Term
Where is the kidneys located?
What are the kidneys function? |
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Definition
Located at the rear of the abdominal cavity in the retroperitoneum, the kidneys receive blood from the paired renal arteries, and drain into the paired renal veins.
With right kidney lower that the left.
Their functions are to: 1- regulate electrolytes 2- maintenance of acid–base balance, 3- and regulation of blood pressure (via maintaining salt and water balance). 4- filtrate the blood by removing wastes which are diverted to the urinary bladder 5- they produce urine, that the kidneys excrete wastes such as urea and ammonium, 6- and they are also responsible for the reabsorption of water, glucose, and amino acids. The kidneys also produce hormones including calcitriol, erythropoietin, and the enzymerenin. |
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Term
| What are the components of the Urinary System? |
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Definition
The urinary system or renal system is the organ system that produces, stores, and eliminates urine. It includes two kidneys, two ureters, the bladder and the urethra.
Urine is formed in the kidneys through a filtration of blood. The urine is then passed through the ureters to the bladder, where it is stored.
About 1-2 litres of urine are produced every day in a healthy human, although this amount may vary according to circumstances such as fluid intake. |
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Term
| What is the structure of the kidney? |
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Definition
The kidney has a bean-shaped structure; each kidney has a convex and concave surface. The concave surface, the renal hilum, is the point at which the renal artery enters the organ, and the renal vein and ureter leave.
The kidney is surrounded by tough fibrous tissue, the renal capsule, which is itself surrounded by perinephric fat, renal fascia (of Gerota) andparanephric fat. |
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Term
| What is the functions of the Urinary System ? |
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Definition
- Removal of waste product from the body (mainly urea anduric acid)
- Regulation of electrolyte balance (e.g. sodium, potassium andcalcium)
- Regulation acid-base homeostasis
- Controlling blood volume and maintaining blood pressure
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Term
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Definition
The first step in urine formation is the filtration of blood in the kidneys.
The basic structural and functional unit of the kidney is the nephron. Its chief function is to regulate the concentration of waterand soluble substances like sodium salts by filtering the blood, reabsorbing what is needed and excreting the rest as urine.
In the first part of the nephron, the renal corpuscle blood is being filtrated from the circulatory system into the nephron. A pressure difference between forces the filtrate from the blood across the filtration membrane. The filtrate includes water, small molecules and ions that easily pass through the filtration membrane. However larger molecules such as proteins and blood cells is prevented from passing through the filtration membrane. The amount of filtrate produced every minute is called the glomerular filtration rate or GFR and amounts to a staggering 180 litres per day. About 99 % of this filtrate is then reabsorbed as it passes through the nephron and the remaining 1 % becomes urine. |
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Term
| How is the urinary system is regulated ? |
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Definition
regulated by the endocrine system by hormones such as antidiuretic hormone-
( two primary functions are to retain water in the body and to constrict blood vessels.) -Vasopressin regulates the body's retention of water by acting to increase water absorption in the collecting ducts of the kidney nephron-., aldosterone, and parathyroid hormone.[2]
The urinary system is under influence of the blood pressure, nervous system and endocrine system. |
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Term
| How are kidneys supplied blood? |
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Definition
The kidneys receive blood from the renal arteries, left and right, which branch directly from the abdominal aorta., the kidneys receive approximately 20% of the cardiac output.[6]
Each renal artery branches into segmental arteries, dividing further into interlobar arteries which penetrate the renal capsule and extend through the renal columns between the renal pyramids. The interlobar arteries then supply blood to the arcuate arteries that run through the boundary of the cortex and the medulla. Each arcuate artery supplies several interlobular arteries that feed into the afferent arterioles that supply the glomeruli.
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Term
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Definition
The interstitum (or interstitium) is the functional space in the kidney beneath the individual filters (glomeruli) which are rich in blood vessels. The interstitum absorbs fluid recovered from urine.
After filtration occurs the blood moves through a small network of venules that converge into interlobular veins. As with the arteriole distribution the veins follow the same pattern, the interlobular provide blood to the arcuate veins then back to the interlobar veins which come to form the renal vein exiting the kidney for transfusion for blood. |
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Term
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Definition
| The kidney and nervous system communicate via the renal plexus, whose fibers course along the renal arteries to reach each kidney.[9] Input from the sympathetic nervous system triggers vasoconstriction in the kidney, thereby reducing renal blood flow.[9] The kidney also receives input from the parasympathetic nervous system, by way of the renal branches of the vagus nerve (cranial nerve X); the function of this is yet unclear.[9][10] Sensory input from the kidney travels to the T10-11 levels of the spinal cord and is sensed in the corresponding dermatome.[9] Thus, pain in the flank region may be referred from corresponding kidney.[9] |
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Term
What is Acid-base homeostasis? |
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Definition
| Two organ systems, the kidneys and lungs, maintain acid-base homeostasis, which is the maintenance of pH around a relatively stable value. The lungs contribute to acid-base homeostasis by regulating carbon dioxide (CO2) concentration. The kidneys have two very important roles in maintaining the acid-base balance: to reabsorb bicarbonate from urine, and to excrete hydrogen ions into urine |
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