Renal Flashcards
What do the kidney contain?
Cortex ➡️ outer layer of kidney
Contains glomeruli and tubular system of the nephron
Medulla ➡️ inner portion
Contains collecting ducts
Pelvis ➡️ upper end of ureter
Divides to form funnel shaped callyses that direct urine from kidneys to ureter
Contains filtered blood that was process into urine
Where are most nephrons found?
The outer area of cortex
Where are the juxtamedullary nephrons found?
Deeper in the cortex, closer to Medulla
What is the function of nephrons and what are the two major portions?
Nephrons are the functioning unit of the kidney
2 major portion:
- Renal corpuscle ➡️ glomerulus: located in Bowman’s capsule
- Renal tubules
- proximal convoluted tubule
- nephron loop
- distal convoluted tubule
The glomerulus originates from
Afferent arteriole ➡️ arriving to glomerulus
How does the kidney flow?
Bowman’s capsule ➡️ proximal convoluted tubule ➡️ descending limb ➡️ loop of Henle ➡️ ascending limb ➡️ distal convoluted tubule
Where is most of the filtered water and sodium reabsorbed?
Proximal Convoluted Tubule
Controls volume and sodium concentration within the vascular system
Activated when kidneys receive signal of low BP, low renal blood flow, low serum Na
Renin – angiotensin – aldosterone system
Renin – angiotensin – aldosterone system
Juxtaglomerular apparatus secretes renin
Renin converts angiotensinogen into angiotensin I ➡️ inc peripheral ctx, secretes aldosterone
Angiotensin I is converted to angiotensin II
What are the two main functions of angiotensin II
Strong vasoconstriction
Stimulates release of length from the adrenal glands which results in sodium reabsorption by kidney
What is synthesized by the nephrons to control renal perfusion by acting as a potent renal vasodilator?
Prostaglandins
What does the kidney do in terms of acid-base balance?
Alters absorption and secretion of hydrogen and bicarb ions
if a substance has the ability to except a free H+ ions, it’s a ?
Base
The ability to gain or lose an H+ ion determines whether a substance is an acid or a base
What are the two electrolyte imbalances increase H+ concentration?
Hypokalemia and hypochloremia
What is renal compensation?
Kidneys control pH and HCO3 the blood
Increase bicarb occurs in the proximal tubule when it senses increase H+ ions
What is the kidneys role in red blood cell production?
Decreased hematocrit or O2 tension
Produces erythropoietin
Increases red blood cell
What is the active form of vitamin D called?
Calciferol
Creatinine normal value
0.5-1.1 mg/dL
End product of muscle and protein metabolism
BUN and normal value
10-30 mg/dL
Concentration of urea in the blood
Estimation of filtrate that is cleared in the glomerulus
Glomerular filtration rate
Refers to kidneys concentrating ability
Urine osmolality
What is the difference in kids kidneys?
Proportionately larger
Renal blood flow and GFR are low at birth and gradually increase as the child develops
Limited ability of the newborn to conserve sodium and excrete excess sodium
Less able to concentrate urine
renal function mature by 1-2 years of age
Renal system purpose
F and E balance Acid-base balance Detoxification of blood and waste elimination Regulates blood pressure Erythropoietin production Vit D activation
Two types of fluid compartments
Intracellular fluid
Extracellular fluid
Three types of extra cellular fluid
Interstitial fluid
Plasma – intravascular
Transcellular water
‼️Normal sodium‼️
‼️ 135-145 mEq/L ‼️
The role of sodium
Main electrolyte in ECF Regulates fluid balance Osmolality Acid-base balance Nerve impulse Muscle contraction Filtered freely at glomerulus
Causes:
Diarrhea, vomiting/NG suctioning, SIADH, burns, fever
Manifestations:
Seizures, lethargy, cerebral edema, decreased LOC, dyspnea, respiratory failure
Hyponatremia
Low sodium levels that are corrected to quickly can result in
Osmotic demyelinization syndrome
High sodium levels that are corrected to quickly can result in
Cerebral edema
Causes:
increased sodium intake, insensible water loss, heat exposure, exercise, DI, diuresis
Manifestations:
Irritability, lethargic, coma, seizures, high pitched cry, flushed skin, muscle weakness, thirst
Hypernatremia
‼️athletes/sport in summer prone to ⬆️Na ‼️
Treatments of hypernatremia
Hypotonic saline
Dialysis
‼️ Normal potassium ‼️
3.5-5.5 mEq/L
The roles of potassium
➡️Mostly intracellular
➡️Responsible for neuromuscular activity and skeletal and cardiac muscles
➡️Renal function is essential
80-90% of intake is excreted by kidneys
The rest is eliminated through bowel and sweat
Relationship between serum pH and potassium
INVERSE
⬇️ pH = ⬆️ K ‼️ Acidosis = hyperkalemia
⬆️ pH = ⬇️ K ‼️ Alkalosis = hypokalemia
Causes for hypokalemia
Not usually related to diet
G.I. fluid loss
Severe diaphoresis
Metabolic alkalosis ➡️ K moves into cell as H+ moves out
Diuretics, corticosteroids, beta adrenergic agonist, Alpha adrenergic antagonist, insulin
Manifestations of hypokalemia
Lethargy Muscle weakness Hypo reflexia Paresthesia PVCs and flattened T waves ➡️ u waves Depressed ST Prolonged PR interval Wake irregular pulse Decreased bowel sounds and constipation
Hypokalemia can potentiate the action of
Digoxin and lead to dig toxicity
Causes for hyperkalemia
Acidosis ➡️ moves K+ out of cell while H+ moves in
Crushing and burn injuries
Medicines: beta adrenergic blockers, potassium sparing diuretics, chemo, ACE inhibitors, NSAID’s
Sickle cell disease
Insulin deficiency
Manifestations of hyperkalemia
Ventricular arrhythmias Peaked T waves Widening QRS Flatten P waves with a prolonged PRI AV conduction delays Muscle weakness Hyperactive reflexes Cramping and diarrhea Paresthesia
Managing MILD hyperkalemia
Loop diuretic
Correct underlying problems ➡️ manage acidosis
Treatment of moderate to severe hyperkalemia
‼️ 1. Calcium chloride or gluconate to manage cardiac effects
‼️ 2. 1-2 ml/kg 25% glucose and 0.1 units/kg regular insulin
‼️ 3. Sodium bicarb to move K+ into cells
‼️ 4. Sodium Ploystyrene sulfonate ➡️ kayexalate
Dialysis
Albuterol moves K+ into the cell and stimulates insulin release
