Renal medicine

Question 1

Where would calyces be found

Answer 1

Within the kidney branching off the renal pelvis

Question 2

What percentage of the cardiac output do they kidneys receive

Answer 2

20%

Question 3

What does Renin do

Answer 3

Renin is the enzyme that converts angiotensinogen to angiotensin I, which is then converted to angiotensin II in the lungs by ACE

Question 4

What is the renin angiotensin aldosterone system

Answer 4

Angiotensin II has four main effects:​

-Generalised vasoconstriction → ↑ SVR ↑ BP​

-Vasoconstriction of efferent arterioles to a greater extent than afferent arterioles in the kidney → ↑ GFR​

-Release of aldosterone by adrenal → ↑ sodium and water retention​

-Stimulates thirst by action on hypothalamus​

Question 5

What is the glomerulus

Answer 5

Fenustrated capillary network allowing passage of water solutes and protein​

Question 6

What are the role of the tubules

Answer 6

Reabsorption, secretion, and excretion occurs in tubules​

Question 7

What determines the filtration rate in the glomerulus

Answer 7

Filtration dependent on the balance between hydrostatic and colloid osmotic pressure
GFR - 125ml/min

Question 8

How much more permeable are glomerular capillaries than normal capillaries

Answer 8

100x times

Question 9

What is clearance

Answer 9

The volume of plasma that iscleared of the substance in unit time

Question 10

What is resorbed in the PCT

Answer 10

100% of glucose and amino acids
90% of bicarbonate
80-90% of inorganic phosphate and water
40-50% of urea

Question 11

What are the roles of the loop of hemle, DCT and collecting duct

Answer 11

Loop of Henle​
-Concentrating urine

Distal convoluted tubule​
-Fine tuning​
-Reabsorption of ions

Collecting duct​
-Variable permeability to water ​
-Antidiuretic hormone (ADH) dependent​
-Achieves the final urine concentration

Question 12

What are the functions of the kidney

Answer 12

Salt and water homeostasis
Acid-base homeostasis
Excretion of waste products
Retention of vital substances
Endocrine functions (produce erythropoietin)

Question 13

Where is ADH released from

Answer 13

Posterior pituitary

Question 14

What stimulates ADH release

Answer 14

Increased osmolality in the hypothalamus​
Decreased plasma volume ​
Angiotensin II

Question 15

What does ADH do

Answer 15

Determines the permeability of collecting ducts

Question 16

How is calcium homeostasis acheived

Answer 16

Parathyroid hormone (PTH) and vitamin D. ​

PTH is released in response to low plasma calcium levels​

PTH acts on the kidney to increase calcium reabsorption in the distal convoluted tubule ​

The kidney also converts 25-hydroxyvitamin D to its active form, 1,25-dihydroxyvitamin D, which increases intestinal calcium absorption and renal calcium reabsorption​

Question 17

What is the process of phophate homeostasis

Answer 17

PTH and vitamin D, plus , fibroblast growth factor 23 (FGF23)​

PTH decreases phosphate reabsorption in the proximal tubule ​

FGF23, produced by osteocytes, further enhances phosphate excretion

Question 18

What is the function of calcitriol

Answer 18

Crucial for calcium and phosphate homeostasis

Question 19

Whereis renin secreted

Answer 19

Juxtaglomerular cells

Question 20

How is the estimated glomerular filtration rate used to ‘stage’ the chronic kidney disease

Answer 20

Stage 1: eGFR >90 (normal), with other tests showing signs of kidney damage (e.g. proteinuria)​

Stage 2: eGFR of 60 to 89 ml/min, with other tests showing signs of kidney damage (e.g. proteinuria)​

Stage 3a: eGFR of 45 to 59 ml/min​

Stage 3b: eGFR of 30 to 44 ml/min​

Stage 4: eGFR of 15 to 29 ml/min​

Stage 5: eGFR <15 ml/min

Question 21

What are the subtypes of acute kidney injury

Answer 21

Pre-renal
Renal
Post-renal

Question 22

What causes pre-renal acute kidney injury

Answer 22

Decreased perfusion of kidneys​

Hypovolaemia​

Hypotension

Question 23

What is acute kidney injury

Answer 23

Sudden decline in renal function​

Typically identified by a rapid increase in serum creatinine levels and/or a decrease in urine output

Question 24

What could result in renal acute kidney injury

Answer 24

Direct damage to renal parenchyma e.g. acute tubular necrosis, glomerular nephritis​

Question 25

What would cause post-renal acute kidney injury

Answer 25

Obstruction

Question 26

What is glomerulonephritis

Answer 26

Immune-mediated disorders IgA nephropathy being the most common type Inflammation of the glomeruli​

Question 27

How is glomerulonephritis diagnosed and treated

Answer 27

Diagnosis via biopsy Treatment immunosuppressive & supportive

Question 28

What are the management options for acute tubular necrosis

Answer 28

Avoid​ Supportive care ( fluid management)​ Renal Replacement Therapy

Question 29

What is pyelonephritis

Answer 29

UTI - bacterial infection (Relatively common) E.Coli most commonly organism​ infection typically ascends from the lower urinary tract, facilitated by factors such as vesicoureteral reflux, urinary obstruction, and instrumentation

Question 30

What are the risk factors for renal cancer

Answer 30

smoking,​ obesity, ​ Hypertension​ certain hereditary conditions like von Hippel-Lindau disease​

Question 31

What are the most common causes of chronic kidney disease

Answer 31

HYPERTENSION and DIABETES Diabetic nephropathy Hypertensive nephrosclerosis

Question 32

What is diabetic nephropathy

Answer 32

Prolonged hyperglycaemia causes cellular damage & inflammation​ -overproduction of advanced glycation end product ​ -activation of protein kinase C​ -increased oxidative stress

Question 33

What are signs of diabetic nephropathy

Answer 33

glomerular hyperfiltration and microalbuminuria,​ Progressing to macroalbuminuria & ↓ eGFR

Question 34

What is hypertensive nephrosclerosis

Answer 34

Structural changes in the kidneys as a result of sustained high blood pressure​ Changes lead to progressive renal damage and eventual decline in kidney function.

Question 35

What are the types of polycystic kidney disease

Answer 35

Autosomal dominant - presents in adulthood, more common, mutations in PKD1 PKD2 genes Autosomal recessive - presents in childhood, rarer, mutation in PKHD1 gene

Question 36

What is dialysis

Answer 36

Remove metabolic waste products, excess body water, and rebalancing electrolytes​

Question 37

What are the types of dialysis

Answer 37

Haemodialysis​ -Fistula or dialysis line​ Peritoneal dialysis

Question 38

What are dental impacts of dialysis

Answer 38

Increased Risk of Oral Diseases​ -Higher prevalence of periodontal disease, dental caries, and oral Candida colonization ​ -This is due to factors such as impaired immunity, altered salivary flow, and poor oral hygiene Management of Bleeding Risks​ -Anticoagulant therapy Timing of Dental Procedures​ -Schedule dental treatments on non-dialysis days to minimize the risk of bleeding and infection. Infection Control​ -Compromised immune systems​ -At higher risk for infections. Impact on Survival​ -Proper dental care associated with improved survival rates in dialysis patients. Oral Health and Systemic Complications: ​ -Poor oral health in dialysis patients has been linked to systemic complications such as cardiovascular disease and pneumonia. ​

Question 39

What factors should dentists be aware of when treating patients with transplants

Answer 39

Post-transplant immunosuppressive therapy -susceptible to infections -can causes gingival overgrowth which may need surgery -can cause oral ulcerations Dental caries more prevelant until oral pH is normalised after transplant

Question 40

Why are platelets affected with kidney disease

Answer 40

Primarily due to the accumulation of uremic toxins, which impair platelet aggregation and adhesion. ​ This results in prolonged bleeding times and reduced platelet reactivity to agonists such as adenosine diphosphate (ADP) and collagen​ Patients on hemodialysis (HD), the interaction of blood with the dialysis membrane can activate platelets, leading to a paradoxical state of both increased platelet activation and impaired function.

Question 41

What drugs should be avoided in patients with renal disease

Answer 41

Probenecid Tetracyclines Aspirin Ibuprofen ( avoid where possible ) Ephedrine Povidone-iodine All increase in toxicity without normal renal function