Published in Zoology
Monday, 05 June 2017 16:25
A true blood vascular sys­tem is absent. In star fish, this system circulates digested food to all body parts. It can be studied under two parts.
  1. Perihaemal system.
  2. Haemal system.
1. Perihaemal system: It has many tubular coelomic si­nuses called perihaemal system because they enclose channels or Haemal system. The perihaemal vessels run parallel to water vascular system and encircle it.
  1. Axial sinus: It is a small tube. It encloses stone canal and axial gland forming an axial complex.
  2. Aboral ring sinus: It is five sided sinus found inside the aboral wall of the central disc. It is incomplete in the region of the canal.
  3. Genital sinuses: Each gonad is encircled by a small genital sinus. It is connected with the aboral ring sinus by very small branch.
  4. Oral ring sinus: It is present around the mouth. It is divided into two
    a) A smaller inner ring. b) A larger outer ring. The oral end of the axial sinus communicates with the inner division of the ring sinus.
  5. Radial perihaemal sinuses: It arises from the outer division of the oral ring sinus and goes into each arm. This sinus in each arm is divided into two by septum. Small, thin branches are given from the radial perihaemal sinuses into the podia.
  6. Marginal sinuses: Longitudinal marginal sinus is present just aboral to the marginal nerve cord.
  7. Peri-branchial sinuses: These are present in the form of circular spaces encircling the basal parts of the gills.
2. Haemal system: It is reduced. It has spaces which do not show epithelial lining These spaces inter-communicate with each other. The haemal channels are enclosed in the coelomic spaces of the perehaemal system. They contain coebmic fluids.

The mouth is surrounded by a oral haemal ring. This runs into the septum dividing the hyponeural ring sinus. From the oral haemal sinus arises radial haemal sinuses. Each one enters into one arm.
The oral haemal ring is connected with the aboral haemal ring through the axial gland. A pair of gastric haemal tufts arise from the sinus in the region of cardiac stomach wall. They open into the haemal plexus of the axial gland.
These haemal channels are in fact not true blood vessels. They contain fluid which helps in the circulation and distribution of digested food materials.




CHOLERA is a specific infectious disease that affects the lower portion of the intestine and is char...

Useful Sites

  • NCBI

    National Center for Biotechnology Information
  • LTO

    Lab Tests Online® by AACC
  • ASCP

    American Society for Clinical Pathology
  • ASM

    American Society for Microbiology
  • The Medical Library®

    Project of

Connect With Us

Contact Us

All comments and suggestions about this web site are very welcome and a valuable source of information for us. Thanks!

Tel: +(92) 302 970 8985-6

Email: This email address is being protected from spambots. You need JavaScript enabled to view it.


This website is certified by Health On the Net Foundation. Click to verify. This site complies with the HONcode standard for trustworthy health information:
verify here.

Our Sponsors

InsightGadgets.comPathLabStudyTheMedicalLibrary.orgThe Physio Club

By using you agree to our use of cookies to enhance your experience on this website.