Renal Flashcards
Are kidneys retra or intra peritoneal?
Retroperitoneal
What spinal lvl kidneys sit?
Which lower
T12-L3
Right usually lower- liver
What is outer and inner layer of kidney called?
Outer- Cortex
Inner- Medulla
Describe urine flow in kidney?
Renal pyramid
Papilla
Minor calyx
Major calyx
Renal pelvis
Proximal ureter
Function ureter?
Carry urine from kidney to bladder
Where are 3 points ureter narrows?
Where pelvis of kidney becomes ureter
At the pelvic brim
Where the ureter passes through the bladder
What muscle is ureter walls composed of? Why?
Smooth
Peristaltic
What prevents urine passing bladder to ureter?
Ureter enter bladder oblique angle
Pressure rises- press ureter- stop urine pass up kidney
Bladder
Function urethra?
Tube through which urine passes from bladder to exterior
How long is male urethra?
How long is female urethra?
Male- 8-10 inch
Female- 2 inch
Urethra
What is functional unit of kidney?
Nephron
What are two different types nephron?
Cortical- tubules short distance medulla- main cortex
Juxtamedullary- tubules long distance medulla- have vasa recta
What is part of nephron in which blood plasma is filtered called?
Renal corpuscle
What does renal corpuscle contain?
Glomerulus- afferent and efferent arteriole
Bowmans capsule- first step urine prod
What are 4 renal tubules, what occurs?
Proximal conv tubule- bulk reabsorption
Loop of Henle- descending loop- H20 permeable
- ascending loop- H20 impermeable- solute reab
Distal convoluted tubule- fine regulation- Ca2+, Na+, K+, HCO3 (is Cl- dependent)
Collecting duct- urine fine tuned
What size can travel from glomerulus to nephron?
10kDa smaller
What can’t tracel from glomeruls to nephron?
Bigger 10kDa
Large negative
Albumin- podocytes prevent
Form glomerular filtrate
State 5 things determine filtration glomerulus?
1) Size of molecule
2) Pressure
3) Size of molecule
4) Charge of molecule
5) Rate of blood flow
What proportion of CO is renal blood flow?
20%
Define GFR?
The volume of fluid filtered by the renal glomeruli per unit of time
How much fluid filtered/day?
180L
125ml/in
How many L of plasma?
3L
How many times is blood plasma filtered?
60 times/day
What is decisive factor for normal regulation GFR?
Hydrostatic pressure- arterial bp
State 3 ways GFR regulated?
1) Autonomic vasoreactive (myogenic) reflex
Smooth muscle capillaries glomerulus/kidney
2) Tubuloglomerular feedback
Increased hydrostatic pressure in glomerulus- increased fluid load
Macula densa sense- vasoconstriction of afferent arteriole
3) RAAS- low bp sensed granular cells- release renin
Define renal clearance?
Virtual plasma volume/min from which substance is completely eliminated
GFR
What is used measure GFR?Why?
Creatine- freely filtered not reabsorbed
How is PCT adapted?
Villi- increase SA
Where is 2/3 primary urine volume reabsorbed?
Proximal tubule
Descending part LOH
Function ascending part LOH?
Impermeable water- transport electrolyte to interstitium
Produce high osmotic pressure
Na K 2Cl co-transport
Function distal tubule?
Active Na transport- Na-Cl cotransporter
10% filtered sodium reabsorbed
Thiazides inhibit
Function collecting duct?
Permeability water- concentration urine
What is responsible for force urine concentration in collecting duct?
High osmotic pressure of renal medulla
What does deficiency of ADH lead to?
Diabetes insipidus
What is rate determining step of RAAS?
Renin
Where is renin produced?
juxtaglomerular cells of the afferent arteriole in the kidney
What controls release renin?
Macula densa- sense reduced Na and Cl conc in distal tubule
Baroreceptors- decreased bp
Neural mechanisms – the juxtaglomerular cells are innervated by abundant beta 1 adrenergic sympathetic nerve fibres, their activation leads to renin secretion
Function angiotensin II?
Act adrenal cortex release aldosterone
Stimulate release ADH from posterior pituitary
Stimulate thirst centre
What is aldosterone?
Mineralocorticoid
Function aldosterone?
Increase Na+ reabsoprtion exchange K+
Regulate amount Na+ reabsorbed in DCT through ENAC
Function ADH/vasopressin?
Affect bp
Release Aq2 channels into principle cells in collecting ducts
Increase water retention
What can cause prerenal, renal, post renal desease
Prerenal- sudden reduction blood flow kidney
hypotension
Renal- direct damage
- ecalmpsia
Post renal- obstruction urinary tract
- kidney stones
What can chronic renal failure cause?
1) Fluid retention- swelling, high bp, pulmonary oedema
2) Hyperkalaemia- potassium not removed
3) Cardiovascular disease- blood pressure not regulated
4) Weak bones- unregulated phosphorous- pull calcium
