LO Flashcards
(78 cards)
Describe the physiological anatomy of the bladder.
▪ Body where the urine is retained
▪ Neck of the bladder is funnel-shaped extension passing into urogenital triangle and connecting with the urethra
▪ Detrusor muscle = smooth muscle cells linked together for the spread of an actio potenial
▪ Trigone on posterior wall - immediately above bladder neck - covers where the ureters enter
Describe the type of innervation that controls the internal sphincter, and its function.
▪ Autonomic innervation
▪ Prevents seminal regurgitation during ejaculation
Which of the following is the correct answer. The nervous supply of the bladder involves: A) Sympathetic Input only B) Parasympathetic Input only C) Somatic Input only D) All of the above
Answer: D
What is the role of sensory nerve fibers that are in the pelvic nerves which innervate the bladder.
Detect stretch signals from the bladder
A) Describe the sympathetic innervation of the bladder, including function.
B) Describe the parasympathetic innervation of the bladder, including function.
C) Describe the somatic innervation of the bladder, including function
A)
▪ Hypogastric Nerves (L1-L3)
▪ Function: causes the relaxation of the detrusor muscle allowing urinary retention
B)
▪ Pelvic nerves (s2-s4)
▪ Function: increased signals lead to the contraction of the detrusor muscle stimulating micturition
C)
▪ Pudendal nerve (S2-S4)
▪ Function: innervates external sphincter providing voluntary control over micturition
Through which plexus do the pelvic nerves connect with the spinal cord?
Sacral plexus (connects mainly with cord segments S2 and S3)
Briefly describe micturition.
▪ Emptying of the bladder when it becomes filled
▪ Filling occurs until the tension on its walls reaches a threshold
▪ Then micturition reflex occurs
What controls the peristaltic contractions of the calyces, pelvis and ureters?
Same control as the bladder (parasympathetic and sympathetic innervate the smooth muscle of the ureter)
How is reflux of urine from the bladder up the ureters ensured?
▪ Ureters course obliquely through the bladder wall for few centimeters
▪ Normal tone of the detrusor muscle when bladder contracts or is full leads to compression of the ureter preventing back flow
Name the condition whereby reflex does occur through the ureters due to anatomical abnormality.
Vesicoureteral Reflux (could damage the ureters, pelvis, and calyces)
Micturition reflex is a single compete cycle (an autonomic spinal cord reflex):
1) Progressive and rapid increase of pressure
a. Micturition reflex is “self-regenerative” - there is an initial contraction when the bladder is partially full-> activation of stretch receptors -> increase in sensory signals to sacral segment from bladder and posterior urethra -> more signals returning to the bladder through pelvic nerves by parasympathetic nerve fibers -> more contractions
2) A period of sustained pressure
a. More and more contractions continue to occur as they repeatedly activate the stretch receptors -> high degree of contraction of the bladder due to continuous contractions -> sustained pressure
3) Return of pressure to the basal one of the bladder
a. After few seconds to a minute the self-regenerative reflex begins to fatigue and cycle of the micturition reflex ceases permitting the bladder to reflex
b. If there is unsuccessful emptying, then nervous elements of the reflex are inhibited for >1 hour until more filling occurs
c. As the bladder becomes more and more full, the reflex occurs more frequently and therefore more frequent powerful contractions occur and that’s when you feel the urge to pee!
d. As contractions become stronger, signals from higher centers will inhibit the pudendal nerve which relaxes the external sphincter
e. Micturition will take place ONLY IF INHBITION SIGNALS TO THE PUDENDAL NERVE ARE STRONGER THAN THE VOLUNTARY STIMULATION SIGNALS
Describe how sufficiently powerful contractions lead to micturition.
▪ Sensory signals -> to the higher centers
▪ Facilitative centers inhibit hypogastric sympathetic nerve
▪ Hypogastric inhibition –> no relaxation of the detrusor and relaxation of internal sphincter
▪ Stimulation of pelvic parasympathetic nerves –> contraction of detrusor by acetylcholine acting on muscarinic receptors on the bladder
Inhibition of parasympathetic pudendal nerve (voluntary control) -> relaxation of external sphincte
Where are the higher control centre of micturition located?
Pons (there is a facilitative and inhibitory centre)
Describe how the higher centers inhibit micturition at partial filling volume of the bladder.
▪ Partial filling -> sensory signals also go up to the higher control centers due to the stretching of the receptors in the posterior urethra and bladder
▪ The control centers are mainly in the pons: there is an inhibitory center and a facilitative center
▪ Once the signal enters the spinal cord and travels up to the pons, it communicates with the cerebral cortex whether it is appropriate to empty the bladder or not
▪ If not, or the urge is not strong/the brain recognizes an empty bladder, then: signals from cerebral cortex will stimulate inhibitory center in the pons
▪ Inhibitory center sends signals which stimulate the hypogastric sympathetic nerve and parasympathetic pudendal nerves and inhibit pelvic parasympathetic nerve
▪ Hypogastric stimulation = detrusor relaxation + internal sphincter contraction (this is by norepinephrine)
▪ Inhibition of pelvic nerves = relaxation of detrusor muscle (acetylcholine on muscarinic (m3) receptor)
Stimulation of pudendal nerve = Contraction of the external sphincter (Acetyl choline on Nicotine receptors)
List abnormalities of micturition.
- Atonic bladder and incontinence due to destruction of sensory nerve fibres -> Overflow Incontinence
a. Despite working efferent fibres
b. Causes:
i. Most common: crush injury to the sacral segment of the spinal cord
ii. Disease that damages dorsal root fibres
1) Example: syphilis -> fibrosis in the dorsal root (called tabes dorsalis) -> tabetic bladder- Autonomic bladder caused by spinal cord damage above sacral region -> periodic but unannounced micturition
a. Micturition reflex disappears for days to weeks due to ‘spinal shock’ but then returns
b. Maybe able to stimulate micturition through stimulation of the skin of the genitialia by tickling or scratching - Uninhibited Neurogenic bladder caused by lack of inhibitory signals from brain -> any small amount of urine will stimulate micturition
a. Partial damage to brain or spinal cord which damages the inhibitory pathways
b. Lack of inhibitory signals but facilitative centre continues to produce signals
- Autonomic bladder caused by spinal cord damage above sacral region -> periodic but unannounced micturition
List Main causes of acute renal failure.
▪ Pre-renal = shock, major trauma (renal hypoperfusion -> loss of kidney function)
▪ Renal = glomerulonephritis, toxic (e.g. medications), malignant hypertension, vasculitis, analgesics
▪ Post-renal = obstruction
A) What are the three types of PKD?
B) List symptoms of PKD.
C) Prognosis?
D) What is the treatment of PKD?
A)
Autosomal Dominant PKD (children are born with it but symptoms do not appear until 30-60 years old)
Autosomal Recessive (Symptoms appear in childhood)
Non-inherited PKD
B) ▪ Abdominal Pain ▪ Hematuria ▪ Hypertension ▪ Kidney Stones
C)
Renal Failure
D)
▪ Medications and surgery for hypertension, pain, UTI;s and removing stones
▪ Dialysis
Kidney Transplant
List kidney functions.
- Maintains electrolyte balance
- Regulates blood pressure
- Produced erythropoietin which is required for RBC production
- Excretion of waste
What is the pathology of nephrotic syndrome?
▪ Damage to the podocytes (epithelial cells) which leads to the loss of protein
Common Causes:
▪ Primary causes = kidney disease (minimal change nephropathy, focal segmental glomerulosclerosis)
▪ Secondary causes = diabetes, lupus, amyloidosis
Describe Nephritic Syndrome.
Symptom/Signs:
▪ Haematuria
▪ Proteinuria (usually less than nephrotic)
▪ Pain
▪ Oliguria (due to damage to glomerulus so less filtration)
▪ Hypertension (reduced filtration -> increase intravascular plasma volume)
▪ Oedema
Pathology:
Antigen-antibody complexes activate complement (these complexes either form at the glomeruli or else where and get to the glomeruli) -> recruitment of WBC -> inflammation and damage of endothelial cells (capillary cells) -> White blood cells and red blood cells get through -> protein also gets through
Common causes:
SLE
Goodpasture Syndrome (Anti-GBM ANTIBODY disease)
A) Describe the clinical presentations of kidney stones.
B) Name some complications of kidney stones.
C) What are the different types of calculi (stones)
D) List risk factors of urinary calculi.
A) ▪ Renal Colic ▪ Hematuria ▪ Pain on urination ▪ Cloudy or foul smelling urine ▪ Frequent urination ▪ Pyelonephritis symptoms (secondary infection -> fever, chills, tachycardia)
B)
▪ Pyelonephritis
▪ Obstructive uropathy –> Hydronephrosis –> post-renal renal failure
C) ▪ Calcium stones (most common)
▪ Uric Acid stones
▪ Cystine stone - due to hereditary condition where your kidneys filter too much cystine -> cystinuria
▪ Infection stone - struvite stones
D) ▪ Hypercalcemia § Sarcoidosis § Renal tubular necrosis § Hyperparathyroidism ▪ Gout ▪ Obstruction ▪ Genetic ▪ Dehydration
A) Name the most common malignant tumor in children
B) Describe features of this condition.
A) Name the most common malignant tumor in children
Wilms’ Tumour
B) Describe features of this condition.
WT1 tumor suppressor gene
Affects children usually under 3
The younger the better the prognosis
Surgery, radio, chemo leads to 90% survival
List the most common carcinomas for the follow: prostate, bladder, renal.
Prostate - adenocarcinoma
Bladder - urothelial (transitional cell) carcinoma
Renal - 4/5 are clear cell carcinoma (ccRCC)
Renal Cell Carcinoma - Clear Cell
A) Presentations?
B) What organ is particularly at risk with the metastasis of renal carcinoma?
C) List risk factors for RCC.
Presentations: ▪ Haematuria ▪ Pain ▪ Mass/Swelling ▪ Paraneoplastic syndrome ○ Pyrexia (if you do fbc and no wbc then think carcinoma) ○ Hormonal disturbances (Increased erythropoietin -> increased RBC -> polycythemia which hints at renal neoplasm) ▪ Metastasis
What organ is particularly at risk with the metastasis of renal carcinoma?
▪ Heart (grows through renal vein -> IVC -> heart)
▪ Lungs same way (‘cannonball lesions’)
List risk factors for RCC.
▪ Smoking
▪ Obesity
▪ Chronic Cystic disease
▪ Men>women