Renal physiology and an introduction to AKI and CKD Flashcards
CALYCES description and function
cupl-like shapes in the kidney, they collect urine and passes it onto the renal pelvis
they are conduits of urine basically
abdominal aorta
part of the aorta and runs through the abdomen
largest artery in the abdomen
what part of the nervous system is renal blood supply controlled by
the sympathetic division of the ANS
bowman’s capsule function
to initiate the ultrafiltration , capturing the initial filtrate and allowing the kidney to selectively reabsorb needed substances and excrete wastes
some key features of the glomerulus
Afferent arteriole
Efferent arteriole
Mesangium
Podocyte cells
* Macular densa cells
* Juxtaglomerular cells
* Mesangial cells
efferent arteriole has a higher pressure than afferent, and a smaller diameter
starlings forces, and how many of them govern glomerular filtration
Forces that govern
the movement of water and solutes
out of a vessel
2
Hydrostatic pressure- force inside
vessel exerts pressure on the
membrane
Oncotic pressure- osmotic force
that drives water movement
the main forces involved in glomerular filtration
glomerular hydrostatic
oncotic
capsular hydrostatic
colloid
colloid pressure and oncotic pressure are thought to be the same
how does the kindey control blood pressure
the primary mechanism is through the RAAS system
also through hormonal regulation, by controlling erythropoeitin and calcitrol levels
also by controlling H2O levels in blood
Calcitriol helps regulate calcium levels, which can influence vascular resistance and blood pressure
organoleptic test of urine and what is analysed during these tests
an assessment based on sensory characteristics that can provide useful initial information about urine composition and potential underlying health conditions.
Colour
Smell
Presence of particles, which could affect clarity
proteinuria
Unusually high levels of protein present in the urine
usually protein levels of above 150mg/24hr indicate proteinuria.
the primary site of action of aldosterone in the nephron is?
the DCT
aldosterone responsible for regulating water and sodium reabsorption
GFR can be measured directly, true or false
false, it cannot
There are various ways GFR can be measured. All these methods involve mesauring the urinary clearance of a specified marker
creatinine normally used as a marker. Creatinine is a waste product in the blood that comes from muscle tissue and digested protein
name which parts of the body produces the following;
angiotensinogen
ACE
Liver
mainly found in the lungs and kidneys
which test is used to diagnose proteinuria
A dipstick test, which is highly sensitive to albumin, the most abundant protein in plasma.
note that the dipstick test might not be bale to pick up smaller or light chain proteins which also contribute to proteinuria. Further tests like urine protein electrophoresis required to detect these proteins
what might increased protein levels in urine indicate
Reabsorption issues in the tubules
Filtration problems at the glomerulus
filtration problems in the kidney can be caused by
reabsorption problems in the kidney can be caused by
Glomerular nephritis
Diabetes
multiple myeloma…etc
Multiple myeloma condition involves overproduction of abnormal immunoglobulins (light chains), which overwhelm the reabsorptive capacity of the tubules.
sodium ion main functions in body
potassium ion main physiological functions
Regulates extracellular fluid (ECF) volume and osmolarity.
Essential for nerve impulse transmission and muscle function.
Maintains intracellular fluid (ICF) homeostasis.
Critical for the generation and propagation of action potentials in cardiac and skeletal muscles.
note that imbalances in levels of both could be life threatening.
sodium imbalances could lead to dehydration, brain cell shrinkage, neurological deficits, confusion etc
ptoassium imbalances could lead to muscle weakness, arrhythmias, respiratory failure..etc
methods used to measure electrolyte concentrations
Ion selective electrodes(primary method)
Flame emission photometry
osmolality and it’s role in the body
a measure of the concentration of particles dissolved in a fluid, such as blood or urine per kg
gives information about the fluid status of the body and about how well the kidneys are working
factors that can cause reduced Kidney function
Intrinsic damage
Decreased blood flow- ischemia
Blockage to urinary tract
Changes in homeostatic mechanisms, i.e. altered
hormonal control
name some extra- renal complications that could cause a reduced or loss in kidney function
extra-renal= complications that affect areas outside the kidney
Diabetes mellitus
Hypertension
Heart failure
Hypercalcemia
Atheroma
Vasculitis
some renal complications that can cause loss in kidney function
Glomerulonephritis
Bladder urethral obstruction
Polycystic kidney disease
Interstitial nephritis
Renal vascular disease
diabetic nephropathy(DN)
also known as diabetic kidney disease, is a chronic condition that occurs when diabetes damages the kidneys
caused by damage to the capillaries in the glomerulus. there are 5 stages to DN
describe what happens in first stage DN
High blood glucose causes non-enzymatic glycation, where glucose molecules bind to proteins in the vascular walls, particularly in the efferent arteriole.
It stiffens the efferent arteriole due to hyaline deposition (hyaline arteriosclerosis), increasing resistance to blood flow exiting the glomerulus.
The stiffened efferent arteriole causes back pressure on the glomerulus, increasing glomerular capillary pressure.
To balance the increased resistance at the efferent arteriole, the afferent arteriole dilates
This compensatory dilation leads to hyperfiltration, with GFR temporarily increasing above normal levels
The increased glomerular capillary pressure (from efferent stiffness and afferent dilation) causes the glomeruli to filter more plasma than usual.
Clinically, this manifests as polyuria (excessive urine output) without significant proteinuria
in first stage DN, damage to the glomerulus is functional, not structural, so the glomerular barriers remain largely intact. Therefore proteinuria is minimal or non-existent, even with the increased glomerular pressure
