Circulatory System: Chapter 9 Flashcards
What are the functions of the Excretory System?
- Balancing Blood pH
- Removes Waste
- Maintain water balance
What is the main organ in the Excretory System
Kidneys
How does urine move. Simple terms
- Kidneys release urine into the ureters which then carries it to the bladder
- urine exits bladder through urethra
What is the functional unit of the kidney? what does it do?
The Nephrons, filters waste from blood and transforms to urine
What are the 3 regions of the Nephron
- Filter
- Tubule
- Collecting Duct
What happens at the filter part in the nephron
- only small molecules (ex: water, ions, urea) can pass through - they are collected by the Bowman’s capsule and go into the nephron - referred to as the filter
-Rbc, proteins, and large molecules are too big to fit through the glomerulus so they remain in the blood.
What happens in the Tubule part of the Nephron
Reabsorbs substances that are useful to the body (glucose,ions) and returns them to the blood stream
What are the 3 sections of the tubule
- Proximal Tubule
- Loop of Henle
- Distal Tubule
What happens in the collecting duct
- receives urine from many nephrons
- urine carried to the renal pelvis of the kidney
What are the 4 main parts of how urine is formed in the nephron
- Filtration of the glomerulus
- Reabsorption
- Secretion
- Water Absorption
What is Urea?
Waste product from the kidneys
What happens in the filtration of the Glomerulus
- water and solutes (salt, glucose, ions) pass through the cell membrane of the glomerulus into the nephron
- the filtrate is where everything is after being filtered
- the filtrate is similar to blood plasma bcs they both include a lot of stuff
Us the blood pressure high in the glomerulus? Why or why not?
Yes. it is 4x higher than other parts of the body
the pressure helps force filtration
Why can’t big molecules such as proteins, platelets, rbc pass through the glomerulus
because they are too big and the capillaries of the glomerulus only allow small things to pass
What happens in reabsorption in the nephron
- useful substances are removed from the filtrate and returned to the blood stream
- involves active and passive transport
How is water removed out of the nephron through what?
Osmosis
What are actively transported out of the nephron?
- Na+ ions, glucose, and amino acids (proteins) are actively transported out of the nephron
- Cl- is negatively charged so the attractive from the Na+ will make Cl- follow them
What happens in secretion of the nephron
- Waste that did not go through the glomerulus can actively move into the nephron
- H+ ions are secreted into the nephron to main blood pH
-K+ ions, drugs also go into the nephron
What happens in the Water Absorption in the nephron
- excess Water is absorb again in the collecting duct
- through osmosis
What is the main fucntion of the loop of henle
- to reabsorb water from filtrate
What is released to regulate water reabsorption
Antidiuretic Hormone (ADH)
- controls the amount of water reabsorbed or excreted in the urine
What is diuretics and examples
- blocks ADH which increases secretion of urine
-ex) alcohol, and coffee
What is an example of a disease of someone who has insufficient ADH
Diabetis Insipidus. they urinate a lot everyday because water is not reabsorbed back to the blood and comes our of the nephron instead
What is hormonal aldosterone
- it is released when there is a drop of Na+
- it stimulates the distal tubule and collecting duct to reabsorb Na+
- which Cl- follows
What is the normal blood pH
7.4 or 7
