The kidneys structure and function Flashcards

1
Q

List some functions of the kidney

A
Water balance
Salt balance
Plasma volume 
Plasma osmolarity 
Excretion of endogenous waste products
Excretion of exogenous waste products
Acid-base balance 
Long term regulation of blood pressure 
Red blood cell production
Activation of vitamin D
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2
Q

Urea, bilirubin and uric acid are breakdown products of what respectively?

A

Urea - protein
Bilirubin - haemoglobin
Uric acid - purines

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3
Q

Erythropoetin is released in response to what? How does it manage this?

A

Hypoxia

Stimulation of red blood cell production

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4
Q

What effect does calcitriol have on the GI tract?

A

Stimulates calcium absorption

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5
Q

Vitamin D undergoes metabolism by two organs, name these

A

Liver

Kidney

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6
Q

What is the kidneys primary function?

A

To regulate the volume, composition and osmolarity of the extracellular fluid

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7
Q

What is the balance concept of homeostasis?

A

Input must match output

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8
Q

List all components of the renal system

A

Kidneys
Ureters
Bladder
Urethra

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9
Q

Describe the macrostructure of the kidney

A
Renal capsule
Renal cortex
Renal medulla
Medullary pyramids
Renal columns 
Minor calyx
Major calyx 
Renal pelvis 
Renal hilum (artery, vein, ureter)
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10
Q

What is the functional unit of the kidney?

A

Nephron

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11
Q

What three processes does the nephron carry out?

A

Glomerular filtration
Tubular reabsorption
Tubular secretion

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12
Q

What are the two types of kidney nephron and which is the most numerous?

A

Juxtamedullary

Cortical (most common)

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13
Q

Describe the changes in vasculature over the course of the nephron

A
Renal artery >
Afferent arteriole >
Glomerulus >
Efferent arteriole >
Peritubular capillaries >
Venule >
Renal vein
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14
Q

The collecting duct receives urinary filtrate from many different nephrons. T/F

A

True

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15
Q

How do the descending and ascending limbs of the loop of henle differ in diameter?

A

Descending limb - thin

Ascending limb - thick

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16
Q

When is the tubular fluid termed urine? Why?

A

After it leaves the collecting ducts

It is no longer modified after leaving the collecting ducts

17
Q

Describe the differences between the two nephron types

A

Juxtaglomerullary - long loop of Henle, vasa recta

Cortical - short loop of Henle, peritubular capillaries

18
Q

What is the role of juxtaglomerullary nephrons?

A

Producing concentrated urine

19
Q

The diameter of the efferent arteriole leaving the glomerulus is larger than that of the afferent arteriole. T/F

A

False - the diameter of the afferent arteriole is larger

20
Q

What forms filtration slits?

A

Podocytes

21
Q

What are the cells of the juxtaglomerular apparatus? What are their respective functions

A

Macula densa - senses ionic concentration of filtrate
Lacis cells - unknown
Granular/juxtaglomerular cells - secretes renin

22
Q

What is urine?

A

Modified filtrate of the blood

23
Q

Around which fraction of the total cardiac output do the kidney receive?

A

1/4 (i.e they have a rich blood supply)

24
Q

What two components of plasma should the urinary filtrate not contain?

A

RBC

Large proteins

25
Q

Write the equation for calculating rate of filtration (for a freely filterable substance)

A

Rate of filtration = plasma concentration x GFR

26
Q

What is the average GFR of a healthy adult?

A

125ml/min

27
Q

What effect should increased plasma concentration have on GFR?

A

Increase

and vice versa

28
Q

Write the equation for calculating rate of excretion

A

Rate of excretion = urine concentration x urine flow rate

29
Q

The rate of excretion changes dramatically depending on hydration status. T/F

A

True

30
Q

How do we know a substance has been reabsorbed? Write the equation for calculating rate of reabsorption

A

Rate of filtration > rate of excretion

Rate of reabsorption = rate of filtration - rate of excretion

31
Q

How do we know when a substance has been secreted? Write the equation for calculating rate of secretion

A

Rate of excretion > rate of filtration

Rate of secretion = rate of excretion - rate of filtration

32
Q

The rates of reabsorption and secretion reflect tubular modification. T/F

A

True

33
Q

What is important to convert when preforming these calculations?

A

The units (must always be litres per minute)