Flashcards in Final Exam: Learning Objectives the Urinary System Deck (27):
What are the major functions of the kidney's?
pH balance, volume and composition of ECF, filtration of metabolic wastes, maintaining proper RBC volume by regulation of EPO, blood volume maintenance by RAAS, Vitamin D conversion ( aids in ca2+ absorption and an increase in bone mass)
Renin produced by juxtaglomerular cells, angiotensinogen to angiotensin I, Angiotensin I to Angiotensin II by ACE via epithelial cells in the lungs, angiotensin II causes aldosterone release from adrenal gland, aldosterone acts on the principal cells of connecting tubules and ducts in the kidney, causes reabsorption of H20, Na+ and secretion of K+, resulting in increased Blood volume and pressure.
EPO is secreted by what structures in the kidneys?
peritubular capillaries of the renal cortex.
Where are kidneys located?
On either side of the vertebral column near the posterior wall of the abdominal cavity
What is the fundamental structural unit of the kidney?
Structure of the nephron
1) Renal/malpighian corpuscle 2) Renal/uriniferous tubule
portion of the nephron, produces urine (Glomerulus and bowman's capsule)
Renal Uriniferous tubule
portion of the nephron/ concentrates urine/PCT/LH/DCT
Responsible for fenestrating glomeruls. Forms filtration slits to filter fluid
Modified pericytes; smooth muscle cells closely associated with endothelium; contained within glomerular basement membrane
What is the function of Mesangium?
1) Support network for glomerular capillaries 2) Phagocytosis (remove residues and proteins from filtration) 3) Endocytosis (processing of proteins) 4) Secretion of IL-1 and PDGF 5) Modulation of glomerular distension
Collecting site for glomerular filtrate
Juxtaglomerular cells (location, activation, function)
1) located in the afferent arteriole 2) activated by macula densa 3) Function is to secrete renin in response to low glomerular filtration rate due to low blood pressure
Macula densa (location, activation, and function)
1) distal convoluted tubule 2) acitvated by low levels of Na+ 3) monitor levels of Na+ in DCT. Responsible for stimulating JG cells to secrete renin if BP low
Juxtaglomerular apparatus; macula densa, JG cells, mesangial cells
chemoreceptor and baroreceptor
JGA (mode of action)
1) BP lowered, glomerular filtration rate lowered, Na+ concentration lowered 2) Macula densa of DCT activated, stimulates juxtaglomerular cells of the afferent arteriole (via ATP, adenosine, NO , and prostglandins 3) JG cells release Renin. 4) Renin causes conversion of angiotensinogen to angiotensin I 5) angiotensin I converted to angiotensin II by ACE 6) angiotensin II mediate increase in BP causes release of aldosterone by the adrenal cortex (k+ also causes the release of aldosterone). 7) Na+ and H2O reabsorbed by the collecting tubules and ducts and K+ is excreted 8) BP and BV increased. 9) once appropriate levels have been reached, walls of the afferent arteriole stretch causing JG to stop secreting Renin
secreted by JG cells, responsible for conversion of angiotensinogen to angiotensin I
Produced by the conversion of angiotensin I by ACE by epithelial cells in the lungs, functions as a potent vasocontrictor raising BP
What mnemonic do you use for the labeling of the components of the nephron?
Shake your booty song (PPPDDDCCPD) 1. PCT 2) PST 3) PTL 4) DTL 5) DSL 6) DCT 7) CT 8) CD 9) PD
Describe the trip of filtrate as it passes through the nephron. include permeability
1) PCT (responsible for removing most water 65-80%) diffusion of Na+, Cl- and, K+ also responsible for removing all glucose, aa, and polypeptides 2) PST (remove remaining glucose via Na+ and glucose Co-transport 3) PTL (freely diffuses water recall cortex highly permeable) 4) DTL (impermeable to H2O. ions transported to cortex, DTL becomes hypoosmotic 5) DST (relatively impermeable to H2O slight absorbance of ions ) 6) DCT (relatively impermeable to H2O 7) CT (relatively impermeable to H2O unless ADH is available ADH works here. 8) CD (ADH and aldosterone work here 9) PD (conducts renal filtrate into the renal pelvis
Ducts of Bellini
Discharge urine into the renal pelvis through openings in the tips of renal papillae
Cortical peritubular capillary plexus of vasa recti; responsible for absorbing ions and water released by the proximal convoluted tubule
Medullary peritubular capillary plexus of vasa recti; function on the loops of henle; ( Drugs and organic acids are transported from the arteriolae rectae of vasa rectae of MPCP to PST)
H2O absorbed along concentration gradient returns H2O from intersitial fluid to the vascular system
Flow of urine
minor calyces, major calyces, pelvicalcalyceal space, renal pelvis, ureter, urinary bladder, urethra