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

Autoradiography, Autoradiography Autoradiography is a modification of t...

Autoradiography Autoradiography is a modification of the radioactive tracer technique. In this technique, the radioactivity is detected by a thin film of photographic emulsion

Define the term hot water blanching, Define the term Hot water blanching? ...

Define the term Hot water blanching? A appropriate water-blanching process in traditional processing is as follows: The sliced material is placed on a square piece of cl

Name element playing significant role in nitrogen fixation, An element play...

An element playing significant role in nitrogen fixation is : 1.  Molybdenum 2. Copper 3. Manganese 4. Zinc An element playing significant role in nitrogen fixation

Cat scratch disease, Cat scratch disease It is caused by Bortenella he...

Cat scratch disease It is caused by Bortenella henselae, a gram-negative, non-motile bacterium. The organism is found in all parts of the world. The cat is an important reserv

Describe new cardio-vascular risk factors, Describe New Cardio-vascular Ris...

Describe New Cardio-vascular Risk Factors ? The major risk factors contributing to the development of atherosclerotic plaques in blood vessels have been known for many years. H

Explain the term- cerebral ischemia, Explain the term- Cerebral Ischemia ...

Explain the term- Cerebral Ischemia Ischemia refers to any of a group of disorders in which the symptoms are caused by vessel blockage preventing a sufficient supply of blood t

Unstable angina, Unstable Angina :  It is indicative of important reversib...

Unstable Angina :  It is indicative of important reversible myocardial ischaernia that needs urgent evaluation and treatment. Medical management usually relieves symptoms and if t

Gonads and ovary - reproduction, Normal 0 false false false...

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

General requirements of implant materials, General requirements of implant ...

General requirements of implant materials 1) Biologically compatibility: an ideal implant material will elicit mainly physiological reactions within the surrounding tissues (bo

Define some food related problems in parkinson''s disease, Define Some Food...

Define Some Food Related Problems in parkinson's disease? As the disease progresses some food related difficulties appear. These are: 1. Difficulty in food preparation

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