Urinary System 1 Flashcards
What is the gross anatomy on the urinary system? And it’s basic function?
Kidneys (2) = FILTER
Ureter (2) = TRANSPORT
Urinary Bladder (1)
= STORAGE
URETHRA (1)
= EMPTY THE BLADDER
What is the kidney’s first function?
(4 sub-functions of this)
Filtration of Blood
- Filters metabolic
Waste
->Excretory
(excretes waste & metabolites of drugs)
- Control pH by excretion of H+/ HCO3-
- Filters Ions
( Na+, K+, Cl-, PO4-)
What is the Kidney’s 2nd & 3rd function?
- Reabsorption of vital nutrients lost to filtration
(shouldn’t have to reabsorb proteins + formed elements bc shouldn’t be able to pass fenestrated capillaries) - Tubular Secretion:
- Fine tuning (blood) according to Body’s Needs
What is the Kidney’s Endocrine function?
- Producing Erythropoietin & stimulating erythropoiesis when [O2] low
- Producing Renin which converts angiotensinogen to Angiotesin 1
- Activation of Vitamin D which contributes to Calcium absorption
What other body systems does the urinary system cooperate with?
- Respiratory system for pH regulation
- Digestive System w/ Ca(2+) Absorption
- Cardiovascular system w/ regulating BP
- Integumentary System w/ Vitamin D absorption
Where are the kidneys located? What are the 3 surrounding structures?
- Retroperitoneal
- @ Costoverterbral Angle
3 Surrounding Structures:- Renal Capsule
- on surface of kidney
to protect against
infection- Adipose Capsule
- fat surrounding the
kidney - cushion to protect
from trauma- Renal Fascia
- C.T. anchoring the
surrounding tissues
& abdominal wall - Envelopes the entire
kidney and the
adrenal gland
- on surface of kidney
- Renal Capsule
What are some gross anatomy of the kidney?
Renal Capsule
Renal Cortex (filtration)
Renal Columns (extensions of the cortex)
Renal Medulla
Renal Pyramids
Renal Papilla
Minor Calyx (Calyces)
Major Calyx (Calyces)
Renal Pelvis
Hilus Ureter
What is lobe of kidney?
Renal Pyramid + half of renal columns adjacent + cortex extending superficially
≈ 8 lobes per kidney
Whats the function of the cortex and medulla of kidney?
Filtration = Cortex
Reabsorption +Tubular Secreation =
Cortex + Medulla
How much of the blood supply goes through the kidney?
25% of Cardiac Output (CO)
What is the artery blood supply of kidney to the capillaries?
Renal Artery
↓
Segmental Arteries
( ≈ 4-5 divisions)
↓
Interlobar Arteries
(renal columns)
↓
Arcuate Arteries
(@ corticomedullary junction)
↓
Cortical Radiate Arteries
Interlobular Arteries
(radiate in cortex)
↓
(3 w/in renal corpuscle)
Afferent Arteriole
↓
Glomerulus
↓
Efferent Arteriole
↓
Capillaries:
–> Peritubular Capillaries
(around PCT & DCT)
–> Vasa Recta Capillaries
(straight- loop of henle)
Renal drainage from capillaries to inferior vena cava?
Capillaries:
Peritubular
Vasa Recta
↓
Cortical Radiate Veins
Interlobular Veins
↓
Arcuate Veins
↓
Interlobar Veins
↓
Renal Veins
↓
Inferior Vena Cava (IVC)
Components of Nephron & function
Renal Corpuscle = filtration
Proximal Convoluted Tubule (PCT)
= reabsorption
Descending limb
(thin segment)
Loop of Henle
Ascending limb
(thick segment)
Distal Convoluted Tubule (DCT)
= reabsorption
Collecting Duct
= reabsorption
= tubular secretion
Papillary Duct
2 renal papilla
What is NFP? What are its compenents?
Net Filtration Pressure
- Made of favorable & opposing pressures
Favorable = Glomerular Pressure 55mmHg
Opposing=
1. Capsular Hydrostatic Pressure 15 mmHg
- Colloid Osmotic Pressure 30mmHg
What is Capsular Hydrostatic Pressure (CHP)?
Capsular Hydrostatic pressure is the the pressure caused by the the inelastic parietal layer of the glomerular capsule pushing back on the glomerular pressure
= 15mmHg
What is Colloid Osmotic Pressure (COP)?
The opposing pressure to the golmerular pressure caused by the proteins called albumens working like sponges to hold fluid in circulation & prevent leaving into the filtrate.
=30mmHg
How do you calculate NFP?
Net Filtration Pressure (NFP) = GP - (CHP + COP)
NFP = 55 - (15 + 30)
NFP = 10 mmHg
What are the 3 ways to regulate filtration?
- Renal Autoregulation
- Neuronal
- Hormonal
= Renin- Angiotensin-Mechanism
What are the 2 mechanisms of renal auto regulation for regulation of filtration? What structure does is involve?
A) Myogenic Mechanism
- afferent arteriole
- stretch
- inflow
B) Tubuloglomerular Feedback
- juxtaglomerular apparatus
- filtration & flow
- Reabsorption (inverse regulation w/ filtration)
- macula densa detect conc of ions in DCT
- macula densa produce or w/hold ATP to cause contriction or dilation of afferent arteriole
- effect flow
What are the 2 ways of neuronal regulation of filtration? What structures, neutransmitters, and effect involved?
- Sympathetic NS
- norepinephrine
–>vasoconstriction
- afferent arteriole
- decreased ↓ GFR
- ↓ Diuresis - Parasympathetic NS
- acetylcholine
–> vasodilation
- afferent arteriole
- increased ↑ GFR
- ↑ Diuresis
What is the hormonal mechanism for regulation of filtration?
What is the stimuli and steps of the mechanism?
What are the 3 effects?
Renin- Angiotensin- Aldosterone Mechanism
↑ BP picked up by the juxtaglomerular apparatus on th the kidney
Renin converts angiotensinogen (produced by liver) into Angiotensin I
Angiotensin I is converted into ACE in Lungs
3 Effects of Angiotensin II:
1) Stimulated the adrenal cortex to produce Aldosterone which increases the Na+ reabsorption from the nephrone which ↑ blood vol & BP
2) Vasoconstricts the efferent arteriole of renal corpuscle => ↑ GP
3) Stimulates release of ADH from posterior pitutary gland which will increase H2O reabsorption in the DCT increased BP
- All 3 effects increase BP => glomerular pressure
What is the PCT lined with?
What is the function of the PCT?
3 methods of doing this?
simple cubiodal w/ microvilli
= Reabsorption of nutrients
- Active transport of Na+ (90% reabsorbed)
- Secondary Active Transport
- vitamins
- a.a
- ions
- glucose - Obligatory Transport (Osmosis)
- 60-90% of H2O reabsoprbed via osmosis
What is transport maximum?
When blood levels are too high there is not enough carriers & this is the maximum transport. When this is reached extra nutrients is excreted.
Ex: diabetes
What is the Loop of Henle and what lines it?
What are the 2 parts?
What is 2 function?
Descending Limb
(Thin Segment)
- simple squamous
- permeable to H2O
Ascending Limb
(Thick Segment)
- simple cubiodal epi.
- permeable to Na+
Function:
1. Counter Current Multiplier
- increase concentration of urine
- Counter Current Exchange
- reabsorption into bloodstream
