Integumentary system - hair, Biology

Assignment Help:

HAIR

  1. Presence of hair is main feature of mammals, absent in whale fish.
  2. Soft hair in embryo of animals are lanugo. Study of hair is tricology.
  3. Part of hair which is outside epidermis is shaft.
  4. Inner part remains in hair follicle is hair bulb or root.
  5. Follicle at its base form hair papillae, rich in b.v. and nerve suply.
  6. In these cells power of division present through out life.
  7. Growth of hair depends on these cells. Around hair scally cuticle present.
  8. Outer part of hair is cortex, fibrous in nature, melanin present in it when melanin is disappeared and tiny air bubbles come, hair turns white.
  9. Inner part of hair is medulla made up of air filled, round, closely attached cells.
  10. Hair is fixed in hair follicle by Henle's layer, Huxley's layer & Hyaline's layer.
  11. Hair follicle is placed obliquely in dermis.
  12. Attached to epidermis by arrector pilli or elevator pilli muscle or arrector polirum muscle.
  13. This muscle is connected to sympathetic nervous system.
  14. Arrector pilli are absent in eye brow, arm's pit & other parts.
  15. In cold and fear, muscle is contracted, hair become straight i.e. cutis anserina.
  16. This time skin looks like goose flesh or duck bumps.
  17. It is under control of adrenalin. In rabbit & cat and other sliff hair are vibrissae.
  18. In rabbit, thigmo receptor, meant to judge burrows at night.
  19. In cat & rabbit if we cut vibrissae locomotion is uncontrolled & it can not run fast.
  20. If we remove all hair from skin, sweating is increased.

1269_hair structure.png


Related Discussions:- Integumentary system - hair

What are the parts of a surgical needle, What are the parts of a surgical n...

What are the parts of a surgical needle. How do you classify surgical needles The surgical needle is comprised of 3 parts: the needle point, the needle body, and the swaged (pr

Hypothalamus and pituitary, Hypothalamus and Pituitary The most obviou...

Hypothalamus and Pituitary The most obvious neuroendocrine link is between the hypothalamus and pituitary. The hypothalamus is a part of the brain which is connected to the pi

What are the cell kinds that form the phloem, What are the cell kinds that ...

What are the cell kinds that form the phloem? What are the major features of those cells? The major cells that form the phloem are the sieve elements and the companion cells an

What are the two big groups into which cells are classified, Q What are the...

Q What are the two big groups into which cells are classified? Cells can be classified as prokaryotic or eukaryotic. Prokaryotic cell is that with no delimited nucleus. Eukaryo

Explain about peptic ulcer, Q. Explain about Peptic Ulcer? Peptic ulcer...

Q. Explain about Peptic Ulcer? Peptic ulcers are one of the more serious forms of gastrointestinal disorders of the gastrointestinal tract particularly the stomach. The prevale

Explain the primary root growth, Explain the Primary Root Growth? Prim...

Explain the Primary Root Growth? Primary Growth in Roots :  Roots grow down and through the soil by adding new cells at the tip of the root (called the root tip). There is a

What are flight adaptations present by birds, Q. What are flight adaptation...

Q. What are flight adaptations present by birds? Wings associated to a well-developed pectoral musculature, less accumulation, pneumatic bones of feces in the bowels due to the

Salt glands in birds and reptiles, Salt Glands in Birds and Reptiles M...

Salt Glands in Birds and Reptiles Marine reptiles for example, iguanas, estuarine sea turtles, crocodiles, sea snakes and marine birds like the marine teleosts do not produce

Effects of earthquakes on buildings, The dynamic response of the building t...

The dynamic response of the building to earthquake ground motion is the most important cause of damages to the building that are induced by earthquake. Failure of the ground and so

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd