Biology Chapter 10: Digestive and Excretory Systems Flashcards
What is the glomerulus? And where does it live?
The glomerulus filters blood, allowing water, ions, and small molecules (like glucose and amino acids) to pass through while retaining larger molecules (like proteins) and blood cells. This process forms the glomerular filtrate, which becomes the basis for urine after further processing in the nephron.
Lives in the renal corpuscle which sits in the renal cortex
What does the bowman’s capsule do and where does it live?
Collects the filtrate from the glomerulus. Lives in the renal corpuscle of the nephron which sits in the renal cortex
What is the purpose of the glomerulus and bowman’s capsule?
filter the blood, separating smaller molecules like water, ions, glucose, amino acids, urea, and other small solutes from larger components like blood cells and plasma proteins. This process forms the glomerular filtrate, which enters the nephron for further processing.
What gets reasborbed in the proximal tubule and where does it live?
Water and nutrients such as glucose, amino acids, potassium, calcium
Does the medulla have a high or low salt concentration?
Medulla is very salty
What is reabsorbed in the descending loop of henle?
Water. Medulla is salty so water diffuses into the medulla for reabsorbed by osmosis
What is reabsorbed in the ascending loop of henle and why?
Ascending loop of henle is impermeable to water. Na+ and Cl- are actively transported into medulla
What is reabsorbed at the distal tubule?
H2O and salt
Distal convoluted tubule is located where?
In the renal tubule, which sits in the renal cortex
ADH promotes water reabsorption on what part of the kidney?
Mostly on the collecting duct but a bit on the DCT. Increased ADH when we’re dehydrated = more water retained
Aldosterone acts on where and does what?
Acts on the DCT and the collecting duct to promote reabsorption of sodium
Parathyroid hormone acts where and does what
Acts on the DCT to promote Ca reabsorption
ANP has what effect?
ANP has opposite affect to aldosterone. It promotes excretion of sodium in the urine and draws water with it - increasing amount of water expelled and decreasing blood pressure
Definition of osmolarity and why ADH reduces osmolarity of the blood
is the measure of the concentration of solute particles in a solution, expressed as the number of osmoles of solute per liter of solution (osmol/L).
ADH reduces blood osmolarity because it increases water retention without increasing solute levels, effectively diluting the blood.
Where are hydrogen ions and potassium ions secreted into the excretory system?
Secreted into the distal convoluted tubule
What is the renin-aldosterone system (RAAS)?
hormone cascade that regulates blood pressure and fluid balance. When blood pressure or sodium levels drop, renin from the kidneys activates angiotensin II, which constricts blood vessels and stimulates the release of aldosterone from the adrenal glands, promoting sodium and water retention to restore blood pressure and volume.
