Branchial heart

Branchial hearts are myogenic accessory pumps found in coleoid cephalopods that supplement the action of the main, systemic heart.[1] Each consists of a single chamber and they are always paired, being located at the base of the gills.[1][2] They pump blood through the gills via the afferent branchial veins. Since they only circulate venous blood, branchial hearts function under predominantly anaerobic conditions.[1] Branchial hearts also appear to be involved in hemocyanin synthesis.[3][2]

Each branchial heart is directly connected to a branchial heart appendage or pericardial gland.[4] The action of the branchial hearts is necessary for the production of primary urine in these appendages via pressure filtration.[5] Branchial hearts may have evolved from the pericardial glands of nautiloids, such as those still found in modern nautiluses.[6]

References

  1. ^ a b c Fiedler, A. & R. Schipp (1987). The role of the branchial heart complex in circulation of coleoid cephalopods. Cellular and Molecular Life Sciences 43(5): 544–553. doi:10.1007/BF02143583
  2. ^ a b Cephalopoda Glossary. Tree of Life web project.
  3. ^ Beuerlein, K., R. Schimmelpfennig, B. Westermann, P. Ruth & R. Schipp (1998). Cytobiological studies on hemocyanin metabolism in the branchial heart complex of the common cuttlefish Sepia officinalis (Cephalopoda, Dibranchiata). Cell and Tissue Research 292(3): 587–595. doi:10.1007/s004410051088
  4. ^ Witmer, A. & A.W. Martin (1973). The fine structure of the branchial heart appendage of the cephalopod Octopus dofleini martini. Cell and Tissue Research 136(4): 545–568. doi:10.1007/BF00307370
  5. ^ Schipp, R., H.R. Schmidt & A. Fiedler (1986). Comparative cytochemical and pharmacological studies on the cholinergic innervation of the branchial heart of the cephalopod Sepia officinalis (L.). Cellular and Molecular Life Sciences 42(1): 23–30. doi:10.1007/BF01975878
  6. ^ Bourne, G.B., J.R. Redmond & K. Johansen (1977). Nautilus pompilius: Branchial circulation enhanced by an auxiliary pumping mechanism. Cellular and Molecular Life Sciences 33(11): 1453. doi:10.1007/BF01918802