Excretion system Flashcards
Explain the permeability in the loop of Henle.
Descending - it is permeable to H2O and impermeable to the salts making it hyper osmotic and the solute concentration increases.
Ascending - impermeable to H2O and permeable to salts it actively pumps them through the thick segments of Na K and Cl ions. It has more solute outside than the filtrate.
How does the ADH effects the process of the collecting duct?
The more aquaporins it allows water to leave it makes urine more concentrated and decreases water.
No ADH- duct is going to be impermeable to H2O and ions are removed from the filtrate Urine is dilute.
Discuss the nephron organisation
Each nephron is supplied with an afferent arteriole forming the capillaries in the glomerulus forming the efferent arteriole. EA will branch forming the peritubular capillaries and vasa recta.
It is a single long tube the glomerulus ( a ball of capillaries) is surrounded by the Bowman’s capsule.
Unwanted substances are secreted into the filtrate in the tubules. At which portion of the nephron are hydrogen and potassium ions both secreted into the filtrate?
Distal Tubule
As filtrate passes through the nephron, nutrients are reabsorbed back into the body. Where does most reabsorption occur?
proximal CT
What is the function of the Anti diuretic hormone?
It determines to which extent the urine becomes concentrated
list the functions of the excretory system
- Excretes waste
- maintain water osmolarity
-Reabsorbes valuable substances
What does regulate urination? Where it is located?
(i) sphincter muscle
(ii) located near the junction of urethra and bladder
What is the functional unit of the kidney’s?
Nephron
How is filtrate formed?
It is formed when blood pressure forces fluid from the blood into the glomerulus into the lumen of the Bowman’s capsule.
