Renal System Flashcards
What diseases is oral health associated with?
Cardiovascular disease Rheumatoid arthritis Respiratory disease Metabolic disease Kidney disease
Shared common risk factors for oral and systemic disease e.g. diet, socioeconomic status
In 2017, what percentage of all death globally were attributed to inflammation related disease
73.4%
What is the function of kidneys
1) Excretory organs
Process blood
Rid body of waste products of metabolism via urine
2) Maintain internal homeostasis of fluid
fluid + electrolytes
Gross anatomy of kidney
Two kidneys (produce urine) ->
Ureters (convey urine) ->
Bladder (store urine) ->
Urethra (void urine)
Common iliac artery -> Abdominal aorta -> renal artery
Common iliac vein -> inferior vena cava -> rena vein
top view
Back: spinous process of vertebra
kidneys in renal fat pad
in front: peritoneum and peritoneal cavity
Macroscopic kidney structure
3 sections:
1) Cortex
85% of kidney tubules/ nephrons
2) Medulla
Urine is concentrated
prevents excess water loss
3) Pelvis
Collection of urine -> ureter
(consult diagram for other structures)
Blood vessels of the kidney
Abdominal aorta-> (blood) -> renal artery -> kidney
Blood: 1.2L/min (1/5th of cardiac output)
What is the pathway of blood vessels of the kidney
Renal artery Segmental arteries lobar arteries Interlobar arteries Arcuate arteries Interlobular arteries Afferent arteries Glomercular capillaries Efferent arteries Peritubular capillaires (vasa recta) - Medulla Interlobular arteries
In the kidney where is the site of filtration?
Glomerular capillaries (glomerulus)
What is the basic functional unit of the kidney
The nephron
What does the nephron consist of?
Cortex:
Glomerulus
Bowman’s capsule
proximal convoluted tubule
Medulla:
Loop of Henle
Cortex:
Distal convoluted tubule
Collecting tubule
What are the types of nephron
Cortical nephron - short loop of henle
Juxtamedullary nephron - where urine is concentrated, reabsorbs water
What is the purpose of the nephron
- filter blood plasma
- excrete waste products of metabolism in urine
What occurs at the renal corpuscle ?
Filtration/removal
What does the renal corpuscle consist of?
Glomerulus
Bowman’s capsule
What does the renal tubule do?
Reabsorption and secretion (conservation/ fine tuning)
What does the renal tubule consist of?
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule
Collecting duct
What is the structure of the glomerulus?
A network of fine capillaries
single layer of endothelial cells resting on a basement membrane
fenestrated - many pores
which allows rapid filtration of blood plasma
surrounded by bowman’s capsule
What is the structure of Bowman’s capsule
Cuplike structure surrounded by glomerulus
Bowman’s space = space within double layer:
Parietal (outer) layer
Visceral (inner) layer - comprised of specialised epithelium - podocytes - wrap around glomerular capillaries
What forms a filtration barrier in the kidney?
Glomerular endothelium
basement membrane
pedicels of podocytes
Pedicels share basement membrane with fenestrated endothelium
What does the filtration barrier do
Movement of filtrate through filtration membrane
freely permeable to water and small molecules
not permeable to large proteins or cells
charge of filtration slits determine which molecules are filtered -vely charged
What occurs in glomerular filtration
It is the first step in blood processing
1) unfiltered blood arrives at the glomerulus via the afferent arteriole
2) blood components filtered through the filtration barrier
3) Filtered blood exits the glomerulus via efferent artieriole
In the glomerular, how is filtration faciliated
By a pressure gradient
- glomerular hydrostatic pressure
- Afferent is wider then efferent
- blood arrives quicker then it leaves
In the glomerular filtration, what is filtered?
Water, glucose, AAs
Urea (protein waste), Creatine (muscle metabolism waste)
Electrolytes:
Na,Cl, Ca, K, PO, Bicarb
In glomerular filtration, what is not filtered?
Cells (RBC/WBC) Large proteins (Haemoglobin) Negatively charged protein (albumin)
What is the Glomerular Filtration Rate?
The rate at which blood is filtered through the glomerulus in to the Bowman’s capsule
Driven by glomerular hydrostatic pressure (+ capsular osmotic pressure)
counteracted by hydrostatic pressure in bowman’s capsule +
Glomerular osmotic pressure
GFR is influenced by hydrostatic and osmotic pressures. What else?
Systemic blood pressure
Renin-angiotensin system
Disease (inflammation - protein leaking across)
What is a health GFR
125ml/min
180l/day
How is kidney function to GFR
Kidney damage reduced GFR
reduced GFR = inefficent blood clearance and waste removal
Waste products accumulate in blood
How do you measure GFR
Serum creatinine (and urea)
What are the stages of chronic kidney disease
1 kidney damage - normal function GFR 90 -100 2 mild loss of function GFR 60 - 89 3a Mild to moderate loss GFR 45 - 59 3b Moderate to severe GFR 30 - 44 4 Severe - dialysis GFR 15 - 29 5 Failure - transplant - GFR 0 - 15
In the real corpuscle how much is filtered?
180l/day -> 99% reabsorbed
Discuss filtration from the proximal convoluted tubule
1) Primary Active transport:
Against concentration gradient
Na-K+ Pump = Basal-lateral side of cells
- requires ATP to change configuration ->ADP
1 ATP to move 3 X Na+ out of cell, in exchange for 2 x K+ into cell
- doesn’t need ATP to bring K+ back
- Drives Na against it’s concentration gradient
- facilitates 65 N+ reabsorbtion
2) Secondary Active transport Against concentration gradient Across apical surface Na Co-transporter Transporting glucose + amino acid Against concentration gradient
3) Passive diffusion
From high concentration to low concentration
Water
Follows Na+
via Aquaporin (due to hydrophobic phosoplipid bilayer)
Osmosis
4) Electrical gradient -
High concentration -> low concentration
Cl- and -ve ions follow Na+