Urinary System
Directions
- Print this PDF worksheet for a hardcopy guide as you work through this lesson.
- Within the lesson click the red linked headings to bring up the desired starting point within the cadaver for your work.
- Use the provided images on the worksheet to annotate and identify specific anatomical structures.
All kidneying aside, it is time to take a serious look at the urinary system. I'm certain you'll be "relieved" to know I'm going to avoid tasteless puns in this lesson! :-o
Urinary system anatomy is pretty straightforward. Rotate your specimen to a lateral perspective so you can appreciate the depth of this anatomy. Of course, kidneys are not located in the arms; you're looking "through" the arms with this lateral view. Since nearly all of our study has been with our male specimen, I'll use the female pelvic specimen for general instruction and then come back to our male to identify some differences.
- Kidney (Right & Left) - The kidney produces urine, a fluid containing water, ions and small soluble compounds.
- Renal Pelvis (Right & Left) - Urine drains from the kidney into a single large funnel shaped cavity, the renal pelvis.
- Ureter (Right & Left) - Urine leaves the renal pelvis through the ureter (u-REE-ter) which conducts it to the urinary bladder.
- Urinary Bladder - Urine is temporarily stored in the urinary bladder. The ureters penetrate the posterior wall of the urinary bladder without entering the peritoneal cavity. They pass through the bladder wall at an oblique angle and the ureteral openings are slit-like rather than rounded. This shape helps prevent the back-flow of urine toward the ureter and kidneys when the urinary bladder contracts.
- External Urethral Sphincter - Composed of skeletal muscle, the external urethral sphincter is actually a modification of deep muscles of the perineum. This provides our control of urine passage into the urethra. Superior to this sphincter is the internal urethral sphincter located right at the junction of the urethra and the urinary bladder. This sphincter is not visible in your specimen.
- Female Urethra - Urine excretion, a process called urination or micturition, occurs when the contraction of the muscular urinary bladder forces urine through the urethra and out of the body.
As you can see, the male urinary system is analogous to the female with a few differences. Most notably, the male urethra is much longer than that of the female. This is primarily because it performs "double duty" for both the urinary and reproductive systems. Occasionally the uniting term "urogenital" is used because of this association. The male urethra is also the ejaculatory pathway for semen, which we will study in another lesson.
- Locate ALL the previously identified urinary system anatomy in the male.
Self-test Labeling Exercises