Wk 8- Renal And Bone Flashcards
List some fracture types and stages of healing- healing?????
Open (compound), closed, greenstick, simple, compound, comminuted, spiral, transverse, haematoma, soft callous, hard callous, remodelling
What do healthy kidneys do that is relevant for bone health? And what does it do when under the influence of parathyroid hormone?
The healthy kidneys
1. activate vitamin D which is required by the gut to Absorb calcium
2. Regulate the levels of calcium and phosphate in the blood.
When under the influence of parathyroid hormone, the healthy kidneys activate more vitamin D, secrete phosphate into the filtrate and reabsorb calcium from it thus keeping the latter in the blood
How does gout differ to osteoarthritis and rheumatoid arthritis in its aetiologies, pathogenesis, typical joints affected and populations at risk?
Common systemic metabolic disorder (disorder associated with Hyperurincaemia
Monosodium irate crystals form in joints and soft tissue causing severe pain and inflammation
Increased incidence in age
big toe -men,
rare in women before menopause- hands after meno
How does osteoarthritis differ in aetiology, pathogenesis, typical joints affected and pop at risk?
Wear and tear resulting in loss of cartilage
reactive bone growth and swelling to surrounding soft tissue causes pain
Tends to affect weight bearing joints
Because it’s caused by wear and tear it is most likely to occur in elderly, overweight or people who have engaged in sports such as netball afl and running
How does rheumatoid arthritis differs in aetiology, pathogenesis, typical joints and pop at risk?
Autoimmune destruction of joints that may affect any synovial joint in the body and cause systemic inflammation
Affects more women than men
Can be diagnosed at any age but typically it is first diagnosed in middle age
The joints are affected by chronic inflammation. (Type IV cell mediated response) formation of pannus: bone erosion, cartilage and tendon degradation -> irreversible joint deformation
Routes of entry for microbes infection the kidney include haematogenous (descending) and urinary (ascending) spread, what are significant differences between these?
Descending infections are likely to affect both kidneys diffuse lay and lead to renal failure. Ascending infections are more likely to affect 1 kidney and usually only a segment of that kidney
What is the papilla and why does it become necrotic?
The renal papilla is the apex of the renal pyramid which projects into the minor calyx, some 15-20 openings of collecting ducts open on its tip
Within the kidney. The pelvis of the ureter divides into 2 or 3 major calyxes each of which divides into several minor calyces
Papillary necrosis occurs in analgesic neuropathy (caused by excessive intake of analgesic mixtures) and in acute pyelonephritis mainly in diabetics and in those with urinary tract obstruction and ascending infections
Describe the impact that renal failure has on the body, particularly the cardiovascular, skeletal and haematological systems?
Renal failure can be acute or chronic and leads to:
- Inappropriate/excessive activation of renin-angiotensin II-aldosterone system. Angiotensin II causes vasoconstriction leading to increased vascular resistance while Aldosterone leads to retention of Na+ & H2O causing an increase in blood volume resulting in systemic
hypertension. - Systemic hypertension is a risk factor for atherosclerosis which can cause left ventricular hypertrophy; ischaemic heart disease, heart failure and cerebral vascular disease. Resulting in increased heart rate & force of contraction.
- Increased blood volume increases hydrostatic pressure leading to oedema, which will be worsened if the individual has proteinuria as the loss of plasma proteins will reduce plasma colloidal pressure.
- Reduced renal activation of 25-hydroxy vitamin D results in decreased calcium absorption from the gut.
- The decrease in serum calcium, leads to increased secretion of parathyroid hormone (PTH). In failure, the kidneys no longer respond to PTH so there is no activation of vitamin D & calcium continues to be lost in urine while serum phosphate levels increase. The
osteoclasts still respond to PTH, resulting in increased breakdown of bone & liberation of calcium &
phosphate into the blood but the former is either lost in urine or binds to phosphate causing soft-tissue
calcification. This loss of bone mineralization coupled with soft-tissue calcification results in renal
osteodystrophy. The soft tissue calcification frequently affects the heart valves causing stenosis &
accelerates atherosclerosis. - Reduced EPO leads to reduced erythropoiesis leading to anaemia leading to lethargy & increased heart
rate. Anaemia will be worse if the individual has haematuria. - In health, the kidney removes 40-60 mmol of acid (H+) a day plus reabsorbs & synthesises bicarbonate
ions but this does not occur in renal failure leading to acidosis. Cells exchange their potassium ions (K+) for
H+ resulting in increased serum K+ levels (hyperkalaemia). Hyperkalaemia may result in muscle stiffness and abdominal pain or can remain asymptomatic until causing potentially life-threatening cardiac
arrhythmias. - Increased nitrogenous wastes contributes to chronic poisoning
What may be the consequence of urinary stone formation? (Prac notes)
- Pain
- Bleeding from damage to lining epithelium of renal pelvis or urinary tract ;
- Obstruction of urine flow -
- Predispose to infection
- May encourage more stone formation (nidus).
- May cause chronic irritation
- Severe cases can result in loss of water (dehydration) and hyponatraemia
What are the potential causes of urinary stone formation?
- Stasis of urine
- Infection
- Pre existing or previous incidence of stones
- Dehydration
- Calcium metabolism disorders (rare) and gout
Which cancers are predominantly paediatric in nature?
Nephroblastoma, Ewing’s sarcoma, and osteosarcoma
Why is the bone so commonly affected by metastases?
Bone is very vascular so arterial metasises are easily distributed to the site plus it’s a good site for tumour cells to become trapped.
Why are kidneys rarely affected by metastases?
The kidneys are a harsh environment, kidney cells have evolved to carry out their function under these conditions but cancer cells from other tissues may not be successful
Why are cancers of the kidney, ureter and bladder generally diagnosed late? What signs and symptoms do they present?
Present with blood in the urine, mild flank pain, an abnormal mass or obstruction late in the progression of the disease, the early stages are asymptomatic
which is least likely to result in renal failure?
ascending or descending infections?
ascending infections are from the lower urinary tract and may only damage one kidney or part of one kidney. the pain experienced induces the patient to seek treatment which will be aggressive to restore health and eradicate infection
whereas descending is likely to affect both kidneys and are more serious as they are blood borne so will lead to damage of both and potentially all nephrons causing renal failure.
reasons why females are at greater risk of urinary tract infections
- short urethra
- urethral opening closer to anus
- lack of prostatic secretions
- increased risk of micro trauma
- hormonal changes in mucous viscosity
list symptoms or complications of urinary stones
- pain
- haematuria (blood in urine)
- obstruction leading to hydronephrosis
- more stones
- infection
- ulceration - increased risk of dysplasia and cancer
- increased risk of infections
causes of urinary stones
- obstruction/stasis of urine
- a pre existing or history of urinary stones
- infection
- dehydration
- calcium metabolism disorders (rare) and gout
list some effects that renal failure has on the body
There are many but the main ones include:
Hypertension, oedema, anaemia, renal osteodystrophy, acidosis, hyperkalaemia, uraemia
glomerulonephritis is usually…
bilaterial as it is usually mediated by antibodies (as part of an autoimmune. disease) or antibody-antigen complexes that are travelling in the blood
what are 2 things that the kidneys do that is important for maintaining bone health?
- activate vitamin D which is required by the gut to absorb dietary calcium
- regulate plasma levels of both calcium and phosphate.
when serum calcium levels fall, parathyroid hormone is released and stimulates osteoclasts to reabsorb bone thus releasing calacium and phosphate into the blood. - in response to PTH, the healthy kidneys activate more vitamin D, excrete phosphate and reabsorb calcium thus increasing serum/blood calcium levels
what is a pathologic fracture
a fracture that occurs in a bone already affected by disease
why are bones commonly affected by secondaries?
the bones have a rich blood supply and contain many growth factors
list things that can predispose us towards sustaining a pathologic fracture?
Osteoporosis, osteomalacia, chronic renal
failure (renal osteodystrophy), Paget’s disease, osteomyelitis,
primary & secondary tumours, arthritis
list things that increase an individuals risk of developing osteoporosis?
Low starting bone mass (determined by genetics, diet &exercise),
ageing,
menopause,
amenorrhoea,
sarcopenia,
reduced physical activity
rheumatoid arthritis is caused by
autoimmune disease
osteoarthritis is caused by
wear and tear
gout is caused by
systemic metabolic disorder
rhuematoid arthritis involves which kind of inflammation?
chronic
gout is associated with
hyperuricaemia
list the main malignancies that affect the male and female urinary systems?
renal cell carcinoma - increase incidence in age (epithelial malignancy)
transitional cell carcinoma- increase incidence in age (transitional epithelium outside the kidney)
nephroblastoma- rare, childhood cancer
(never a normal renal cell, it was an embryonic cell that mutated)
list causes of glomerulonephritis and possible consequences?
causes
-post infection or autoimmune
-antibodies targetting the glumerus
-circulating antibodies in the blood (can be bilaterial)
consequence:
end stage renal failure
why is the renal papilla susceptible. to toxic injury and ascending infections?
part of the renal pyramid that projects out into the calyx where urine is at its more concentrated before leaving the kidney. if something is toxic, the papilla can be damaged by this
or
when theres an ascending infection
list the factors that contribute to attaining peak bone mass
genetics
physical activity
good nutrition while growing
list the risk factors for the development of osteoporosis and things that can accelerate bone loss
not getting to your peak bone mass
low starting bone mass
things that can accelerate:
corticosteriods
glucocorticoids
NSAIDS
amenorrhea
sarcopenia
menopause
what impact does renal failure have on the musculoskeletal system?
healthy kidneys:
1. activate vitamin D which is required for dietary calcium absorption
2. regulate levels of phosphate and calcium in the blood
renal failure:
it stops activating vitamin D
as a result
-serum levels go down
-less calcium absorption
-Parathyroid hormone levels go up as a result of these which is normally sends activate more vitamin D signal and reabosrb calcium from filtrate and get rid of phosphate signal. HOWEVER
when the kidneys arent working, they dont respond to PTH. thereofore vitamin D isn’t activated and they’re allowing calcium to be lost in urine filtrate and theyre keeping phosphate in the blood.
osteoclasts will respond by breaking down more and more bone so liberated phosphate and calcium can bind to the high levels of phosphate causing soft tissue calcification or be pee’d out. This break down of bone causes weakened bones/loss of bone mass.
this process is called renal osteodystrophy
