Exam 4 (Chapters 23 & 24) Flashcards
What are the functions of the kidney?
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What hormones does the kidney produce?
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What wastes & foreign substances does the kidney clear from the body?
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Principal & intercalated cells are located in these areas of the renule tubule & are responsible for performing these functions
Location: Distal convulated tubule & collecting duct
FUNCTIONS:
–principal cells: receptors for hormones (aldosterone, ANP, ADH, PTH); salt & water balance
–intercalated cells: acid-base balance; reabsorb K+ & secrete H+
Blood plasma is filtered by glomerulus in kidneys…explain how the NFP (net filtration pressure) of glomerulus is determined
Plasma is filtered by moving from glomerulus into glomerular (Bowman’s) capsule (both are part of renal corpuscle of kidneys)
NFP=GBHP-(CHP+BCOP)
GBHP=glomerular hydrostatic pressure (BP in glomerulus)
CHP=capsular hydrostatic pressure (pressure in capsular space)
BCOP=blood colloid osmotic pressure (pressure from plasma proteins-albumin, etc)
When kidney has a high GFR, explain how the tubuloglomerular feedback loop functions to lower the GFR
Juxtaglomerular Apparatus:
- Macula densa detects higher solute (NaCl) concentration & secretes ATP
- Mesangial cells metabolize ATP to adenosine
- Adenosine stimulates granular cells found on afferent arteriole to constrict (reduces blood flow to glomerulus & reduces GFR)
What does Angiotensin II do to the cardiovascular system, endocrine system & hypothalamus?
Angiotensin II raises BP:
- widespread vasoconstriction
- stimulate release of aldosterone from adrenal cortex
- stimulate release of ADH from posterior pituitary
- stimulate hypthalamus to increase thirst & water intake
- constrict efferent arteriole in kidneys (impact glomerular BP)
Steps leading to formation of Angiotensin II
Diagram paper
**formation of Angiotensin II triggered by drop in BP
How does ADH regulate facultative water reabsorption in collecting duct of renal tubule?
Notes (ADH action in controlling water loss & how it forms concentrated urine)
Which segments of loop of Henle are water reabsorption taking place? What happens to the tubular fluid as a result?
- thin segment of loop of Henle (only reabsorb water; mostly in descending limb); no solute reabsorption
- thick segment of loop of Henle (only reabsorbs solutes; mostly in ascending limb); no water reabsorption
Altering the GFR (glomerular filtration rate)
-changing glomerular BP (via changing afferent arteriole diameter or efferent arteriole diameter); changing CHP, changing BCOP
Myogenic mechanism, form of intrinsic renal autoregulation
Kidney will adjust blood flow through afferent arterioles
BP low, afferent arteriole will dilate to increase blood flow & increase GFR
Actions of what hormones on kidney will result in an increase in BP?
-Aldosterone & ADH are released when one has low BP & acts to increase one’s blood volume & BP
**Natriuretic peptide is released when one has high BP & acts to decrease the BP
Voiding urine involves involuntary micturition reflex as well as voluntary control…what controls these reflexes
INVOLUNTARY REFLEX:
controlled via parasympathetic nervous system (betwee S2 & S3)–signals relax internal urethral sphincter (urine void)
VOLUNTARY CONTROL:
stretch receptors from bladder carry signals to the pons (micturition center)
-cerebrum controls external urethral sphincter until one voluntarily urinates
Respiratory acidosis & respiratory alkalosis are acid-base imbalance…explain the causes of each
RESPIRATORY ACIDOSIS
-CO2, H+ ions & pH
RESPIRATORY ALKALOSIS
-CO2, H+ ions & pH
