RAAS and Micturition

Micturition, 500, 1

• __ (term) = Urination

• A full bladder comfortably able to hold __ mL of urine, at maximum _ L

internal sphincter, external sphincter

Micturition cycle

• Urine passes through the __ __ to urethra

• Then __ __ (voluntary) to release/void

Pontine Storage Area, Pontine Micturition Center

Neural control of micturition

The __ __ __ is a region of pons that inhibits act of urination

The __ __ __ is a region of pons that promotes act of urination

M3 Rs

Under normal circumstances, which ANS receptor type has the most significant influence on micturition?

Nephron, Minor calyx, Major calyx, papilla

Renal anatomy

Ureters, detrusor muscle, internal sphincter, prostate, external sphincter, urethra, external urethra

Bladder anatomy

Collecting ducts, pelvis, ureter

• Filtrate fluid in nephrons travel into the __ __ (nephron)

  • Empty into renal __ → Then directly proceed to the __

Peristalsis, renal stone, cramping

Ureters have smooth muscle that contract to move urine down to bladder via __

• Strong … contractions in presence of __ __ to ureter produces a “__” abdominal pain

Collapsed, contracts, closed, reflux

Ureters course through detrusor muscle to prevent blackflow

• Ureters are usually __ (expanded/collapsed), except when squeezing urine into bladder

• When detrusor __ to urinate, it will squeeze the ureters __ (open/closed) = prevents __

Minimal (lesser), detrusor relaxation, internal sphincter contraction

Sympathetic Innervation of Bladder

• __ influence compared to parasympathetic

• Beta-2 Rs → __ __ (muscle contraction/constrict vs dilation/relax)

• Alpha-1 Rs → __ __ (muscle contraction/constrict vs dilation/relax)

Primary, M3, detrusor constriction, internal sphincter dilation

Parasympathetic Innervation of Bladder

• __ control, and done via __ Rs

  • Rs actions → __ __ and __ __ (muscle contraction/dilation)

Pudendal nerve, external, mechanoreceptors

• Voluntary/somatic Innervation of Bladder

  • __ __ → Contraction of the __ sphincter

• Sensory Innervation of Bladder

  • Stretch __ thru bladder wall and bladder neck

Pressure, mechano, micturition contractions, detrusor, external, micturition

Micturition Reflex

• Bladder __ increases and thus __receptors are stretched

• Parasympathetic - Sends reflex of many small “__ __” to the __ and relax internal sphincter

• Voluntary control of the __ sphincter allows patient to initiate or prevent __

Contraction, relaxation, internal, relaxation, external

Micturition Reflex

Renin

Produced by juxtaglomerular apparatus to raise BP/blood volume

Afferent arterial baroreceptors, Macula Densa, sympathetic

With Renin

• __ __ __ sense a decreased afferent arteriole pressure

• __ __ sense Na+ delivery with sodium cotransporter and tubular flow rates with cilia

• __ (sympathetic/parasympathetic) stimulation involved

DCT, salt, Angiotensin II, aldosterone, ADH

After passing renin and still Low flow rate to the __ (part of nephron)

• Result is increased __ retention and systemic volume and blood pressure

• Done via __, __, and __

Systemic bp, renal artery stenosis, efferent arteriole

What stimuli can cause decreased afferent arteriole pressure? 

• Low __ __

• Low flows and pressures to kidney (i.e. __ __ __)

• __ __ dilation

Renin, angiotensin I, ACE, angiotensin II, RAAS, efferent arteriole constriction, afferent pressure

After decrease in afferent a is sensed by granular cells, what happens upon returning afferent arteriole pressure back to set point (RAAS)?

• Increase __ → Increase __ __ → __ converts I to II → Increase __ __ → Activate __ → Systemic pressure and volume increase with __ __ __ (arteriole action) → Normalized __ __

Perfusion, juxtaglomerular

From RAAS/Goal of RAAS:

• Water and salt retention, means an increased __ to __ apparatus

Aldosterone, Na-H+, efferent, increase, ADH, constriction

Angiotensin II receptor locations and actions

• Adrenal cortex - produces __

• Kidney - ___ exchange in PCT

• Renal arterioles -  constricts __ arteriole more to __ (increase/decrease) GFR

• Hypothalamus - Produced __

• Systemic arterioles - Direct vaso__

Contraction alkalosis

State where Na-H exchange occurring in low volume states in kidney

Adrenal cortex, PCT, renal arterioles, hypothalamus, systemic arterioles

5 targets of Angiotensin II

Endocrine - (2)

Renal anatomy - (2)

Systemic - (1)

Aldosterone

Produced by adrenal glands and in response to elevated K+ levels

Principal, DCT, H+, intercalated

Aldosterone

• Acts at __ cells of late __ and collecting duct

  • Some increased __ secretion at __ cells

Lumen Na+, Na-K ATPase, lumen K+

Aldosterone’s 3 mechanisms lead to increased K+ secretion and increased Na+ reabsorption

• More __ __ channels

• More __ __ (enzyme) pumps and more activity

• More __ __ channels

adrenal insufficiency, primary hyperaldosteronism

Pathophysiology of Aldosterone

• Addison’s Disease from __ __

• Conn’s syndrome from __ __

Hyponatremia, Hypernatremia

• Is SIADH a problem of hyponatremia or hypernatremia?

• What occurs from defective V2 receptors? - Large amounts of dilute urine (hypo/hypernatremia?)

Primary Hyperaldosteronism

Elevated aldosterone in absence of appropriate stimulus, renin should be suppressed

Hypertension, hypokalemia, metabolic alkalosis

HHM Triad in Conn Syndrome - (3)

Aldosterone, adrenal glands

Common causes of Conn syndrome

• __-secreting tumors

• Hyperplasia of the __ __

Increased osmotic, decreased blood

ADH

Osmoreceptors detect__ __ pressure

Baroreceptors detect __ __ pressure

(increased/decreased — pressure)

absorption of water, blood pressure

What would happen from mutation making V2 receptors less effective?

(1) Less __ of __ from kidneys

(2) Lowered __ __

Low renin

A patient has a history of Conn Syndrome. Which would be expected?

__ __ levels - RAAS component