gu Flashcards
(220 cards)
What is the innervation of bladder relaxation?
- Autonomic sympathetic (noradrenergic)
- T10-L2 nuclei
- Urethral contraction (smooth muscle component but remember the main part of the sphincter is skeletal muscle)
- Inhibits detrusor contraction
Spinal reflexes for bladder
- Reflex bladder contraction - sacral micturition centre
- Guarding reflex - onuf’s nucleus (rhabdosphincter - skeletal muscle so somatic)- the guarding reflex occurs to prevent voiding of the bladder caused by unexpected abdominal pressure.
- Receptive relaxation - sympathetic - the smooth muscles of the proximal part of the stomach relax and dilate when food enters the stomach. This receptive relaxation enables a large amount of food to amass in the stomach with a minimal rise in intragastric pressure.
What is the function of the proximal convoluted tubule?
Reabsorption of:
- some water and Na+
- some other ions
- all glucose and amino acids
What is the function of the distal convoluted tubule?
- Regulating acid-base balance
- By secreting H+ and absorbing HCO3-
- Also regulates Na+ level
What is the structure of the collecting duct in the kidney?
Principal cells:
- Regulate Na+ reabsorption and K+ excretion
- Respond to aldosterone and ADH
Intercalated cells:
- Exchange H+ for HCO3-
What is the structure of urothelium?
- Complex stratified epithelium
- Can stretch in 3 dimensions
- Layer of umbrella cells - make it urine proof
What is the innervation of bladder contraction?
- Autonomic parasympathetic (cholinergic)
- S3-S5 nuclei
- Drive detrusor contraction
What is the innervation of A-δ fibres (bladder stretch) and C fibres (bladder pain)?
- Sensory autonomic
- S2-S4 nuclei
Functions of the prostate
- Produces testosterone and dihydrotestosterone (5x more potent)
- Produces PSA (prostate specific antigen)- liquefies semen
Storage lower urinary tract symptoms (LUTS)
Occur when bladder should be storing urine -> need to pee
Frequency
Urgency
Nocturia
Incontinence
More common in females
Voiding lower urinary tract symptoms (LUTS)
Occur when bladder outlets obstructed -> hard to pee
Poor Stream
Hesitancy
Incomplete emptying
Dribbling after finishing urination
More common in males
What is Prehn’s sign?
- Used to determine the cause of testicular pain
- Performed by lifting the scrotum and assessing the consequent changes in pain
- Prehn’s sign positive = pain relief upon elevation
What is the cremasteric reflex?
Stroke inner thigh, ipsilateral testicle should elevate
What is an unsafe bladder?
One that puts the kidneys at risk - caused by prolonged high pressure
What is erectile dysfunction?
- Persistent inability to attain amd maintain an erection sufficient to permit satisfactory sexual performance
- Commonly found in men over 40
- Up to 10% of men are affected
Pathophysiology of erectile dysfunction
- Neurogenic - failure to initiate
- Arteriogenic - failure to fill (mc)
- Venogenic - failure to store
prolactin
Innervation of the penis
- Sympathetic - T11 - L2
- Parasympathetic - S2-S4
Aetiology of erectile dysfunction
- Atherosclerosis
- Diabetes
- Age
- Hypogonadism
- Trauma to pelvic plexus
- Iatrogenic - surgery that damages pelvic plexus, drugs
- Psychosomatic
Treatment of erectile dysfunction
- Treat underlying cause
- oralphosphodiesterase type 5 inhibitor drugs- increase blood flow
- Psychosexual counselling if necessary
- Intracavernosal injection
- Vaccuum assisted device
- Implant
Pathophysiology of acute kidney injury
Accumulation of usually excreted substances:
- K+ (arrhythmias)
- Urea (pruritis + uremic frost, confusion if severe)
- Fluid (pul + peripheral oedema)
- H+ (acidosis)
Pre-renal AKI
Due to hypoperfusion of the kidneys, leading to decreased GFR
- Hypovolaemia
- Reduced cardiac output (cardiac failure, liver failure, sepsis, drugs)
- Drugs that reduce blood pressure (ACE-i, ARBs, NSAIDs, loop diuretics)
Renal AKI
A consequence of structural damage to the kidney, eg: tubules, glomeruli, interstitium, bvs. May result from persistent pre-renal and post-renal causes, damaging renal cells
- Toxins and drugs (eg: antibiotics, contrast agent, chemo)
- Vascular causes (eg: vasculitis, thrombosis, etc)
- Glomerular, tubular (MC) or interstitial causes
Post-renal AKI
Least common (10%) - due to acute obstruction of the flow of urine -> increased intratubular pressure and decreased GFR
- Renal stones
- Blocked catheter
- Enlarged prostate
- GU tract tumours
- Neurogenic bladder
Diagnosis of AKI
- Establish cause (pre, intra, post) w KDIGO classification
- Check K+, H+, urea, creatining w U+E
- FBC + CRP check for infection
- Renal biopsy will confirm intrarenal cause, ultrasound for post renal