Urinary System Flashcards
What is excreted in urine
Urea
Uric Acid
Creatinine
-
Nitrogen (H+)
Medication / Toxins
Minimum urine excrete per day
500mL
Important electrolytes balanced by Kidney
Sodium, Potassium, Hydrogen
Two main hormones created by Kidney
Calcitriol
Erythropoietin
Calcitriol function
- Stimulates calcium & magnesium uptake from GIT
2. Reduces calcium loss in Kidney
Erythropoietin function
stimulates erythropoiesis in red bone marrow
Renal threshold for glucose is
9mmol/L
The kidneys control blood pressure and volume by;
Conserving or eliminating water.
Blood pressure is regulated by the release of Renin from kidneys
Pathway triggered by release of an enzyme from the kidney to control blood pressure:
Renin-Angiotensin-Aldosterone pathway
Layers of Kidney
Renal Capsule (deep) Adipose capsule (middle) Renal Fascia (superficial)
Layers of ureters
Inner mucous membrane
Muscularis - smooth muscle
Adventitia - outer coat connective tissue
Small triangular area in back of bladder
trigone
Two sphincters of urethra
Internal Urethral Sphicter (involuntary)
External Urethral Sphincter (Voluntary)
Male Urethra passes through
Prostate
Three stages of Urine formation
- Glomerular filtration
- Tubular reabsorption
- Tubular secretion
What substances pass through glomerulus ?
Water, elecrolytes, amino acids, glucose, hormones, ketoacids, creatinine, urea, uric acid, toxins
Which substances do not pass through the glomelerus ?
Blood cells, plasma proteins, platelets
What is the GFR
Glomerular Filtration Rate - the amount of filtrate formed in the renal cropuscle of both kidneys each minute
Normal GRF
90ml/min
What happens when Albumin leaks into urine
Loss of osmotic pressure within the blood - resulting in oedema.
Where is reabsoption occuring
Mainly in Proximal Convoluted Tubule
Water, amino acids, glucose, electrolyes
Hormones that affect kidney reabsorption of sodium, chloride, calcium & water
Angiotensis 2 Aldosterone Antidiuretic hormone Atrial natriuretic peptide parathyroid hormone
What does the RAAS Do?
Increases blood pressure
Basic RAAS pathway
Kidneys: Release enzyme Renin
Liver: Renin converts angiotensinogen to angiotenisin
Lungs: Angiotensin 1 is conversted into Angiotensin 2 by an enzyme called ACE
Adrenal Cortex: Angiotensin 2 causes the release of Aldosterone
What does Angiotensin 2 do
- triggers pituitary gland to release ADH
2. Stimulates Adrenal Cortex to release Aldosterone
What does Aldosterone do?
Increases renal absorption of water and sodium
What affect does Parathyroid hormone have on the Kidneys
Stimulates release of calcitriol.
It causes the kidney to reabsorb calcium and magnesium.
