Structure and Function of the Kidneys - Introduction to the Kidneys - Anatomy

The function of the kidneys now each kidney weighs approximately 160 grams and measures 11 centimeters long and approximately 5 to 7 centimeters wide we can see from this image here the approximate location of the kidneys we have two of them and they were located on either side of the vertebral column and they lie below the diaphragm on the liver in the case of the right kidney it's below the liver here now what we're going to do is we're going to skip this part and come back to this little statement here but we're going to move on to the functions of the kidney so the primary function is the regulation of extracellular fluid plasma and interstitial fluid okay so that's the primary function of the kidney to regulate the extracellular fluid and that extra cell you of extracellular fluid is plasma and interstitial fluid and this is the fluid around the cells and this is done by the formation of urine which is a modified filtrate of plasma so when we have the filtration of plasma eventually we get urine production so all the functions of the kidneys regulate the volume of plasma which also relates the blood pressure regulate the concentration of waste products in the plasma regulation of the concentration of electrolytes so sodium ions potassium carbon II ions as well in the plasma and finally regulation of the pH of plasma as well now let's look at the structure of the kidneys and then we can talk about its function finally just to summarize the video so we can see here is a cross-section of the kidneys you can see how it's got the cortex on the outside the medulla then it drains into the renal pelvis the ureter and then eventually you can see in the diagram but we'll have the urinary bladder so the pair of kidneys lie on either side of the vertebral column, they lie below the diaphragm and ever urine which is made in the kidneys is drained into a cavity called the renal pelvis which is this region here and then the urine is then channeled from the renal pelvis to the urinary bladder via two long ducts called your Rita's okay so this is one of the  ureters here now the kidney has two main regions the outer cortex and the medulla here you can see the outer cortex or the renal cortex and here you can see the renal medulla which is this region here so here's the cortex on the outside and this region here is the medulla okay so the outer cortex is reddish-brown and granular because there is a high number of capillaries and the medulla is striped due to the presence of tubules and blood vessels now we can divide the kidney into a variety of different cavities so we have each pyramid which projects into a small depression called the minor calyx here are the renal pyramids here are the renal columns and they form these minor calyx here calluses here and remember these minor calyce's form the major calyx here's a major calyx haze and major calyx here here and they all form a funnel known as the renal pelvis and what the renal pelvis does as we've just mentioned it collects the urine produced from the filter it the modified filter of plasma collects this urine and transports it to the urinary bladder via the ureter okay now let's move back onto this part here so each kidney contains many tiny tubules that empty into the cavity drained by the ureter that makes sense we've seen that here so remember the tubules drain into the renal pelvis and into the ureter now each of the tubules receives a blood filter it from the capillary bed called a glomerulus now you can see in this image here because we require a very Macross Copic image of a nephron but a glomerulus imagine we have the blood coming from the arteries or to be specific the afferent arteriole it's going to drain into this capillary bed which is called the glomerulus and once it drains through that it's going to form this filter it and the filter it's going to pass through the tubules and once there's some modifications that it's going to drain into the renal pelvis eventually and finally, the filtrate is modified as it passes through the different regions of the kidney of the tubule and it finally forms urine finally the ureter undergoes peristalsis contractions so there is a pacemaker located in the renal calyce's on the pelvis which contains smooth
muscle and the calluses and pelvis. 

undergo rhythmic contractions which may 

aid in the emptying of urine from the kidney.