Renal physiology and an introduction to AKI and CKD

Question 1

CALYCES description and function

Answer 1

cupl-like shapes in the kidney, they collect urine and passes it onto the renal pelvis

they are conduits of urine basically

Question 2

abdominal aorta

Answer 2

part of the aorta and runs through the abdomen

largest artery in the abdomen

Question 3

what part of the nervous system is renal blood supply controlled by

Answer 3

the sympathetic division of the ANS

Question 4

bowman’s capsule function

Answer 4

to initiate the ultrafiltration , capturing the initial filtrate and allowing the kidney to selectively reabsorb needed substances and excrete wastes

Question 5

some key features of the glomerulus

Answer 5

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

Question 6

starlings forces, and how many of them govern glomerular filtration

Answer 6

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

Question 7

the main forces involved in glomerular filtration

Answer 7

glomerular hydrostatic
oncotic
capsular hydrostatic
colloid

colloid pressure and oncotic pressure are thought to be the same

Question 8

how does the kindey control blood pressure

Answer 8

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

Question 9

organoleptic test of urine and what is analysed during these tests

Answer 9

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

Question 10

proteinuria

Answer 10

Unusually high levels of protein present in the urine

usually protein levels of above 150mg/24hr indicate proteinuria.

Question 10

the primary site of action of aldosterone in the nephron is?

Answer 10

the DCT

aldosterone responsible for regulating water and sodium reabsorption

Question 11

GFR can be measured directly, true or false

Answer 11

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

Question 12

name which parts of the body produces the following;
angiotensinogen
ACE

Answer 12

Liver
mainly found in the lungs and kidneys

Question 13

which test is used to diagnose proteinuria

Answer 13

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

Question 14

what might increased protein levels in urine indicate

Answer 14

Reabsorption issues in the tubules
Filtration problems at the glomerulus

Question 15

filtration problems in the kidney can be caused by

reabsorption problems in the kidney can be caused by

Answer 15

Glomerular nephritis
Diabetes

multiple myeloma…etc

Multiple myeloma condition involves overproduction of abnormal immunoglobulins (light chains), which overwhelm the reabsorptive capacity of the tubules.

Question 16

sodium ion main functions in body

potassium ion main physiological functions

Answer 16

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

Question 17

methods used to measure electrolyte concetrations

Answer 17

Ion selective electrodes(primary method)
Flame emission photometry

Question 18

osmolality and it’s role in the body

Answer 18

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

Question 19

factors that can cause reduced Kidney function

Answer 19

Intrinsic damage
Decreased blood flow- ischemia
Blockage to urinary tract
Changes in homeostatic mechanisms, i.e. altered
hormonal control

Question 20

name some extra- renal complications that could cause a reduced or loss in kidney function

extra-renal= complications that affect areas outside the kidney

Answer 20

Diabetes mellitus
Hypertension
Heart failure
Hypercalcemia
Atheroma
Vasculitis

Question 21

some renal complications that can cause loss in kidney function

Answer 21

Glomerulonephritis
Bladder urethral obstruction
Polycystic kidney disease
Interstitial nephritis
Renal vascular disease

Question 22

diabetic nephropathy(DN)

Answer 22

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

Question 23

describe what happens in first stage

Answer 23

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