Term
|
Definition
Excretion-Removal of organic waste products from body fluids
Elimination-Discharge of waste products into environment
Homeostatic Regulation |
|
|
Term
|
Definition
Regulate Blood Volume and Pressure-Adjust volume of water lost in urine, release erythropoietin and renin
Regulate plasma concentration of ions-synthesis of calcitriol, etc
Stabilize blood pH
Conserve nutrients |
|
|
Term
|
Definition
retroperitoneal. Maintained by overlying peritoneum, contact with adjacent organs, support CT
Covered by fibrous capsule |
|
|
Term
|
Definition
| Exit for ureter, entrance of renal arter and renal nerve, exit of renal vein |
|
|
Term
|
Definition
| Renal cortex, renal medullo, renal pyramids, renal papilla, renal lobe, minor calyx, major calyx, renal pelvis |
|
|
Term
|
Definition
Basic functional unit
1) Renal corpuscle
2) Renal tubule |
|
|
Term
|
Definition
Glomerular capuscle +glomerulus (capillary network)
BP forces fluid and dissolved solutes out glomerular capillaries and into capsular space-->Filtration |
|
|
Term
|
Definition
protein-free solution
By end of nephron, composition changes and becomes tubular fluid
Passive filtartion |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Epithelium covering capillaries. Have feet that wrap around individual capillaries |
|
|
Term
| Proximal Convoluted Tubule |
|
Definition
Reabsorb organic nutrients, plasma proteins and ion. Release into interstitial fluid(peritubular fluid)
Solute concentration of peritubular fluid increases, that of tubular fluid decreases
Water moves out through osmosis |
|
|
Term
|
Definition
Descending Limb-fluid flows towards renal pelvis
Ascending limb-not permeable to water and solutes. Active transport sodium and chloride out of tubular fluid
High solute concentration in peritubular fluid of medulla |
|
|
Term
|
Definition
immediately passes adjacent to afferent and efferent arterioles
1)active secretion of ions, acids, drugs and toxins
2)selective reabsorption of sodium ions from tubular fluid
3)selective reabsorption of water |
|
|
Term
|
Definition
| Epithelial cells of DCT closest to glomerulus
Closely associated with smooth muscle fibers(juxtaglomerular cells) in wall of afferent arteriole
-->Juxtaglomerular complex |
|
|
Term
|
Definition
Endocrine structure that secrets the hormone erythropoietin and enzyme Renin
Regulate blood volume and pressure |
|
|
Term
|
Definition
Receive tubular fluid from many nephrons
Several collecting ducts merge to for a papillary duct (delivers urine to a minor calyx) |
|
|
Term
|
Definition
| Must abundant organic waste. From breakdown of amino acids |
|
|
Term
|
Definition
| Generated in skeletal muscle tissue through breakdown of creatine phosphate |
|
|
Term
|
Definition
| Product of breakdown and recycling of RNA |
|
|
Term
|
Definition
1) Filtration: blood pressure forces water across filtration membrane in renal corpuscle.
2) Reabsorption: removal of water and solute molecules from tubular fluid into peritubular fluid->re-enter circulation at peritubular capillaries. Water reabsorption passively through osmosis
3) Secretion: transport of solutes from peritubular fluid into tubular fluid. Further lower plasma concentration of undesirable materials |
|
|
Term
| Important Notes on the Nephron Process |
|
Definition
Filtration occurs exclusively in renal corpuscle across glomerular capillary walls
Reabsorption of nutrients occurs primarily at PCT
Active secretion occurs primarily at DCT |
|
|
Term
|
Definition
Net force promoting filtration. Pressure at glomerulus is higher than capillary blood pressure elsewhere because of difference in diameters of affer/efferent arterioles.
Efferent arteriole has smaller diameter, resistance/back up->increase in bp
Kidney filtration will stop if glomerular blood pressure falls significantly |
|
|
Term
| Glomerular Filtration Rate (GFR) |
|
Definition
| amount of filtrate produced in the kidneys each minute. 125 mL/minute |
|
|
Term
| Events at the Proximal Convoluted Tubule |
|
Definition
Cells actively reabsorb organic nutrients, plasma proteins and ions from filtrate. Transport to peritubular fluid
Osmotic forces pull water out of PCT into peritubular fluid.
Both solute and water diffuse into peritubular capillaries
H+ can be actively secreted into tubular fluid to regulate blood pH |
|
|
Term
| Events at the Nephron Loop |
|
Definition
Reabsorbs >.5 remaining water, .66 sodium and chloride ions remaining in tubular fluid
Descending:permeable to water, not solutes. Water flows in/out by osmosis
Ascending:impermeable to water and solutes. Actively pumps NA and CL out of tubular fluid into surrounding peritubular fluid
->concentration gradient in medulla, highest concentration of solutes at bottom of loop |
|
|
Term
| Events at the Distal Convoluted Tubule |
|
Definition
| Impermeable to solutes, changes in tubular fluid composition can occur only through active reabsorption/secretion.
Primary function:ACTIVE SECRETION
Cells actively transport NA out and K/H in
Ion pumps respond to Aldosterone
ADH |
|
|
Term
|
Definition
Produced by adrenal cortex
In response to lowered NA ion concentrations/elevated K concentrations in blood
Higher Aldosterone levels, more NA reclaimed and K lost |
|
|
Term
|
Definition
Controls amount of water reabsorbed along DCT/collecting duct
No ADH, DCT impermeable to water
Increase ADH, increase in water permeability, more concentrated the urine |
|
|
Term
|
Definition
1) Autoregulation-local regulation
2) Hormonal regulation-started by Kidneys
#) Autonomic regulation-sympathetic division of ANS |
|
|
Term
| Local GFR (auto)regulation |
|
Definition
Minor variations in bp through changes in diameters
GFR rates remain relatively constant |
|
|
Term
|
Definition
| Long term adjustments to stabilize GFR
Angiontensin II, aldosterone, ADH secretion is integrated by renin-angiotensin system |
|
|
Term
|
Definition
Glomerular pressure remains low->juxtaglomerular complex releases renin(enzyme)
Renin converts inactive angiotensinogen to angiotensin I
converted to angiotensin II by ACE |
|
|
Term
| Effects of Angiotensin II |
|
Definition
1) Brief/powerful vasoconstriction in peripheral capillary beds->elevates bp in renal arteries
2) Constriction of efferent arterioles at the nephron-> elevates glomerular pressures and filtration rates
3) Triggers release of ADH at CNS->stimulates reabsorption of H20 and NA, induces thirst sensation
4) Secretion of aldosterone by adrenal cortex and of E/NE by adrenal medulla->sudden, dramatic increase in bp. Stimulates NA reabsorption along DCT |
|
|
Term
|
Definition
1) Increases water permeability of DCT->stimulates reabsorption of water from tubular fluid
2) Induces sensation of thirst
*Under angiotensin II stimulation and independent stimulation by drop in bp stimulates hypothalamic neurons |
|
|
Term
|
Definition
Stiumlates reabsorption of sodium and secretion of potassium along DCT
Occurs under angiotension II stimulation and in response to rise in K concentration of blood |
|
|
Term
| Atrial Natriuretic Peptide (ANP) |
|
Definition
Opposes renin0angiotensin system.
Released by atrial cardiac muscles when high blood volume/pressure levels
1) decrease rate of NA reabsorption in DCT
2) dilation of glomerular capilaries->increase in filtration/water loss
3) inactivation of renin-angiotensin system, inhibition of renin, aldosterone, ADH
-Accelerated loss of NA, increase in urine volume->lowers blood volume and pressure |
|
|
Term
| Sympathetic Activation and Kidney Function |
|
Definition
Shift blood flow away from kidneys to lower filtration rate
Direct effect: constriction of afferent arterioles->decreases GFR, slows filtration |
|
|
Term
|
Definition
| Stores urine. Superior surface covered by peritoneum
Trigone-triangular area within the urinary bladder that is bounded by ureteral openings and entrance to urethra
Internal urethral sphincter-involuntary control over urine discharge
Transitional epithelium-continuous with renal pelvis/ureters also lines urinary bladder |
|
|
Term
|
Definition
Three layers of smooth muscle of bladder.
Contraction compresses bladder, expels contents to urethra |
|
|
Term
|
Definition
External Urethral Sphincter
-skeletal muscle fibers, contractions under voluntary control |
|
|
Term
|
Definition
Coordinates process of urination
Stretch receptors in wall of bladder are stimulated as it fills
Increases level of fiber activity-stimulates interneurons that relay sensations to thalamus. Become consciously aware
Motor neurons stimulate detrusor muscle->contraction elevates fluid pressures. Need relaxation of external sphincter (voluntary control)
Internal sphincter relaxes afterward(involuntary)
Once volume of bladder exceeds 500 mL, can generate enough pressure to force open internal sphincter. |
|
|
