A&P: The Urinary System Flashcards
What is the primary purpose of the urinary system?
- filter blood
What are 4 functions of the urinary system?
- Remove organic waste products
-> ex: urea - Regulate BV & BP
- Regulate plasma concentrations of ions (NA+, K+, Cl-)
- Help stabilize blood pH by control loss of H+ and bicarb (HCO3-)
Name the structures that urine passes through once it leaves the kidney
Kidney -> ureters -> urinary bladder -> urethra
Kidneys are _______, which are organs located behind the peritoneum
retroperitoneal
What is the kidney surrounded by? and what specific type of tissue cushions the kidneys?
- surrounded by dense, fibrous renal capsule
- cushioned with adipose tissue
What is the indentation on the kidney that acts as the point of entry for the renal artery and renal nerve, and exit for the renal vein and ureter?
Hilus
Name the 2 sections of the kidney. Know which ones are outer/inner.
- Renal Cortex (outer)
- Renal Medulla (inner)
What part of the kidney would you find renal pyramids and columns?
Renal Medulla
What is stored in the renal pyramids and columns?
- Renal Pyramids
-> Nephrons - Renal Columns
-> BV
Describe the pathway of filtrate through the nephron, starting from the afferent arteriole
Afferent arteriole -> glomerulues (renap corpuscle) -> Bowmans Capsule (renal corpsule) -> PCT -> LH -> DCT -> CD -> minor calyx -> major calyx -> renal pelvis -> ureter
- Afferent arteriole: brings blood to glomerulus
- Efferent arteriole: blood leaves glomerulus and goes to peritubular capillaries
-> Peritubular capillaries: surround PCT and DCT to allow substances to be secreted/reabsorbed
What is the name of the BV that substances can be reabsorbed into as it moves through the nephron?
Peritubular Capillaries/Vasa Recta
What does filtration exclusively occur?
Renal Corpuscle (Glomerulus and Glomerular/Bowmans Capsule)
What part of the nephron does nutrient reabsorption primarily occur?
PCT
What part of the nephron does secretion primarily occur?
PCT & DCT
What is the main functions of LH and CD?
Regulate water and Na+/K+ ions lost in urine
Blood that is NOT filtered out into the glomerulus capsule, will move through what structure?
- efferent arteriole -> peritubular capillaries
What are the two parts to the renal corpuscle
- Glomerulus (Capillary)
- Glomerular Capsule (Bowman Capsule)
What type of substances are filtered out at the glomerular capsule/bowmans capsule?
- Urea
- Glucose
- Water
- FA
- Ions
- AA
T/F: The secretion of ADH will NOT cause thirst
False, ADH causees water to reabsorbed back into BV because your BP/BV is low. This means that you will get thirsty.
What substances are reabsorbed at the PCT?
- H2O
- Ions (K+, NaCl-, HCO3)
- Organic nutrients (ex: Glucose)
What substances are reabsorbed AND secreted at the DCT?
-
Reabsorbed
-> Water
-> Na+ (from NaCl)
-> HCO3- -
Secretion
-> Ions
-> K+, H+ (acids)
What substances are reabsorbed at the LH?
All move into ascending VR:
- H2O
- Na+
- Cl- (ions)
What are 3 metabolic waste products that get excreted in urine? Know where they originated from
- Urea: originated from AA (containing N) that got broken down into ammonia (toxic)
- Creatine: made from SkM tissue from creatine phosphate
- Uric acid: from breakdown and recycle of nucleic acids (purines)
How does the RAAS system function and its effects on ADH?
- Low BP/BV stimulates JGA
- JGA (Juxtaglomerular apparatus) releases renin (enzyme) from kidney/nephron
- Renin converts inactive angiotensinogen (liver) to angiotensin I
- Angiotensin I is converted to angiotensin II via ACE (enzyme made in lung)
- Angiotensin II promotes vasoconstriction and releases aldosterone and ADH
-> Aldosterone is released from the adrenal gland
–> Stimulates increase Na+ reabsorption (+ secretes K+)
—> Na+ reabsorption causes H2O to also be reabsorbed
—->BV increases, so BP also increases - ADH is released from posterior pituitary
-> Increases water permeability at DCT and CD
–> Increases H2O reabsorption
—> BV increases so BP also increases
What is the stimulus for the RAAS system to “turn on”?
Low BP/BV stimulates JGA
What system does the atrial natriuretic peptide (ANP) oppose?
Opposes action of RAAS
What cells release ANP? What causes ANP to be released?
- Cardiac muscle cells
- Released when BV/BP is too high
What 3 things does ANP do?
- Decrease rate of Na+ reabsorption in DCT
-> If Na+ stays in DCT, water will also stay in the DCT, so it will be urinated out. This will concentrate the blood (bc low H2O), causing decrease in BV -> decrease BP - Dilates of glomeruluar capillaries
- Inhibits Renin, Aldosterone, and ADH secretion
Another name for ADH is ______
Vasopressin
Know what is secreted/reabsorbed at different parts of the nephron
check physio slides lol
What substances are filtered out at the Renal Corpuscle
- Urea
- Glucose
- H2O
- Ions
- FA
- AA
