Question
Which of the following tissues does NOT contain Type I collagen?
| A. |
Bone |
| B. |
Tendon |
| C. |
Cartilage (hyaline) |
| D. |
Skin |
|
Correct Answer » C Explanation |
 |
Clinical Reasoning for the Correct Answer:
– Type I collagen is abundant in bone, tendon, and skin, providing high tensile strength.
– Hyaline cartilage is composed primarily of Type II collagen, not Type I.
Why Option A is Incorrect (Bone):
– Bone’s organic matrix is mostly Type I collagen; essential for tensile resistance.
Why Option B is Incorrect (Tendon):
– Tendons contain parallel bundles of Type I collagen; crucial for withstanding stretching.
Why Option C is Correct (Cartilage, hyaline):
– Hyaline cartilage (articular surfaces, trachea, nasal cartilage) mainly contains Type II collagen.
– Lacks significant Type I collagen except in the perichondrium (not present in articular cartilage).
Why Option D is Incorrect (Skin):
– Skin’s dermis contains large amounts of Type I collagen, giving strength and structure.
High‑Yield Synopsis:
Type I Collagen:
– Major Locations:
– Bone, dermis of skin, tendon, ligaments, fascia, sclera, dentin, cornea, aponeuroses, fibrocartilage
– Not Found In:
– Hyaline cartilage, elastic cartilage, basement membranes
– Key Differentials:
– Type II collagen: Hyaline and elastic cartilage, vitreous humor
– Type III collagen: Reticular fibers (blood vessels, uterus, granulation tissue)
– Type IV collagen: Basement membranes
– Clinical Correlates:
– Osteogenesis imperfecta (Type I collagen defect), Ehlers-Danlos syndrome (subtypes involve Type I/III)
– Key Point:
– Absence of Type I collagen in hyaline and elastic cartilage distinguishes them from fibrocartilage and other Type I–rich tissues