Final Exam: Learning Objectives the Urinary System

Question 1

What are the major functions of the kidney’s?

Answer 1

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)

Question 2

RAAS

Answer 2

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.

Question 3

EPO is secreted by what structures in the kidneys?

Answer 3

peritubular capillaries of the renal cortex.

Question 4

Where are kidneys located?

Answer 4

On either side of the vertebral column near the posterior wall of the abdominal cavity

Question 5

What is the fundamental structural unit of the kidney?

Answer 5

The Nephron

Question 6

Structure of the nephron

Answer 6

1) Renal/malpighian corpuscle 2) Renal/uriniferous tubule

Question 7

Renal/Malpighian corpuscle

Answer 7

portion of the nephron, produces urine (Glomerulus and bowman’s capsule)

Question 8

Renal Uriniferous tubule

Answer 8

portion of the nephron/ concentrates urine/PCT/LH/DCT

Question 9

Podocytes

Answer 9

Responsible for fenestrating glomeruls. Forms filtration slits to filter fluid

Question 10

Mesangial cells

Answer 10

Modified pericytes; smooth muscle cells closely associated with endothelium; contained within glomerular basement membrane

Question 11

What is the function of Mesangium?

Answer 11

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

Question 12

Urinary space

Answer 12

Collecting site for glomerular filtrate

Question 13

Juxtaglomerular cells (location, activation, function)

Answer 13

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

Question 14

Macula densa (location, activation, and function)

Answer 14

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

Question 15

JGA (compostion)

Answer 15

Juxtaglomerular apparatus; macula densa, JG cells, mesangial cells

Question 16

JGA (function)

Answer 16

chemoreceptor and baroreceptor

Question 17

JGA (mode of action)

Answer 17

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

Question 18

Renin

Answer 18

secreted by JG cells, responsible for conversion of angiotensinogen to angiotensin I

Question 19

Angiotensin II

Answer 19

Produced by the conversion of angiotensin I by ACE by epithelial cells in the lungs, functions as a potent vasocontrictor raising BP

Question 20

What mnemonic do you use for the labeling of the components of the nephron?

Answer 20

Shake your booty song (PPPDDDCCPD) 1. PCT 2) PST 3) PTL 4) DTL 5) DSL 6) DCT 7) CT 8) CD 9) PD

Question 21

Describe the trip of filtrate as it passes through the nephron. include permeability

Answer 21

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

Question 22

Ducts of Bellini

Answer 22

Discharge urine into the renal pelvis through openings in the tips of renal papillae

Question 23

CPCP

Answer 23

Cortical peritubular capillary plexus of vasa recti; responsible for absorbing ions and water released by the proximal convoluted tubule

Question 24

MPCP

Answer 24

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)

Question 25

Venulae rectae

Answer 25

H2O absorbed along concentration gradient returns H2O from intersitial fluid to the vascular system

Question 26

Flow of urine

Answer 26

minor calyces, major calyces, pelvicalcalyceal space, renal pelvis, ureter, urinary bladder, urethra

Question 27

Function of ureter

Answer 27

conduct urine to the urinary bladder for removal.