Can be veins, can be arteries, can be capillaries, can be the aorta..
The tube through which sperm travels is called the vas deferens.
Blood vessels - arteries, capillaries and veins.
The tube through which oxygen travels down to the lungs is called the trachea. It is also known as the windpipe and is a crucial part of the respiratory system.
The tube that the egg passes through is called the fallopian tube. It is where fertilization typically occurs, as the egg travels from the ovary to the uterus.
The tube that travels from the kidney to the bladder is called the ureter, not to be confused with the tube that travels from the bladder to the exit point from the body, which is called the urethra.
urethra
fallopian tube
It travels through a "Pipe" and explodes out the "Vent", or possibly the "Side Vent", and another world for the hole at the top is the Crater.
lava tube
The phenomenon is called lava tube formation, where molten lava flows through a natural tunnel-like structure underground. Lava travels through these tubes, allowing it to move further away from the volcanic vent.
in humans, the egg is fertilized in the fallopian tube. the egg is released from the ovary and waits there in hopes of being fertilized. this is called ovulation. the sperm travels through the cervix, through the uterus, and into the fallopian tube where it looks for the egg.chickens have an organ called infundibulum where the sperm will be. then they lay the fertilized egg.Uterine (Fallopian) Tube
The tube through which food travels down is called the esophagus. It connects the throat (pharynx) to the stomach and is responsible for transporting food via a series of muscular contractions known as peristalsis. Once food is swallowed, it moves down the esophagus and enters the stomach for further digestion.