Connective Tissue (Valentine)

Question 1

Characteristics of Connective Tissue (CT)
* Supports ?
* Vascularised or Avas.?
* Cells lack ?
* more or less? cohesive
* No ? membrane

Functions of Connective Tissue
* Joins ? together
* Gives ?, subdivides ?
* ? support of body (bone tissue)
* ? (adipose and vascular effects)
* ? & ? (adipose)
* ? & ? mechanisms (? and ? cells)

Answer 1

Characteristics of Connective Tissue (CT)
* Supports epithelia
* Vascularised
* Cells lack polarity
* less cohesive
* No basement membrane

Characteristics of Connective Tissue (CT)
* Supports ?
* Vascularised or Avas.?
* Cells lack ?
* more or less? cohesive
* No ? membrane

Functions of Connective Tissue
* Joins tissues together
* Gives form, subdivides organs
* physical support of body (bone tissue)
* thermoregulation (adipose and vascular effects)
* nutrition & storage (adipose)
* defense & repair mechanisms (inflammatory and immune cells)

Question 2

Relevance

• Basic understanding of ?, ? and ?.
• ? and ?
• ?
• ?
• ? terminology and development
  – Malignant tumors: SARCOMAS (Gr. Sarcos – flesh)

2. Components of Connective Tissue

A. Cells:
* ?
* ?

B. Fibers:
* ?
* ?
* ?

C. Ground Substance
* ?
* ? (tissue) fluid

Answer 2

Relevance

• Basic understanding of tissue organization, development and functioning.
• trauma and healing
• inflammation
• edema
• tumor terminology and development
  – Malignant tumors: SARCOMAS (Gr. Sarcos – flesh)

2. Components of Connective Tissue (CFG)

A. Cells:
* Resident
* Transient

B. Fibers: (cre)

• Collagen
• Elastic
• Reticular

C. Ground Substance
* Macromolecules
* Interstitial (tissue) fluid

Question 3

A. Resident Cells: Fibroblasts

• The most ? cell population of CT (connecti. tiss.)
• They synthesize the ? of the CT: collagenous, elastic, and reticular

Resident Cells: Reticular cells (note: CFG -> cre (r stands for reticular here)
- Special ? that synthesize a fine type of collagen fibers that offer scaffolding to the parenchyma (specialized epithelial cells) of various organs (lymph nodes, liver, spleen, etc.).

Parenchymatous organs need ? for their internal organization but are not subjected to high ?.

Answer 3

A. Resident Cells: Fibroblasts

• The most numerous cell population of CT (connecti. tiss.)
• They synthesize the fibers of the CT: collagenous, elastic, and reticular

Resident Cells: Reticular cells (note: CFG -> cre (r stands for reticular here)
- Special fibroblasts that synthesize a fine type of collagen fibers that offer scaffolding to the parenchyma (specialized epithelial cells) of various organs (lymph nodes, liver, spleen, etc.).

Parenchymatous organs need support for their internal organization but are not subjected to high mechanical stress.

Question 4

Resident Cells: Adipocytes

• Cells specialized in depositing ?.
• Can be of 2 types:

? – contain multiple droplets (“brown fat”); (n in brown similar to m)
? – a single big round drop of lipids (“white fat”)

(recall: CFG -> c for cells: resident or transient)

Resident Cells: Macrophages
* Resident ? cell of CT (yellow arrow)
* May be named by ?. Example: ? cells are macrophages in the liver; ? are macrophages in bone.

Resident Cells: Mast Cells
* Cells filled with basophilic ? (stained blue with H&E)
* They are involved in ? and ? reactions

Answer 4

Resident Cells: Adipocytes

• Cells specialized in depositing lipids.
• Can be of 2 types:

multilocular – contain multiple droplets (“brown fat”); (n in brown similar to m)
unilocular – a single big round drop of lipids (“white fat”)

(recall: CFG -> c for cells: resident or transient)

Resident Cells: Macrophages
* Resident phagocytic cell of CT (yellow arrow)
* May be named by location. Example: kuppfer cells are macrophages in the liver; osteoclasts are macrophages in bone.

Resident Cells: Mast Cells
* Cells filled with basophilic “granules” (stained blue with H&E)
* They are involved in inflammatory and allergic reactions

Question 5

Transient CT Cells = White Blood Cells

B. Fibers of Connective Tissue

1. Collagen Fibers (cre) from CFG
   * The most ? fibers of CT
   * Are what in color?; a large number of collagen fibers gives a white color to ? tissue: ?, tunica albuginea, sclera of the eye, etc.

recall:
ligament -> fibrous connective tissue
tendon -> fibrous connective tissue too

• Very high ? strength, very ?, can only stretch ?% of initial length.

Answer 5

Transient CT Cells = White Blood Cells

B. Fibers of Connective Tissue (CFG -> cre)

1. Collagen Fibers (cre) from CFG
   * The most numerous fibers of CT
   * Are white; a large number of collagen fibers gives a white color to collagen-rich tissue: tendons, tunica albuginea, sclera of the eye, etc.

recall:
ligament -> fibrous connective tissue
tendon -> fibrous connective tissue too

• Very high tensile strength, very strong, can only stretch 5% of initial length.

Question 6

Collagen (as a substance)

• The most abundant ? in the body representing ? of its dry weight in humans
• Many cells synthesize collagen – such as ?, chondroblasts, ? , odontoblasts, etc.
• ? is formed in the fibroblast, transported outside the cell, and then assembled into collagen ?.
• Vitamin ? (which letter) is an important cofactor in collagen synthesis.

Answer 6

Collagen (as a substance)

• The most abundant protein in the body representing 30% of its dry weight in humans
• Many cells synthesize collagen – such as osteoblasts, chondroblasts, fibroblasts, odontoblasts, etc.
• Procollagen is formed in the fibroblast, transported outside the cell, and then assembled into collagen fibroblasts.
• Vitamin C (which letter) is an important cofactor in collagen synthesis.

Question 7

2. Elastic Fibers (CFG -> cr”e”)

• Individual, ? and anastomosing (a cross-connection between adjacent channels,) fibers
• Produced by many cell types including ?
• color? grossly
• Can stretch #? times original length, and ?
• Found in ? and elastic ?, which organ?, vocal cords, ?, ? of ear, epiglottis, etc.

3. Reticular Fibers

• Form a fine network (reticulum) that can be *stained by ? * → aka ? fibers
• synthesized by ?, ? cells, ? cells and ? muscle cells.
• Serve as a ? to cells or cell groups of various organs.

Answer 7

2. Elastic Fibers (CFG -> cr”e”)

• Individual, branching and anastomosing (a cross-connection between adjacent channels,) fibers
• Produced by many cell types including fibroblasts
• pale yellow grossly
• Can stretch 2.5 times the original length, and recoil
• Found in aorta and elastic arteries, lungs, vocal cords, dermis, pinna of ear, epiglottis, etc.

3. Reticular Fibers

• Form a fine network (reticulum) that can be *stained by silver * → aka argentaffin fibers
• synthesized by reticular cells, liver cells, smooth muscle cells, and skeletal muscle cells.
• Serve as a scaffolding to cells or cell groups of various organs.

scaffolding: a temporary structure on the outside of a building, made usually of wooden planks and metal poles (pic in question)

Question 8

C. Ground Substance

• ?, ?; bathed in ? fluid
• Produced by ? cells (cells: resident and transient)
• Composed of:
• ? (GAGs)
• e.g.? acid; ? sulfate; ? sulfate;
  dermatan sulfate; heparan sulfate
• GAGs link to ? protein to make ?
• Properties of these molecules allow for binding of ?, resisting ? forces, cell adhesion to ?, cell migration, barrier to bacterial/ venom ?

Answer 8

C. Ground Substance

• amorphous, gel-like; bathed in interstitial fluid
• Produced by resident cells (cells: resident and transient)
• Composed of:
• “G”lycosaminoglycans (GAGs); “G”round substance
• e.g.hyaloronic acid; chondroitin sulfate; keratan sulfate; dermatan sulfate; heparan sulfate
• GAGs link to core PROTEin to make PROTEoglycans
• Properties of these molecules allow for binding of water, resisting compressive forces, cell adhesion to fibers, cell migration, barrier to bacterial/ venom penetrations

Question 9

Interstitial (Tissue) Fluid

• A solution of ? and ? derived from plasma
• Bathes the ?, ? and ?, aids in removing ?
• Fluid dynamics maintain proper balance in ?
• Tissue fluid determines skin ?; a decrease in skin turgor is a ? sign of dehydration
• ? are important in fluid movement and prevention of edema
• Not visible on slides

Answer 9

Interstitial (Tissue) Fluid

• A solution of nutrients and dissolved gases derived from plasma
• Bathes the cells, fibers and ground substance, aids in removing waste
• Fluid dynamics maintain proper balance in CTs
• Tissue fluid determines skin turgor; a decrease in skin turgor is a late sign of dehydration
• lymphatics are important in fluid movement and prevention of edema
• Not visible on slides

Question 10

** Edema ** = Abnormal accumulation of ?

increased ? permeability

Answer 10

** Edema ** = Abnormal accumulation of tissue fluid

increased vascular permeability

Question 11

Adipose connective tissue

• Composed of adipocytes: ? cells
• Functions:
  – Energy storage
  – Endocrine: adipocytes produce ** ? **, which has regulatory effect on body fat.
  ? levels are proportional to body fat. It signals to the brain (satiety center) that the body ?
  – Protection (absorbs forces in ?
  – ?
• When ? outnumber other cell types → adipose tissue

Answer 11

Adipose connective tissue

• Composed of adipocytes: fatty cells
• Functions:
  – Energy storage
  – Endocrine: adipocytes produce ** leptin **, which has regulatory effect on body fat.
  Leptin levels are proportional to body fat. It signals to the brain (satiety center) that the body has had enough to eat.
  – Protection (absorbs forces in digital fatty pad)
  – insulation
• When adipocytes outnumber other cell types → adipose tissue

Question 12

White Adipose Tissue
* Morphology: ? fat cells – one lipid ?

Functions:
* ? storage
* ?
* Endocrine = hormone
“ ? ” secretion

Brown Adipose Tissue
* Morphology: ? fat cells – ? lipid droplets; many mitochondria
* Found in ? and ? animals
* Function: ? generation

Answer 12

White Adipose Tissue
* Morphology: unilocular fat cells – ONLY one lipid droplet

Functions:
* energy storage
* insulation
* Endocrine = hormone
“ LEPTIN ” secretion

Brown Adipose Tissue
* Morphology: multilocular fat cells – several lipid droplets; many mitochondria
* Found in hibernating and newborn animals
* Function: heat generation