Exam 3: Connective Tissue, bone and cartilage Flashcards Preview

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Flashcards in Exam 3: Connective Tissue, bone and cartilage Deck (77):

Where is connective tissue (CT) found?

In every organ system except the CNS


Characteristics of CT

*Relatively few cells *Abundant matrix *Matrix contains varying amounts of protein fibers * CT is typically classified on the basis of the type of MATRIX, FIBER DENSITY, and FIBER ORGANIZAITON


List the FIVE functions of CT

1. Physically supports other tissues 2. Binds tissues together 3.Provides structural framework and opposes gravity 4. Helps to create body CONTOURS 5. Houses Specialized tissues, (i.e): -Blood forming tissues (hematopoietic) -Lymphoid Organs


What are the Three types of of CT?

1. Embryonic CT 2. Adult CT -Loose -Dense 3. Special


What are the characteristics of LOOSE ADULT CT?

*high ratio of fibroblast to fibrous components *type I collagen *usually found beneath epithelial tissues of most organs


What are the characteristics of DENSE ADULT CT?

*High Ratio of fibrous components to fibroblast *thicker bundles of collagen than in loose CT *No specific orientation of collagen bundles in dense irregular dense CT *highly ordered bundles of collagen in dense regular CT


What modalities can be associated with Adult CT?

Reticular and Elastic


What modalities can be associated with Special CT?

adipose, cartilage, bone, hematopoietic


Give the location and Function of Type I collagen fibers

General CT and BONE; Tensile strength.


List the steps of Collagen fiber synthesis

1. Type I collagen is synthesized as a prePROpeptide 2.The signal (pre-) sequence is cleaved after translocation of the polypeptide into the endoplasmic reticulum (ER) lumen 3.Pro-collagen molecule c̅ terminal non-helical ends (secreted into extracellular matrix by fibroblasts) 4. Terminal non-helical ends are cleaved into form tropoCOLLAGEN. (tropocollagen spontaneously assembles into staggered arrays to for collagen fibers c̅ characteristics 64 nm banded pattern) 5. BOOM collagen


List the steps of elastic fiber synethesis

1. Elastin is also synthesized as a prePROprepitde 2.secreted as a propeptide 3. converted to tropoelastin 4.Assembled into amorphous fibers or sheets c̅ the aid of fibrillin


What are the principal cell types found in CT?

Fibroblasts and Fibrocytes; they are also the most numerous


Functions of Fibroblasts and Fibrocytes:

secretion and maintenance of CT matrix secrete precursor fibrous molecules secrete the amorphous components of the matrix, including the glycosaminoglycans.


What are Glycosaminoglycans?

GAGS are large, negatively charged polysaccharides consisting of repeated disaccharide units.


What are the four groups of GAGS

Hyaluronic Acid Heparin and Heparan Sulfate Chondroitin sulfate and Dermatan Sulfate Keratan Sulfate


Where is hyaluronic acid found

cartilage, skin, synovial fluid, and general CT


Where is heparin and heparan sulfate found?

basement membrane, skin, lung, liver, blood vessels, mast cell granules


Where are chondroitin sulfate and dermatan sulfate found?

cartilage, bone, skin, blood vessels, heart, cornea


Where is Keratan Sulfate found?

Cartilage, cornea, and intervertebral disk


What are the common type of resident cells in fibrous CT?

macrophages, mast cells, plasma cells.


What are three types of macrophages?

Monocytes, kupffer cells, microglial cells.


mast cell characteristics:

stain with toluidine blue Large metachromatic granules with histamine and heparin Involved in hypersensitive response to allergens.


Plasma Cell characteristics:

Activate B lymphocytes Large pale nuclie with "clock-face" distribution of chromatin Prominent Golgi


Define carcinoma in situ

tumor cells that have not invaded the basement membrane and remain confined within the epithelial layer.


Define Microinvasive carcinoma

decrease in cadherins, basement membrane breaks down. Collagenase IV breaks down BM allowing tumor cells to invade the subjacent CT


Define Invasive Carcinoma

They secrete: 1. Autocrine Motility Factors 2. Vascular premeability factors 3. Angiogenic factor this can lead to metastasis


Where are adipocytes derived from?

undifferentiated mesenchymal cells and are distinguished by their unique appearance.


What are the two types of adipocytes?

1. White fat is distributed throughout the body - unilocular (one fat drop) 2. Brown fat cells contain numerous smaller lipid droplets -multilocular -slightly more cytoplasm -abundant mitochondria, which give them their brown coloration


Identify the following Tissue

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adult CT: Reticular Tissue


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Adult CT: elastic Tissue


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Dense Rugular CT, 400x


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Areolar CT, 400x


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Elastic Connective Tissue Is, 100x


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Elastic CT xs, 100x


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Adipose Tissue, 100x


Identify the following tissue:

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Adipose Tissue, 400x


Cartliage can be identified based on it's matrix, list the three types of cartilage


1. Hyaline

2. Elastic

3. Fibrocartilage


T/F Cartilage may form part or all of the Skeletal system in Vertebrates?



In Vertebrates, what does the skeletal system begin as?




Characteristics of HYALINE cartilage


  • Most common type
  • Avascular
  • Contains type II collagen Fibers
  • surronded by perichondrium
  • Translucent, bluish gray
  • Solid, but flexible
  • chondrocytes are often found in cell groups (resulting from cell division)


List some locations where Hyaline cartilage may be located:


  • External auditory meatus
  • Larynx
  • Tracheal Cartilages
  • Bronchial Cartilages
  • Fetal Long Bones
  • Articular ends of bone


What are the growth patterns of hyaline cartilage?


  • Appositional
  • Interstitial


Identify the structures below:


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A: Fibrous perichondrium

B: Chondrogenic Pericondrium

C: Lacuna

D: Condrocytes

E: Matrix


What are found in the matrix of the cartilage?


  • Chondroitin Sulfate
  • Collagen Fibers
  • Proteoglycans


List some fun facts about Elastic Cartilage


  • Specialized by the addition of elastic fibers to the matrix
  • Surronded by perichondrium
  • Yellow color b/c of elastic fibers
  • more apaque, felxible, and elastic than hyalin
  • chondrocytes mostly located singly
  • Type II collagen plus elastic fibers
  • found in
    • auricle (pinna) of the ear)
    • Epiglottis


What features can be associated with fibrocartilage?

  •  increased collagen in the matrix
  • reduced cellularity compared to hyaline cartilage
  • Not surronded by perichondrium
  • Opaque appearance from fibrous texture
  • Type I collagen
  • Single sparse chondrocytes


Riddle me this, where could I find some fibrocartialge?


  • Intervertebral Discs
  • Pubic Symphysis
  • insertion of some tendons and ligaments
  • Closely associated c dense connective tissue or hyaline cartilage


The cells that produce the martilage matrix are called?


  1. Chondroblast
  2. Chondrocytes


Chondrocytes occuply small cavities in the ECM Called____?

Lacunae, two chondrocytes my occupy a single lacuna


where is perichondrium found?


outer fibrous layer, and inner chondrogenic layer.


Identify the following tissue:

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Elastic Cartilage


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Hyaline Cartilage, 100x


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Hyaline Cartilage, 400x


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Hyaline Cartilage, 400x


Bone is formed by ______ which become _______

Osteoblasts, osteocytes


Bone is elongated through ______ growth of a _______ _________ model

appositional, hyaline cartilage


t/f, bone is highly vascular and is found in close proximity to capillaries?




The bone matrix consist of _______ which is organic and ________ which is inorganic

osteoid, hydroxyapatite.


Based on the arrangement of the matrix, list the three types of bone tissues

  1. Woven Bone (development and bone repair)
  2. Compact Bone (aka lamellar bone)
  3. Spongy Bone (aka trabecular or cancellous bone)


List the characteristics of compact bone

  1. Lacks cavities and forms a dense plate on the outside of long/flat bones
  2. concentric (haversian) lamellae that encircle a central BV(and nerve) forming an osteon or haversian system
  3. Osteocytes are found between the lamellae located in lacunae connected to each other and the haversian canal via canaliculi
  4. Volkmann's canals run perpendicular to the Haversian canals & connect the Hav. Canals to each other and surface of the bone.


Trabecular (spongy) bone characteristics:


  1. Has a 3-D lattice of branching, bony spicules intertwined to form trabeculae surronding the bone marrow spaces in the long & flat bones.


List the structures on the diagram below

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A: Fibrous Periosteum

B: Osteogenic Periosteum

C: Lacuna

D: Lamellae

E: Canaliculus

F: Haversian Canal

G: Volkmann Canal


What are the four macroscopic structures of Bone?


  1. Peristeum
  2. Marrow (medullary) cavity
  3. Endosteum
  4. Sharpey's Fibers


List the SEVEN noncollagenous proteins

  1. Osteocalcin
  2. Osteonectin
  3. Osteopontin
  4. Bone Sialoprotein
  5. Osteoprotegerin
  6. Macrophage colog-stimulating factor
  7. RANKL


Where are osteoprogenitor cells found and how are they formed?


  • Stem cells: adult bone lining cells
  • They are found in the inner portion of the periosteum, in the endostum, and lining vascular canals of compact bone.
  • derived from mesenchyme of the embryonic somite (sclerotome), posses mitotic potential
  • Give rise to osteoblast and bone lining cells


Where are osteocytes found and derived from?

  • Derived from osteoblasts and are trapped by the matrix they secrete
  • found in lacuni


Where are osteoclast cells derived from?

monocyte lineage, which, in turn, is derived from the monocyte precursors in bone marrow.


What is ARF



a cycle that occurs at adult remodeling sites and deuring development


Converts bound calcium to free calcium



How do osteoblasts regulate Osteoclasts?


  1. PTH is the primary regulator of bone turnover
  2. Low PTH levels, osteoblasts stimulate bone formation
  3. High PTH levls, osteoblasts are stimulated to release osteoclast-differntiation factors.
  4. PTH stimulates the differentiation of monocyte precursors to form osteoclasts and the formation of ruffled borders on osteoclasts
  5. Elevated PTH levels result in eroded bone and fibrosis of the resulting spaces (osteitis fibrosa)
  6. PTH hormone binds receptors on teh osteoblast
  7. osteoblast stimulated to synthesize M-CSF and RANKL
  8. Ostoblast releases M-CSF
  9. M-CSF bind to M-CSF receptor on the monocyte that just happend to drop by
  10. Monocyte now a macrophage and expresses RANK
  11. RANK binds to RANKL (couples osteoblast and macrophage)
  12. Macrophage becomes a multinucleated immature osteoclast.
  13. Osteoblast secretes ostoprotegerin
    1. osteoprotegerin binds to RANKL with greater affinity than RANK
    2. Inhibits maturation of osteoclasts
    3. PTH blocks syn. of osteoprotegerin
  14. a non-functional osteoclast uncouoples from the osteoblast and becomes a functional osteoclast
  15. Calcitonin acts to reduce bone resoption.


Identify the bone tissue below


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Cancellous bone (spongy Bone)


Identify the bone tissue:


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Cancellous bone


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Cancellous Bone


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Bone (dry ground)


Identify the tissue sample:


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Dry ground bone


Identify the tissue sample below:


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dry ground bone


Identify the tissue sample below


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dry ground bone