Lecture 11 Flashcards
Average daily water gains and losses equation
[Intake (2.2 L/day)+ Metabolic production (0.3L/day)]- Output (2.5L/day)= 0
Hypotension
a decrease in systemic blood pressure below accepted low values (bp less than 90/60)
Nephron
the functional unit of the kidney and is responsible for 5 main functions-
1. Excreting waste
2. Regulating blood volume
3. Controlling electrolytes
4. Marinating blood pH
5. Producing vitamin D via PTH
Excessive water loss causes __________ blood pressure
decreased
What does vasopressin influence?
H20 reabsorption
regulates the permeability of cells in the kidney
Increased permeability= increased reabsorption and low urine output
What does Aldosterone influence?
Na+ reabsorption
K+ secretion
What does Atrial natriuretic peptide influence?
H2O reabsorption
Na+ reabsorption
K+ secretion
Antidiuretic hormone (ADH)
a chemical produce in the brain that causes kidneys to release less water, thus decreasing the amount of urine produced
Vasopressin
is an antidiuretic hormone (ADH) that is synthesized in the hypothalamus and is secreted from the posterior pituitary
Vasopressin primary function
to increase water reabsorption in the kidneys (to conserve body water, maintain homeostasis and increase blood volume/ blood pressure)
What triggers vasopressin release?
Low blood pressure is detected & High plasma osmolarity
Osmolarity
the measure of different solutes in the plasma (osmolarity is the most potent stimulus for vasopressin release)
Zona glomerulosa
the zone of the adrenal gland in which aldosterone is produced
RAAS (renin-angiotensinogen pathway)
critical regulator of blood pressure (blood volume and electrolyte balance)
Aldosterone
a steroid hormone that is synthesized in the adrenal cortex that regulates sodium and therefor water.
Aldosterone 3 main functions
- Na+ reabsorption (to retain water)
- K+ secretion
- Acting on the distal tubule and collecting duct
What controls aldosterone synthesis?
negative feedback
Stimulators of aldosterone
- High plasma potassium concentration
- Angiotensin II (low blood pressure)- RAAS
Inhibitors of aldosterone
High osmolarity/ extracellular fluid
Angiotensin 2
increases vasopressin, stimulates thirst and is a potent vasoconstrictor and increases proximal tube Na+ retention
Atrial Natriuretic Peptide (ANP) Effects
- Na+ and H2O reabsorption (lowers blood pressure)
- K+ reabsorption