Wool and Mohair Flashcards
Define wool
hair from a sheep
Define mohair
fleece of an Angora goat
Which countries lead in wool production?
China and Australia
Which countries lead in mohair production?
South Africa and Texas (U.S.)
What is a primary hair follicle?
Primary hair follicles are larger in size, are the first follicles to develop, are arranged in groups of three, and are fully emerged at birth.
All accessory structures are present (arrector muscle, sebaceous glands, sweat glands).
They appear in bundles with secondary fibers.
What are secondary follicles?
Secondary follicles are smaller in size. They are associated with the primary follicles. They normally emerge between 1 and 3 weeks of age.
Secondary follicles have an incomplete set of accessory structures (they lack arrector muscles and sweat glands).
What factors affect follicle development?
- Adverse prenatal environment
- early postnatal environment
both can limit fiber growth
What fibers do consumers prefer and why?
They prefer the fibers from secondary follicles because they are more fine.
What is the cuticle?
The scaly outer layer that is present in all wool fibers.
What is the cortex?
The cortex are the needle like cells present in the wool fiber. It determines the crimp (waves in wool fiber).
What does ortho mean and what does it relate to?
Ortho- soft, elastic
relates to the cortex
What does para mean and what does it relate to?
para- hard, less elastic
relates to the cortex
What is the medulla?
Medulla are the hollow air spaces in the wool fiber. They are absent from finer wools.
What are kemp?
Kemp are larger fibers without a solid core, they have lots of medulla.
What do arrector muscles do?
Make hairs stand up on end
Define fleece
wool from a single sheep
define clip
amount of wool from a flock of sheep
What is the primary constituent of wool?
Keratin is wool’s primary constituent. It is a protein that serves as the building block of the wool fiber.
Describe the chemical composition and arrangement of keratin.
Keratin is composed of long, flexible polypeptides with sulfur containing amino acids like methionine and cysteine.
Sulfide bonds hold the polypeptide bonds together in a helical arrangement.