• 32 strips
  • Checked October 2026

Excretory System Comic Ideas

Three comic strip premises per press, each with a labeled beat for every organ in it.

Excretory System Comic Ideas

Show all 32
  1. One minute inside a kidney, timed with a stopwatch4 panels. Renal artery: blood flows in, and between them the two kidneys filter about half a cup of it every minute. Glomerulus: water, wastes and small molecules are filtered out of it. Tubule: almost all of that water goes back to the blood. Renal vein: the filtered blood leaves, a little urine is on its way to the ureter, and more blood is already arriving.
  2. Extra Water tells how it left the body4 panels. Kidneys: 'I was in the blood until a kidney filtered me out with the wastes.' Ureters: 'A thin tube of muscle squeezed me downward.' Bladder: 'I waited in a hollow, stretchy bag with the rest.' Urethra: 'The muscles let go, and out I went.'
  3. Blood makes its rounds past four cleaning stops4 panels. Liver: ammonia in the blood is turned into urea. Kidneys: urea, extra salts and extra water are filtered out. Lungs: carbon dioxide passes out of the blood and is breathed out. Skin: sweat glands take a little water and salt. Then the blood goes round again.

Next step Comic formats for a school project

All 32 strips

The path of urine 8

  • A bladder who keeps raising a hand in class 5 panels. Kidneys: they go on making urine all through the lesson. Ureters: two tubes keep delivering it. Bladder: it stretches, then signals the brain: find a toilet soon. Brain: at the bathroom it tells the muscles that hold the urethra shut to relax, and the bladder wall to squeeze. Urethra: the urine leaves.
  • A laundromat that washes blood and drains what is left 4 panels. Kidneys: two machines wash the blood, and wastes and extra water come out as urine. Ureters: two hoses squeeze it along, a little at a time. Bladder: a balloon-shaped tub swells as it fills. Urethra: one drain at the bottom of the tub lets it out of the body.
  • A map of the whole route with a pin on every stop 6 panels. Renal artery: blood carrying wastes flows into each kidney. Kidneys: they filter it and make urine. Renal vein: the filtered blood flows back out. Ureters: the urine goes down two thin tubes. Bladder: it is stored. Urethra: it leaves the body.
  • A town's waste service: two sorters, two chutes, one tank 4 panels. Kidneys: two bean-shaped sorting sheds take wastes and extra water out of the blood passing through. Ureters: two chutes with squeezing walls push the urine down. Bladder: a stretchy tank fills and holds it. Urethra: the brain gives the word, the gate opens and the tank empties.
  • An airport where wastes check in for a one-way trip 4 panels. Kidneys: at two check-in desks, wastes and extra water are taken off the blood and tagged as urine. Ureters: two moving walkways carry them on. Bladder: a departure lounge that stretches as it fills. Urethra: the gate opens and everyone leaves by the one exit.
  • Extra Water tells how it left the body 4 panels. Kidneys: 'I was in the blood until a kidney filtered me out with the wastes.' Ureters: 'A thin tube of muscle squeezed me downward.' Bladder: 'I waited in a hollow, stretchy bag with the rest.' Urethra: 'The muscles let go, and out I went.'
  • Two springs, two streams, one lake and one way out 4 panels. Kidneys: on each side of the spine a bean-shaped spring gives off urine, made from wastes and extra water in the blood. Ureters: a thin stream runs down from each. Bladder: both empty into one lake that rises as it fills. Urethra: a single outlet at the bottom lets the lake drain.
  • The two ureters do the wave 4 panels. Kidneys: two bean-shaped kidneys make urine from wastes and extra water. Ureters: the muscles in their walls tighten and relax in turn, like a crowd doing the wave, and push it down. Bladder: the urine arrives in small amounts and the bladder stretches. Urethra: the last tube lets it out.

Inside one kidney 8

  • A car wash that the blood drives through 4 panels. Renal artery: blood drives in carrying wastes. Glomerulus: in the spray bay, water, wastes and small molecules wash off, and proteins and blood cells stay on board. Tubule: the next bay hands back almost all the water, with minerals and nutrients. Renal vein: the blood drives out filtered, and the runoff is urine.
  • A lost-and-found desk beside the filter 4 panels. Renal artery: blood arrives with wastes in it. Glomerulus: water, wastes and small molecules pour through the filter into the tubule. Tubule: the desk hands back what the body needs, almost all the water with minerals and nutrients, to the blood vessel alongside. Renal vein: the blood leaves filtered; what nobody claimed is urine.
  • A red blood cell too big to go through the filter 3 panels. Glomerulus: water and wastes zip through the thin walls of the tiny blood vessels, and a red blood cell cannot fit. Tubule: it watches almost all of that water being taken back into the blood. Renal vein: the red blood cell leaves the kidney with the filtered blood, having never left the blood at all.
  • Blood before and after one trip through a kidney 4 panels. Renal artery: 'before', blood carrying urea, extra salts and extra water. Glomerulus: the filter lets them through, with much else. Tubule: what the body needs is returned to the blood. Renal vein: 'after', the filtered blood, with urea, extra salts and extra water taken out.
  • One minute inside a kidney, timed with a stopwatch 4 panels. Renal artery: blood flows in, and between them the two kidneys filter about half a cup of it every minute. Glomerulus: water, wastes and small molecules are filtered out of it. Tubule: almost all of that water goes back to the blood. Renal vein: the filtered blood leaves, a little urine is on its way to the ureter, and more blood is already arriving.
  • Panning for gold in a kidney stream 4 panels. Renal artery: blood rushes into the kidney. Glomerulus: a pan with tiny holes lets water, wastes and small molecules through, while proteins and blood cells are too big and stay in the blood. Tubule: a helper picks the gold back out: almost all the water, with minerals and nutrients. Renal vein: filtered blood flows out, and the gravel left over is urine.
  • Urea and Water pass the filter; only Water is asked back 4 panels. Renal artery: Urea and Water ride into the kidney together. Glomerulus: both pass through the filter into the tubule. Tubule: Water is taken back into the blood, and Urea is left behind. Renal vein: Water leaves in the filtered blood while Urea heads for the ureter as urine.
  • Zoom in four times: kidney, nephron, filter, tubule 4 panels. Kidney: a bean-shaped organ about the size of a fist. Nephron: one of about a million filtering units inside it. Glomerulus: a cluster of tiny blood vessels where water and wastes pass out of the blood. Tubule: the tube beside it, where needed things go back to the blood and the rest becomes urine.

Every organ as a character 8

  • A body outline with one more organ colored in each panel 5 panels. Kidneys: two beans just below the rib cage, one on each side of the spine; they make urine. Lungs: where carbon dioxide leaves the blood. Liver: the largest organ inside the body; it makes urea from ammonia. Skin: all over; it sweats. Large intestine: a long hollow tube at the end of the digestive tract; it removes solid waste.
  • A cleanup crew where each member takes one kind of waste 5 panels. Liver: it turns poisonous ammonia into urea. Kidneys: they filter urea, extra salts and extra water out of the blood as urine. Lungs: they breathe out carbon dioxide. Skin: its sweat glands let out sweat, a salty liquid. Large intestine: it takes back usable water and removes solid waste.
  • Ammonia gets a makeover at the liver and leaves as Urea 4 panels. Liver: Ammonia, who is poisonous, walks in and walks out as Urea. Blood: Urea rides the bloodstream to a kidney. Kidneys: the filters take Urea out of the blood. Bladder: Urea waits in the urine with the extra water until it is time to leave.
  • Blood makes its rounds past four cleaning stops 4 panels. Liver: ammonia in the blood is turned into urea. Kidneys: urea, extra salts and extra water are filtered out. Lungs: carbon dioxide passes out of the blood and is breathed out. Skin: sweat glands take a little water and salt. Then the blood goes round again.
  • Carbon Dioxide and Urea leave by different doors 4 panels. Blood: two wastes ride together, Carbon Dioxide and Urea. Lungs: Carbon Dioxide passes into the tiny air sacs and is breathed out. Kidneys: Urea is filtered out with the extra water. Bladder: Urea waits in the urine, and Carbon Dioxide is long gone.
  • Four ways out of the body, a waste for each 4 panels. Kidneys: the way out marked urine, for urea, extra salts and extra water. Lungs: the way out marked breath, for carbon dioxide. Skin: the small one marked sweat. Large intestine: the last one, for solid waste, the parts of food that could not be digested.
  • The large intestine insists it belongs on the list 3 panels. Kidneys: they point to the urine they make from wastes in the blood. Lungs: they point to the carbon dioxide they breathe out. Large intestine: it takes back the last usable water, removes solid waste, and points out that some lists count that too.
  • The skin's job interview for the excretory team 4 panels. Kidneys: 'We filter the blood and make urine.' Lungs: 'We breathe out carbon dioxide.' Liver: 'I turn ammonia into urea.' Skin: 'I sweat. Mostly to cool the body down, to be honest.' It gets the job, part time.

Something goes wrong 8

  • A full bladder and a brain that is busy 4 panels. Bladder: it is full and stretched, and it signals the brain. Brain: busy, it keeps the muscles around the urethra squeezed shut. Bathroom: now the brain tells those muscles to relax and the bladder wall to tighten. Urethra: the urine leaves, and the bladder wall relaxes to fill again.
  • A hot afternoon when the sweat glands take over 4 panels. Sun: the body is getting warm. Skin: its sweat glands let out sweat, a clear, salty liquid. Sweat: it evaporates and helps to cool the body. Kidneys: they are still the ones removing the urea, and how much urine they make today depends partly on how much water left as sweat.
  • A very big glass of water, and what the kidneys do next 4 panels. Blood: after a big drink there is extra water in the blood. Kidneys: they filter the extra water out and make more urine. Ureters: they squeeze it down, a little at a time. Bladder: it fills sooner than usual and signals the brain.
  • Carbon Dioxide, a waste gas, looks for the way out 3 panels. Blood: Carbon Dioxide, a waste gas, rides the bloodstream and finds no way out. Air sacs: in the lungs it passes out of the blood into the tiny air sacs. Breath out: the next time the body breathes out, it is blown out with the air.
  • The cells make too much acid and the tubules deal with it 3 panels. Cells: as they work, the body's cells produce acid. Blood: it carries the acid to the kidneys. Tubule: it removes the excess acid from the blood, and the acid leaves in the urine.
  • The leftovers still hold water the body can use 3 panels. Leftovers: the parts of food that cannot be digested arrive, still watery. Large intestine: it takes back the remaining usable water. Way out: the solid waste that is left is removed from the body.
  • More salt in the blood than the body needs 4 panels. Blood: there is extra salt in the blood. Glomerulus: salt and water pass through the filter into the tubule. Tubule: the salt and water the body needs go back to the blood. Urine: the extra salt stays behind and leaves with the extra water.
  • Urine tries to go back up and meets a one-way valve 4 panels. Kidneys: urine is made and sent down. Ureters: their muscles squeeze it toward the bladder. Valve: where each ureter enters the bladder, a valve stops the urine from flowing back up. Bladder: the urine stays put until it is time to leave by the urethra.

How it works

These excretory system comic ideas each give a cast and one labeled beat per panel: the organ and what it does there. The strips in Something goes wrong open on a small problem, such as a full bladder, and show the body putting it right.

Read the full guide

The path of urine, a panel each

Kidneys: two bean-shaped organs below the rib cage filter wastes and extra water out of the blood as urine. Ureters: two thin tubes of muscle squeeze it downward. Bladder: a hollow organ that stretches as it fills, then signals the brain. Urethra: the tube that lets the urine out.

Inside one kidney

Each kidney holds about a million nephrons. In each, a filter called the glomerulus lets water, wastes and small molecules out of the blood, and a tubule returns almost all the water with whatever the body needs. What is left is urine.

  • Give each waste a color of its own and keep it in every panel, so a reader can follow it out of the body.
  • Draw the bladder small in one panel and larger in the next. It stretches as it fills.

Questions and answers

How do you make a comic strip about the excretory system?

Pick a cast, such as a town's waste service with two sorters, two chutes and one tank. Give each organ a panel, in the order urine travels, and write the organ's name in the caption.

What organs are in the excretory system?

The kidneys, ureters, bladder and urethra: the urinary system. Wider lists add the lungs, which breathe out carbon dioxide, the skin, which sweats, the liver, which turns poisonous ammonia into urea, and the large intestine, which removes solid waste. Follow your class's list.

How many panels does an excretory system comic need?

Four cover the path of urine. Five or six leave room for the brain's signal, or for blood entering and leaving the kidney. A strip set inside one kidney can be told in three.

What is a funny excretory system comic idea?

Choose Funny: the skin at a job interview admitting that sweat is mostly for cooling, a red blood cell too big to go through the filter, or Ammonia getting a makeover at the liver.

More tools

Show 6 more

Browse Drawing Ideas