The afferent arterioles are a group of blood vessels that supply the nephrons in many excretory systems. They play an important role in the regulation of blood pressure as a part of the tubuloglomerular feedback mechanism. The afferent arterioles branch from the renal artery, which supplies blood to the kidneys. Accordingly, what is the difference between afferent and efferent arterioles?
Afferent arterioles carry blood to the glomerulus while efferent arterioles take blood away from the glomerulus. The main difference between afferent and efferent arterioles is the structure, function, and composition of each type of blood vessels in the glomerulus of the kidney.
Also, where are the afferent and efferent arterioles located? The afferent arteriole is the arteriole that brings blood to the glomerulus. It is larger in diameter than the efferent arteriole. The efferent arteriole is the arteriole that carries blood away from the glomerulus.
Moreover, what is the function of the afferent Arteriole?
Afferent arterioles have two functions: they serve to connect the renal artery to the glomerular capillaries and they take an active role in controlling not only the local blood pressure inside the kidney but also your overall body's blood pressure.
What happens when afferent Arteriole constricts?
Overall the constriction of the afferent arteriole decreases both blood flow and filtration pressure where as constricting the efferent arteriole decreases blood flow but increases filtration pressure. The fact that both can be altered allows independent regulation of both GFR and blood flow.
Related Question Answers
Where is the afferent Arteriole located?
The afferent arterioles branch from the renal artery, which supplies blood to the kidneys. The afferent arterioles later diverge into the capillaries of the glomerulus. What is afferent and efferent?
Afferent neurons are sensory neurons that carry nerve impulses from sensory stimuli towards the central nervous system and brain, while efferent neurons are motor neurons that carry neural impulses away from the central nervous systme and towards muscles to cause movement. Which is bigger afferent or efferent arterioles?
The afferent arteriole is the arteriole that brings blood to the glomerulus. It is larger in diameter than the efferent arteriole. When the afferent arteriole is larger, more blood would flow into the efferent arteriole, which is of a smaller diameter, resulting in increased blood pressure in the glomerulus. What causes afferent Arteriole constriction?
Sympathetic Nerves Under conditions of stress, sympathetic nervous activity increases, resulting in the direct vasoconstriction of afferent arterioles (norepinephrine effect) as well as stimulation of the adrenal medulla. If blood pressure falls, the sympathetic nerves will also stimulate the release of renin. Are arteries efferent or afferent?
These arteries extend outwards to become afferent arteries, glomerular capillaries and efferent arteries. Efferent arteries that arise from glomeruli near the medulla give rise to arterial vasa recta (spuria) through which the medulla receives most of its blood supply. How does the afferent Arteriole respond to an increase in blood pressure?
This mechanism works in the afferent arteriole that supplies the glomerulus. When blood pressure increases, smooth muscle cells in the wall of the arteriole are stretched and respond by contracting to resist the pressure, resulting in little change in flow. What is Bowman's capsule?
Bowman's capsule (or the Bowman capsule, capsula glomeruli, or glomerular capsule) is a cup-like sack at the beginning of the tubular component of a nephron in the mammalian kidney that performs the first step in the filtration of blood to form urine. A glomerulus is enclosed in the sac. How is Na+ reabsorbed?
Sodium passes along an electrochemical gradient (passive transport) from the lumen into the tubular cell, together with water and chloride which also diffuse passively. Water is reabsorbed to the same degree, resulting in the concentration in the end of the proximal tubule being the same as in the beginning. Does renin constrict afferent Arteriole?
A reduction in afferent arteriole pressure causes the release of renin from the JG cells, whereas increased pressure inhibits renin release. When afferent arteriole pressure is reduced, glomerular filtration decreases, and this reduces NaCl in the distal tubule. Which artery delivers blood to the afferent Arteriole?
A large amount of blood enters the kidneys at the hilum through the renal artery and leaves the kidneys through the renal vein. Interlobular arteries of the kidney extend to afferent arteriole which supplies blood to the capillaries of the glomerulus. How does the JGA regulate blood pressure?
The juxtaglomerular cells, derived from smooth muscle cells, of the afferent arteriole secrete renin when blood pressure in the arteriole falls. Renin increases blood pressure via the renin-angiotensin-aldosterone system. What is the function of Bowman's capsule?
Bowman's capsule is a cup-like sack at the beginning of the tubular component of a nephron in the mammalian kidney that performs the first step in the filtration of blood to form urine. The glomerulus is a tuft of small blood vessels called capillaries located within Bowman's capsule within the kidney. What is the diameter of afferent Arteriole?
16.3 pm
Where does filtration occur?
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 liters of fluid are filtered by the kidneys every day. What is the function of glomerulus?
The main function of the glomerulus is to filter plasma to produce glomerular filtrate, which passes down the length of the nephron tubule to form urine. What is the structural and functional unit of kidney called?
The nephron is the microscopic structural and functional unit of the kidney. It is composed of a renal corpuscle and a renal tubule. The renal corpuscle consists of a tuft of capillaries called a glomerulus and an encompassing Bowman's capsule. A healthy adult has 1 to 1.5 million nephrons in each kidney. How does blood flow through the glomerulus?
Blood flows into the kidneys through the renal artery and enters the glomerulus in Bowman's capsule. In the glomerulus, the blood flow is split into fifty capillaries that have very thin walls. After passing through the afferent arteriole, the filtered blood enters the vasa recta. Where does blood go after the efferent Arteriole?
Afferent arterioles branch off which ultimately leads into the glomerulus of Bowman's capsule. From here, efferent arterioles begin to form the venous system and subdivide into another set of capillaries known as the peritubular capillaries. Blood then leaves the kidney and enters the venous circulation. What is Vasa recta in nephron?
In the blood supply of the kidney, the straight arterioles of kidney (or vasa recta renis) are a series of straight capillaries in the medulla (Latin: vasa, "vessels"; recta, "straight"). They lie parallel to the loop of Henle. What happens if glomerular filtration rate is too high?
If GFR is too low, metabolic wastes will not get filtered from the blood into the renal tubules. If GFR is too high, the absorptive capacity of salt and water by the renal tubules becomes overwhelmed. What does angiotensin II do?
Angiotensin, specifically angiotensin II, binds to many receptors in the body to affect several systems. It can increase blood pressure by constricting the blood vessels. It can also trigger thirst or the desire for salt. Angiotensin is responsible for the release of the pituitary gland's anti-diuretic hormone. What increases glomerular filtration rate?
Glomerular filtration is occurs due to the pressure gradient in the glomerulus. Increased blood volume and increased blood pressure will increase GFR. Constriction in the afferent arterioles going into the glomerulus and dilation of the efferent arterioles coming out of the glomerulus will decrease GFR. How do you increase blood flow to the kidneys?
Reduction of sympathetic stimulation results in vasodilation and increased blood flow through the kidneys during resting conditions. When the frequency of action potentials increases, the arteriolar smooth muscle constricts (vasoconstriction), resulting in diminished glomerular flow, so less filtration occurs. What does it mean if your GFR is 56?
A GFR of 60 or higher is in the normal range. A GFR below 60 may mean kidney disease. A GFR of 15 or lower may mean kidney failure. Does GFR affect blood pressure?
Increases in renin-angiotensin system activity and GFR follow, and sodium balance is maintained at normal blood pressure. These studies suggested that, without the increase in GFR, the sodium-retaining actions of AngII predominated and required an increase in arterial pressure to maintain sodium balance. Does angiotensin II increase or decrease GFR?
A number of other mechanisms can affect renal blood flow and GFR. High concentrations of Angiotensin II can constrict the glomerular mesangium, reducing the area for glomerular filtration. Angiotensin II is a sensitizer to tubuloglomerular feedback, preventing an excessive rise in GFR. What forces govern the glomerular filtration?
The forces that govern filtration in the glomerular capillaries are the same as any capillary bed. Capillary hydrostatic pressure (Pc) and Bowman's space oncotic pressure (πi) favor filtration into the tubule, and Bowman's space hydrostatic pressure (Pi) and capillary-oncotic pressure (πc) oppose filtration. What happens if glomerular filtration rate decreases?
A decrease or decline in the GFR implies progression of underlying kidney disease or the occurrence of a superimposed insult to the kidneys. This is most commonly due to problems such as dehydration and volume loss. An improvement in the GFR may indicate that the kidneys are recovering some of their function. 
