What do we mean by stones?
In chemistry, we know that solutes precipitate out of solution to form particles due to the high concentration of the solution. In the human body, certain substances cannot be absorbed by the body and are precipitated out of the body fluid to form crystals, which we call stones. When a stone occurs in the kidney, we call it a kidney stone; when a stone occurs in the gallbladder, we call it a gallstone, etc.
What is urinary stone disease?
Stones in the human urinary system are collectively called urinary stones, and the clinical term for this disease is urolithiasis. Some patients are unaware of the presence of stones in the human body, while others suffer from unbearable pain, which brings a lot of inconvenience to people’s normal life and work. Even those patients without obvious symptoms, when diagnosed with urinary stones, they should be treated promptly to avoid delaying the disease.
What organs are included in the human urinary system?
The human urinary system is composed of the kidneys, ureter, bladder and urethra. In men, the prostate should also include the prostate gland because the prostate gland wraps around part of the urethra and constitutes the urethra of the prostate. The kidneys and ureters are symmetrically distributed according to the central axis of the body. Urine is produced from the kidneys and then expelled from the body through the ureter, bladder, and urethra.
Where are the kidneys located in the body? What is its structure?
The kidneys are paired substantial organs in the body and resemble fava beans in shape. In adults, the kidneys are about 12-15 cm long, 5-6 cm wide, 3-4 cm thick, and weigh about 120-150 grams. The kidneys are located in a position above the abdomen just behind the intestine and immediately behind the posterior abdominal wall. They are positioned very high in the abdomen, with their upper part reaching behind the last rib, which means that the kidneys can be partially protected by the rib cage. If you open the kidneys, you will see that they are divided into two parts: the core or medulla, which consists of a slightly pinkish cone, and the outer layer, the cortex, which is brownish in color. If you look with the help of a microscope, you will see that the medulla and cortex of the kidney are a dense network of tiny capillaries and tiny ducts through which the blood passing through the capillaries can be filtered to form urine to remove excess fluid and waste from the body. The funnel-shaped structure that initially receives urine is called the calyces. 2 to 3 calyces can converge into a single calyx, while 3 to 4 calyces merge into a renal pelvis. Urine passes through the calyces and calyces and converges into the renal pelvis, and then is discharged into the bladder through the ureter.
What does the kidney do for the body?
The kidneys play an important role in the body by filtering the blood and ensuring that the ion concentrations are just right so that all the cells of the body can work in perfect order. ‘Electrical’ tissues such as nerves and muscles depend on the normal level of ions inside and outside the cells to coordinate their work. The kidneys regulate the fluid flow in the body and play a very important role in excretion: the elimination of waste products, especially nitrogenous waste products produced by the cells from protein breakdown. This waste is first converted into ammonia, which the liver converts into urea to reduce toxicity. The urea in the blood is carried to the kidneys, where it is excreted in the urine. If the kidneys do not perform their extremely important function well, the human body will collapse very quickly.
What part of the body is the ureter in? What is its function?
The ureters are a pair of slender tubular organs rich in muscle fibers located behind the peritoneum, normally on either side of the spine, with the upper end starting at the junction of the renal pelvis and the lower end ending at the bladder. The length of the ureter is about 25-30 cm in men and 25-28 cm in women, and it is usually divided into upper, middle and lower segments. The upper ureter starts at the junction of the pelvic ureter and ends at the crossing of the iliac vessels; the middle ureter starts at its crossing of the iliac vessels and ends at its entry into the bladder; after reaching the bladder, the ureter has to travel a distance within the bladder wall to enter the bladder, and this section is called the lower ureter. The diameter of the ureter is generally 7-9 mm, and there are three narrowing sites: the first narrowing is at the junction of the pelvis and ureter, the second narrowing is at the point where the ureter crosses the iliac vessels downstream, and the third narrowing is at the point where the ureter penetrates the bladder wall. When kidney stones fall into the ureter, they often tend to stay in these three strictures, causing obstruction and painful symptoms. The function of the ureter is to pass urine from the renal pelvis into the bladder. The input is accomplished by the regular movement of the smooth muscle of the ureter, known as ureteral peristalsis.
What part of the body is the bladder in? What is its function?
The bladder is an organ that stores urine and is located just behind the pubic symphysis and in front of the pelvic bone. Its shape, size and location are related to the amount of urine stored. In adults, a voided bladder is flat and a filled bladder is conical, with the plane up and the sides facing downward, upside down in the pelvic cavity. The function of the bladder is to store urine and to urinate intermittently. Under normal conditions, when urine accumulates in the bladder to a certain level, it reflexively causes the body to urinate, thus expelling the urine from the body.
What is the structure of the urethra in both men and women? What are the differences?
The male and female urethra have different structures in the human body. The adult male urethra is about 16-20 cm long, with a sigmoid curve, and its entire length can be divided into three parts; the prostate, the membrane and the spongy part. The spongy part can be divided into the urethral bulb and the urethral penis body. Clinically, the spongy urethra is called the anterior urethra, and the membranous and prostatic urethra is called the posterior urethra. The internal diameter of the urethra is about 5-7 mm, and there are three strictures and three dilatations in the whole length. The strictures are the internal urethra, the urethral membrane and the external urethra, and the dilatations are the prostate, the urethral bulb and the urethral navicular fossa. The enlarged part is where the stone can easily stay. In contrast, the female urethra is short and straight, located below the pubic symphysis, about 3 to 5 cm long on average, and the beginning of the urethra is lower than in men.
What is the location of the male prostate in the body? What is its structure?
The male prostate is located between the neck of the bladder and the urogenital septum and weighs about 20 g. The prostate gland encircles part of the urethra, which forms the prostatic urethra. The prostate gland is made up of tubular vesicular glandular tissue and prostatic ducts. There are about 30-50 vesicles in the prostate gland, which come together to form a total of 15-30 prostatic ducts, also called prostatic excretory ducts, which open on both sides of the urethra in the seminal mound. If the prostate duct is blocked, it can lead to storage of prostate fluid, which can form prostate stones over time.
Why do you get urinary stones?
The causes of urinary stones are complex, and most of them are unknown. However, mankind has never given up on the study of this disease. Archaeological findings confirm that humans have been suffering from urinary stones for thousands of years. The famous Roman physician Galen proposed in 130-200 AD that stone disease is related to genetics, race, climate, diet, water, alcohol, gout, rheumatism and metabolic diseases, and that gout stones and urinary stones are of the same nature and origin. There are also many records of stone disease in ancient China. The term “stone shower” in Chinese medical texts refers to urolithiasis. Although stone disease has been extensively documented in ancient Chinese and foreign literature, there is no obvious research on the formation of stones. In the 18th and 19th centuries, with the development of biochemistry and physiology of physical chemistry, people began to emphasize the basic causes, components and types of stones. In the 19th century, British and French medical professionals did a lot of research on urinary stones and clearly affirmed that diet was related to the formation of urinary stones. By the middle of the 19th century Meckel Von Hemsbac proposed that urinary stone formation relies mainly on some organic matter with other precipitable substances, arguing that: urinary stones are formed by the action of the adhesive or sticky matrix of organic matter formed by inflammation of the urinary tract. In the 20th century, with the development of research, it was recognized that, in addition to the causes of stones mentioned by the previous authors, having stones is actually a symptom of a systemic disease, resulting from a disturbance of systemic metabolism. In modern times, although the cause of most urinary stones is still unknown, with the development of technology, a consensus has been reached on the final classification of the cause into metabolic disorders and local factors, and some causes of urinary stones can be clearly diagnosed, for example, hyperparathyroidism is one of the causes of urinary stones.