Question

For the following two questions, please provide a response of at least one paragraph (and you can certainly write more); question 1b, though technically part of question one, should rate two or three sentences separate from the response for 1a.While there are ‘correct’ answers to these two problems, the emphasis of this assignment is how well you can defend and support your response from the resources available to you.

1. a) How are the glomeruli of kidney nephrons supplied with oxygen and nutrients? Support and defend your response. (It’s not the afferent arteriole.)

2. b) Explain why the afferent arteriole is not the answer to part a.

3. A particular substance can only be removed from the body via the urinary system. However, it is stipulated that there are no anatomical structures or physiological mechanisms within the nephron or its surrounding blood vessels capable of actively transporting the specified substance. Based on that fact, what is the maximum percent of the substance that can be removed from the blood per pass through the kidneys? Support and explain your response from the resources available to you.

Answer 1

2-)

Filtration is the mass movement of water and solutes from plasma to the renal tubule that occurs in the renal corpuscle. About 20% of the plasma volume passing through the glomerulus at any given time is filtered. This means that about 180 lites of fluid are filtered by the kidneys every day. Thus, the entire plasma volume (about 3 liters) is filtered 60 times a day.Note that the kidneys filter much more fluid than the amount of urine that is actually excreted (about 1.5 liters per day).

1a) The glomerulus  is a network of small blood vessels capillaries known as a tuft, located at the beginning of a nephron in the kidneys. The tuft is structurally supported by the mesangium - the space between the blood vessels - made up of intraglomerular mesangial cells.

1b)mesengial cells are specialised cells in the kidney that make up the mesangium of the glomerulus. Together with the mesangial matrix, they form the vascular pole of the renal corpuscle.The mesangial cell population accounts for approximately 30-40% of the total cells in the glomerulus.Mesangial cells can be categorized as either extraglomerular mesangial cells or intraglomerular mesangial cells, based on their relative location to the glomerulus. The extraglomerular mesangial cells are found between the afferent and efferent arterioles towards the vascular pole of the glomerulus.The extraglomerular mesangial cells are adjacent to the intraglomerular mesangial cells that are located inside the glomerulus and in between the capillaries.cap primary function of mesangial cells is to remove trapped residues and aggregated protein from the basement membrane thus keeping the filter free of debris.