M104 T3 flscs from Cat Flashcards
What vertebral levels do the kidneys span?
T12 - L3
What vertebral level is renal pain usually referred to?
T12 (the cutaneous area, T12 - subcostal nerve)
What is the weight of each normal adult kidney?
120-170 g
What are the approximate dimensions of each kidney?
6x11x3 cm
Approximately how many nephrons are there per
kidney?
1.25 million
What are the two types of nephron?
cortical and juxtamedullary nephrons
What proportion of all kidney nephrons are cortical nephrons?
70-80%
Where are cortical nephrons located?
cortex - short loop of Henle into medulla
What proportion of all kidney nephrons are juxtamedullary nephrons?
20-30%
Where are juxtamedullary nephrons located?
closer to the medulla, LoH
What is the depth of juxtamedullary nephrons like?
they extend deep into the renal pyramids
What symp nerves innvervate the kidneys?
postganglionic fibres from the coeliac ganglion
What is the efferent parasymp supply of the kidneys?
vagus nerve
renal plexus in hilum
What is the blood supply of the kidneys?
ant&post renal arteries (supply from abd aorta)
l&r renal veins
What is the effect of renal innervation?
can control tone of efferent arterioles, which involves modification of the GFR and RBF
During glomerular filtration, what types of substances remain in the blood?
cells and large mlcs (RBCs, lipids, proteins, most drugs, metabolites
What is the passage of water during tubular reabsorption?
passive osmosis along the osmotic gradient created by Na+ ions
What type of substances can’t be filtered at the glomerulus and why?
some endogenous substances and drugs
due to their size or protein binding
What are the two types of pumps involved in tubular secretion?
For organic acids or drugs (e.g. uric acid, diuretics, antibiotics - e.g. penicillin)
For organic bases or drugs (e.g. creatinine, procainamide)
What are the five major stages of urine formation?
glomerulular filtration of blood PT - filtrate reabsorption, secretion into tubule LoH urine concentration DT urine modification CD - final urine modification
What is the normal GFR?
125 mL/min = 180 L/day
What is the normal normal plasma volume?
2-3 L
What’s the first stage of urine formation?
glomerular filtration
What cations are reabsorbed into the PT and by what %?
Na+ & K+ - 65 %
What anions are reabsorbed into the PT and by what %?
HCO3-, 80-90 %
Cl-, 50 %
What waste products are reabsorbed into the PT and by what %?
glucose, 100 % proteins & amacs, 100 % H2O - 65 % Ca2 & Mg2 - variable urea, 50 %
What substances are secreted into urine and by what %?
urea - variable
creatinine - small amount
H+ & NH4+ - variable
What happens to the remaining fluid after it has passed through the PT?
enters the LoH
What is the function of the LOH?
to recover fluid and solutes from the glomerular filtrate
What are the two stages of extraction in the LoH?
h2o extraction in the desc. limb
Na+ & Cl- extraction in the asc. limb
Through what passage is water extracted through into the thin descending limb?
Aquaporin-1 channels
How is the thin descending limb adapted for h2o extraction?
cells are flat
is freely permeable to water via AQP-1 channels
allows for passive h2o movement via tight junctions
Through what passage is Na+ and Cl- extracted through into the thick ascending limb?
Na+/K+/2CI- (NKCC2) co-transporters
What substances are extracted in the thick ascending limb?
Na+, K+ and CI-
How is the thick ascending limb adapted for Na+, K+ and CI- extraction?
h2o-impermeable tubular walls
specialised NKCC2 co-transporters
What is the tonicity of fluid entering the LoH from the PT?
isotonic - 300 mOsm
What occurs in the desc. LoH?
water is reabsorbed
What is the tonicity of fluid at the tip of the LoH after the desc. LoH?
hypertonic - 1200 mOsm
What happens to the hypertonic fluid at the tip of the LoH?
the solutes contained in the hypertonic fluid are pumped out at the asc. LoH
What is the tonicity of the filtrate entering the DT?
hypotonic - 150 mOsm
What is the process by which the tonicity / conc of medullary filtrate varies (iso, hyper, hypo) over a short distance?
Countercurrent Multiplication
How does Countercurrent Multiplication result in varied tonicity in the medulla?
creates a large osmotic gradient within the medulla
allows passive reabsorption of water from tubular fluid in desc. LoH
What transporter facilitates countercurrent multiplication in the asc. limb of the LoH?
Na+/K+/2CI-
SIADH Treatment:
V, receptor blockers (ADH inhibitors), e.g. demeclocycline, Tolvaptan
What happens to all that water and solutes reabsorbed from the tubule?
It is all taken back into the peritubular vessels and vasa recta surrounding the tubule
What occurs in the DT?
further adjustment of urine
active absorption and secretion of solutes
What solutes are actively reabsorbed / secreted in the DT?
Na+ and CI- ; reabs
K+ reabs, swapped in for H+
The exchange of which ions in the DT results in the further adjustment of urine?
exchange of K+ in for H+ - secreted into the tubular fluid
How is the collecting duct adapted for Na+, K+ and CI- extraction?
it’s relatively impermeable to h2o & solute movement
but ADH can increase its permeability
What are the major two forms of Diabetes Insipidus?
nephro and neurogenic
What causes nephrogenic Diabetes Insipidus?
renal inability respond normally to ADH
What causes neurogenic Diabetes Insipidus?
decreased neural synthesis of ADH
What types of drugs are used to treat neurogenic Diabetes Insipidus?
ADH analogue - desmopressin
anti-convulsive - carbamazepine
What types of drugs are used to treat nephrogenic Diabetes Insipidus?
diuretics - chlortalidone
anti-inflammatory - indometacin
What are the four types of Diabetes Insipidus?
nephrogenic DI
neurogenic DI
Dipsogenic DI
Gestational DI
What is the opposite condition of Diabetes Insipidus and what’s it caused by?
SIADH - excessive release of ADH
due to; head injury or the unwanted effects of drugs
What are some of the effects of SIADH?
hyponatraemia and possibly fluid overload
What drug type is used to treat SIADH?
ADH inhibitors
What bones make up the posterior abdominal wall?
Ribs 11 & 12
Lumbar vertebrae
Sacrum
What muscles make up the posterior abdominal wall?
Diaphragm
Quadratus Lumborum
Psoas Major (& Minor)
lliacus
Abdominal Aorta Branches Bifurcates into the common iliac vessels at
L4/5
Greater, lesser and least splanchnic nerves synapse at
suprarenal glands.
the coeliac and aorticorenal ganglion to innervate the suprarenal glands.
Abdominal Pain Somatic
Well localised, sharp or stabbing, Felt in skin, muscle, fascia and parietal peritoneum
Abdominal Pain Visceral
Poorly localised, dull ache or throbbing, Caused by stretching, ischaemia or chemical damage
Dermatomes Stomach:
felt in skin of dermatomes T5-9
Dermatomes Appendix:
T10 (umbilicus)
Dermatomes Gallbladder:
T7-9
Dermatomes parietal peritoneum involvement:
C3,4
Two modes of action of diuretics
2) Modification of content of the filtrate 1) Direct action on the cells of the nephron (more common)
Two major applications of diuretic agents:
1) Reduce circulating fluid volume 2) Removal of excess body fluid (oedema)
Two major applications of diuretic agents:
1) Reduce circulating fluid volume 2) Removal of excess body fluid (oedema)
What is the number of nephrons in each kidney affected by?
age - numbers decline
What is the number of nephrons in each kidney affected by?
age - numbers decline
What is the significance of the line of Brodel?
is an important access route for both open and endoscopic surgical access of the kidney, as it minimises the risk of damage to major arterial branches
What is the significance of the line of Brodel?
is an important access route for both open and endoscopic surgical access of the kidney, as it minimises the risk of damage to major arterial branches
Which renal artery is longer and why?
the right, bc it has to cross the vena cava posteriorly
Which renal artery is longer and why?
the right, bc it has to cross the vena cava posteriorly
What are the two divisions of the renal artery?
anterior (75% of the blood supply)
posterior (25%)
What are the two divisions of the renal artery?
anterior (75% of the blood supply)
posterior (25%)
What are the two main symptoms of diabetes insipidus?
polydipsia and polyuria
What are the two main symptoms of diabetes insipidus?
polydipsia and polyuria
Is diabetes insipidus related to diabetes?
no but it does share some of the same signs and symptoms
Is diabetes insipidus related to diabetes?
no but it does share some of the same signs and symptoms
What is the most important water homeostatic hormone?
ADH
What is the Mw of ADH?
x>1000
What is the Mw of ADH?
x>1000
In the late DT and early CD, what cell type is involved in Na/K exchange?
principal cells
In the late DT and early CD, what cell type is involved in Na/H exchange?
a & b-intercalated cells
What processes occur in a-intercalated cells?
acid (H+) secretion in exchange for Na+ or K+
via ATPase or H/ATPase
HCO3- reabsorption
What processes occur in b-intercalated cells?
acid (H+) reabsorption
via Pendrin
HCO3- secretion
What do a & b-intercalated cells help regulate?
acid-base regulation
In the late DT and early CD, what cell type is involved in Na/K exchange?
principal cells - this exchange forms part of the RAAS
What do a & b-intercalated cells help regulate?
acid-base regulation
What’s the half life of ADH in plasma circulation?
10-15 min
What cell type and receptors are acted on by ADH?
V2 receptors
principal cells on the DT/CD basal membranes
What is the effect of ADH stimulation of V2 receptors?
intracellular AQP2 water channels are activated
What happens to tubule reabsorbed water and solutes?
It is all taken back into the peritubular vessels and vasa recta surrounding the tubule
What happens to tubule reabsorbed water and solutes?
It is all taken back into the peritubular vessels and vasa recta surrounding the tubule
What’s an example of a drug that can cause SIADH?
ecstasy
What are two examples of ADH inhibitors used to treat SIADH?
demeclocycline, Tolvaptan
