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

Describe the basic types of leukocytes, Q. What are the kinds of leukocytes...

Q. What are the kinds of leukocytes and how are they classified into granulocytes and agranulocytes? The kinds of lymphocytes are leukocytes, neutrophils, monocytes, basophils

Define the maintenance of weight loss, Define the Maintenance of Weight Los...

Define the Maintenance of Weight Loss? Once an individual has managed to lose weight to a desirable level, it must not be assumed that the weight loss will be maintained automa

Monosaccharide sugars, Monosaccharide Sugar - carbohydrate consisting o...

Monosaccharide Sugar - carbohydrate consisting of a single sugar unit Have an aldehyde or a ketone group and 2-5 alcohol groups depending of the # of carbons

Optical rotation in organice compounds, how the optical rotaion occurs in g...

how the optical rotaion occurs in glucose and ribose?

Explain the occurrence of vitamin B2, Explain the Occurrence of vitamin B 2...

Explain the Occurrence of vitamin B 2 Vitamin B 2 (riboflavin) occurs in nature almost exclusively in a combined form i.e. esterified with phosphoric acid as riboflavin-5'-ph

Define general characters and classification of arthropoda, Define General ...

Define General Characters and Classification of Arthropoda? These are metamerically segmented animals with an exoskeleton of cuticle. Scliizocoelic coelom is much reduced and is

Genetic material, Assuming that variability of populations were non-genetic...

Assuming that variability of populations were non-genetic, that is, not controlled by genetic material, once again chance events alone would determine which of the organisms would

How is the human karyotype usually represented, Can two normal individuals ...

Can two normal individuals of the same species with sexual reproduction have identical genomes and identical karyotypes? How is the human karyotype usually represented? Except

Saliva spreading - temperature relations in animals, Normal 0 f...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

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