Excretory System Flashcards
what is the function of the excretory system?
Regulate the volume and composition of body fluids by removing waste and returning substances to the body for re-use
what are the parts of the excretory system?
renal artery
renal vein
aorta
inferior vena-cava
kidney
ureter
bladder
urethra
what are the parts of the kidney?
renal cortex
renal medulla
renal artery
renal vein
renal pelvis
ureter
what are the parts of the nephron?
Glomerulus/Bowman’s Capsule
Proximal Tubule
Distal Tubule
Loop of Henley (ascending and descending)
Collecting Duct
what happens to ur urine when you are dehydrated?
it becomes more yellow bc it has a higher concentration of solutes bc when one is dehydrated they don’t have enough water to dilute their urine
What process happens at the glomerulus/bowman’s capsule? describe what happens in the process?
filtration
blood enters glomerulus from renal artery and some small solutes dissolve into bowman’s capsule
what solutes do not dissolve into bowman’s capsule?
blood cells and other large molecules (protiens)
what is the pressure in bowman’s capsule?
High
what is the process that happens in proximal tubule and describe what happens in that process?
reabsorption
glucose is reabsorbed into bloodstream through active transport
what is the process that happens in the descending loop of henley and describe what happens in that process?
reabsorption
water is reabsorbed into bloodstream through osmosis
what is the process that happens in the ascending loop of henley and describe what happens in that process?
reabsorption
Na+ is reabsorbed into bloodstream through active transport
what is the process that happens in the distal tubule and describe what happens in that process?
secretion
waste material, medications, and ions such as H+ and K+ is transferred from blood to nephron through active transport
what is the reason H+ is transferred into the nephron?
in order to maintain the pH levels of blood
what is the process that happens in the collecting duct and describe what happens in that process?
reabsorption
last chance for water reabsorption
reabsorption in this part is activated by a hormone called ADH which is activated if one is dehydrated to absorb more H2O into the blood
In NaCl which parts are transported between the blood and nephron through passive and active transport?
Na+ -> active
Cl- -> passive
How do we maintain homeostasis with regards to the pH of our blood?
1) We increase the rate of breathing which releases carbon dioxide faster (and carbon dioxide increases the pH of our blood).
2) We release more H+ ions in our urine to try to reduce the acidity of the urine and raise the ph.
How does alcohol and caffeine affect ADH?
It stops this hormone (which tells the body to stop urinating) causing one to urinate more than necessary.
What is the top and bottom of the Nephron called?
Cortex and Medulla
Explain the difference between the terms filtration, reabsorption, secretion and excretion
Filtration- fluids (water & solutes) filtered out
of blood into nephron
Reabsorption- water + solutes back to blood from nephron
Secretion- pump out any other unwanted solutes to urine from blood
Excretion- expel concentrated urine (N waste + solutes + toxins) from body
List three substances that are filtered from the glomerulus into Bowman’s capsule and three substances that are NOT.
Substances that ARE filtered:
1. Water
2. sodium chloride
3. glucose
4. amino acids
5. hydrogen ions
6. potassium ions
7. urea
8. vitamins
9. minerals
Substances that ARE NOT filtered:
1. Plasma
2. proteins
3. erythrocytes
4. platelets
Which substances move from the filtrate to the capillary bed though Passive Transport
negatively charged ions like Cl-, bicarbonate
Which substances move from the filtrate to the capillary bed though Osmosis
Water
Which substances move from the filtrate to the capillary bed though Active Transport (3 substances)
glucose, amino acids, positively charged ions like Na+, K+, H+
Where is water reabsorbed in the nephron?
Everywhere except the ascending loop of Henle