Unit 13 Patho Flashcards
What happens when extracellular fluid volume decreases?
Blood pressure decreases
What happens if ECF volume and BP fall too low?
The body cannot maintain adequate blood flow to the brain and other essential organs.
The kidneys work with the cardiovascular system to ensure what?
That blood pressure and tissue perfusion remain within an acceptable range.
What is the function of the kidneys?
Clear harmful substances by filtering the blood.
Regulates: Blood pH, Volume, Pressure, and Osmolality
Produce hormones
The Primary function of the proximal tubule, in a nephron, is?
Reabsorption of ions, organic molecules and water
The primary osmoreceptors are located in the:
Hypothalamus
What is the kidneys role in regulation of osmolarity?
The body integrates kidney function with behavior drives (from hypothalamus), such as thirst, to maintain blood osmolarity at a normal value of 290 mOsM.
What is the kidneys role in maintenance of ion balance?
They keep concentrations of key ions within a normal range by balancing dietary intake with urinary loss
Sodium (Na+) is the major ion involved in the regulation of ECF and osmolarity
What is the kidneys role in homeostatic regulation of pH?
(what happens if too acidic or alkaline)
-The pH of plasma is normally kept within narrow range.
-If ECF becomes too acidic, the kidneys remove H+ and conserve bicarbonate ions (HCO3-) which acts as a buffer
-If ECF becomes too alkaline, kidneys remove HCO3- and conserve H+
What is the kidneys role in excretion of wastes?
The kidneys remove metabolic waste products or foreign substances such as drugs and environmental toxins.
-Metabolic waste include creatinine form muscle metabolism and the nitrogenous wastes urea and uric acid
-A metabolite of hemoglobin called urobilinogen gives urine its yellow color
-Hormones are another endogenous substance the kidneys clear from the blood
What is the kidneys role in hormone production? (3 pathways)
Although kidneys are not endocrine glands, they play an important role in three endocrine pathways:
1) Cells synthesize erythropoietin, the cytokine/hormone that regulates RBC synthesis
2) They also release renin, an enzyme that regulates the production of hormones involved in sodium balance and BP homeostasis
3) Renal enzymes help convert vitamin D3 into a hormone that regulates Ca2+ balance
Describe the anatomy of the urinary system. (From kidneys to urethra)
Urine production begins in the kidneys -> passes through smooth muscle tube called ureter -> from the two ureters leading from each kidney they go to the urinary bladder -> the bladder expands and fills with urine until, a reflex called micturition or urination, the bladder contracts and expels through the urethra.
What occurs in the Glomerulus?
(Part of nephron)
Filtration occurs (first step of urine formation)
-Does not filter RBCs and proteins
Filtration is the movement of fluid from blood into the lumen of nephron.
Once the filtered fluid is entered its called filtrate.
What occurs in the Proximal tubule?
(part of nephron)
(Found in Cortex of Kidney)
Reabsorption occurs here. Salts, water, Potassium, glucose and amino acids are reabsorbed back into the blood flowing through the capillaries.
What occurs in the Loop of Henle?
(Typically found in Medulla of Kidney)
Has some role in reabsorption of sodium, calcium, potassium, and magnesium (Electrolytes)
Main role in concentrating the urine
What occurs in the Distal Tubule?
(part of nephron)
(Found in Cortex of Kidney)
More reabsorption occurs of sodium and calcium
However secretion takes place. Substances like: Hydrogen, potassium, and ammonium.
(Also takes in waste that escaped filtration)
Then takes urine to the collecting duct
What is water balance?
Homeostasis of water and electrolytes.
This depends on the integration of kidneys (slow), respiratory and cardiovascular systems.
-Thirst and cravings for salts are behavior mechanisms. (Only major way of replacing water that is lost
What is the response to decreased blood pressure and volume?
-There is an increase in cardiac output, vasoconstriction.
-Increased thirst
-The kidneys conserve salt and water to minimize volume lost
What is the response to elevated blood pressure and volume?
-Decreased cardiac output and vasodilation
-The kidneys excrete salts and water in urine
What is Diuresis?
Removal of excess water
What is the primary sign of Diabetes Mellitus?
An elevated blood glucose concentration
What happens if Type 1 Diabetes mellitus is left untreated?
Osmotic diuresis causes polyuria (Excessive urination) and polydipsia (Excessive thirst)
What is Vasopressin/ADH?
A hormone that adds or removes water pores to the apical membrane under the direction of the posterior pituitary gland
How does ADH affect people?
ADH causes the collecting ducts to become more permeable to water, allowing water to be reabsorbed, and pee becomes more concentrated and less diluted.
What is the Countercurrent Exchange System?
The exchange of fluid/solutes between two vessels whose currents are flowing in opposite directions
-Responsible for how the body concentrates urine excretions
What is the Renin-Angiotensin Pathway (RAS)?
A complex pathway that produces a hormone called Angiotensin II. Angiotensin II works to stimulate the secretion of Aldosterone.
What are some of the effects of Angiotensin?
Effects:
-ANG II increases VDH/Vasopressin secretion
-Stimulates thirst
-Participates in sympathetic stimulation of increasing BP
Describe the Potassium Balance in the kidneys.
K+ is reabsorbed in the proximal tubule and ascending limb of the loop.
-K+ may be secreted into the collecting duct if stimulated by hyperkalemia
What is the difference between Hypokalemia and Hyperkalemia?
-Hypokalemia causes muscle weakness because its more difficult for hyperpolarized neurons and muscles to fire action potentials. (Danger being failure of reparatory or heart muscles)
-Hyperkalemia (more dangerous) is the depolerization of excitable cells that prevents them from repolarizing, making them less excitable.(Can lead to cardiac arrhythmias)
Describe the Acid-Base Balance.
pH is the measurement of H+ concentration. Its measured on a logarithmic scale. (pH above 7=basic, alkaline) (ph below 7=acidic)
-pH changes can denature proteins
What is Acidosis? How does it affect the body?
A condition in which there is too much acid in the body fluids.
-This can cause neurons to be less excitable.
-Patients may present with confusion, disorientation, or they can be in a coma.
-Can be induced by hypoventilation
-Can be offset by hyperventilation
What is Alkalosis? How does it affect the body?
A condition in which there is a buildup of excess base or alkali in the body.
-Can cause neurons to become hyperexcitable
-Patients may present with numbness, tingling, and muscle twitches
How do UTIs happen?
(1)UTIs start with contamination in the lower urinary tract, (2) bacteria then colonizes in the urethra and bladder, (3) this then triggers an inflammatory response, (4) Neutrophils invade area, (5) Bacteria multiplies and evade immune system. (6) If progressed the bacteria can ascend to kidneys
(7) Bacteria colonizes in kidneys causing upper UTI
What is a common bacteria for UTIs?
E-coli (80% of cases)
What are some risk factors associated with UTIs?
-Pregnancy
-Menopause
-Sex (condoms)
-Catheterization
What are s/s of lower UTI?
-Dysuria
-Pain while urinating
-Increase of frequency of urination
-Hematuria (Blood in urine)
-Burning sensation when urinating
-Cloudy urine
-Urine has offensive smell
What are s/s of upper UTI?
-Malaise
-Fever
-Rigors
-Vomiting
-Loin and/or back pain
Signs of shock in sever cases
Which s/s of upper UTI are considered the “Triad”?
Fever,
Vomiting,
Loin and/or back pain
If there is bacteria usually cause a lower UTI, what other complication can that cause?
Can cause Cystitis (Inflammation of bladder), Prostatitis (Inflammation of prostate), urethritis (Inflammation of urethra).
Lower UTI can progress into an upper UTI, this can cause what other complication?
Pyelonephritis (Inflammation of kidneys) {This can cause acute renal failure}
Which gender is more susceptible of getting UTIs?
Women
What is the def. of Acute Renal Failure?
What is glomerular filtration?
Decrease in glomerular filtration rate. (Damage in kidneys)
The rate of how fast the glomerulus filters blood and filtrate is produced.
(Blood that does not get filtrated goes through the efferent arteriole)
What are the 3 main causes of ARF?
Pre-renal: Due to sever decrease in BP, or decrease in flow to kidneys. “Before kidney”
Intra-renal: Direct damage, inflammation, infection, drugs, and autoimmune disease. “In kidney” (Most common)
Post-renal: Obstruction of urine flow. “After kidney”
What are the 4 intra-renal types?
1) Acute glomerulus nephritis (Inflammation of glomerulus)
[Main cause is auto-immune disorder such as systemic lupus]
2) Acute tubular necrosis [50% of acute renal failure]
(Death of cells in nephron)
3) Acute interstitial nephritis (Inflammation of the interstitial space in the kidney)
[Mostly due to to Allergies/infection]
4) Vascular
Why do we have a decreased in GFR?
-Can be caused by vascular.
(We see endothelial dysfunction, vasoconstriction, inflammatory cells)
-Can be caused tubular changes
(We see damaged cells, cells loss -> cause necrotic bodies obstruction in tubules. Filtrate and urine will backflow)
What are functional characteristics of ARF?
-Decreased GFR
-Decreased urine output
-Increase nitrogenous waste in blood
What are structural characteristics of ARF?
-Cell death (Apoptosis/Necrosis)
-Loss of adhesion in intrinsic renal cells
