M1 Histology, Block 2: Connective Tissue

Front 1

Name some sites where CT is located.

Back 1

o Padding organs and other regions of body
o Fascia throughout body
o Underneath epithelium
o Can be fluid-like or gel-like
o Wide distribution

Front 2

Which of the following is NOT a role of CT?
A. Structural
B. Metabolic
C. Defensive
D. Energetic

Back 2

D. Energetic is incorrect

Front 3

What is the origin of CT?

Back 3

mesodermal and specific neural crest cells that proliferate to form a primitive CT called mesenchyme in the early embryo

Front 4

What are the two general components of CT?

Back 4

Cells and ECM

Break down ECM further.

Hint 4

1. Ground Substance - composed of GAGs (hydrophilic), proteoglycans (like condroitin sulfate), proteoglycan aggregates (hyaluronic acid), adhesive glycoproteins (involved in cell communication. ex. fibronectin, laminin)
2. Tissue Fluid
3. Fibers (1. Collagen and its four types, 2. Elastic fibers, 3. Reticular fibers)

Front 5

What is ground substance a component of and what are its components?

Back 5

Ground substance is a component of ECM.

Ground substance's components are: GAGs (hydrophilic), proteoglycans (ex. chondroitin sulfate), proteglycan aggregate (hyaluronic acid), adhesive glycoproteins (fibronectin and laminin)

Other components of ECM are tissue fluid and fibers.

Front 6

Which component of ground substance are very negatively charged structures that form a difficult to compress gel?

A. GAGs
B. Proteoglycan
C. Proteoglycan Aggregate
D. Adhesive glycoprotein

Back 6

A. GAGs

Front 7

What component of ground substance does hyaluronic acid fall under?


A. GAGs
B. Proteoglycan
C. Proteoglycan Aggregate
D. Adhesive glycoprotein

Back 7

C. Proteoglycan Aggregate

makes a huge tree-like branched structure. This is what fills the ground substance and forms the physical barrier to bacteria that try to tunnel in. Some bacteria can produce hyaluronuase to degrade these, though.

Front 8

What component of ground substance does chondroitin sulfate, dermatin sulfate, keratin sulfate and heparin sulfate fall under?

A. GAGs
B. Proteoglycan
C. Proteoglycan Aggregate
D. Adhesive glycoprotein

Back 8

B. Proteoglycan

Front 9

What component of ground substance does fibronectin and laminin fall under? What are fibronectin and laminin important for function wise?

A. GAGs
B. Proteoglycan
C. Proteoglycan Aggregate
D. Adhesive glycoprotein

Back 9

D. Adhesive glycoprotein

• Fibronectin: cell migration, adhesion, motility
• Laminin: important in epithelia, forms part of basal lamina

Front 10

What are the three components (general) that make up the ECM?

Back 10

Ground substance, Tissue Fluid, Fibers

Front 11

Fibers are secreted by fibroblasts. Fibers come in three "flavors". Name them.

Back 11

1. Collagen Types I thru IV.
2. Elastic Fibers
3. Reticular Fibers

Hint 11

Collagen Type I: most common, found in dermis of skin, bone tendon, dentin, fascia
Type II: very thin fibrils around hyaline and elastic cartilage
Type III: major component of reticular fiber
Type IV: found in basal lamina and epithelium, doesn't form fibrils or fibers!

Elastic fibers: produced by fibroblasts or smooth muscle, found in all loose CT

Reticular fiber: collagen type III. provides framework for bone marrow and lymphoid organs and spleen. Delicate, forms quickly. Prominent during embryogenesis and inflammation processes.

Front 12

Which fiber, one of three components of ECM, can be produced by fibroblasts OR smooth muscle?

Back 12

elastic fibers

(two other fiber types are collagen and reticular fiber)

Front 13

Which fiber, one of three components of ECM, has 5 subdivision types?

Back 13

Collagen!
o Type I : most common, found in dermis of skin, bone, tendon, dentin, fascia, organ capsules, fibrous cartilage
o Type II: very thin fibrils found in hyaline and elastic cartilage
o Type III: the major component of reticular fiber
o Type IV: found in basal lamina and epithelium. Doesn’t form fibrils or fibers!

Front 14

Which fiber, one of three components of ECM, may form branchign sheets with fenestrations in blood vessels?

Back 14

Elastic fibers


(two other fiber types are collagen and reticular fiber)

Front 15

Which fiber, one of three components of ECM, provides the framework of bone marrow and lymphoid organs and spleen, is very delicate and thus is constructed quickly and is prominent during embryogenesis and inflammatory processes?

Back 15

Reticular fibers

(the two other fibers are collagen and elastic)

Front 16

True or False:

Reticular fibers are about half as large as a collagen fiber.

Back 16

True!

Front 17

Which fiber, a part of the ECM, is argyrophilic and thus we silver-stain to visualize it?

Back 17

Reticular Fiber!

Front 18

What is the principal cell fo the CT that stays in the CT?

A. Eosinophil
B. Fibroblasts
C. Lymphocytes
D. Macrophages
E. Mast Cells
F. Monocytes
G. Neutrophils
H. Plasma Cells

Back 18

B. Fibroblasts

Front 19

Compare and contrast the fibroblast active form with the fibroblast inactive form.

Back 19

• Active form:
 Nucleus is oval or spindle-shaped, very euchromatic, nucleoli
 Cytoplasm not discernable at LM level
 EM reveals abundant RER, Golgi
• Inactive fibroblast (fibrocyte)
 Nucleus very spindle-shaped, very heterochromatic (thus very dark)
 Cytoplasm not apparent with LM; very thin EM
 Low metabolic rate

Front 20

Oval shape, eccentric nucleus with prominent "negative" golgi and "clock-face" chromatin.

A. Eosinophil
B. Fibroblasts
C. Lymphocytes
D. Macrophages
E. Mast Cells
F. Monocytes
G. Neutrophils
H. Plasma Cells

Back 20

H. Plasma Cells

Also produces antibodies.

Front 21

What cells are identifiable by their indented nucleus?

A. Eosinophil
B. Fibroblasts
C. Lymphocytes
D. Macrophages
E. Mast Cells
F. Monocytes
G. Neutrophils
H. Plasma Cells

Back 21

D. Macrophages

These are also very phagocytic, and they contain lysosomes and phagosomes in their cytoplasm.

Front 22

Are small (6-7 micrometers in diameter) though have large, heterochromatic nucleus and a thin thin ring of cytoplasm around it.

A. Eosinophil
B. Fibroblasts
C. Lymphocytes
D. Macrophages
E. Mast Cells
F. Monocytes
G. Neutrophils
H. Plasma Cells

Back 22

C. Lymphocytes

These exist in T and B flavors. B lymphocytes differentiate into plasma cells

Front 23

Horse-shoe shaped nucleus.

A. Eosinophil
B. Fibroblasts
C. Lymphocytes
D. Macrophages
E. Mast Cells
F. Monocytes
G. Neutrophils
H. Plasma Cells

Back 23

F. Monocytes

these are also large, round cells ~ 12-20 micrometers in diameter, and they are precursors of macrophages. Found in CT and peripheral blood.

Front 24

Has a small, centrally located nucleus, granules contain GAGs, heparin and histamine.

A. Eosinophil
B. Fibroblasts
C. Lymphocytes
D. Macrophages
E. Mast Cells
F. Monocytes
G. Neutrophils
H. Plasma Cells

Back 24

E. Mast Cells

becomes activated in allergic reactions

Front 25

Most prevalent WBC.

A. Eosinophil
B. Fibroblasts
C. Lymphocytes
D. Macrophages
E. Mast Cells
F. Monocytes
G. Neutrophils
H. Plasma Cells

Back 25

G. Neutrophils

Front 26

Multi-lobed nucleus with 3-5 lobes. Has two types of granules (one w/ enzymes, others w/out), highly phagocytic.

A. Eosinophil
B. Fibroblasts
C. Lymphocytes
D. Macrophages
E. Mast Cells
F. Monocytes
G. Neutrophils
H. Plasma Cells

Back 26

G. Neutrophils

Front 27

What cell type is associated with the accumulation of dead bacteria and dead [insert cell type] can form pus?

A. Eosinophil
B. Fibroblasts
C. Lymphocytes
D. Macrophages
E. Mast Cells
F. Monocytes
G. Neutrophils
H. Plasma Cells

Back 27

G. Neutrophils

Front 28

Bi-lobed nucleus, distinct eosinophillic granules which are lysosomes.

A. Eosinophil
B. Fibroblasts
C. Lymphocytes
D. Macrophages
E. Mast Cells
F. Monocytes
G. Neutrophils
H. Plasma Cells

Back 28

A. Eosinophil

Front 29

An increase in this type of cell can indicate presence of a parasitic infection.

A. Eosinophil
B. Fibroblasts
C. Lymphocytes
D. Macrophages
E. Mast Cells
F. Monocytes
G. Neutrophils
H. Plasma Cells

Back 29

A. Eosinophil

Front 30

Identify the CT cell type.

Back 30

Active fibroblast

- Nucleus is oval or spindle-shaped, very euchromatic, nucleoli
- Cytoplasm not discernable at LM level
- EM reveals abundant RER, Golgi

Front 31

Identify the CT cell type.

Back 31

Elastic fiber

- squigglies

Front 32

Identify the CT cell type.

Back 32

Inactive fibroblast

- Nucleus very spindle-shaped, very heterochromatic (thus very dark)
- Cytoplasm not apparent with LM; very thin EM
- Low metabolic rate

Front 33

Identify the CT cell type.

Back 33

Monocyte

o Large, round cell, 12-20 micrometers in diameter, distinct horseshoe-shaped nucleus
o Precursors of macrophages
o Are found in connective tissue and peripheral blood

Front 34

Identify the CT cell type.

Back 34

Macrophage

o Very phagocytic
o Indented nucleus, cytoplasm visible
o Lysososmes and phagosomes in their cytoplasm

Front 35

Identify the cell type.

Back 35

Lymphocyte

o Large, heterochromatic nucleus with thin thin ring of cytoplasm around it
o Small, 6 to 7 micrometers in diameter
o T and B lymphocytes exists
o B lymphocytes become plasma cells

Front 36

Identify this cell type.

Back 36

Plasma Cell

o Oval shape, eccentric nucleus
o Basophilic cytoplasm with prominent “negative” golgi
o Round nucleus, clumped chromatin “clock-face”
o Produce antibodies, “protein factories”

Front 37

Identify this cell.

Back 37

Plasma Cell

o Oval shape, eccentric nucleus
o Basophilic cytoplasm with prominent “negative” golgi
o Round nucleus, clumped chromatin “clock-face”
o Produce antibodies, “protein factories”

Front 38

Identify this cell type.

Back 38

Mast Cell

o Small, centrally located neucleus, granules contain GAGs, heparin and histamine
o Becomes activated in allergic reactions

Front 39

Identify this cell type.

Back 39

Mast Cell

o Small, centrally located neucleus, granules contain GAGs, heparin and histamine
o Becomes activated in allergic reactions

Front 40

Identify this type of CT cell.

Back 40

Neutrophils

o Most prevelant WBC
o Multi-lobed nucleus with 3-5 lobes, 12 -15 micrometers
o Two types of granules (one with enzymes and one with non-enzymes)
o Highly phagocytic (responsible for cardinal signs of inflammation, or dolor (pain), calor (warmth), tumor (swelling), rubor (redness)
o After intracellular digestion, remnants are stored or eocytosed
o During this process most neutrophils die: the accumulation of dead bacteria and dead neutrophils can form pus

Front 41

Identify this type of cell.

Back 41

Eosinophil

o Bi-lobed nucleus, about 12-14 micrometers
o Distinct eosinophillic granules whichar e lysosomes
o Phagocytic and increase in number with parasitic infections

Front 42

What type of CT cell is this?

Back 42

Brown Adipose

o multiple droplets of lipids (multilocular)
o central nucleus
o used in thermoregulation
o babies and hibernating animals have a lotta this

Front 43

Identify the CT cell type.

Back 43

Yellow or White adipose

o Cells synthesize and store lipid for nutrition and insulation
o Nucleus and cytoplasm are displaced by large lipid droplet
o May appear as small clusters of cells or large accumulations

Front 44

Which statement is FALSE?

A. Neutrophils are responsible for the cardinal signs of infection.
B. Monocytes differentiate Macrophages
C. Mast cells found in CT only, not blood
D. T lymphocytes differentiate into Plasma cells
E. Platelets are formed by megakaryocytes in bone marrow

Back 44

D. T lymphocytes differentiate into Plasma cells

Only B lymphocytes differentiate into plasma cells

Front 45

What type of cell fits the following description:

• Biconcave, 7.5 micrometer in diameter
• Filled with hemoglobin
• Actin-containing cytoskeleton
• No cellular organelles

A. Erythrocytes
B. Leukocytes
C. Platelets

Back 45

A. Erythrocytes

Front 46

List the 5 different leukocyte cells presented in lecture. Which is most abundant? Which is least abundant?

Back 46

• Neutrophils: 40-75% of WBc’s
• Lymphocytes: 20-50% of WBCs
• Eosinophils: 5% of WBCs (unless we have parasitic infection, in which case this will be higher)
• Monocytes: 1-5% of WBCs
• Basophils: 0.5% of WBCs

Front 47

Basophils, the least common of WBC, is similar to __________ because of its nucleus and similar to __________ because of its granules.

Back 47

Basophils have a bi-lobed nucleus, similar to eosinophils ; similar to mast cells because of granules that contain heparin and histamine.

Front 48

What does this describe:

• non-nucleated, disk like cell FRAGMENT
• promotes blood clotting
• do have organelles in them
• formed by megakaryocytes in bone marrow
• responsible for clot formation

Back 48

Platelets!

Front 49

Where and by what cells are platelets formed?

Back 49

Platelets are formed by megakaryoctes in bone marrow.

Front 50

Regarding hematopoiesis, what do the mesoblastic, hepatic and myeloid periods refer to, respectively?

Back 50

Early early blood cells stem from mesenchymal cells in yolk sac and body stalk (from hypoblast). These are called mesoblastic. Eventually then blood cells are made in the liver for a while (hepatic) and then finally when bone marrow is present, it is made in bone marrow (myeloid).

Front 51

Pluripotential hematopoietic stem cells arise from a single type of stem cell and proliferate to form.... (hint: 2)

Back 51

Lymphoid multipotential cells (migrate to lymphoid organs, eventually produce B and T lymphocytes).

Myeloid multipotential cells (remain in bone marrow but give rise to the rest of WBC precursors - neutrophilic granulocyte, eosinophilic granulocyte, basophilic granulocyte, monocytes - as well as magakryocytes and erythrocytes.

Front 52

___________ have fibers that measure less than 7 micrometers in diameter.

A. Loose CT
B. Dense Irregular CT
C. Dense Regular CT
D. Elastic CT
E. Reticular CT

Back 52

A. Loose CT

Front 53

____________ is a passageway for nerves and blood vessels.

A. Loose CT
B. Dense Irregular CT
C. Dense Regular CT
D. Elastic CT
E. Reticular CT

Back 53

A. Loose CT

Front 54

________ have fiber bundles that measure at least 7 micrometers in diameter and dermis of skin is a good example.

A. Loose CT
B. Dense Irregular CT
C. Dense Regular CT
D. Elastic CT
E. Reticular CT

Back 54

B. Dense Irregular CT

Front 55

Have collagen bundles in parallel rows. Tendons and ligaments are examples.

A. Loose CT
B. Dense Irregular CT
C. Dense Regular CT
D. Elastic CT
E. Reticular CT

Back 55

C. Dense Regular CT

Front 56

Which type of CT is composed of mainly inactive fibroblasts?

A. Loose CT
B. Dense Irregular CT
C. Dense Regular CT
D. Elastic CT
E. Reticular CT

Back 56

C. Dense regular CT