We use cookies to give you the best experience possible. By continuing we’ll assume you’re on board with our cookie policy

Details of Urochordata Essay Sample

The whole doc is available only for registered users OPEN DOC
  • Pages:
  • Word count: 473
  • Category: blood

Get Full Essay

Get access to this section to get all help you need with your essay and educational issues.

Get Access

Details of Urochordata Essay Sample

Urochordata is one of the sub phylum of chordate. Tunicates or Urochordata are all marine and colonial or solitary. Some species lead a sedentary life and others are pelagic. The Ascidian tunicate has formed a wrinkled cylinder or sac with 3-4 inches in length and has a broader base by which the organism is attached to the rocks or other substrates. Large aperture is present at the free end that is more or less terminal position which is the mouth or the inhalant siphon. Atrial or exhalent aperture is present little behind the aperture. Water current flows into the organism by the mouth and passes out through the atrial aperture. Disturbing of the animal makes it to squirts out jets of water through the atrial aperture and this gave the organism the name sea squirt. Anterior end of the animal is made by the oral aperture and posterior end is attached to the substrates and in the dorsal position the atrial aperture is placed.

The body of the animal is enclosed into a tough tunicine, a substance made of cellulose. The underlying ectoderm of the body wall secretes the test as cuticle but the mesoderm cells invade and give rise to the connective tissue. Test is attached in the region of the mouth and artial aperture where the blood vessels enter, others regions of the body wall are not attached and hence a loose covering is formed. The body wall of the animal is called as the mantle which is underlying below the tunic. Mantle consists of a matrix of connective tissue, blood vessels, muscles and nerves are found upon the ectoderm. Mouth and atrial apertures was the region attached to the tunic and produced into short prolongations called as the oral and artial siphons. Sphincter muscles help in closing the apertures.

Mouth leads to the short stomodaeum that is formed by the infolding of the ectoderm. Stomodaeum is followed by the pharynx which occupies the major part of the body from mouth to base. These regions are covered by the atrial or peribranchial cavity and all these parts are enclosed by the mantle. Long the mid ventral line the pharynx is attached to the mantle and free at the dorsal and lateral parts. Atrial aperture is an exterior opening for the atrial cavity. Pharynx is a food collecting apparatus and the animal feeds on small organisms which come into the mouth along the water current. The pharynx is perforated by numerous gill silts or stigmata and the lining of pharynx and edges of the stigmata are ciliated. There is a ciliated groove in the inner median line called as the endostyle. Respiration takes place by the passing of water through the stigma. The transverse and vertical region of the pharyngeal region contains blood vessels.



We can write a custom essay

According to Your Specific Requirements

Order an essay

You May Also Find These Documents Helpful

What Infuences Blood Pressure

Hypothesis Obesity is one of the factors influencing increase of systolic and diastolic blood pressure. Nowadays, obesity is a big problem among mankind especially in well-developed countries. The statistics show that in this countries (e.g. USA, UK) majority of people faces cardiovascular problems. Is it rather due to unhealthy lifestyle or inappropriate diet? This question is difficult to answer, but probably the mixture of these...

Measuring the Dependence Between Blood Pressure and...

The aim of the investigation is to examine the dependence between the blood pressure and the hour. The role of the blood is to supply organism with oxygen and nutrients. To reach every part of the body, blood is distributed by artery tissues. Because of the large size of human body, blood is pumped from the heart to arteries under certain pressure enabling in filling...

Warm Up Case

This increases blood flow through muscle tissues which allows an increase in metabolism also muscle temperature. Also it allows haemoglobin to release oxygen more frequently to the muscles which require it. Increases range of motion around a joint and there are hormonal changes. The body increases its production of various hormones responsible for regulating energy production. During warm-up this balance of hormones makes more carbohydrates...

The Effect of Stress on Physical Health

The effect of stress has always been viewed as having psychological effects. However, recent research has contradicted this notion. Stress is notorious for causing many physical ailments such as obesity, Crohn’s disease, weakness of heart and most skin conditions. According to the Center for Disease Control and Prevention, 90% of all illness and disease is stress-related. The fact that a staggering 90% of illness is...

Diarrhea Infection Case

Diarrhea describes bowel movements (stools) that are loose and watery. It is very common and usually not serious. Many people will have diarrhea once or twice each year. It typically lasts two to three days and can be treated with over-the-counter (OTC) medicines. Some people have diarrhea often as part of irritable bowel syndrome or other chronic diseases of the large intestine. Doctors classify diarrhea...

Get Access To The Full Essay
Materials Daily
100,000+ Subjects
2000+ Topics
Free Plagiarism
All Materials
are Cataloged Well

Sorry, but copying text is forbidden on this website. If you need this or any other sample, we can send it to you via email.

By clicking "SEND", you agree to our terms of service and privacy policy. We'll occasionally send you account related and promo emails.
Sorry, but only registered users have full access

How about getting this access

Become a member

Your Answer Is Very Helpful For Us
Thank You A Lot!


Emma Taylor


Hi there!
Would you like to get such a paper?
How about getting a customized one?

Couldn't Find What You Looking For?

Get access to our huge knowledge base which is continuously updated

Next Update Will Be About:
14 : 59 : 59
Become a Member