HISTO LAB - CT Flashcards
– responsible for providing and maintaining form
CONNECTIVE TISSUE
-made up mainly of non-living material, extracellular matrix
CONNECTIVE TISSUE
-matrix: physically links cells and tissues, gives mechanical support to the different organs
CONNECTIVE TISSUE
-contains blood vessels and nerves; serves the needs of avascular epithelium
CONNECTIVE TISSUE
CT component
CT Cells originate from —————–
precursor cells in primitive mesenchyme
ct fibers are made up of
proteins and polysaccharides
most abundant protein in the human body
collagen
-key element of all CT, basement membrane, external laminae of muscles and nerve cells
collagen
-synthesizes collagen and reticular fibers
collagen
CT fiber
may be arranged as parallel fibers or discontinuous sheets
-has properties of stretching and elastic recoil
elastin
GS is hydrophobic or hydrophilic
hydrophilic
-form a medium for the passage of molecule throughout supporting tissues
ground substance
-for the exchange of metabolites with the circulatory system
ground substance
-gel-like: serves as lubricant, barrier to invasive microorganism
ground substance
embryonic CT which originates from the mesoderm and neural crest ectoderm
- Mesenchymal CT
Mesenchymal CT originates from?
mesoderm and neural crest ectoderm
fibers of Mesenchymal CT
uniformly distributed sparse collagen fibers (reticular type)
cells of Mesenchymal CT
undifferentiated mesenchymal cells (a homogenous population of cells but may also have stem/progenitor cells)
transient type of tissue
mucoid CT
LOCATION OF MUCOID CT
-location: umbilical cord and fetal organs
-matrix of mucoid ct
jelly-like
-fibers: mucoid ct
delicate network of collagen fibers
-cells:mucoid ct
scattered star-shaped fibroblasts (w/ flattened processes that appear to fuse with neighboring cells)
-ground substance: mucoid ct
soft, very abundant, appears homogenous in fresh state, composed chiefly of hyaluronic acid
-residue: contains granules and fibrillar precipitates when fixed; exhibits staining reactions of mucin
mucoid CT
– most widely distributed CT
- Loose/Areolar CT
CT found in almost every microscopic section of the body
- Loose/Areolar CT
-fills up empty spaces
- Loose/Areolar CT
-serves as packing and anchoring material
- Loose/Areolar CT
-supports epithelium where it encompasses the lamina propia (thick layer beneath the epithelial lining of stomach and intestines)
- Loose/Areolar CT
- flexible, but not very resistant to stress
- richly supplied with blood vessels, lymphatic vessels and nerves
- Loose/Areolar CT
-cells of loose ct:
holds a collection of all types of cells, more abundant than fiber
-ground substance of loose ct:
moderate
-cells: adipocytes which may be isolated, in small groups (loose and dense irregular CT), in large aggregates (fat)
- Adipose CT
-efficient thermal insulators
- Adipose CT
-primary storage site for neutral fats (triglycerides)
- Adipose CT
-key regulators of the body’s overall energy metabolism
- Adipose CT
- shock absorbers
- richly vascularized
- Adipose CT
-cells of adipose ct:
adipocytes which may be isolated, in small groups (loose and dense irregular CT), in large aggregates (fat)
– spherical
- large due to the presence of a single lipid droplet
- nucleus appears flattened, displaced on one side
- surrounded by reticular fibers
*Adipocyte
what fibers surround an adipocyte
reticular
*As the number of adipocytes grow, they are pushed aside these fibers forming the ————- (where other CT cells and blood vessels are located).
fibrous septum
2 Types of Adipose Tissue
– found only in fetus, newborn, hibernating animals
-function: heat production during the first months of postnatal life
- Brown or Multilocular
2 Types of Adipose Tissue
20% of body weight
-function: reserve energy source through homeostatic mobilization & mobilization of triglycerides
- White or Unilocular –
- forms the supportive stroma of lymphoid organs, hematopoietic bone marrow and endocrine glands
- Reticular CT
-fibers of Reticular CT:
reticular fibers (Type III) which anastomose forming a delicated 3D closed-meshed network: lattice fibers
-cells of reticular ct:
reticular cells (modified fibroblasts)
-elements create a cell-lined system that allows passage of lymphocytes and lymph
Reticular CT
- contains most of the components found in loose CT
- but has more fibers and fewer cells
DENSE CONNECTIVE TISSUE
-orientation and arrangement of collagen bundles make it resistant to stress
DENSE CONNECTIVE TISSUE
– densely packed coarse Type I collagen
-fibers and cells oriented into parallel cylinders
- Dense Regular CT
– main functional component of tendons and ligaments
• Dense regular collagenous or fibrous CT
is Dense regular collagenous or fibrous CT vascular or not
AVASCULAR
-cells of dense reg collagenous ct:
fibrocytes (appear stellate when the tendon is cut in cross section, sometimes termed tendinocytes)
– occurs infrequently
Dense elastic CT
-location of dense elastic
yellow ligaments (ligamentum flava) of vertebral column, suspensory ligaments of penis
fibers of dense elastic
-thick elastic fibers with thin collagen fibers + flattened fibroblasts
cells of dense elastic
-fibroblasts branch frequently and fuse with one another
-ground substance of dense elastic:
scanty
-individual fibers are surrounded by a network of reticular fibers
what type of ct
Dense elastic CT
– collagen fibers forming unaligned 3D meshwork
Dense Irregular CT
function of Dense Irregular CT
-function: provide resistance to stress in all directions (because of the haphazard arrangement)
location of Dense Irregular CT
-location: fasciae, reticular region of dermis, periosteum, joint capsules, membrane capsules around kidneys, liver, testes, lymph nodes, heart valves
ground substance of Dense Irregular CT
-ground substance: scanty, located between fibers and cells with some bv
cells of Diffuse Lymphoid CT
-cells: irregularly scattered in a loose manner lymphoid cells
stroma of Diffuse Lymphoid CT
reticular fibers + reticular cells
location of Diffuse Lymphoid CT
inter-nodular, deep cortical, medullary regions of lymph nodes
Peri-arteriolar lymphoid sheath of spleen
Nodular regions of tonsils and Peyer’s patches
CT with closely packed lymphoid cells
Dense lymphoid CT
– compact, circumscribed condensations of lymphocytes
Lymph nodules
– pale central portion of lymph nodules, with large lymphocytes showing mitotic figures;
Germinal center of Flemming/ Secondary nodules
site of active production of lymphocytes (but newly formed cells die locally and are disposed by macrophages)
Germinal center of Flemming/ Secondary nodules
– irregular elongated condensation of lymphocytes in the medulla of lymph node
Lymphatic cord
-plasma cells are more numerous in?
medullary cords
-only ———— lymphocytes reach the CVS
small and medium-sized
—– do not circulate (under normal conditions)
large lymphocytes and plasma cells
– specialized fibrous CT composed of chondrocytes (islands of cells) surrounded by an intensely basophilic ECM
-avascular
CARTILAGE
-solid and firm, somewhat pliable (accounts for special resilient properties)
CARTILAGE
-key tissue in growing bones
CARTILAGE
-serves as shock absorbing and sliding area for joint
CARTILAGE
-facilitates bone movement
CARTILAGE
-cartilage matrix: serves as route for diffusion of nutrients, makes up 40% of cartilage, primarily composed of type II collagen and GS
CARTILAGE
a) – glassy, amorphous and homogenous staining matrix which appears bluish white
Hyaline
cartilage with -low cell-matrix ratio (more matrix)
hyaline cartilage
cells of hyaline
chondrocytes (w/in lacuna) are embedded and evenly distributed throughout the matrix
fibers of hyaline
-fibers: type II collagen fibers
GS of hyaline
-ground substance: abundant in acidic sulfhydryl group (sulphated proteoglycans) responsible for intense basohilia
-surrounded by perichondrium
elastic and hyaline cartilage
location of hyaline
-location: articular surfaces of synovial joints, walls of larger respiratory passages, temporary skeleton of fetus
– most resilient cartilage
b) Elastic
matrix of elastic cartilage
-matrix: opaque, high cell-matrix ratio (more cells)
fibers of elastic cartilage
-fibers: elastic fibers + type II collagen fibers
location of elastic cartilage
-location: pinna of ear, Eustachian tube, epiglottis, corniculate and cuneiform cartilages of larynx
least resilient cartilage
Fibrocartilage
location of fibrocartilage
-location: (regions subjected to pulling forces) intervertebral disks, articular disks of sterno-clavicular joint, other areas of insertion of tendons and ligaments
fibers of fibrocartilage
-fibers: type I collagen (makes the matrix acidophilic)
cells of fibrocartilage
-cells: chondrocytes in lacuna dispersed in linear arrangement
- vascularized, rigid
BONE
-dynamic plastic tissue
BONE
-heavily mineralized ECM, making It hard and brittle
BONE
storage depot for: ?% calcium
?% phosphorus
?% Na and Mg
99% calcium
85% phosphorus
65% Na and Mg
BONE MATRIX compnents
– calcium and phosphorus
-impart strength, inflexibility, and hardness
A. Inorganic (65%)
BONE MATRIX compnents
– proteoglycan, GAGs, glycoproteins, type I collagen fibers
B. Organic (35%)
BONE CELLS
– derived from undifferentiated mesenchymal cells
-have the capacity for mitosis
-found adjacent to newly formed bone matrix
A. Osteoprogenitor cells
BONE CELLS – originate from osteoprogenitor cells -squamous, cuboidal or columnar -with basophilic cytoplasm -responsible for formation of bone matrix -found on surfaces of developing bones
Osteoblasts
BONE CELLS
- mature, principal cells of fully formed bone
- flattened cells, oval nucleus
- function: maintain mineralized matrix
Osteocytes
BONE CELLS
– giant, multinucleated cells
-seen in areas where active bone resorption occurs
Osteoclasts
Types of Bone
– has trabeculae or spicules, regions between are filled with bone marrow
-osteocytes and numerous BV lie within the immediate vicinity of this bone
-occupy greater part of epiphysis
- Spongy or Cancellous
Types of Bone
solid mass occupying the shaft or diaphysis
-presence of osteons
-interstitial lamellae: layers of bone between haversian systems
-Volkmann’s canals: vascular channels w/c connect adjacent Haversian canals
- Compact or Dense
– specialized CT surrounding the bone periphery; made up of osteoprogenitor cells
Periosteum
– supporting tissue lining the medullary canal of bones; made up of osteoprogenitor cells
Endosteum
endosteum is made up of what cells
osteoprogenitor
–bone development, growth, maturation
OSTEOGENESIS or HISTOGENESIS OF BONE
OSTEOGENESIS or HISTOGENESIS OF BONE involves
a. osteoblast formation
b. mineral deposition
c. bone remodelling at resoprtion sites
formed at diaphysis
-site of increase bone diameter
*Primary ossification center –
located at epiphysis
-site of longitudinal bone growth
*Secondary ossification center –
– occurs in mesenchymal membrane
-condensation of mesenchymal cells leads to differentiation into osteoblasts to form primary bone tissue
- Intramembranous ossification
-forms flat bones
- Intramembranous ossification
-also contributes to the growth of short bones and thickening of long bones
- Intramembranous ossification
-presence of hyaline cartilage (shape resembles a small bone)
Intracartilaginous /Endochondral ossification
-forms short and long bones
Intracartilaginous /Endochondral ossification
-allows functional stresses to be sustained during skeletal growth
Intracartilaginous /Endochondral ossification
region where bony shaft is separated from bony epiphysis
Epiphyseal plate –
5 zones of osteogenesis
- Zone of reserve cartilage – resting zone
- Zone of proliferation
- Zone of maturation and of hypetrophy
- Zone of cartilage degeneration (Calcified cartilage)
- Osteogenic (ossification) zone
red fluid tissue that circulates through CVS, propelled by the pumping action of heart
BLOOD
relative volume of cells (45%) and plasma (55%)
Hematocrit
– upper part, WBC + platelets
Buffy coat
– method that displays diff cell types of peripheral blood to greatest advantage
Blood smear
– circulating, anucleated cells
- stain pink or salmon with eosin
- about 7.4 um
- size reference
- -devoid of organelles and nucleus
- RBC
–smallest and lightest
-tiny irregular masses of basophilic cytoplasm
Platelets
-derived from megakaryocytes in bone marrow
Platelets
-form clumps
Platelets
granules of platelets
-granules: alpha, beta, lambda
-function: blood clotting, clot retraction, clot dissolution
Platelets
– leukocytes with numerous granules & lobulated/segmented nucleus
Polymorphonuclear granulocytes
– fine violet/lilac/pink granules
- Neutrophil
-3-5 lobes joined by nuclear strands
- Neutrophil
-increase in number during bacterial infections
- Neutrophil
-active phagocyte
- Neutrophil
-heterochromatin (periphery of nucleus) & euchromatin (center of nucleus)
neutrophil, basophil, eosinophil
-less lobes, ______ mature
less
– large, coarse, bright red-orange granules
Eosinophils
-bilobed nucleus but small, 3rd lobe may be present
Eosinophils
-release arylsulfatase & histaminases at sites of allergic rxn
Eosinophils
phagocytosis of Ag-Ab complexes
Eosinophils
1st line of defense against parasite infection
Eosinophils
increase in number during allergic rxns and parasitic infections
Eosinophils
– not as numerous, rarest
- vary in size
- stain dark blue
- obscured nucleus
- heterochromatin (periphery of nucleus) & euchromatin (center of nucleus)
- activated: release histamines and leukotrienes that produce inflammatory response
Basophils
- few or no granules in cytoplasm
Mononuclear agranulocytes
- – main functional cells of lymphatic/immune system
Lymphocytes
-show more variations in size
Lymphocytes
-ribosomes: basis for slight basophilia
Lymphocytes
- small: intensely staining, slightly indented, spherical nucleus, pale blue cytoplasm
- medium: more abundant cytoplasm, larger nucleus, less heterochromatic
Lymphocytes
– long life span
-involved in cell-mediated immunity
T lymphocytes
– variable life spans
- production of antibodies
- humoral immunity
B lymphocytes
– immune surveillance
NK Cells
–largest of all WBC
Monocytes
-many fine, small, dense azurophilic granules (lysosomes)
Monocytes
-leaves BV during inflammation and transforms into tissue macrophage
Monocytes
agranulocyte which participates in phagocytosis
Monocytes
-basophilic cytoplasm
Monocytes
-stains lightly than lymphocytes
Monocytes
-nucleus shape: round, oval, indented, horseshoe
Monocytes
Proteins found in 3 fibers
Collagen
Elastin
Fibrillin
Soluble fiber in blood
Fibrinogen
Insoluble fiber in blood
Fibrin
Unclotted blood
Plasma
Clotted blood
Serum
WBC with spongy nucleus and brainlike convolutions
Monocytes
Type of WBC
Vacuole may be present
Light gray cytoplasm
Monocyte
Formed element that is refractile
Platelets/thrombocytes
Forms the bulk of CT
ECM
Where cells and fibers are suspended
ECM
A fixed cell which produces GS and fibers
Fibroblast
Layer of CT that encloses glands
Capsules
What does eosinophil release at sites of allergic rxn
Arylsulfatases and histaminasrs
What does basophil release when activated?
Histamines and leukotrienes
In lymphocytes, these are the basis for slight basophilia
Ribosomes
Contain granules called lysosomes
Monocytes
-concentrates Ag and presents it to lymphocytes
Monocytes