session 1 Flashcards
what is the functional unit of the kidney? describe it
nephron
pale>>corticol region
dark>>medullary region
kidneys cant regenerate new nephrons, and the # decline wiht age!
functions of kidney
Function of the Kidney
– Regulation: control the concentrations of key substances in extracellular fluid
– Excretion: excretes waste products
– Endocrine: synthesis of renin, erythropoietin, prostaglandins
– Metabolism: active form of Vitamin D, catabolism of insulin, PTH calcitonin
describe fluid compartments of the body
plasma contains cells and large organic molecules but interstitial fluid normally doesn’t
what is the predominent cation and anion in the ECF?
ECF:
Cation>> Sodium Na+
Anion>> Chloride Cl-
kidenys function by making large amount of an ultra-filtrate of plasma
means plasma w/out cells and large organic molecules
efferent and afferent arterioles bring blood to and from kidney, creating a high constant filtration pressure.
why is this improtsnt?
the pressure is important in in driving small molecules and water out of the plasma at a rate of 125ml/min or (180L per day)
this is the GFR!
(GFR) describes the flow rate of filtered fluid through the kidney
why does the kidney consume so much oxygen?
bc when the ultrafiltrate enter kidneys tubules 99% of it is reabsorbed! and this process is metabolically very demanding!
how much blood flow does the kindey need?
why is it necessaryit gets this much?
it needs (4ml/min/g) to deliver the oxygen and glucose needed to maintain their activity
location of kidney
(ureter travels at tips of transverse processes)
lower border>> L2/3
layers of kidney
Structure of Kidney
kidneys can be divided into2 steps each of which their anatomical correlate:
1) filtration= glomeruli
2) resoptio and excretion= tubular system
water and osmoalarity
water likes people! ( what keep the partay going)
kidenys effect ECF directly!
indirect effect on ICF
what happens if u fail to control the ECF volume?
changes in BP, tissue fluid and cell function!
The pH of extra cellular fluid is critical
what does it depend on?
- Depends in part on the concentration of bicarbonate in plasma
- Failure to control bicarbonate concentration will have serious consequences
______L is filitered, but then is reabsorbed, leaving____L left for excretion
180L is filitered, but then is reabsorbed, leaving 1L left for excretion
where is EPO released?
ibrocytes in the cortex release the hormone erythropoietin, which stimulates the formation of red blood cells in the bone marrow. Modified fibrocytes of the medulla secrete prostaglandins which are able to decrease blood pressure
where is the major site of reabsorption taken place? what sort of things r reabsorbes there?
how do these reabsorbed material leave? via what?
PCT
– ~60-70% of Na and water
– ~80-90% of K+
– ~90% of HCO3-
– Normally, 100% of glucose and a.a
– Water follows osmotic gradients, so filtrate remains isotonic with plasma
– Reabsorbed materials leave by peritubular capillaries
what r the 2 memebranes of the epithelial cells lining th tubules?
apical (lumnal) and basolateral side
describe the free ion distribution across cell membranes
how can particles transport across cell membranes?
transcellulary and paracellulary
what r the different types of transport?
Active transport: moves solutes from a region of their lower to a higher concentration (needs energy)
- -Primary: transport coupled DIRECTLY to an energy source (ex: Na-K atpase pump, H+ atpase, Ca+ atpase)
- -Secondary: (coupled transport or co-transport) 3aks primary, 2 or more substances interact w/ a specific membrane protein (Carrier) & r trasnported together across membrane
Osmosis: transport of water from areas of high to low concentration
how is Na+ reabsorbed in thick acending limb, distal tubule, collecting duct,
Thick asceding
via Na+/K+/2Cl- cotransporter (apical side)
via /Na-K atpase pump (basolateral side)
Distal
Enac,
Na/Cl cotransporter
collecting duct
Enac
what is Tm? transport maximum
use Glucose as ex
for most substances that r actived reabsorbed or secreted, there is a LIMIT RATE at which the solute can be transported.
- when the amount of solute delivered to the transport systems exceeds the capacity of the carrier proteins & specific enzymes ivolved int eh transport process!*
- (ex : Tmax of glucose is 375mg/min, whereas the filtered load of glucose is only 125 ml/min, if G increases above 375, the excess glucose is not reabsorbed and is passsed to urine)*
TRansporters ma ysta8bilon more than they can!
decribe the Relationship between glucose filtration, reabsorption and excretion to the plasma glucose concentration
function of Anti-dieuretics
reduce Na+ reabsorbtions
Why are the kidneys described as being retroperitoneal organs?
Structures that lie behind the peritoneum are termed “retroperitoneal”.
At approximately what vertebral level would you find the right kidney?
At approximately what vertebral level would you find the left kidney?
RIGHT>> T12‐ L1/3
LEFT>> T11‐ L1
In relationship to the Aorta and the IVC, where do the left renal vein and right
renal arteries pass?
Left renal vein
Left renal vein passes in front of the aorta
Right renal artery
Right renal artery passes behind the IVC
(vein is so VEIN so meaaaaan)
From the hilum, describe the course of the ureter
In females what does the phrase “water under the Bridge refer to?
In females, the ureters pass through the mesometrium and under the uterine arteries on the way to the urinary bladder.
What is the term used to describe the junction between the Pelvis of the kidney
and the ureter?
pelvi‐ ureteric (or uteropelvic) junction
What is the term used to describe the junction between the ureter and the
bladder?
where the most common sites for stones becoming lodged
in the urinary tract are located.
- Pelviureteric junction,
- Bifurcation of the common iliac artery
- Where ureter enters the bladder
what bony landmarks that you can see on the X‐ray would
show you the approximate course of the ureter?
- L1‐2 is about the hilum
- Ureter runs along close to the tip of transverse processes
- Across SI joint
How long is the urethra in the adult male and female?
Male ~20 cm
Female ~4 cm
Label different regions of the male urethra/ penis
label structures that surround kidneys
Describe the course of the ureters and the relationships to the uterine vessels, ovary/vas and the urethra in both males & females
in males: that the ureter passes under ductus deferens, superior to seminal vesicles
in women: that the ureter descends posterior to ovary & into base of broad ligament, passing under uterine artery
Identify the musculature of the bladder
- the bladder wall contains specialised smooth muscle, known as detrusor muscle.
- Its fibres r orientated in 3 directions, longitudinal, transverse, oblique.
- It receives innervation from both the sympathetic & parasympathetic nervous systems.
- in region of the bladder neck, the detrusor muscle runs circularly as involuntary internal sphincter
identify the anatomical position of the bladder
- lies posterior to pubic bones and pubic symphysis
- empty is tetrahedron in shape and lies entirely within the true pelvic cavity;
- spherical when full & may reach as high as umbilicus
structure of bladder, its ureteric openings
- It is hollow, highly distensible, and tetrahedral in shape.
- 2 ureteric openings at superolateral corners and internal urethral opening inferiorly
- has a triangular area defined by these openings that is called the trigone
- has a ridge between 2 urethral openings called the interureteric fold
what is the trigone of the bladder?
in the bladder the mucosa is thrown into rugae except within
trigone, which is smooth.
Shape of the Bladder, external feautures!
what is significant about the apex of the bladder?
at the anterior angle or apex of the bladder is a site of attachment of urachus—fibrous remnant of fetal allantois,
which is seen as median umbilical ligament on anterior abdominal wall
Identify the anatomical position of the prostate
inferiorly to the neck of the bladder
superiorly to the external urethral sphincter
posteriorly to the prostate lies the ampulla of the rectum
with the levator ani muscle lying inferolaterally to the gland.
what follows the efferent arteriole?
Describe the course of the ureters and the relationships in the pelvis to the iliac vessels
blood supply in kidney
renal artery> segmental> interlobar> arcuate> interlobular> afferent> glomerulus> efferent> vasa recta> peritubular capillaries> venous outflow
layers of kidney
Behind the parietal peritoneum what muscle do the ureters lie on? Which boney land mark defines the course of the ureter in the abdomen
Psoas major
Tips of the transverse processes
Blood supply of ureters
The blood supply for the ureter is a segmental artery from the renal, gonadal, vesicle and uterine arteries
