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

Describe structure of biological compounds, Describe Structure of biologica...

Describe Structure of biological compounds? Structure :  The most important chemical compounds in living systems are probably the organic compounds. The term "organic" in the

Ph of food in pectic ulcer, Q. PH of food in pectic ulcer? PH of food: ...

Q. PH of food in pectic ulcer? PH of food: It has. a little therapeutic importance except for patients with lesions in the mouth or oesophagus. Most foods are considerably les

Explain dietary assessment criteria for vitamin a, Explain Dietary Assessme...

Explain Dietary Assessment Criteria for Vitamin A? Several methods can be adopted for the dietary assessment of vitamin A such as food frequency, weekly or 3 day food weighmen

Define primary level care - public nutrition, Define Primary Level Care - P...

Define Primary Level Care - Public Nutrition? This is the first level of contact of an individual, the family and the community with the national health system. It is possible

Ecology, What is the role of ecology to the evolution theory.

What is the role of ecology to the evolution theory.

Define sample collection and estimation of blood glucose, Define Sample col...

Define Sample collection and estimation of blood glucose? The aim of blood glucose estimation is to diagnose or to exclude or to monitor the anti-diabetic therapy. For blood gl

Calculate the insulin bolus and drip rate , Mrs. M is a 35-year-old Hispani...

Mrs. M is a 35-year-old Hispanic female with no known past medical history; does not have a primary care provider (PCP). She presents to the emergency department with the following

Explain galactosemia, Galactosemia Inability  of conversion of galactos...

Galactosemia Inability  of conversion of galactose  to glucose results in the accumulation of galactose in  the  blood  -  known  as galactosemia. The biochemical defect usuall

Explain the expanding frontiers of nutrition, Explain the Expanding Frontie...

Explain the Expanding Frontiers of Nutrition? While the essential nutrients mentioned in Table are indispensable and our diets need to provide them all in adequate quantities,

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