Help with passage way through kidney.

Question

Include the following terms: 

glomerulus, Bowman's capsule, proximal convoluted tubule, distal convoluted tubule, Loop of Henle, Collecting duct, ureter, urethra, bladder, renal arteries, peritubular capilaries, medullary pyramids, renal columns, calyces, cortex, medulla.

Answer 1

      From a gross anatomy standpoint, there is an outer portion and an inner portion to the kidney. The outer portion is the cortex. The renal corpuscle (made up of the glomerulus and Bowman's capsule) is located in the cortex. The medulla is the inner portion that surrounds the renal pelvis. On the medial side of the kidney, the indented area known as the hilus is found. This is where blood and lymph vessels, nerves, and the ureters enter and exit the kidney. Within the hilus, is the renal pelvis. The renal pelvis is the urine collection chamber that forms the beginning of the ureter. 

     In various species, the medulla has numerous, pyramid-shaped areas with an apex pointing to the renal pelvis or directly to the ureter. These are known as the medullary pyramid. In other species, the medullary pyramids fuse to occupy the entire inner portion, pushing the cortex to outside layer. The calyx is an extension of the renal pelvis into which the medullary pyramids fit. The calyces act as funnels that direct fluid into the renal pelvis. The renal column is a extension of the cortex into the medulla, allowing for the cortex to be better anchored onto the medulla. 

 

 

    The microscopic anatomy of the kidney is made up of hundreds of thousands of nephrons, that filter, reabsorb, and secrete substances from the blood. The nephron is the most basic functional unit of the kidney. Blood flows through branches of the renal artery into the afferent arteriole. The afferent arterioles carry blood to the glomerular capillaries that make up the glomerulus. It is surrounded by a double-walled capsule called Bowman's capsule. The filtered blood flows out of Bowman's capsule through the efferent arteriole. It becomes the peritubular capillaries that surround the nephron. These capillaries converge into larger and larger venules, eventually becoming the renal vein.  Once the blood passes through the glomerulus, the substance that has been filtered out is called the glomerular filtrate. This filtrate passes into a continuation of the Bowman's capsule in to the proximal convoluted tube (PCT). The filtrate is now called the tubular filtrate. 

     From the PCT, the filtrate flows through the Loop of Henle. It descends into the medulla of the kidney, makes a U-turn, and returns back into the cortex. The ascending portion of the Loop of Henle is the distal convoluted tube (DCT). The filtrate from all of the the DCTs  from all of the nephrons within the kidney empty into tubules known as the collecting ducts. These ducts carry the filtrate through the medulla, emptying into the renal pelvis. Once the filtrate empties from the collecting ducts, it is now urine and will empty into the bladder from the kidney via the ureter. The urine is then expelled from the bladder out of the body through an external opening called the urethra.