hyaline cartilage the model of future bone:

ability to grow interstitially and appositionally


chondrogenic cells

arrise from mesenchymal cells
can become chondroblasts & chondrocytes (cartilage forming) and osteoprogenitor cells (bone forming)



from mesenchymal cells (in chondrification center) and chondrogenic cells (in inner perichondrium)
-form matrix and fibers of cartialge
-RER, protein synthesis, GA --- basophilic



-from chondroblasts
-large nucleus and prominent nucleolus
- trapped in lacunae
can go back to being chondroblasts
-monitor matrix composition and synthesize necessary molcules to maintain catilage matrix


hyaline cartialage matrix

contains delicate fibers - made out of proteins and collagen (type II)
-collagen = tensile strength
-proteoglacans and glycoproteins
-extra cellular fluid - attracted by the sugars = plump and cushiony (60-80% of weight is in proteoglycans)
proteoglycans form 3D matrix - cushion and resilience
-avascular, no nerves, resists force


capsular (pericellular) matrix

intense stained thin layer of matrix immediately around lacuna
-hi9gh concentration of sulfated proteoglycans, hyaluronan and glycoproteins
-fine collagen fibers form woven capsule around each chondrocyte


territorial matrix

- is the lighter-staining matrix that surrounds the isogenous group
-contains a lower concentration of sulfated proteoglycans than the capsular matrix and is thus lighter-staining
-contains collagen


interterritorial matrix

represents the majority of the matrix
fills the space around the territorial matrix



adhesive glycoprotein
assists chondroblasts and cytes to adhere to ECM


elastic cartiallage

similar to hyaline
contains type II col
ear, auditory tubes, epiglottis and larynx
-moer and arge chondrocytes that hyaline
more prominent territorial matrix



transitional form bw dense CT and yaline cartilage
-little amorphous collagen - contains type 1 collagen (acidophilic)
-lacks perichondrium
located where tough support or tensile strength is needed
-TMJ, vertebral disks, pubic sumphysis, menisci of the knee joint,
junction between tendons and bone
-chondrocytes occur in groups of parallel rows, alternation with thick bundles
fibroblasts secrete their proteoglycans



wear and tear of articular cartiallage of certain joints = degenerative joint disease - GAGS are modified with age = less water = cartilage thinsa nd wears away,friction bw bone surfaces - bone is innervated = PAIN - swelling stiffness and range of motion


what is bone

specialized CT - mineralized and has cells, vessels, and nerves
continuously being remodeled
storage of minerals
bone marrow for blood cell
supports and protects



long bones - 2 bulbous ends of a bone
hyaline cartilage covers the articulating surfaces


epiphyseal (growth) plates

long bones - hyaline cartilage plates that allow bone growth in length -disappear ~18-20 yrs



angulation bw the epiphyseal plate and the diaphysis



long cylindrical shaft bw the 2 epiphyses


marrow (medullary) cavity

core of the long shaft - bone marrow



external CT capsule of bone - Does not cover articular surfaces and where tendons attach to bone - covers part of epiphyses
2 layers: OUTER fibrous layer: dense collagenous CT; blood vessels, lymph vessels, nervers; anchored to bone via sharpey's fibers (bundles of collagenous fibers) - does not slide or peel off
INNER cellular layer: not defined if bone is inactive - nonrowing bone it contains periosteal cells; covers actively growing cells; contains osteoprogenitor cells; repair of bone fractures


periosteal cells

found in inner cellular layer of periosteum when bone is not actively growing - these cells may differentiate into osteoblasts if necessary (ex stim by bone repair)


osteoprogenitor cells

found in periosteum inner layer when bone is actively growing (called periosteal cells) and in the endosteum (called endosteal cells).
can do mitosis
from mesenchymal stem cells and dif into osteoblasts or chondrogenic cells (in low O2 tension)



internal CT capsule of bone
consist of thin CT layer with a single row of osteoprogenitor cells which may turn into osteoblasts (line the bone - endosteal cells)
lines the bone marrow cavity; haversian and volkmans canals; bony spicules(smaller) and trabeculae (larger) of spongy bone


Haversian and Volkmans canals

VERTICAL and HORIZ respectively
intercnnected tunnels that allow small vessels and nerve fibers to reach deep into the bone


inorganic compoenent

BONE MATRIX (1 of 2) - inorganic minerals that give bone it's hardness - 65% of dry weight; hydroxyapatite crystals (calcium phos); bicarb; citrate; magnesium; NA;K


organic component

BONE MATRIX (2of2) - a) fibers - type 1 collagen b) ground substance: proteoglycans(bind growth factors), glycoproteins (osteonectin, sialoproteins, osteopontin, osteicalcin), growth factors (bone morphogenic proteins BMP) c) bone specific VIT K dependent proteins (osteocalcin) d) growth factors and cytokines (BMPs)



multadhesive glycoprotein - part of organic component - glue bw collagen and hydroxyapatite cyrstals



multiadhesive glycopro - made up of osteopontin - helps cells bind to bone matrix
sialopro 1 and 2: help bind cells to bone matrix and begins calcium phos formation during minerlization



traps calcium from the blood steram and stimulates osteoclasts to remodel bone. VIT K dependent protein


Bone mophogenic proteins (BMPs)

reg proteins - induce mesenchymal cells to differentiate into osteoblasts. used following surgery to stimulate bone formation


cell lineage of bone

messenchymal stem cells --> osteoprogenitor cells -->osteoblasts (or ---> bone lining cells) ---> osteocytes

mononuclear hemopoietic progenitor cells -->osteoclasts (bone remodeling)



from osteoprog cells and can dif into osteocytes; when they get trapped in their secretions = osteocytes
cuboidal-columnar shape
secrete organic component of matrix (osteoid)
hihg levels of enzyme alkaline phosphatase - splits pyrophos groups in macro molecules of matrix
mineralization of bone matrix
gap junctions for communication



Pre-bone - newly formed non-mineralized bone
collagen type 1 and bone matrix proteins (BMPs)


bone lining cells

arise from osteoblasts and cover the bone surface - protect. prevent some resorption by osteoclasts
support nutrition of osteocytes
uptake and release of calcium and phos by bone tissue
gap junctions



grown up osteoblasts - enclosed in lacuna - stuck in their matrix extretions
cytoplasmic processes which radiate from cell are enlosed in canaliculi
gap juntions via cytoplasmic processes
periosteocytic space for exchange of O2 and nutrients
surrounded by osteoid



multinucleated; acidophilic; motile cells
derived from mononuclear hemopoeitic prog cells in bone marrow
resorb and remodel bone
lie in enzymatically etched shallow depression = Howship's lacuna on bone surface
3 regions - ruffled border, clear zone, basolateral region
acid environment breaks down the inorganic component
lysosomal hydrolases and metalloproetinases (collaginase and gelatinase) released into subosteoclastic compartment for breakdown of ORGANIC components
when complete their resorption assignment =apoptosis


ruffled border

- bone resorption - thick cell membrane with infoldings (ruffles) site of exocytosis of hydrolytic enzymes and secretion of protons
endocytosis of broken down bone


clear zone

lacks organelles, has actin microfillaments, actin ring; sealing zone that isolates acidic and corrosive elements


drugs with biphosphonates and estrogens

stimulate osteoclast apoptosis


compact bone

dense solid bone - forms a shell around the exterior of long bones
skull cap (calvaria) has outer table of compact bone with a pericranium (periosteum) and inner table of compact bone lines with dura matter (periosteal layer)
contains haversian systems (osteons)


cancellous bone

spongy-lines marrow cavity of long bones = DIPLOE in skull cap
has bone trabeculae and spicules which protrude from the inner surgace of compact bone
no haversian system in small bone spicules - large bones may have
irregular arrangement of bone lamellae


Primary Bone

immature woven bundle of collagen-random- less mineral content but more cells and ground substance (still weaker)- temporary- formed during fetal development: replaced with secondary. also formed during bone repair... resorbed by osteoclasts and new bone formed by osteoblasts


secondary bone

mature- lamellar. consists of parallel or concentric bone lamellae. more collagen fibers and mineral content=stronger - may be spongy or compact


lamellae structure

1) outer circumferential lamellae - deep to periosteum and surround bone like tree rings - Sharpe's fibers anchor periosteum to underlying compact bone
2) interstitial lamellae - remnants of old osteons
3) Haversian canal system (OSTEONS)- wafer thin bone lamellae. Volkmans (connect osteons) and haversian (enclose neurovascular bundle) canals
4) inner circumferential lamellae 0 around marrow cavity



damage to the articular hyaline cartilage - damaged cartilage may calcify, die and be replaced wtih bone


Rheumatoid arthritis

Rheumatoid arthritis is an autoimmune disease that attacks the synovial joints, damaging the articular cartilages, producing disfigurement of the joints and severe pain.


Gouty arthritis

Gouty arthritis is caused by the accumulation of uric acid crystals in the joints, especially in the joints of the fingers and toes. These sharp crystals cause excruciating pain. Gout may be a side effect of thiazide diuretics used to treat high blood pressure.



Rickets is a disorder that results from calcium deficiency during development, or from inadequate dietary supply of vitamin D which is necessary for calcium absorption form the GI tract. In this disorder, osteoid does not mineralize properly.



rickets in adults



reduction in bone mass both in the
organic and inorganic components of its matrix.postmenopausal women.Normally, osteoclast activity is controlled mainly by parathyroid hormone (PTH) and to a lesser extent by interleukin 1 and tumor necrosis factor. In women of child-bearing age, estrogens inhibit the production of these substances, restricting osteoclast activity.


intramembranous ossification

FLAT BONES --- initial site of osteogenesis is in membrane of mesenchyme
mesenchymal cells diff into osteoprog cells which then turn into osteoblasts
osteoblasts begin deposition of organic component (osteoid) = primary bone (immature/woven).
primary bone begins to take shape of (eosinophilic) spicules and trabeculaes = 3D network over time.
osteonectin, sialoproteins, & osteocalcin secreted by osteoblasts to glue cells to bone matrix, initiate CA phos formation, and trap CA ions from blood respectively === mineralization
osteoblasts get trapped = osteocytes with canaliculli connections
primary bone resorbed by osteoclasts and secondary bone laid down by osteoblasts (initially spicules and trabeculae form spongy bone and vascular CT in spaces becomes bone marrow... spaces filled in by secondary deposition = compact bone


endochondral ossification

hyaline cartilage formed first - calcified - and then replaced by bone model - model for LONG BONES
PRIMARY OSS- DIAPHYSIS - hyaline cartilage has the shape and grows interstitally (LENGTH) and appositionally (WIDTH) - When the perichondrium surrounding hyaline cartillage becomes vascularized=signal for chondrogenic cells in its inner cellular layer to become osteoprog cells -->osteoblasts --->perichondrium becomes periostium;;; new osteoblasts in inner layer of periosteum secrete bone matrix and bony collar begins via intramembranous ossification. cartilage matrix begins to calcify and the cartilage begins to die nutrients cant get to them). the cells hypertrophy(accumulate glycogen and vacuoles) and produce alkaline phos. osteoclasts penetrate the bone colar - periosteal bud follows - hemopoetic stem cells containing osteoprog cells - begin to form bone matrix in dead cartilage area
SECONDARY OSS- EPIPHYSIS - no bone collar - osteoprog cell come in and = osteoblasts- cartilage growth above (and below articular cartilage of joint) the epiphyses and bone formation with cartilage destruction below the epiphyses (diaphyseal side)


zones of the epiphyseal plate

-zone of reserve cartilage - resting zone - typical hyaline cartillage
-zone of proliferation - chondrocytes prolif and look like they are in stacks parallel to long axis - interstiatial growth with organic matrix production
-zone of hypertrophy -glycogen in chondrocytes and enlarged lacunae
-zone of calcified cartilage - lacunae coalesce and calcification of cartilage matrix - death of chondrocytes
-zone of resorption and ossification - calcified cartilage remnants form spicules in direction of diaphysis, blood vessels bring in osteoprog cells; osteoprog cells migrate to calcified area to dif into osteoblasts (mixed spicule)


calcified cartilage w/ H&E

basophilic (blue) and does not contain cells- they dead.


mineralized bone w/ H&E

acidophilic (pink) - contains living cells


around age 20 which zone goes away to stop growth

zone of prolif starts to slow dane on ossification outruns growth of cartilage = epiphyseal closure


mineralization of bone

osteocalcin and other sialoproteins binds Ca ions
lots of Ca, PO4 and alkaline phosatase
in the vessicles of calcium and phos - formation of CaPO4 = hydroxyapatite crystals -sharp end pierce the vessicle and deposit in the bone matrix


bone remodeling responds to these hormone

parathyroid and calcitonin


bone repair mechanisms

intramembranous bone formation, cartilage formation and endochondral bone formation
1) blood clot
2) neutrophils arrive then macrophages to clean up
3) CT grows into the blood clot from fibroblasts - form granulation tissue (came in from new blood vessels that move in) = soft cartilage+granulation tissue=soft callus
4) soft callus bridges the bone ends and osteoprog cells dif into osteblasts to secrete new osteoid. froms in the direction of the fracture
5) osteogenic buds grown in and cartilage calcifies and is replaced by bone via endochondral ossification = bony callus
6)endosteal prolif results in bone spicules growing toward marrow cavity - spongy bone first then compact bone
7) in the mean time the bony callus is slowly broken down by osteoclasts
8) remodeling to orig shape



genetic disporder -the cartilage in the growth plates is replaced by bone at a very slow rate resulting in short bones in the upper and lower limbs... the zones of proliferation and hypertrophy are slender and disorderly


myelin in CNS

formed by oligodendrocytes - foot like process that wrap around the axon


myelin in the PNS

formed by schwann cells - hugs the axons - forms sheeth around multiple axons



anterograde - SLOW transport



retrograde - fast transport


blood brain barrier formed by

astrocytes - star shaped and their footlike processes extend toward capilareis. many foot process of astrocytes cover the vessel



derived from monocytes- phagocytotic cleaner cells


tumors in the brain

can pretty much only arise from glial cells as no ohter cell can divide - or from somewhere else if malignant


ependylmal cell

type of glial cell lining venritcles of brain and central canal of the spinal cord, move CSF - ciliated


node of ranvier

schwann cells myelination only


organic component of bone is

osteoid - secreted by osteoblasts - GAGS- proteoglycans, type I, osteocalcin, osteonectin, sialoproteins, BMPs


help with the nutritional support of osteocytes and protect bone surfaces from resorption by osteoclasts

bone lining cells which are derived from osteoblasts


howships lacuna?

grove where osteoclats have broken downs ome bone


protoplasmic astrocytes -

primarily in gray matter


fibrous astrocytes

primarily in wite matter



myelinates moer than one axon, CNS


multiple sclerosis

demyelination of white matter in the CNS - ONLY WHITE MATTER and ONLY CNS