WEEK 1 - Renal Anatomy and Physiology 2

What process of urine formation filters blood into Bowman’s capsule?

Glomerular Filtration

Which part of the nephron reabsorbs essential substances from the filtrate?

Proximal Convoluted Tubule (PCT)

What is the movement of substances from blood into the renal tubule called?

Tubular Secretion

What structure delivers oxygenated blood to the kidney?

Renal Artery

What arteriole brings blood into the glomerulus?

Afferent Arteriole

What is the network of fenestrated capillaries inside the nephron called?

Glomerulus

What arteriole carries blood away from the glomerulus?

Efferent Arteriole

Which capillaries surround the PCT and DCT and allow reabsorption and secretion?

Peritubular Capillaries

What is the capillary network adjacent to the Loop of Henle?

Vasa Recta

What tubular structure filters blood in the nephron?

Glomerulus

What capillaries allow exchange of water and salts in the nephron?

Vasa Recta

Which blood vessel drains processed blood from the kidney?

Renal Vein

What is the final vessel that returns blood from the kidney to the heart?

Inferior Vena Cava

Which tubular structure receives filtered substances from the glomerulus?

Bowman’s Capsule

What type of filtration allows glucose and amino acids to pass into filtrate?

Non-selective Filtration

What nephron process reclaims glucose, amino acids, and sodium?

Tubular Reabsorption

Which nephron process is responsible for disposing of unfiltered wastes?

Tubular Secretion

Which arteriole drains blood from the glomerulus to peritubular capillaries?

Efferent Arteriole

What part of the renal circulation involves exchange at the PCT and DCT?

Peritubular Capillaries

Which blood vessel returns deoxygenated blood from the kidney to the heart?

Renal Vein

What is the direction of blood flow from renal artery to the heart?

Renal Artery > Afferent Arteriole > Glomerulus > Efferent Arteriole > Peritubular Capillaries > Vasa Recta > Renal Vein > Inferior Vena Cava > Heart

What process occurs when fluid moves from glomerular capillaries into Bowman’s space?

Glomerular Filtration

Which part of the nephron is mainly responsible for water and salt exchange?

Vasa Recta

What part of the nephron receives the filtrate directly from the glomerulus?

Bowman's Capsule

Which nephron segment immediately reabsorbs glucose, amino acids, sodium, and water?

Proximal Convoluted Tubule (PCT)

What type of transport is involved in reabsorption in the PCT?

Passive and Active Transport

Which limb of the Loop of Henle is permeable to water?

Descending Limb

Which limb of the Loop of Henle is impermeable to water but allows passive Na⁺ reabsorption?

Thin Ascending Limb

Which part of the Loop of Henle actively reabsorbs Na⁺ and Cl⁻?

Thick Ascending Limb

What nephron segment adjusts sodium levels under aldosterone control?

Distal Convoluted Tubule (DCT)

What hormone regulates sodium reabsorption in the DCT?

Aldosterone

Where is the final concentration of urine regulated?

Collecting Duct

What hormone controls water reabsorption in the collecting duct?

ADH (Antidiuretic Hormone)

After the collecting duct, what structure receives the final urine product?

Papillary Duct → Minor Calyx

Which part of the nephron has non-selective filtration for low molecular weight solutes?

Bowman's Capsule

What is the passive process of water reabsorption in the descending limb called?

Passive Water Reabsorption

What sets up the concentration gradient in the medulla for later water reabsorption?

Thick Ascending Limb of the Loop of Henle

Where does urine formation officially end in terms of nephron structures?

Papillary Duct → Minor Calyx

What is the term for the fluid as it passes through the nephron tubules?

Glomerular Filtrate

When is the fluid officially called "urine"?

After it leaves the collecting duct

What is the normal glomerular filtration rate (GFR)?

120 mL/min

What type of test is used to evaluate GFR?

Clearance Test

What percentage of renal blood flow is filtered in the glomerulus?

10%

At Bowman’s capsule, the glomerular filtrate is ___ with plasma.

Isosmotic

What is the specific gravity of the glomerular filtrate?

1.010

What components are normally absent in glomerular filtrate?

Cells and High Molecular Weight Substances (e.g. most proteins)

What is the equation for Net Filtration Pressure (NFP)?

HPg - (HPc + πg)

What is the normal value of hydrostatic pressure in the glomerulus (HPg)?

55 mmHg

What is the normal value of hydrostatic pressure in Bowman’s capsule (HPc)?

15 mmHg

What is the normal value of colloid osmotic pressure in the glomerulus (πg)?

30 mmHg

What is the net filtration pressure under normal conditions?

10 mmHg

Which arteriole dilates when blood pressure is low to maintain filtration?

Afferent Arteriole

Which arteriole constricts when blood pressure is low to maintain filtration?

Efferent Arteriole

What effect does dilation of the afferent arteriole have on glomerular pressure?

Increases it

What is the innermost layer of the glomerular filtration barrier?

Fenestrated Endothelium

What is the middle layer of the glomerular filtration barrier?

Basement Membrane

What is the outermost layer of the glomerular filtration barrier?

Podocyte Layer

What is the function of the fenestrated endothelium?

Allows passage of water and small solutes

What is the function of the basement membrane in the glomerular barrier?

Provides molecular filtration

What cells form the podocyte layer of the glomerular barrier?

Podocytes

What structures form between podocyte foot processes?

Filtration Slits

The glomerular filtration barrier restricts passage of substances larger than what molecular weight?

70,000 Da (70 kDa)

After the collecting duct, urine flows into what structures in order?

Renal Calyces → Renal Pelvis → Ureter → Bladder → Urethra

Which arteriole has a wider diameter and brings blood into the glomerulus?

Afferent Arteriole

Which arteriole has a narrower diameter and takes blood out of the glomerulus?

Efferent Arteriole

What does the pressure difference between the afferent and efferent arterioles enhance?

Filtration

What is the innermost layer of the glomerular capillary barrier?

Fenestrated Endothelium

What is the middle layer of the glomerular capillary barrier?

Basement Membrane

What is the outermost layer of the glomerular capillary barrier?

Podocyte Layer

What are the foot-like extensions of podocytes called?

Foot Processes

Where does the filtrate go after passing through the filtration barrier?

Bowman’s Space

What is the effect of the shield of negativity in the glomerular filtration barrier?

Repulsion of negatively charged plasma proteins

Which plasma protein is most commonly repelled by the shield of negativity?

Albumin

What is the general molecular weight cutoff for filterability in the glomerulus?

70,000 Daltons

Why might some small molecules still be unfilterable despite being

Negative Charge

What condition suggests damage to the glomerular filtration barrier, especially the podocyte layer?

Albuminuria

What does the presence of albumin in urine normally indicate?

Glomerular Barrier Damage

What system is activated when blood pressure or plasma sodium is low?

RAAS (Renin-Angiotensin-Aldosterone System)

What enzyme is secreted by the kidney to initiate RAAS?

Renin

What is the inactive form of angiotensin produced in the blood?

Angiotensin I

What enzyme converts Angiotensin I to Angiotensin II?

Angiotensin-Converting Enzyme (ACE)

Where is ACE produced?

Lungs

What is the active form of angiotensin that affects GFR and sodium levels?

Angiotensin II

How does Angiotensin II affect the afferent arteriole?

Vasodilation

How does Angiotensin II affect the efferent arteriole?

Vasoconstriction

What is the net effect of Angiotensin II on glomerular pressure and GFR?

Increases GFR

Where does Angiotensin II directly increase sodium reabsorption?

Proximal Convoluted Tubule (PCT)

What hormone is secreted by the adrenal cortex in response to Angiotensin II?

Aldosterone

Where does aldosterone increase sodium reabsorption?

Distal Convoluted Tubule (DCT)

Which sodium reabsorption site is aldosterone-dependent?

Distal Convoluted Tubule (DCT)

Which sodium reabsorption site is not aldosterone-dependent?

Proximal Convoluted Tubule (PCT)

What hormone is secreted to increase water reabsorption in the collecting duct?

Antidiuretic Hormone (ADH)

What is another name for ADH?

Vasopressin

Where is ADH produced?

Hypothalamus

Where is ADH stored and released?

Posterior Pituitary

Which part of the nephron is under ADH control for water reabsorption?

Collecting Duct