Secondary Condition: Bladder Management
by J. Glen House, MD
Spinal Cord Injury Secondary Condition: Bladder Management
Bladder management after a spinal cord injury is important to maintain quality of life and to maximize life expectancy. To accomplish ideal bladder management, it is necessary to understand the anatomy of the bladder and how it functions before and after a spinal cord injury. If this information is understood and management and follow-up are appropriate, then complications that may interfere with life can be eliminated or greatly reduced.
Anatomy
When discussing the anatomy of the bladder, we must also mention the kidneys and the connection between these two structures. Discussion of the urinary system is often divided into two parts.
The first part, the “upper urinary tract,” includes the kidneys, the ureters and the ureterovesical junction. The kidneys are two bean-shaped organs located on each side of the spine in the back part of the abdomen. The role of the kidney is to filter waste matererial from the bloodstream and excrete (get rid of) it from the body through urine. Once the waste product (urine) is separated in the kidney, it travels down the ureter (the tube between the kidney and the bladder) to the bladder and waits for the appropriate time of urination as determined by the person. The ureterovesical junction (UVJ) is the area where the ureter enters into the bladder wall. This is a very important area because it acts as a “one-way valve.” The ureter enters the bladder wall at an angle so that as the bladder fills with urine it begins to compress this entry location. This helps to prevent urine in the bladder from traveling up the ureter to the kidney as it begins to fill (approximately 500 mL).
The other part of the urinary system is the “lower urinary tract,” which includes the bladder, sphincter and urethra. The bladder is divided into two areas: the detrusor and trigone. The detrusor (the top part of the bladder) is made up of crisscrossing muscle fibers. The trigone (the lower part of the bladder) is often referred to as the bladder neck. The sphincter is further divided into the internal and external sphincter. The internal sphincter is the junction between the bladder and the urethra; it is made up of circular muscles that are not controlled voluntarily. The external sphincter is under voluntary control; it is that muscle you squeeze tight when you have a full bladder and are trying to delay urination. It is also the muscle that you relax when it is time to urinate. The urethra is a tube that connects the bladder to the outside.
Nervous system control of the bladder
The bladder is controlled by the autonomic nervous system and the voluntary component of the nervous system. The autonomic nervous system control is further divided into the parasympathetic and sympathetic nervous system (see previous description of the autonomic nervous system under the main anatomy section).
