Connective tissues

Question 1

3 components of connective tissues

Answer 1

Extra cellular matrix - (Ground substance, Fibres) and cells

Question 2

Examples of connective tissue

Answer 2

It is the most abundant form of tissue which are highly vascularised, present in:
-Bone
-Cartilage
-Mesentery (connects intestine to abdomen)
-Tendons and ligaments
-Adipose tissue (energy storage)

Question 3

Functions of ground substance

Answer 3

-Provides biochemical support
-Clear, semi solid gel
-Composed of glycoproteins and complex carbohydrates:
-Hyaluronic acid
-Glucosamine
-Profound water-binding ability
-Provides tissue volume
-Supports intercellular exchange of substances

Question 4

Function of fibres

Answer 4

Provide structural support and tensile strength
EX. Collagen (strongest, most abundant, 28 types 1-4 most common) and Elastin (provide stretch and recoil, found in skin/lungs)

Question 5

Cells: function and naming

Answer 5

Synthesise, secrete and recycle ECM

Naming cells:
synthesise - …blasts
maintain - …cytes
breakdown - …clasts
Full name is determined by tissue it originates from.

Question 6

Most common connective tissue

Answer 6

Fibroblasts
secrete fibres and components of ground substance

Question 7

Synthesises dentin in teeth

Answer 7

Odontoblasts

Question 8

Maintain ECM in adipose tissue

Answer 8

Adipocytes

Question 9

Recycle ECM in bone (breakdown)

Answer 9

Osteoclasts

Question 10

Loose connective tissue (fewer fibres more ground substance - stain lighter) examples:

Answer 10

Areolar tissue - universal packing material found beneath skin, surrounding capillaries.

Adipose tissue - found in isolation or small cluster, energy store, shock absorption. Found in breasts, abdomen, finger etc.

Reticular tissue - delicate branched network (type 3 collagen) provide structure to highly cellular organd.

Question 11

Dense connective tissue (more fibres) examples:

Answer 11

Dense regular - closely packed collagen fibres running in same direction, provides tensile strength (in tendons)

Dense irregular - closely packed interwoven in different directions, found in dermis of skin or around organs.

Elastic - dominated by elastic fibres, allows recoil, found in skin, arteries and lungs etc.

Question 12

Connective tissue disorders with oral manifestations

Answer 12

Scurvy - lack of vit c, defective collagen formation causes blood vessels, tendons and skin to become fragile.

Lupus (SLE) - autoimmune disease, autoantibodies target own cells in skin, bones, tendons etc. Symptoms, dryness + soreness

Sjogren’s - Autoimmune disease, autoantibodies affect glands producing saliva + tears. oral manifestations - dental caries and candidiasis.

Question 13

Where is keratin present in the oral cavity

Answer 13

Present on the gingiva and the dorsal surface of the tongue. Absent from floor of mouth, mucosal surfaces of the cheeks and lips. Reflective of abrasive forces.

Question 14

In thin skin what three layers lie beneath the keratinised layer

Answer 14

Layer 1

= epidermis
Layer 2

= dermis
Layer 3

= subcutis or subcutaneous

Question 15

Which oncogenic pathogen interacts with keratinocytes in this layer?

Answer 15

The human papilloma virus has a tropism (affinity) for keratinocytes. It can access
the epidermis through abrasions. Note that HPV has many different types. HPV-16
and 18 are the main causes of cervical cancer and are significant in cancer of
the oropharynx but HPV infection does not appear to be a significant risk
factor for cancer of the mouth.

Question 16

What cells populate the subcutis

Answer 16

Adipocytes, solvents are used to remove the wax from sections prior to staining with
aqueous solutions. The solvents will remove lipid hence the “bubble” appearance
of the layer. There is only a little cytoplasm to pick up the stain.

Question 17

comment on the distribution of fibres in the epidermis

Answer 17

There and none present

Question 18

How do the fibres between the epidermis and the papillary dermis differ from the section of thick skin?

Answer 18

Here at the interface between the epidermis and the papillary dermis, the fibres appear to be more longitudinally orientated compared with the preparation of thick skin. In the reticular dermis the density of elastic fibres appears greater than in the preparation of thick skin.