Coxal glands, Biology

Assignment Help:

Coxal Glands

There is a pair of coxal glands, in almost all the segments in Onychophora (Peripatus). Developmentally; in every segment a hollow follicle or somite arises and in the trunk region, they become divided in dorsal and ventrolateral portions. The ventrolateral portion grows into the appendages and its cavity makes the end sac of the coxal gland. The end sac opens by a ciliated canal, the coelomostome, into acoiled excretory canal. The terminal portion of the canal is enlarged to form a vesicle or bladder. So the coxal glands are derived from coelomoducts. In arthropods there is a likeness in the formation of coxal glands from coelomoducts and the creation of gonads and their ducts.

In crustaceans they are found in third and sixth segments and they are suitably. named depending upon the site of their opening to outside. The one located at the base of the third segment opens at the base of the antenna, therefore called antennal gland. The one located in the sixth segment opens at the base of the second maxilla, and is termed as maxillary gland. Antennal gland is present in the larval forms of Ostracoda, Copepoda, Branchiopoda, Branchiura, Cirripedia and lower Malacostraca but TP the adults of these groups have maxillary glands. The adult amphipod and decapod crustaceans comprise antennal glands. Mysidacea, a primitive group of crustaceans have both of the antennal and maxillary glands functional. Most arachnids have a pair of coxal glands opening in the sixth segment, opening at the base of third pair of walking legs. In Limulus, there are four pairs of coxal glands.


Related Discussions:- Coxal glands

Prevention of coronary heart diseases, Q. Prevention of Coronary Heart Dise...

Q. Prevention of Coronary Heart Diseases? In view of the steep rise in the incidence of chronic degenerative coronary heart diseases, several programmes have been formulated to

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

Eexplain importance of mitosis for the embryonic development, What is the i...

What is the importance of mitosis for the embryonic development? Every embryo grows from a single cell that suffers mitosis and operates other cells that also divide themselves

Define future challenges for dynamical network, Define Future challenges fo...

Define Future challenges for dynamical network? Graph theory is an old field of mathematics where biological applications are driving new advances. Mathematicians are supplemen

Quality adjusted life years (qalys), Normal 0 false false f...

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

Zoonoses disease-vaccinia-like disease, Vaccinia-like disease Smallpox caus...

Vaccinia-like disease Smallpox caused by variola virus (VARV) has successfully been eradicated in the last quarter of the 20th century. However, vaccinia like viruses (VLVs) , viz.

What is the contraceptive mechanism of the iud, What is the contraceptive m...

What is the contraceptive mechanism of the IUD? The IUD (intrauterine device) is a piece of plastic coated with copper that is inserted within the uterus by a doctor. Copper is

Nutrition education for prevention of vitamin a deficiency, Define Nutritio...

Define Nutrition Education for prevention of vitamin a deficiency? Ignorance, you may recall studying earlier, is an important determinant of vitamin A deficiency. There is, th

Explain the meaning of life style modification, Explain the Meaning of Life...

Explain the Meaning of Life Style Modification Life Style Modification (LSM) is an important aspect in the treatment of diabetes. LSM will help the people who are pre-diabetic

What is osmotic pressure, What is osmotic pressure? Osmotic pressure is...

What is osmotic pressure? Osmotic pressure is the pressure formed in an aqueous solution by a region of lower solute concentration upon a region of higher solute concentration

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