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

Metamorphosis, Metamorphosis The phenomenon of metamorphosis is descri...

Metamorphosis The phenomenon of metamorphosis is described as a process during development which involves a remarkable change in morphology and physiology of the larva, so tha

Define role of lipids in controlling gene expression, Define role of Lipids...

Define role of Lipids in Controlling Gene Expression? In the lipogenic pathway, the genes that encode the enzymes of the fatty acid synthase complex are co-ordinately expressed

Explain about the cellular senescence - geriatric nutrition, Explain about ...

Explain about the Cellular senescence - Geriatric Nutrition? Aging brings about an irreversible state of growth arrest at the cellular level. Though the cells are viable and me

What is the peripheral nervous system, Define the Peripheral Nervous Syste...

Define the Peripheral Nervous System (PNS) Peripheral nervous system consists of cranial and spinal nerves. There are twelve pairs of cranial nerves. They arise from brain.

What is ventilation, What is ventilation   A.  An increase in the hydro...

What is ventilation   A.  An increase in the hydrogen ion concentration in the interstitial spaces of the  brain stem leads to an increase in the duration of the respiratory cy

#title a&p, list all of the parts of a generalized cell that might be invol...

list all of the parts of a generalized cell that might be involved support movement coordination respiration digestion transportation excr production making proteins and reproducti

How does biogeography contribute to an evolution, How does biogeography con...

How does biogeography contribute to an understanding of evolution? In biogeography studies, same animals that seem to be closely related are adapted to dissimilar environments

Discuss mental nerve and its anatomic variation, Discuss mental nerve, its ...

Discuss mental nerve, its anatomic variation and surgical importance. Mental nerve, branch of inferior alveolar nerve is a very important landmark during osteotomy procedures.

Auditing, Definition of auditing According to the International Sta...

Definition of auditing According to the International Standard on Auditing (ISA) No. 200 Objective and common Principles Governing an Audit of Financial Statements, the obj

Fracture and its various types, Fracture - It is a break of a bone. Bone f...

Fracture - It is a break of a bone. Bone fracture are of many types - (i) Green stick fracture - It is merely a crack, the bone remains partly intact. (ii )     Sim

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