Lecture 4 - Connective Tissue

Question 1

Connective tissue cell

-Star shaped with an
oval nucleus

-Most numerous

-Produce extracellular
 matrix by synthesizing
& secreting mature 
proteoglycans &glyco-
proteins & precursor
molecules of various 
types of collagens &
elastin.
- Wound repair

Answer 1

Fibroblast

Question 2

Connective tissue cell

-are phagocytic and
derived from
Monocytes ( white
blood cells )

-Monocytes migrate to 
tissues & differentiate
 into Macrophages .
Kupffer cells in liver
Osteoclasts in bone 
Microglial cells in CNS 
-very granular
-mobile
-have many lysosomes
to breakdown the
phagocytic material

Answer 2

Macrophages

Question 3

Connective tissue cell

- From differentiation 
of B lymphocytes.
-synthesize & secrete
Immunoglobulin (anti-
bodies)
-have a prominent 
cartwheel nucleus with
a well developed
nucleolus
-abundant rough endo
plasmic reticulum &
Golgi apparatus
-move throughout
 matrix

Answer 3

Plasma cells

Question 4

Connective tissue cell

\_\_\_\_\_\_\_
and 
basophils have same
progenitor in the bone
marrow
-found around blood
vessels
-produce heparin ( an 
anticoagulant )
-produce histamine (a
vasodilator)

Answer 4

Mast cells

Question 5

Connective tissue cell

• storage of energy
• protection

Answer 5

Fat cells (Adipocytes)

Question 6

-protein collagen arranged in bundles
- most abundant of all the fibers
- parallel running fibrils for strength
-white/yellow in appearance
-soft-flexible-strong
-not elastic or extendable
-boiling turns it to gelatin
- Vitamin C is cofactor for collagen
synthesis
SCURVY: inadequate wound healing

Answer 6

Collagen

Question 7

• protein elastin
  
  • thin yellow fibers
  • stretch and return to normal
  • connect to one and other

Answer 7

Elastin

Question 8

• protein collagen and glycoproteins
  - similar to collagen thinner
  - form reticular framework

Answer 8

Reticular fibers

Question 9

viscous material – gel like

	- hyaluronic acid
	- Mucopolysacharide
	- mucoproteins

Answer 9

Ground substance

Question 10

Type of connective tissue

• present in embryo and umbilical cord .
• Sub divided into 1) mesenchyme found primarily in the embryo. It consists of spindle shaped cells that make contact with the neighboring cells . Consists of reticular fibers with a few collagen fibers.
• The other form is 2) mucous connective tissue , and is present in umbilical cord .It consists of a homogenous ground substance , jelly like in consistence ,called Wharton’s jelly .

Answer 10

Embryonic

Question 11

Type of connective tissue

-also called areolar CT.
Characterized by loosely arranged fibers and abundant cells .
-Lies beneath epithelia and lines the internal surfaces of the body.
-Is the site of inflammatory and immune responses.

Answer 11

Loose

Question 12

Type of connective tissue

• is characterized by abundant fibers and few cells .
• Fibers are mainly collagen arranged in bundles oriented in various directions that can with stand stresses on organs .
• Found in sub mucosa of the intestinal tract , deeper layer of dermis .

Answer 12

Dense irregular

Question 13

Type of connective tissue

• characterized by ordered and densely packed arrays of fibers and cells and very little ECM.
• Fibers are arranged in parallel arrays and provide maximum strength.
• Is the main functional component of tendons, ligaments and aponeuroses.

Answer 13

Dense Regular

Question 14

Type of connective tissue

-Reticular fibers provide a supporting framework for the cellular constituents of various tissues and organs e.g. lymph nodes.

Answer 14

Reticular tissue

Question 15

Type of connective tissue

• Elastic tissue is mainly composed of elastic fibers capable of stretch and distension .
• Fibers are thinner than collagen, and are arranged in a branching pattern.
• Take up special dyes like orcein and resorcin- fuchsin.
• Found in the dermis of the skin , aorta , vertebral ligaments , larynx etc.

Answer 15

Elastic tissue

Question 16

Type of connective tissue

-plays an important role in energy homeostasis.
Consists of 2 types , white and brown

Answer 16

Adipose tissue

Question 17

Type of adipose tissue

• Predominant type in adults .
• Serves to store energy , insulation, cushioning of vital organs and secretion of hormones .
• Unilocular cells with a single large fat inclusion that pushes the nucleus towards the periphery .

Answer 17

White Adipose tissue

Question 18

Type of adipose tissue

• Abundant in newborn and is markedly reduced in adults .
• In the newborn makes about 5% of the total body mass and is found in the back , along the upper half of the spine and towards the shoulders.
• Cells are multilocular , rich in mitochondria and surrounded by abundant blood vessels.

Answer 18

Brown adipose tissue

Question 19

Type of cartilage

• It is avascular .
• It is surrounded by perichondrium ( except in articular cartilage ).
• It consists of chondrocytes surrounded by collagen matrix .
• It occurs in the temporary skeleton of the embryo , articular cartilage, the cartilage of nose, larynx, trachea, bronchi and costal cartilages.

Answer 19

Hyaline Cartilage

Question 20

Type of cartilage

• It is avascular .
• It is surrounded by perichondrium.
• It consists of chondrocytes surrounded by matrix of elastic fibers and collagen fibers. The elastic fibers can be seen under light microscope when stained by orcein.
• It occurs in external ear , epiglottis and auditory tube

Answer 20

Elastic Cartilage

Question 21

Type of cartilage

-It is avascular.
-It lacks a perichondrium.
-It consists of chondrocytes and fibroblasts surrounded by collagen fibers and a less rigid extracellular matrix.
It is found in intervertebral discs , articular discs of the knee joint, sternoclavicular joints and pubic symphysis.

Answer 21

Fibrocartilage