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 is flap tearing, What is Flap tearing Poor preoperative surgical p...

What is Flap tearing Poor preoperative surgical planning can result in flap of small size with inadequate exposure of the underlying bone. In an effort to increase the visibili

Explain different amino acids found in proteins, How many different protein...

How many different proteins, each composed of 8 amino acids, can be constructed using the 20 different amino acids found in proteins?

Estimation of depth of burn injury, Estimation of Depth of Burn Injury: ...

Estimation of Depth of Burn Injury: A thermal injury is described as partial thickness or full thickness, depending on the depth  and  severity of tissue damage a) First D

Endocrine glands - kidney, KIDNEY S - Origin . They develop from the ...

KIDNEY S - Origin . They develop from the mesoderm of the embryo. The kidneys secrete three hormones: renin, erythropoetin and calcitriol. (i) Renin . Whenever the rat

Extractive use of biodiversity, Q. Extractive use of biodiversity? This...

Q. Extractive use of biodiversity? This includes direct use such as harvesting of wild plant species for use as food, fuel, fodder, fibre, shelter or medicine and hunting anima

What are three main components of cytoskeletan, What is the cytoskeleton, a...

What is the cytoskeleton, and what are three of its main components? The cytoskeleton is a network of long protein strands located in the cytosol. Three main components are

Gateway reaction-entry clone and destination vector, (1) From the above gat...

(1) From the above gateway reaction (entry clone and destination vector); (i) which plasmid will be selected for when transformed into E.coli (A or B) and why? (ii) which an

Membrane carbohydrate, The  extracellular   surface  of  the  plasma  membr...

The  extracellular   surface  of  the  plasma  membrane   is  frequently  covered  with  a protective  coat  of carbohydrate. A Sugar  residue  of this  carbohydrate  coat can  be

Mitosis, What is the role of mitosis in growth?

What is the role of mitosis in growth?

Why are the plants having single-seeded fruits, Why are the plants having s...

Why are the plants having single-seeded fruits and plants having fruits with surplus one seed? The Plants that produce single-seeded fruits, for instance, avocado and mango oft

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