TracheaThe windpipe, a straight tube from the larynx to the bronchi. Rings of cartilage hold it open.
LungsThey lie in the chest, one each side of the heart. The trachea ends in two bronchi, one to each lung.
DiaphragmA sheet of muscle with a thin tendon at its center. It makes a complete wall between the chest and the abdomen.
LiverThe largest gland in the body, in several lobes. It lies against the diaphragm and covers much of the stomach.
StomachIt lies close to the diaphragm on the cat's left side. The liver covers a good part of it.
SpleenA flat, elongated organ on the left side. A part of the omentum holds it alongside the stomach.
Greater omentumA thin sheet that hangs from the stomach like an apron. More or less laden with fat, it covers the intestines. Lift it to find them.
Digestive tract 10
GallbladderA small sac in a cleft of the liver. Its duct joins the ducts from the liver, and the bile reaches the duodenum.
PancreasA long gland bent near its middle. One part lies in the bend of the duodenum and the other behind the stomach.
DuodenumThe first part of the small intestine. Ducts from the liver and the pancreas empty into it.
JejunumThe part of the small intestine between the duodenum and the ileum. No mark shows where it begins or ends.
MesenteryA thin, much-folded sheet that suspends the small intestine. It hangs from the abdomen's back wall.
IleumThe last part of the small intestine. It opens into the side of the large intestine, on the cat's right.
CecumA short blind pouch at the start of the large intestine. It ends in a blunt cone.
Ascending colonThe first part of the colon. It runs toward the head on the cat's right side.
Transverse colonThe part of the colon crossing the body from right to left.
Descending colonThe last part of the colon. It runs back toward the tail and ends in the rectum.
Urinary system 7
KidneysThey lie against the back wall, behind the lining of the abdomen. The right kidney is a little nearer the head than the left.
Adrenal glandsTwo small oval bodies toward the head and midline from each kidney. They usually do not touch it. Older cat manuals call them suprarenal bodies.
Renal arteryOne to each kidney from the side of the aorta. It enters at the hilus, the notch on the kidney's inner edge.
Renal veinIt carries blood from the kidney to the posterior vena cava. The left one crosses over the aorta to get there.
UretersA narrow tube from each kidney's hilus back to the bladder.
Urinary bladderA pear-shaped sac. Its narrow neck points toward the tail. The neck leads into the urethra.
UrethraThe narrow tube that carries urine out of the body. It starts at the neck of the bladder.
How this list was compiled: Every name checked on 2026-09-30 in two cat anatomy texts read in full: Jacob Reighard and H. S. Jennings, Anatomy of the Cat (1901), https://archive.org/details/anatomyofcat00reig, and Alvin Davison, Mammalian Anatomy with Special Reference to the Cat (1903), https://archive.org/details/mammaliananatomy00davi. Today's spellings and the names adrenal glands and urinary bladder are from OpenStax, Anatomy and Physiology 2e, sections 17.6, 22.1, 23.5 and 25.2, https://openstax.org/books/anatomy-and-physiology-2e/pages/23-5-the-small-and-large-intestines. Licence: own work
The drawing: Drawn for this site on 2026-10-04 by script as splines, nothing traced. Laid out after public domain figures: Wilder and Gage, Anatomical Technology as Applied to the Domestic Cat (1882), figs. 76 and 101 (the cat's outline from below); St George Mivart, The Cat (1881), figs. 89 and 105 (viscera in place; kidneys, vessels and bladder); Alvin Davison, Mammalian Anatomy with Special Reference to the Cat (1903), fig. 60 (alimentary canal). Licence: own work
How it works
This cat digestive system diagram follows a dissection lab. First the cat as it is opened, with the greater omentum still over the intestines. Then the tract laid out from duodenum to descending colon. Then the kidneys and bladder behind it.
Read the full guide
Whole cat, then the digestive tract
The first view is also a cat respiratory system diagram: trachea, lungs and diaphragm, with the liver, stomach and spleen behind. In the second view the omentum is lifted away. Follow the small intestine from the duodenum through the jejunum and ileum to the cecum, then the colon: ascending, transverse, descending.
Urinary system
The third view works as a cat kidney diagram. With the gut lifted out, each kidney shows its renal artery and renal vein at the hilus, an adrenal gland nearby, and a ureter running back to the urinary bladder and urethra.
The cat lies on its back, so its left side is at the top of each view.
The cecum is easy to miss: look for a short pouch where the ileum meets the colon.
Questions and answers
What are the parts of a cat's digestive system?
After the mouth and esophagus: the stomach, then the small intestine in three parts (duodenum, jejunum, ileum), then the large intestine (cecum, colon and rectum). The liver, gallbladder and pancreas empty into the duodenum through ducts.
What covers the intestines when a cat is first opened?
The greater omentum. It is a thin sheet, usually with fat in it, that hangs from the stomach and lies over the intestines like an apron. Lift it and the coils of the small intestine show.
How do you tell the jejunum from the ileum?
By position only. Nothing marks where one ends and the next begins. The jejunum follows the duodenum; the ileum is the last stretch, and it opens into the side of the large intestine beside the cecum.
Which cat kidney sits nearer the head?
The right one. Both lie against the back wall, one each side of the backbone, behind the lining of the abdomen.