Renal System
Urinary system, also known as kidney system, is the organ of the body responsible for producing, storing, and eliminating urine. Making urine is a process in which the kidneys filter wastes from the blood and excess water. In order to fill the bladder with urine, two thin tubes called ureters take urine from the kidneys. The urethra eliminates waste disposed of by the bladder when it is full. The urinary system can suffer from a range of infections and problems, including blockages and injuries.In humans, the renal system has kidneys that produce urine, ureters, bladders, and urethra that convey, store, and expel urine.
Humans have much in common with other mammalian species, but our excretory system differs in particular structurally and functionally. It is the elimination function of the body that is emphasized by the terms excretory and urinary. In addition to eliminating waste, the kidneys also secrete and actively store substances that are equally important to survival.
The Kidney
Concave kidneys with a convex surface on one side and reddish brown on the other. Usually after the 12th thoracic vertebra and the third lumbar vertebra lie on either side of the vertebral column and outside the peritoneum outside the abdominal cavity. As the kidneys have long axes, the upper end is tilted toward the spinal column (vertebral column) but the lower end aligns with the axes of the body. Within the medial concave border, a cavity called the renal sinus (kidney), which is connected to the hilus, can be found. In addition to connecting the arteries and veins of the kidneys, lymphatic vessels and nerves, the hilus lies near the upper end of the ureters.The Ureters
From the kidneys, urine travels through narrow ducts that measure between 25 centimeters and 30 centimeters (9.8 and 11.8) long and 4 to 5 millimeters (0.16 to 0.20 inches) wide. They are attached to the peritoneum, which lines the abdomen and pelvis, with a layer of connective tissue.The distance between the ureters and the wall of the bladder increases when the bladder is distended with urine. When the ureters pass through the muscular wall of the bladder, a narrow opening opens into the bladder cavity. The oblique course of the ureters acts as an inner valve; when distended, the ureters press against the part of the muscular wall of the bladder that penetrates the ureters, preventing the re-circulation of urine into the ureters.
The Urinary Bladder
The urinary bladder is a hollow muscle organ that holds wastes from the urinary system. This organ rests underneath the peritoneum and behind the symphysis pubis. Depending on how much urine the bladder contains, the bladder's shape and size may vary. Located in the midline of the front of the body, the symphysis pubis is the joint connecting the two hip bones. Its shape is square when it is empty and lies within the pelvic cavity; it takes on a circular shape when it is distended and extends into the lower abdomen. A bladder has a body, consisting of a fundus, a neck, an apex, and two inferolateral surfaces located below and to either side of the bladder, although these features are not readily noticeable when the bladder is either empty or only slightly distended.Located immediately adjacent to the urethral opening, the bladder's neck is the lowest and most permanent part of the organ. The urethra is attached to the prostate, which is a gland located around the base of the urethra.
There is a triangular surface to the bladder and the peritoneum covers it. The pelvic cavity is largely supported by the levator ani muscles, which make up the major portion of the pelvic floor. Pelvic fascia is the layer that covers and supports the bladder in one way or another. There are multiple layers of fascia in the pelvic cavity. An organ, blood vessel, and nerve are surrounded by fascia. A kind of hammock is formed between the pubovesical ligaments and the inferolateral surfaces and neck of the bladder by the fascia.
The Urethra
By way of the urethra, urine leaves the bladder for the exterior. Male men have a 20-centimeter long tube that carries urine as well as semen as well as secretions from their prostate, bulbourethral, and urethral glands. The diameter of this urethral opening varies between 0.5 and 0.8 centimeters along its length during urination and ejaculation, but at other times it touches and the lining forms longitudinal folds. Male urethra consists of three distinct parts, prostatic, membranous, and spongy, each named according to the structure through which it passes rather than due to any inherent characteristics.During its descent through the prostate, the prostatic branch of the male urethra extends almost vertically from the base of the gland to its apex, describing a slight curve with concavity toward the apex. In the middle portion of the urethra, it is the widest and dilatable part, and it measures 2.5 to 3 centimeters long. Between the two membranes of the male urethra lies a membrane called the urogenital diaphragm. Exceptionally, the urethra is narrow here as it is surrounding by muscles, the sphincter urethrae, and does not open externally. Each side of it has two bulbourethral glands. Neither the membrane urethra nor the urogenital diaphragm is attached strongly to the urethra. Those parts of urethra in the male that traverse the penis are called spongy parts. It passes through the corpus spongiosum during its passage through the penis. It is about 2.5 centimeters below the urogenital membrane where the bulbourethral glands connect with the spongy urethra, but many mucous glands also connect with it.
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