Urinary system Lecture 3 Flashcards
What causes an increase and decrease in ADH?
- increase happens in response to :
-low BP or volume
-increase in plasma osmolarity
-Increase in Angiotensin II
-Nicotine , Nausea - Decrease happens in response to:
-Increase in ANP
-Alcohol
What reactions does aldosterone deficiency have on sodium and blood pressure ?
- sodium excretion
- Low blood pressure
How is ANP (Atrial Natriuretic Peptide) secretion activated?
- Increase in blood pressure
- hypervolemia
- Exercise
What does ANP cause?
- Increases glomerular filtration by vasodilation of the afferent arteriole
- decreases Cardiac output by inhibiting sympathetic nervous activity to the heart and blood vessels
- Increases Sodium and water excretion
What effects does the SNS and PSNS have on the regulation of urine?
- PSNS has NO EFFECT
SNS effects:
- increase in SNS impulses causes aff+eff arterioles constrict
- Decrease in SNS impulses causes aff+eff arterioles relax
If urine is normal , what constituents does it include?
- H20
- Nitrogenous waste
-urea~ from AA metabolism
-uric acid~ from nucleic acid breakdown
-creatinine~ from breakdown of creatine in skeletal muscle
If urine is abnormal , what constituents does it include?
its abnormal when you have protein and glucose in your urine
What are the steps that take place during micturition (bladder) reflex aka urination ?
- It starts with the kidney then the urine travels down to the ureter and it travels further to the urinary bladder with the help of gravity and peristalsis. then it travels down to the urethra with contraction of smooth muscle and produces a pressure gradient that causes urination.
What is the normal arterial pH levels and what is too high and too low and what does it cause
- 7.35-7.45 is normal
- 6.8-7.35 is known as acidosis
- 7.45 -8.0 is known as alkalosis
- any pH below 6.8 or above 8.0 results in death
What are some main roles of kidney in pH balance ?
- it reabsorbs bicarbonate which helps with the buffer system in our body
- it also excretes hydrogen because if hydrogen levels go up it can cause acidosis
What are some sources of H+(acids) in the body?
- Carbonic Acid formation (only volatile acid)
- Non volatile acids
-Organic acids resulting intermediary metabolism
-Inorganic acid produced during breakdown of nutrients
What 3 things can be caused by the fluctuations in hydrogen ?
- Changes in excitability of nerve and muscle cells
-Acidosis :depression of the CNS
-Alkalosis : overexcitability of the PNS and later the CNS - Marked influence on enzyme activity
- Changes influence K+ levels in body
What are three lines of defense against changes in [H+]?
- Chemical buffer systems
- Respiratory mechanisms of control
- Renal mechanisms of pH of control
How do Chemical buffer systems work?
- They don’t get actually removed but instead get paired
- Bases take up H+ and acids give up a H+ when they are in the buffer solution to balance.
What are the four buffer systems that are in your body?
- Carbonic acid
- Protein buffer system
- Haemoglobin
- Phosphate buffer system