Term
| Effects of diminished ECF volume |
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Definition
| Lower BP and hypoperfusion, may lead to hypovolemic shock. |
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Term
| Effects of increased ECF volume |
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Definition
| Increased BP and pulmonary edema. |
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Term
| Effects of abrupt changes in Na output |
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Definition
When Na input suddenly increases it takes some time for the excretion of Na to match the increased levels of Na ingestion. During this time, the ECF becomes hyperosmotic, and transcellular water movement and water addition kicks in to retain osmolarity homeostasis. This increase in water volume results in added weight.
Decrease in Na ingestion has the opposite effect. |
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Term
| Effects of increased ICF volume |
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Definition
| Cells swell up, presents a problem when they are in an enclosed space like a skull. This results in cerebral edema. |
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Term
| Effects of diminished ICF volume |
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Definition
| Cerebral hemorrhage. Cells inside the brain shink and causes the brain to retract away from the skull. This causes the veins in the meninges to tear since they are attached to both the brain and the skull. |
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Term
| Requirements of kidney regulation |
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Definition
1. Detection of disturbances (afferent mechanism)
2. Correction of disturbances (efferent mechanism) |
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Term
| Sensors of ECF volume (afferent mechanism) |
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Definition
1. Low pressure baroreceptors (most important)
a. Cardiac atrial and ventricular sensors
b. Pulmonary sensors
2. High pressure baroreceptors
a. Carotid sinus
b. Aortic arch
c. Juxtaglomerular apparatus
3. CNS
4. Liver |
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Term
| Types of low pressure baroreceptors |
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Definition
Type A: Secrete ANP in response to increased HR
Type B (more important): responds to stretch |
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Term
| Effectors of ECF volume (efferent mechanism) |
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Definition
1. RAAS system
2. AVP
3. Sympathetic response
4. ANP |
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Term
| Angiotensin II main functions |
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Definition
1. Stimulates aldosterone production
2. Stimulates AVP production and thirst in hypothalamus
3. Acts on kidneys to decrease Na and water excretion through preferential efferent arteriole constriction (increases GFR=increased excretion)
4. Increases Na, H transporter activity
5. Increase sensitivity of TG feedback, changes GFR to affect reabsorption or secretion in peritubular capillaries |
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Term
|
Definition
1. Lowered ECF lessens stretch in cardiac myocyte baroreceptors.
2. This inhibits the release of ANP, which lowers sodium excretion.
3. Signals to brain to induce thirst and produce AVP.
4. Signals to JG complex of kidneys to produce Renin, which in turn stimulates ANG II and Aldosterone production. |
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Term
|
Definition
| Between the vascular pole and the distal tubule. Has granular cells and macula densa, capable of secreting renin for local control of filtration in a single glomerulus. |
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Term
|
Definition
Stimulated by
1. Hypoperfusion
2. Sympathetic input to JGA
3. Hypotension
4. Vasoconstrictors like endothelin, PGE2, PGI2
Inhibitors
1. NO, increased [K]
2. Ang II, Aldosterone (feedback inhibition) |
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Term
|
Definition
| Increases excretion of solutes through increasing GFR and inhibiting Na channels in the collecting tubules. |
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Term
| Mechanism of sympathetic nerves |
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Definition
Increase Na reabsorption through
1. Stimulating renin release
2. Increasing renal vascular resistance
3. Stimulating Na, K ATPase
4. Stimulating Na, H exchanger |
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Term
|
Definition
1. Stimulates Na, K, Cl transporter
2. Stimulates urea reabsorption
3. Increases renal water reabsorption |
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Term
| Effect of BP on Na secretion/retention |
|
Definition
Act through RAAS
Peritubular capillary starling forces
Na reabsorption in thin descending limb
Na, H transporter expression.
High BP leads to increased Na excretion
Low BP leads to decreased Na excretion |
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Term
|
Definition
Osmoreceptors in the midbrain, located outside the BBB, can directly respond to changes in plasma osmolarity.
Response is modlated by baroreceptor input. |
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Term
|
Definition
|
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Term
|
Definition
1. Hyperosmolarity
2. Non-osmotic stimuli
ECF volume depletion increased
ECF volume expansion decreased
Pregnancy
Nausea
Drugs
Tumors |
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Term
| Hypoosmolarity vs. Decreased ECF volume |
|
Definition
| Kidneys balance ECF volume over osmolarity. |
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