Question

Feathers are arranged in rows within 'tract' in the skin. These tracts are separated by non-feathered spaces called

• A. Pterylae
• B. Pneutrylae
• C. Apteria
• D. Pneuteria

Hint:

Surgical incisions in birds and poultry are typically made through the bare apteria to minimize blood loss and avoid damaging active feather follicles in the pterylae.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
In birds, feathers do not grow uniformly or randomly across the entire surface of the skin.
Instead, they are organized in distinct, localized tracts.
Understanding this anatomical arrangement is important for poultry production, processing, and veterinary medicine.

Step 2: Detailed Explanation:
The specialized arrangement of feathers on a bird's body is called pterylosis.
The skin surface is divided into two distinct areas:
Pterylae: The defined tracts of skin where feathers actively develop and insert. These tracts are arranged in symmetric patterns along the head, neck, back, wings, and breast.
Apteria: The bare, non-feathered spaces of skin that separate the pterylae. While apteria lack contour feathers, they may contain down feathers or semi-plumes.
This anatomical arrangement of having feathered tracts separated by bare spaces serves several physiological functions:
- It reduces the weight of the plumage while still providing effective insulation and flight capabilities.
- It facilitates the movement of muscles and limbs during flight by preventing feather crowding.
- It assists in thermoregulation, as birds can adjust their feathers to expose the bare skin of the apteria to release excess body heat.
In poultry processing, understanding these tracts helps optimize defeathering procedures.

Step 3: Final Answer:
The non-feathered spaces that separate the feather tracts are called apteria.