Flashcards in Urinary 1 - Anatomy + GFR Deck (59):
Describe the position of the kidneys, in regards to vertebral levels:
T12 --> L2/3
What is the approx. length, width and thickness of a kidney?
Length = 12 cm
Width = 6 cm
Thickness = 3 cm
What is the approx. weight of a kidney?
Describe the relation of the uterus to the bladder:
Uterus lies superior and posterior to the bladder
What is the approx. length of the urethra?
Males = 20 cm
Females = 4 cm
Describe the anatomical course of the ureter:
- Descends down abdomen along anterior surface of psoas major
- Cross pelvic brim into pelvic cavity, anteriorly crossing bifurcation of common iliac arteries
- Down lateral pelvic walls, turning anteromedially at ischial spine level
- Pierce bladder poster-laterally and obliquely
What is the approx. length of a ureter?
What type of epithelium lines the ureters?
What arteries supply the ureters? (divide into upper, middle and distal regions)
Upper - Renal artery, branches of Gonadal artery and Abdominal aorta
Middle - Common iliac artery and Gonadal artery
Distal - Branches of Common + Internal iliac arteries, and Uterine (Females) / Superior vesicle (Males)
Explain the saying 'water under the bridge', and its surgical significance:
Ureters run underneath the uterine arteries 2 cm superior to the ischial spine (Females only)
Must take care not to damage during hysterectomy
Which kidney lies slightly lower in the abdomen, and why?
Right kidney lies slightly lower, due to Liver pushing it down.
Describe the position of the bladder in regards to the pubic bone and pubic symphysis:
Lies posterior to pubic bone and pubic symphysis
What shape is the bladder when empty?
What shape is the bladder when full?
What is the trigone of a bladder?
Area of smooth mucosa (no rugae) between the ureteric openings and the urethra.
Very sensitive to stretch - sends signals to brain when stretched to a certain degree.
What is the Median Umbilical Ligament, and what area of the bladder does it attach to?
Fibrous remnant of the Urachus and Fetal Allantois, located on the anterior abdominal wall.
Extends from APEX OF BLADDER to umbilicus.
What is the name of the ligament which attaches the apex of the bladder to the umbilicus?
Median umbilical ligament
What type of epithelial cells line the bladder?
what are the layers of the detrusor muscle?
Inner = longitudinal
Middle = circular
Outer = longitudinal
What is the main function of the transitional epithelia and rugae in the bladder?
Allow distension of the bladder without stretching the wall (therefore doesn't send nerve signals for micturition as soon as urine deposited in the bladder)
What area of the bladder lining does not have rugae?
What type of muscle is the detrusor muscle?
Name the region of the kidney which invaginates the medulla:
What is a renal papilla?
Region of the medullary pyramid where urine empties into the minor calyx
Name the 4 layers surrounding the kidney, from innermost to outermost:
1 - Thick fibrous capsule
2 - Perirenal fat
3 - Renal fascia (encircles kidney and adrenal glands)
4 - Pararenal fat
Name the 3 physiological narrowings of the ureter:
1 - Ureteropelvic junction
2 - Crossing over iliac vessels
3 - Ureterovesical junction
Name the 6 main functions of the Kidney:
1 - Regulate most ECF/plasma ions
2 - Maintain H20 balance
3 - Helps maintain body pH
4 - Excrete waste products and foreign components
5 - Produce Erythropoetin and Renin
6 - Convert vitamin D to Calcitriol (regulating plasma calcium and phosphate)
Once the Renal arteries have entered the renal hilum, name the arteries they branch into:
What is the name of the arteries which lie either side of every renal pyramid?
Segmental arteries in the kidneys branch into what arteries?
Describe the position of Interlobar arteries:
Situated either side of every renal pyramid
Interlobar arteries branch into which arteries?
Arcuate arteries branch into which arteries?
What is the name of the arteries which pass through the cortex, and divide to form afferent arterioles in the kidneys?
Which renal vein is longer than the other and why?
Left renal vein is longer than the right.
- As IVC lies to the right of the abdominal aorta
- Allows other veins to drain into it ie Adrenal/Gonadal
What is the average renal blood flow / min?
What percentage of blood from the renal artery is filtered at the glomerulus?
Is the Macula densa located closer to the afferent or efferent arteriole?
What causes the capillary endothelium to become leaky inside the glomerulus?
Podocytes on the visceral layer of the Bowmans capsule make filtration slits
Name the 3 filtration barriers in the glomerulus:
1 - Capillary endothelium
2 - Basement membrane
3 - Podocyte layer
What is the capillary endothelium (within the glomerulus) permeable to?
- Filtrate (via filtration slits)
What filtration barrier of the glomerulus prevent anion and protein filtration? How?
- Contains negatively charged glycoproteins which repel anions and proteins
What is the maximum radius of a particle which can be filtered at the glomerulus?
1.48 nm (Inulin)
What forces in the glomerulus contribute to filtration pressure?
1 - Hydrostatic pressure in the capillary
2 - Hydrostatic pressure in the Bowmans capsule
3 - Oncotic pressure difference
What is the net filtration pressure in the glomerulus?
What are the 2 types of autoregulation to maintain GFR?
1 - Myogenic response
2 - Tubular-Glomerular feedback
How does the myogenic response maintain GFR?
If high bp = increase resistance in afferent arteriole
If low bp = increase resistance in efferent arteriole
How does Tubular-Glomerular Feedback maintain GFR?
- Macula densa cells detect [NaCl] in distal convoluted tubule
--> If too high = stimulates juxtaglomerular cells to secrete Adenosine into efferent arteriole = vasodilation
--> If too low =
1) stimulates juxtaglomerular cells to secrete prostaglandins into afferent arteriole = vasodilation
2) stimulates juxtaglomerular cells to secrete Renin
Where are Macula densa cells located?
In the wall of the distal convoluted tubule
Where are the juxtaglomerular cells located?
In the afferent and efferent arteioles
Why would juxtaglomerular cells secrete Adenosine into the efferent arteriole?
To cause vasodilation of the efferent arteriole, to decrease GFR
Why would juxtaglomerular cells secrete Prostaglandins into the afferent arteriole?
To cause vasodilation of the afferent arteriole, to increase GFR
What would cause the juxtaglomerular cells to secrete Adenosine into the efferent arteriole?
Macula densa cells would stimulate them, after detecting increased [NaCl] in the distal convoluted tubule.
What would cause the juxtaglomerular cells to secrete Prostaglandins into the afferent arteriole?
Macula densa cells would stimulate them, after detecting a decrease in [NaCl] in the distal convoluted tubule
What cells release Renin?
How is GFR / Renal clearance calculated?
([substance in urine] x flow rate of urine) / [substance in plasma]
Name an intrinsic and extrinsic substance that may be used to calculate GFR:
Intrinsic = Creatinine
Extrinsic = Inulin
What is the normal GFR range?
Males = 115 - 125 ml/min
Females = 90-100 ml/min