The kidneys are the principal organ.
renal
Yes.
The organs in the renal system are the kidneys, ureters, bladder, and urethra. The kidneys filter waste and excess fluids from the blood to form urine, which then travels through the ureters to the bladder for storage before being excreted through the urethra.
Renal is a word that refers to the kidney. Anything that is renal (renal artery, for example) is found with the kidney. And the kidney is part of the excretory system that eliminates waste from your body via the blood stream.
The renal pelvis is in the kidney.
A portal circuit is found in the cardiovascular system. A renal circuit is found in the kidneys. Both are fond in the arteries in either organ
Cardiac, renal, digestive, integumentary(skin), nervous, musculoskeletal and endocrine.
The Renal artery attaches to the Kidneys.
it belongs to the excretory system because it takes out wastes from the body
The kidneys
Actually, earthworms have no respiratory system at all, they get the oxygen and nitrogen that they need from the soil.
The word 'renal' refers to the kidneys, so renal cancer would be a tumour which has started in the kidneys.