Connective Tissue Flashcards Preview

ESA 1 - Body Logistics > Connective Tissue > Flashcards

Flashcards in Connective Tissue Deck (18)
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1
Q

What are the 4 basic types of tissue?

A
  1. Nervous
  2. Epithelial
  3. Muscle
  4. Connective
2
Q

What are the types of CT?

A
  1. Proper

Specialised

  1. Adipose
  2. Blood
  3. Bone
  4. Cartilage
  5. Haemopoietic (bone marrow and lymphoid)
3
Q

What cells does CT arise from?

A

Mesenchymal stem cells

4
Q

Suggest 6 functions of CT?

A
  1. Connects cells to form tissues, tissues to form organs and organs to form the body. Some CT provides support (cartilage/bone).
  2. Transport: medium for diffusion of nutrients and wastes.
  3. Protection: cushion between tissues and organs, and insulation (adipose).
  4. Storage (adipose).
  5. Defence against infection (blood/lymph/fixed and wandering cells)
  6. Wound healing (macrophages, fibroblasts, myofibroblasts).
5
Q

What are the 3 general components of CT proper?

A
  1. Cells
  2. Fibres
  3. Ground substance
6
Q

Which cells secrete the fibres (collagen) and ground substance of CT?

A

Fibroblasts

7
Q

As well as producing CT, what is an important role of fibroblasts?

A
  • Wound healing
  • Scar tissue formation - myofibroblasts = modified fibroblasts containing actin. Responsible for wound contraction when tissue loss has occurred.
8
Q

What are the 3 types of fibres in CT and why are these important?

A
  1. Collagen - flexible with high tensile strength
  2. Reticular - provide a supporting framework
  3. Elastin - allows tissue to recoil after stretch
9
Q

What is the most common protein in our body?

A
  • Collagen

- 1/4-1/3 of whole-body protein content

10
Q

How many types of collagen do we have and which is the most common?

A
  • 28

- Type I (90% of all collagen)

11
Q

What is the difference between type I, II, III & IV collagen?

A
  • Type I: fibrils (composed of alpha chain triple helix) aggregate into fibres and fibre bundles (e.g. tendons, organ capsules and skin dermis).
  • Type II: fibrils do not form fibres (e.g. hyaline and elastic cartilage).
  • Type III: fibrils form fibrils around muscle and nerve cells and within lymphatic tissues and organs - reticulin.
  • Type IV: unique form present in basal lamina of basement membranes.
12
Q

What are reticular fibres and where are they primarily found?

A
  • Consist of type III collagen.
  • Form an irregular anastomosing network throughout lymph nodes, with lymphocytes densely packed in the spaces between the fibres.
13
Q

What are elastic fibres composed of?

A
  • Primary component = elastin.

- Enfolds and is surrounded by fibrillin microfibrils.

14
Q

Where are elastin fibres found?

A
  • Occur in most CT but to widely varying degrees.
  • Important role in:
    ~ dermis
    ~ artery walls (allows stretch and recoil)
    ~ lungs
    ~ elastic cartilage
15
Q

Which disease is associated with abnormal elastic fibres?

A
  • Marfan’s syndrome
  • Autosomal dominant - abnormal expression of fibrillin gene
  • Abnormally tall, arachnodactyly, frequent joint dislocation, risk of aortic rupture.
16
Q

What is the ground substance of CT made up of?

A
  • Proteoglycans = large macromolecules consisting of a core protein to which glycosaminoglycans (GAGs) are bound.
  • High water content - viscous.
17
Q

Why does ground substance have a high water content?

A

GAGs attract water as they are:

  • strongly hydrophilic
  • highly negatively charged - attract cations (e.g. sodium ions), causing water to be sucked into the matrix
18
Q

Describe the properties of a unique GAG.

A
  • Hyaluronic acid
  • Bound to proteoglycans by a linker protein - forms giant hydrophilic macromolecules.
  • Present in ground surface of cartilage - allows it to resist compression without inhibiting flexibility.