Causes of Chest Pain or Discomfort. We can divide the causes of chest pain into two major categories: those caused by cardiac issues, and those caused by other, non-cardiac issues. Causes of cardiac chest discomfort (pain) Canadian Cardiovascular Society Classification of Angina Class I â Angina occurs only with strenuous exercise. Class III â Angina occurs with mild activity such as climbing 1 fight of stairs or walking level for 1 to 2 blocks. Class IV â Angina occurs with any physical activity and may be present at rest. See also: Types of Angina. Other Cardiac Causes of Chest Pain or Discomfort Acute Pericarditis.
NEPHRIDIA:- In earthworm excretion occurs through nephridium. The excretory system in earth worm is closely associated with its closed circulatory system. Each segment of ea â¦ rthworm consists of a pair of nephridia or in some species cluster of nephridium.he excretory system in earth worm is closely associated with its closed circulatory system. Each segment of ea â¦ rthworm consists of a pair of nephridia or in some species cluster of nephridium.
An earthworm is a tube-shaped, segmented worm found in the phylum Annelida.They are commonly found living in soil, feeding on live and dead organic matter. Chemical: In addition to dead organic matter, the earthworm also ingests any other soil particles that are small enoughâincluding sand grains up to 1/20 of an inch (1.25 mm)âinto its gizzard, wherein those minute fragments of grit grind everything into a fine paste which is then digested in the intestine.