Urination

The Manneken Pis, a popular bronze statue in Brussels.

urination is a biological process by which the urinary bladder expels the urine, when it is full.

The bladder is compressed by the other organs when it is empty. Its filling occurs progressively, until the tension of its walls rises above a threshold value, which triggers a neurogenic reflex called micturition reflex, which produces urination (urination), and if this is not achieved, it at least causes urination. conscious desire to urinate.

The process of urination is controlled voluntarily most of the time. Poor or absent control of urination is called urinary incontinence.

Reflex of micturition

Reflex urination is a fully automatic spinal process. In the walls of the urinary bladder there are sensory receptors called bladder wall stretch receptors that capture the pressure and increase in bladder volume. The most important are those located in the bladder neck. These sensory receptors elicit action potentials that are transmitted along the pelvic nerves to the sacral segments S-2 and S-3. Motor fibers of the parasympathetic nervous system originate in these sacral nuclei and end in nerve ganglion cells located in the bladder wall, in charge of innervating the detrusor muscle of the bladder. This reflex arc is repeated for a few minutes each time to increase bladder pressure and is consciously inhibited by the brain if urination does not occur.

Man pissing in a minute.

Sometimes the cluster of micturition reflexes is so great that the nerve impulse passes through the pudendal nerve to the external urinary sphincter to inhibit it. If this inhibition is stronger than the voluntary conscious signals from the brain, involuntary urination (urinary incontinence) will occur.

Brain control of urination

Grey wolf peeing to mark its territory.

Patients exhibiting urine samples to Constantine the African for diagnostic purposes.

Victuring can be inhibited or precipitated by brain centers that are:

• Powerful facilitating centers and inhibitors in the brain trunk, perhaps located in the protuberance.
• Several centers located in the cerebral cortex, which are mostly inhibitors but can also be exciting.

Brain control of urination occurs by the following means:

• Through the spinal cord, the encephalic nuclei stimulate the sacral parasympathetic centers so that — through the nerve, they can relax the external sphincter muscle, when there is a desire to urinate. In addition, there is abdominal contraction and relaxation of the pelvic soil, which facilitates urination.
• Through the spinal cord, the encephalic nuclei stimulate the sympathetic centers that produce contraction of the trigone and the external sphincter, preventing urination.

Viding symptoms

When you have a urinary tract disease, there may be unpleasant symptoms when you urinate such as:

1. Dirty: it is a raging pain or scozor during the passage of the urine through the urethra. This isolated symptom or together with one of the following define the Hospital syndrome.
2. Polaquiuria: is the increase in the number of urines for 24 hours, usually of little amount.
3. Nicturia: is the increase in urination during the night (see also enuresis and parasomnia).
4. Hematuria: it is the expulsion of blood with the urine.
5. Piuria: is the expulsion of pus with the urine.
6. suprapubic pain or hypogastric pain: it is a pain in the lower belly or in the lower part of the abdomen when measured.
7. Tenesmus urinary: it's the feeling of wanting to pee again, when it's just done.
8. Nephrotic colic: it is a spasmodic pain originated in the lumbar region that radiates towards the external genitals, of great intensity.
9. Anuria, oliguria: When the urination is less than 400-600 ml/day, or less than 20 ml/hour if the patient is prone. If in less than 100 ml in 24 hours it is considered anuria

Disorders related to urination

• Paruresis: impossibility to urinate in certain situations.
• Constant Miction Syndrome: Syndrome that leads the affected to constantly urinate in a lapse less than 10 minutes during the night.
• Spinal disorders: the spinal section above the sacral marrow (being unharmed these segments) causes the loss of superior control of the urination, retaining the reflection but automatically. Spinal injury in the sacral segment causes loss of the reflex of urination, urine retention, with bladder dilation and overflowing urination, a disorder that is observed by injury of a peripheral component of the reflection.