Renal And Urinary Physiology 2 Flashcards
What does the loop of Henle do?
It concentrates urine
Where does the loop of Henle receive filtrate from?
Receives filtrate from PCT
What are the two regions of the loop of Henle?
Descending region
Ascending region
What is the descending region of the loop of Henle made of?
Simple squamous epithelium
What is the descending region of the loop of Henle permeable to?
Its permeable to water
What is the ascending region of the loop of Henle made of?
Simple cuboidal epithelium
What is the ascending region of the loop of Henle impermeable to?
Its impermeable to water
What does the distal convoluted tubule do?
2
Performs final adjustments of urine
Active secretion of absorption
Write a note on absorption in the DCT.
2
Tubular cells actively reabsorb Na+ and Cl-
In exchange for potassium or hydrogen ions
What is the DCT lined with?
Simple cuboidal epithelium
What happens in the collecting ducts?
2
Re-absorption
Secretion
What is re-absorbed in the collecting system?
3
Sodium ions
Bicarbonate
Urea
What is secreted in the collecting system?
Hydrogen or bicarbonate ions
What is controlled by secreting hydrogen or bicarbonate ions?
pH
What hormones regulate water and solute loss?
Aldosterone
Anti-diuretic hormone
Where is aldosterone produced?
The adrenal cortex
When is aldosterone produced?
3
When plasma Na + is too low
When plasma K+ is too high
Angiotensin II stimulates it
What is concentration measured in?
Osmolarity
What happens if blood osmolarity rises?
2
Water reabsorption increases
Urine volume decreases
What happens if blood osmolarity falls?
2
Water reabsorption decreases
Urine volume increases
What measures blood osmolarity?
Neurons in the hypothalamus osmoreceptors
What does the level of osmolarity measured determine?
It determines how much antidiuretic hormone is secreted by the posterior pituitary gland
What produces antidiuretic hormone?
Posterior pituitary gland
List the events that happen after high blood osmolarity occurs.
(5)
This is sensed by osmoreceptors in the hypothalamus
Posterior pituitary gland increases its ADH release
ADH increases the permeability of the collecting duct to water
Increased water reabsorption
Blood osmolarity falls
What must happen for blood osmolarity to fall?
Increased water reabsorption
What are diuretics?
Chemicals that enhance urine output
What is an osmotic diuretic?
A substance that is filtered but not reabsorbed
What does caffeine do to osmolarity?
Caffeine inhibits renal sodium reabsorption
What does alcohol do to osmolarity?
Alcohol inhibits ADH release
What is urinalysis?
A physical and/or chemical examination of the urine
What does composition of normal urine vary with?
It varies with the metabolic and hormonal events of the body
What might bilirubin in urine indicate?
It may indicate liver damage or disease
What might glucose in urine indicate?
Diabetes
What might haemoglobin in urine indicate?
May be a sign of kidney damage, infection, kidney or bladder stones, kidney or bladder cancer or blood disorders
What might ketones in urine indicate?
Diabetes or high protein diet
What might nitrite in urine indicate?
Urinary tract infection
What might abnormal urine pH indicate?
Kidney or urinary tract disorder
What might protein in urine indicate?
Large amount may indicate a kidney problem
What might high urine specific gravity indicate?
Result of not drinking enough fluids
