Prelecture Renal and Cardiac Flashcards Preview

Advanced Pathophysiology > Prelecture Renal and Cardiac > Flashcards

Flashcards in Prelecture Renal and Cardiac Deck (74)
Loading flashcards...
1
Q

Circulatory Circuit

A
Absorption and delivery of nutrients 
O2 uptake and delivery
Removes wastes (C02) from tissues
2
Q

Lymphatic circulation

A

System of channels and nodes

Reabsorbs fluid that leaks from the vascular network into the interstitium and returns it to the general circulation

3
Q

Vessels

A

Arterioles - smooth muscles (contract)
Venules - connective
Capillaries - single layer of epithelial

4
Q

Explain the circulation of blood through the heart

A

Blood enters into the right atrium from the superior vena cava then goes through the tricuspid valve into the right ventricle then into the pulmonic valve into the pulmonary circulation into the pulmonary artery then pulmonary vein dumps into the left atrium then mitral valve through the left ventricle goes through the aortic valve into the aorta then clean oxygenated blood into the body

5
Q

3 layer of arteries and veins

A

Intima - in contact with blood
Media - smooth muscle (thickest section of arteries)
Adventitia - collagenous connective tissue (thickest section in veins)

6
Q

Characteristics of lymphatic vessels

A

Lymphatic vessels have valves to keep flow moving in one direction and is able to contract minimally due to contractile fibers

7
Q

Principles of flow

A

Blood flow - movement along a pressure gradient within the vascular bed
Pressure - blood moves from a area of higher pressure (ARTERIES) as it comes from the left side of the heart to an area of lower pressure (VEINS) the greater the difference the greater the blood flow
Resistance - more resistance less blood flow

8
Q

Poiseuille’s law

A

Vessel length - double the length increases resistance and decreases flow by 50%. Cut length of vessel in 1/2 we reduce resistance and increase flow by 100%
Vessel Radius - most important factor - if you double the diameter (2cm to 4cm) increase flow 160x (decrease the resistance)
Blood Viscosity - more viscous = more resistance
(Polycythemia or dehydration)

9
Q

Definition of velocity

A

how fast is the flow

10
Q

Parabolic profile of laminar flow

A

The blood in the center moves faster than blood in the outer layers

11
Q

What changes blood flow

A

Turbulent flow - something is interrupting the forward flow of blood - Thrombus or Atherosclerosis

12
Q

Bruit

A

Turbulent blood flow you can hear with a stethascope

13
Q

Thrill

A

Turbulent blood flow you can feel and hear

14
Q

What is responsible for plasma colloid osmotic pressure (keeping our fluid in our vessels)

A

Plasma proteins (albumin and proteins)

15
Q

An obstruction in lymphatic flow (not vascular flow) allowing fluid to collect in the interstitium

A

Lymphedema

16
Q

Thoracic pump

A

when you take a deep breath in expanding your lungs you are increasing pressure in the thoracic cavity sucking blood through the venous side of the body into the right side of the heart

17
Q

Lymphatic flow is controlled by

A

Increasing colloid osmotic pressure and stimulation of contractile fibers (lymphatic pumps)

18
Q

Blood flow is controlled by central mechanisms mediated by:

A

Autonomic nervous system
Venous system flow controlled by pressure gradient from veins and venous and thoracic pumps
Intrinsic autoregulatory mechanisms

19
Q

Extrinsic Mechanisms

A

Mechanisms outside the blood vessels. Sympathetic nervous system

20
Q

What does the release of norepinephrine do?

A

Results in vasoconstriction via Alpha 1 receptors

21
Q

What does the release of epinephrine do?

A

Results in vasodilation via the Beta 2 adrenergic receptors

22
Q

Movement of lymph is enhanced by

A
Lymphatic pumps
Compression of lymphatic channels (increased physical activity)
Intrathoracic pressure changes (increased respiratory rate) 
Lymphatic contractions (increased BP)
23
Q

What are the kidneys responsible for?

A

Kidneys are responsible for fluid and electrolyte homeostasis, ridding the body of water and soluble wastes

24
Q

How much fluid is filtered and reabsorbed via the kidneys?

A

The kidneys filter 7L/hour of fluid and reabsorb 99%

25
Q

2 important endocrine fx of the kidneys

A

Production of erythropoietin and activation of vitamin D (cofactor for intestinal calcium absorption)

26
Q

What are 2 mechanisms that the renal system performs

A
Degrades insulin (20%)
Produces prostaglandins (potent vasodilators to counteract vasoconstriction of Angiotensin and ADH)
27
Q

What do the kidneys use ADH for

A

To maintain plasma osmolality (viscosity or fluid balance)

28
Q

What do the kidneys use Aldosterone for

A

To maintain electrolyte balance

29
Q

What is the purpose of nephrons

A

Nephrons are the functional units of a kidney they perform all filtration, reabsorption, and secretary functions

30
Q

What percentage of renal fx and nephrons can you lose without being symptomatic

A

50% - 1 kidney

31
Q

Losing or damaging 75-90% of nephrons result in

A

Serious renal impairment

32
Q

Every time the creatine doubles you lose what percentage of renal function?

A

50%

33
Q

CVA

A

Costovertebral angle is the external landmark for the kidneys

34
Q

Location of the kidneys

A

Retroperitoneal space, under the diaphragm. Right kidney is slightly lower than the left

35
Q

3 Divisions of the Renal Parenchyma

A

Pelvis - urinary collecting structures (calyces)
Medulla - middle portion, renal pyramids
Cortex - outer portions (glomeruli and nephron tubules)

36
Q

What are Nephrons composed of

A

Glomerulus (capillary tuft, Bowman capsule)

Tubules (loop of Henle)

37
Q

Glomerulus

A

Site of filtration, basement membrane prevents cells & large proteins from passing

38
Q

Indicator of basement membrane dysfunction

A

Proteinuria

39
Q

What do proximal convoluted tubules do?

A

Reabsorb water, electrolytes, and all of the glucose, amino acids, proteins and vitamins

40
Q

Loop of Henle

A

Thin descending limb receives filtrate from proximal convoluted tubules and delivers to ascending limb and its permeable to water.
Thick descending limb contains NA, K, and CL that pumps ions into the interstitium. It is impermeable to water

41
Q

Distal convoluted tubules

A

Remove electrolytes and performs further reabsorption using aldosterone and angiotensin II to stimulate tubule cells to reabsorb Na and H20. Then ANP keeps us from reabsorbing fluid. Process controls how much salt and water we have reabsorbed. If we save Na we are removing K

42
Q

What two cells are in the collecting duct?

A
Principle Cells (P) respond to antidiuretic hormone
Intercalated Cells (I) participate in acid base balance by regulating the secretion of acid
43
Q

GFR value

A
Normal
Hospital >90
Community >60
anything over 90 is abnormal
GFR provides info on kidney fx
44
Q

What determines GFR

A

Filtration pressure and the permeable surface of the glomerular membrane
Capillary hydrostatic pressure and Bowman capsule oncotic pressure favor filtration
Plasma/capillary oncotic pressure and Bowmancapsule hydrostatic pressure which oppose filtration

45
Q

What is the most important physiologic regulator of GFR

A

Blood volume
Increased Blood Volume = increased GFR = extra fluid excreeted
Decreased Blood Volume = decreased GFR = fluid is conserved

46
Q

How does SGLT2

work to reabsorb glucose in the kidney

A

Glucose is filtered freely across the glomerular membrane. All filtered glucose is reabsorbed in the proximal tubule by a sodium-dependent cotransporter (SGLT2) If these transporters are overwhelmed by excessive tubular loads of glucose glycosuria results

47
Q

Should glucose be in the urine

A

NO if it is there hyperglycemia may be present

48
Q

Regulation of acid-base balance in the kidneys

A

Kidneys excrete excess H+ and regulate the concentration of HCO3- (bicarb).
HCO3- is filtered freely through the glomerulus and must be efficiently reabsorbed to maintain acid base balance

49
Q

Where does the secretion of potassium happen and how is it regulated

A

In the distal tubules and is regulated by aldosterone which increases K excretion. Aldosterone saves Na and excretes K

50
Q

When PaCO2 is high (acidosis)

A

The kidney compensate by excreting more H+ and by creating new HCO3-

51
Q

When PaCO2 is low (alkalosis)

A

The Kidneys compensate by excreting some of the filtered HCO3-

52
Q

Explain RAAS

A

If there is a low BP the kidneys sense that and produce RENIN then is activated with ANGIOTENSINOGEN (liver) to produce ANGIOTENSIN 1 (mild vasoconstrictor) that is activated by a (ACE) CONVERTING ENZYME in the lungs to make ANGIOTENSIN II (strong vasoconstrictor) which causes the systemic arteries to vasoconstrict and increase BP.

53
Q

What else does Angiotension II do in the RAAS system

A

Angiotensin II works on the adrenal cortex which puts out Aldosterone which goes into the collecting tubules and tells the body to reabsorb salt and water which then increases blood pressure

54
Q

Antidiuretic Hormone (ADH)

A

AKA Vasopressin TAPWATER HORMONE
Secreted from the posterior pituitary
Increases the permeability of the collecting tubule to water, resulting in increased reabsorption of water and reduced blood osmolality (how concentrated blood plasma is). Reabsorbed water dilutes the blood and reduces osmolality, causing the body to decrease ADH release

55
Q

If osmolality is too low

A

ADH secretion is completely inhibited and collection tubules become impermeable to water. Results in a large amount of diluted urine. We dump it

56
Q

Affects blood volume without affecting blood osmolality

A

Aldosterone, Angiotensin II, and Natriuretic Peptides
Aldosterone and Angiotensin II increase sodium and water reabsorption at the same time. Natriuretic peptides inhibit their reabsorption

57
Q

When is renin released

A

decreased blood flow to the kidneys
reduced serum sodium levels
activation of sympathetic nerves to the juxtaglomerular cells

58
Q

When are natriuretic peptides

A

Atrial cells in the heart must be overstretched by excessive blood volume
Inhibits the actions of angiotensin II
Results in loss of sodium and water in the urine

59
Q

ACE Inhibitors

A

Diuretic agent that inhibits the formation of angiotensin II and aldosterone.

60
Q

Loop diuretics

A

Diuretic agent that block the Na, K, Cl pump in the ascending loop of Henle

61
Q

Thiazide like diuretics

A

Block Na reabsorption, excrete K

62
Q

Erythropoietin

A

Stimulates erythrocyte development in the bone marrow so anytime the kidneys sense a lack of oxygen in the blood stream they think its lack of blood cells so erythropoietin is produced to make more blood cells

63
Q

Vitamin D

A

Metabolized in the kidney to make it a active form of vitamin D for calcium reabsorption in the intestine. If the kidneys sense there is a low serum calcium they will activate more Vitamin D to absorb more calcium through the GI system into the plasma system

64
Q

Age-related changes in the GI system

A

Infant - Low GFR (has reduced ability to make concentrated urine
Elderly - Decrease GFR,
Kidneys decrease in size and fx in 40’s by the 60’s it is significant. Decreased renal blood flow. Susceptible to fluid and electrolyte imbalances and renal damage

65
Q

Specific Gravity

A

1.005 - 1.030
The higher the specific gravity the more concentrated the urine is indicating dehydration. The lower the SP indicated hydration and dilute urine

66
Q

Serum Creatine

A

> 1.0 - 1.2

Used for evaluating medications

67
Q

BUN

A

10-20

Increased value indicates decreased kidney function or dehydration

68
Q

Urine should be…

A

Pale yellow with a pH of 6

Slightly acidic

69
Q

The urine osmolality and SG changes throughout the day

How so?

A

In the morning you are slightly dehydrated with a higher SG

70
Q

What should you NOT see in the blood?

A
Protein
Glucose
Epithelial cells
Erythrocytes
Leukocytes
Bacteria
Crystals
Stones
Casts (WBC/RBCs)
71
Q

WBC casts are r/t?

A

Pyelonephritis

72
Q

RBC casts are r/t?

A

Glomerulonephritis

73
Q

What is found in the urine specifically in women b/c of anatomy

A

Leukocytes

74
Q

What do epithelial cells casts indicate

A

Sloughing of the tubular cells (acute tubular cells)