Unit 3 Flashcards
85% of nephrons- short loops of Henle
Cortical nephrons
15% of nephrons- longer loops of Henle
Juxtamedullary nephrons- primary site of urine concentration
Where fluid is filtered out of the blood and into the nephron
Glomerulus in the renal corpuscle (Bowman’s capsule)
Average UO
60ml/hr
The rate at which fluid filters from the blood into the Bowman’s capsule
Glomerular Filtration Rate
Major site of reabsorption in the nephron
Proximal tubule
Na is mainly reabsorbed in this part of the nephron
Proximal tubule
Known as the salt retaining hormone, also increases secretion of K
Aldosterone
Acts in the collecting tubules, which transmits urine from the nephron and concentrates urine/absorbs water
Antidiuretic hormone (ADH)
ADH is synthesized in the _____ and stored in the _____.
Hypothalamus, posterior pituitary
Angiotensin II is a potent ______
Vasoconstrictor
Acts in the distal tubule to increase reabsorption of Na and secretion of K
Aldosterone
Acts in the collecting tubules to concentrate the urine and reabsorb water
ADH
Two effects of ADH:
- vasoconstrictor blood vessels to increase BP
2. increases reabsorption of water to increase blood volume
Increased ADH causes increase of water in blood, low serum Na, edema, and concentrated urine
SIADH
The best way to measure GFR
Plasma creatinine
Reflective of renal function
GFR
Type of ARF where kidneys are normal but hypo perfusion of the kidney causes failure
Prerenal ARF
Type of ARF that occurs due to obstruction of urine
Postrenal ARF
Type of ARF that results from loss of renal function due to structural damage to the glomeruli and/or tubules
Intrinsic ARF
Increased levels of this denote a decreased renal clearance and decline in GFR
Creatinine
CKD-kidney damage with normal/increased GFR (GFR >90)
1
CKD-kidney damage with mild disease in GFR (GFR 60-89)
2
CKD-moderate decrease in GFR (GFR 30-59)
3
CKD-severe decrease in GFR (GFR 15-29)
4
CKD-kidney failure (GFR < or equal to 15 or dialysis)
5
Blood urea levels _____ with a high-protein diet, excessive tissue breakdown, or GI bleed
Rise
Kidneys receive _______ of CO for glomeruli to remove metabolic wastes and regulate body fluids and lytes
20-25%
Pushes water out of the capillary into interstitial spaces (30-40mmHg arterial, 10-15mmHg venous)
• Aka capillary hydrostatic pressure
• Rise in arterial or venous pressure increases capillary pressure
• Weight of gravity in dependent parts of the body
Capillary filtration pressure
Pulls water back into the capillary (28mmHg)
• Osmotic pressure generated by the plasma proteins that are too large to pass through the pores of the capillary wall
Capillary colloidal osmotic pressure
Opposes the movement of water out of the capillary (-3mmHg)
Interstitial hydrostatic pressure
Pulls water out of the capillary into the interstitial spaces (8mmHg)
• Reflects the small amount of plasma proteins that normally escape into the interstitial spaces from the capillary also pulls water out of the capillary and into the tissue spaces
Tissue colloidal osmotic pressure
Edema throughout the body
Anasarca
Increased permeability of glomerulus
o Massive proteinuria and lipiduria (fatty casts)
o Also hypoalbuminemia, generalized edema, hyperlipidemia
o Loss of plasma proteins (albumin and globulins- meaning infection is also possible…) in the urine
Nephrotic syndrome
Proliferative inflammatory response
o Sudden onset of hematuria (red cell casts), proteinuria, diminished GFR, oliguria, signs of impaired renal function
o Caused by damage to the capillary wall in glomerulus- letting RBCs escape into the urine
o Causes extracellular fluid accumulation, HTN, and edema due to decreaed GFR and enhanced tubular reabsorption of salt and water
o Can occur in SLE or other infections…
Nephritic syndrome
Hereditary defect of glomerular basement membrane that results in hematuria and can progress to chronic renal failure
Alport syndrome (type of glomerulonephritis)
Edema cause:
Force of increased volume in capillaries that pushes fluids out
Hypervolemia that causes pulmonary edema
Also heart failure, renal failure and pregnancy
Increased capillary hydrostatic pressure
Edema cause: Decrease in plasma proteins like albumin
From kidney disease (patient peeing out proteins- nephrotic syndrome)) or lack of synthesis of proteins (malnutrition or liver disease because liver produces proteins)
Burns or wounds (loss of protein from denuded skin areas)
Decreased capillary oncotic pressure
Edema cause: Causes localized edema
Response from an inflammatory issue or infection
• Release of histamine or other chemical mediators from injured cells that allows proteins and fluid movement into interstitium
Toxins, bacterial infections, vitamin C deficiency, prolonged ischemia, burns
Increased capillary permeability
Edema cause: Localized edema because excessive fluid and protein are not returned to the general circulation
Damage to lymph node or removal- cancer, infections, surgery, congenital absence or abnormality of lymph vessels
• Chylothorax
Lymph obstruction
The amount of blood that the heart ejects in a minute
Cardiac output (4.2-8L)
Amount of blood ejected with each beat
Stroke volume
Filling of the ventricles/volume work of the heart before contraction begins/amount of stretch applied to the ventricles as it fills with blood
Preload
Resistance to ejection of blood from the heart/pressure or tension work of the heart
Afterload
Determined by the interaction of actin and myosin filaments of cardiac muscles
Contractility
CO formula
SV x HR
There is a direct relationship between the volume of blood in the heart and the stretch or length of cardiac fibers at the end of diastole and the force of contraction during the next systole in a normal functioning heart
Frank-Starling Law
CO x SVR =
Blood pressure
Most significant factor in causing target organ damage
Systolic HTN
HTN is caused by:
Increases in CO, PVR, or both
Average age of onset of HTN is:
30
Most common predisposing factor in essential HTN is:
Increased PVR
Two stimuli for secretion of renin:
- renal hypo perfusion (decrease in renal blood flow)
2. macula densa in distal tubule senses a concentration of Cl
Primary mechanism in atherosclerosis development
Inflammation with oxidative stress and activation of macrophages
What can cause a regression of atherosclerotic lesions and improve endothelial function?
A decrease in LDL using statins
Occurs secondary to ischemic/toxic injury to the renal tubules, SNS stimulation and angiotensin II causes severe vasoconstriction, leading to hypoxia and cellular damage
Acute tubular necrosis
A decrease in ability to excrete ______ will result in hyperparathyroidism in CRF
Phosphate
An early manifestation of CRF…
Hypertension
Decrease in the ability to activate vitamin D, excrete phosphorous, and form growth factors leads to:
Osteodystrophy
Significant cause of renal failure, severe HTN is a contributing factor, reflux is the most common cause…
Chronic pyelonephritis
- True aneurysm that involves the entire circumference of the vessel with gradual and progressive vessel dilation
- Vary in diameter and length and may involve ascending and transverse portions of the thoracic aorta or may extend over large segment of the abdominal aorta
Fusiform abdominal aortic aneurysm
Below level of renal artery and involves bifurcation of the aorta and proximal end of the common iliac arteries
Abdominal aortic aneurysm
Chronic disease of the arterial system that results in abnormal thickening/hardening of the vessel walls
- smooth muscle cells and collagen fibers migrate to the tunica media and cause it to stiffen and harden
- can be from HTN or PVD
Arteriosclerosis
Inflammation of the heart muscle and condition system without evidence of MI
-from virus, radiation, hypersenstivity reactions, chemical/physical agents (cocaine)
Myocarditis
Most important cause of myocarditis in US? And clinical features?
Coxsackie viruses and enteroviruses/ flu-like symptoms
Myocarditis progresses to….?
Dilated cardiomyopathy (diagnosed with biopsy- shows inflammation- no CAD)
_____ should be suspected whenever a young, previously healthy, normotensive person experiences cardiomegaly and heart failure
Cardiomyopathies
Heart’s ability to contract = _____ dysfunction
Systolic
What type of CM? Myofibril disarray- muscle fibers in the heart are not in the typical lattice pattern
Produces uncoordinated contraction and relaxation and can lead to sudden death
Hypertrophic CM (HoCM)
What type of CM?
- Abnormal ventricular hypertrophy and abnormal diastolic filling
- Wall of septum is thicker than it should be- can obstruct left ventricular outflow tract
Hypertrophic CM (HoCM)
What type of CM?- Progressive cardiac enlargement (increase in heart size and cardiomegaly) and dilation
- Grossly impaired systolic function
- Heart has difficulty contracting
Dilated CM
What type of CM?
Excessive rigidity of ventricular walls
-From amyloid infiltrations or idiopathic
-Least common type of myopathy
-Symptoms are similar to pericarditis and HF (especially RHF)
Restrictive CM
Secretion of ADH is stimulated by:
- ) increased plasma osmolality
2. ) decrease in BP
Slowly progressive disease caused by the accumulation of lipid-laden macrophages within the arterial wall which leads to the formation of plaque lesions
Atherosclerosis
When blood flor through the coronary arteries does not meet the metabolic demands of the heart
Myocardial ischemia
Associated with fixed coronary obstruction, occurs with increased demands of the heart, subsides with rest, unless it becomes more serious.
Stable (classic) angina
Myocardial ischemia without anginal pain- reason is unclear
Silent angina
Abnormal vasospasm of one or more coronary arteries, with or without atherosclerosis, most occurring at rest
(Can be from hyperactive SNS or increased calcium influx in arterial smooth muscle)
Prinzmetal (variable) angina
Combination of classic and variant angina- seen in ppl with worsening CAD and could be a signal that infarction is near
Unstable angina
Steps to atherosclerotic plaque formation
1) endothelial injury
2) cellular proliferation
3) macrophage migration
4) process of LDL oxidation into foam cells
5) fatty streak formation
6) fibrous plaque development over time