[08.01] Review of Renal Physiology and CKD and Dialysis_ The Burden of Illness V2 (1).pdf

Paired retroperitoneal organs

How are the kidneys anatomically described based on their location?

Renal pelvis

What part of the kidney is joined to the urinary bladder via the ureters?

Approximately one million

How many nephron units are contained in each human kidney?

Renal corpuscle and a tubule

What are the two main components that make up a nephron?

Afferent arteriole

Which blood vessel supplies the tuft of capillaries in the renal corpuscle?

Efferent arteriole

Which blood vessel exits the renal corpuscle after the capillary tuft?

Proximal convoluted tubule (PCT)

Which segment of the tubule follows immediately after the glomerulus?

Proximal convoluted tubule

Which segment of the nephron is described as the most intricate due to the high volume of activity?

Renal artery

What is the primary vessel through which blood enters the kidney?

Interlobar, arcuate, and cortical radial arteries

The renal artery divides into which three subsequent types of arteries?

Peritubular capillaries

The efferent arterioles subdivide into what second set of capillaries?

Glomerular filtration

What is the term for the volume of filtrate formed per unit of time from the glomerulus?

Tubular reabsorption

What is the process called when the direction of transfer is from the tubular lumen into the interstitium?

Tubular secretion

What is the process called when solutes move from the peritubular-capillary plasma into the tubular lumen?

Hyperkalemia

In Case #1, B.F.'s regular consumption of bananas despite CKD led to which manifestation of disordered tubular secretion?

20%

What percentage of plasma entering the glomerulus is normally filtered into Bowman’s capsule?

8 nanometers (80 Å)

What is the maximum molecular diameter allowed to pass through the pores of the glomerular membrane?

Strong negative electrical charge

What electrical characteristic of the glycosylated proteins lining glomerular pores helps repel certain solutes?

Endothelium, basement membrane, and podocytes

What are the three components that make up the filtration barrier of the glomerulus?

Filtration slits (or slit pores)

What are the spaces located between the podocytes called?

Albuminuria

What is the term for the presence of albumin in the urine, often caused by the loss of negative charges in the glomerular wall?

Glomerular filtration

The presence of albuminuria in a patient with Diabetic Kidney Disease is a manifestation of a disorder in which renal process?

125 ml/min

What is the normal Glomerular Filtration Rate (GFR) for a healthy individual?

10% lower

How do normal GFR values for women compare to those for men?

99%

What percentage of the 180 L of filtrate formed daily is normally reabsorbed?

Inulin

Which substance is considered ideal for measuring GFR because it is freely filtered and neither secreted nor reabsorbed?

Muscle mass

Endogenous creatinine clearance is a frequent but less accurate measure of GFR because it can be affected by what patient factor?

Reduced GFR

What happens to the GFR when there is constriction of the afferent arteriole?

Increased GFR

What happens to the GFR when there is constriction of the efferent arteriole?

Reduced renal blood flow

What is the overall effect on renal blood flow when both the afferent and efferent arterioles are constricted?

Glucose

Which solute is 100% reabsorbed in the proximal tubule after leaving the glomerulus?

Passive diffusion

What is the movement of molecules from an area of higher concentration to lower concentration called?

Facilitated diffusion

What is the term for diffusion aided by specific channels that accompany molecules?

Solvent drag

What is the movement of solutes called when they are aided by the movement of water?

Active transport

What mechanism uses energy (ATP) to move solutes against an electrochemical gradient?

Sodium-potassium (Na+-K+) ATPase

What primary pump facilitates sodium reabsorption throughout various segments of the nephron?

3 Na+ out, 2 K+ in

What is the specific ion exchange ratio of the Na+-K+ ATPase pump?

Furosemide

Which medication induces diuresis by blocking the sodium-potassium-2 chloride channel in the thick ascending limb?

Principal cells

Which cells in the distal tubule are responsible for potassium secretion and sodium reabsorption?

Intercalated cells

Which cells in the distal tubule are responsible for bicarbonate reabsorption and hydrogen ion secretion?

Acidification of the urine

The release of hydrogen ions into the urine by intercalated cells is also known by what term?

Aldosterone

Which hormone heightens the action of principal cells to enhance sodium reabsorption and potassium secretion?

Hypokalemia

What electrolyte abnormality results from the increased potassium secretion seen in hyperaldosteronism?

Antidiuretic hormone (Vasopressin)

Water reabsorption in the collecting ducts is dependent on the presence of which hormone?

Posterior pituitary gland

Which gland secretes antidiuretic hormone (ADH)?

65%

What percentage of sodium and water are reabsorbed in the proximal tubule?

Descending thin limb of Henle’s loop

In which tubular segment is 10% of water reabsorbed but no sodium is reabsorbed?

Ascending thin and thick limb

In which segment of the loop of Henle is 25% of sodium reabsorbed but no water?

Dehydration

In what physiological state does the collecting duct system reabsorb more than 24% of filtered water?

80-90%

What percentage of filtered bicarbonate is reabsorbed in the proximal tubule?

Carbonic acid (H2CO3)

H+ combines with filtered HCO3- to form which substance during the process of bicarbonate reabsorption?

Renin

A drop in arterial blood pressure stimulates the secretion of what substance from the kidneys?

Intrarenal baroreceptors and macula densa receptors

What two types of sensors in the kidney trigger renin secretion?

Angiotensin I to Angiotensin II

Renin facilitates the conversion of which substances in the RAAS pathway?

Increased arteriolar constriction

What is the effect of Angiotensin II on vascular smooth muscle to help increase blood pressure?

Adrenal cortex

Which part of the adrenal gland is stimulated by Angiotensin II to secrete aldosterone?

Thirst

What sensation is triggered in the brain by Angiotensin II to increase water ingestion?

Proteinuria, uremia, and acidosis

What are three manifestations of disordered renal function associated with CKD?

Chronic Kidney Disease (CKD)

What is the current medical term that encompasses a range of pathophysiologic processes associated with abnormal kidney function?

Albuminuria

The risk of CKD progression is closely linked to both the GFR and what other marker?

CKD stages 3–5

The term "chronic renal failure" typically corresponds to which stages of CKD?

Acute Kidney Injury (AKI)

What is the new term for Acute Renal Failure?

Reversible

Unlike CKD, Acute Kidney Injury is often considered to have what characteristic regarding its duration?

End Stage Renal Disease (ESRD)

What is the "dispiriting" term now replaced by the term CKD Stage 5?

Uremic syndrome

What syndrome results from the accumulation of toxins, fluids, and electrolytes that the kidneys can no longer excrete?

Renal replacement therapy (RRT)

Dialysis and kidney transplantation are forms of what general type of therapy?

Ischemic heart disease, stroke, and lower respiratory infection

CKD became the fourth leading cause of death in the Philippines in 2019, following which three conditions?

Diabetes mellitus

What is the leading cause of ESRD in both the United States and the Philippines?

Glomerulonephritis and Hypertension

After diabetes, what are the next two leading causes of kidney failure among Filipinos?

Hyperfiltration and hypertrophy

What two adaptive mechanisms of remaining nephrons eventually become maladaptive in CKD?

More than 3 months

To be defined as CKD, abnormalities in kidney structure or function must be present for how long?

AER ≥ 30 mg/g

What level of Albumin Excretion Rate is considered a marker of kidney damage?

Histology (biopsy) and imaging (ultrasound)

Aside from GFR and albuminuria, what are two other ways to detect kidney damage mentioned in the sources?

ACE inhibitors and ARBs

Albuminuria levels guide the dosage of which two specific classes of renoprotective drugs?

Diabetes, hypertension, and cardiovascular disease

Screening for early CKD should primarily target patients with which three conditions?

eGFR and albuminuria

An ideal initial screening approach for CKD consists of measuring which two parameters?

Serum creatinine, serum cystatin C, and urine albumin-creatinine ratio (uACR)

The "triple marker" panel for CKD confirmation includes which three markers?

Steady state

Equations for estimating GFR are only valid if the patient is in what state regarding their serum creatinine?

Underestimate

The Cockcroft-Gault formula is not recommended for clinical use partly because it may do what to actual kidney function?

CKD-EPI Creatinine Equation (2021)

Which specific equation is recommended by the joint NKF/ASN Task Force to estimate GFR?

Creatinine, cystatin C, age, weight, and gender

The eGFR calculator requires what five pieces of patient information?

Stage 5 CKD

An eGFR of less than 15 ml/min per 1.73m² indicates which stage of CKD?

Stage 3

Symptoms of kidney disease like edema and anemia often do not appear until which stage?

Nonsteroidal anti-inflammatory agents (NSAIDs)

Which common class of over-the-counter pain relievers can lead to kidney damage?

Appetite loss, nausea, and hiccups

What are three gastrointestinal or general symptoms associated with uremic syndrome?

Funduscopy

Which physical examination technique is important for detecting diabetic retinopathy associated with nephropathy?

Asterixis or pericardial friction rub

The presence of which two physical signs usually signifies the presence of uremic syndrome?

Systemic

Why is there no specific physical examination finding that definitively pinpoints CKD?

Intraglomerular hypertension and proteinuria

Slowing CKD progression focuses on reducing which two factors?

SGLT2-inhibitors

Which class of medications, originally for diabetes, has been shown to slow CKD progression even in non-diabetic patients?

Finerenone

Which mineralocorticoid receptor antagonist is used to slow down CKD and treat heart failure?

Azotemia

What is the term for elevated levels of creatinine in the blood?

Uremia

Which term refers specifically to the clinical signs and symptoms of high creatinine, rather than just the lab value?

Uremic symptoms, intractable hyperkalemia, and acidosis

What are three clinical indications for initiating maintenance dialysis?

Refractory to medical therapy

For hyperkalemia or acidosis to be an indication for dialysis, they must have what characteristic?

Kidney transplantation

Which ESRD treatment option offers the best potential for complete rehabilitation?

None

How many of the kidney's endocrine or anti-inflammatory functions does dialysis replace?

Hemodialysis

Which therapeutic modality is used by more than 90% of ESRD patients in the United States?

4 hours

How long does a typical hemodialysis session usually last?

Continuous

In contrast to hemodialysis, what is the frequency/nature of peritoneal dialysis?