Urinary complete deck Flashcards
Define the Levator Ani…
An important pelvic floor muscle.
Stretched during pregnancy and birth.
Pudendal, perineal and inferior rectal nerves
Inferior rectal nerves open the external anal sphincter.
Can create stimulation of the perineal nerves and allow urination.
Arrange the process of micturation in the correct order below:
1 - Action potential travels to brain via sensory neurons
2 - This sends action potential to the sacral region S2/S3 via sensory (afferent) neurones in pelvic nerves.
3 - Detrusor muscle S T R E T C H E S
4 - Decreased somatic activity causes external urinary sphincter to relax.
5 - Action potential also travels to brain via sensory neurons
1 - Detrusor muscle S T R E T C H E S
2 - This sends action potential to the sacral region S2/S3 via sensory (afferent) neurones in pelvic nerves.
3 - Parasympathetic fibrers in pelvic nerves send action potential back to bladder - bladder wall contracts, internal sphincter relaxes
4 - Action potential also travels to brain via sensory neurons
5 - Decreased somatic activity causes external urinary sphincter to relax
At what age does the micturation reflex kick in (humans)?
Develops at approx 2 years of age due to the development of the afferent nephron.
Parasympathetic afferents also synapse with neurons which pass up cord to brain to the micturition centre.
When it is appropriate to micturate, what is the sequence……
1 - Contracts detrusor / relaxes internal sphincter (when approps’).
2 - Relaxation of external sphincter.
3 - Descending neurones cause inhibition of pudendal nerve signals.
4 - Increased parasympathetic signals to bladder.
Descending neurones cause inhibition of pudendal nerve signals.
1 - Relaxation of external sphincter
2 - Increased parasympathetic signals to bladder
3 - Contracts detrusor / relaxes internal sphincter (when approps’)
When it is NOT appropriate descending neurones cause INCREASED pudendal nerve signals AND THE CONTRACTION OF THE SPHINCTER.
Order the process below for
1 - Cortical inhibition of the parasympathetic reflex is removed.
2 - Midflow stop is achieved by contraction of external urethral sphincter (voluntary – pudendal nerve) with delayed reflex relaxation of detrusor muscle.
3 - Active micturition – external sphincter relaxes – abdominal muscles contract
4 - External urethral sphincter relaxes…
1 - Cortical inhibition of the parasympathetic reflex is removed.
2 - External urethral sphincter relaxes…
3 - Midflow stop is achieved by contraction of external urethral sphincter (voluntary – pudendal nerve) with delayed reflex relaxation of detrusor muscle
4 - Active micturition – external sphincter relaxes – abdominal muscles contract
Explain incontinence…..
Nope.
Ok then……
Damage to nerves controlling micturition/continence:
Spinal cord transection (above S2) removes cortical inhibition from parasympathetic reflex: ‘automatic bladder’
Damage to sacral cord removes parasympathetic innervation of detrusor muscle: bladder is paralysed and distends until overflow incontinence ensues
Name three Urinary Tract Pathologies…..
Renal failure
Excretion fails due to low glomerular filtration rate (poor blood supply or disease of the kidney itself) Treatable with dialysis, transplant. Possible kidneys stones due to build up of materials. Travels from kidney to ureter.
Diabetes insipidus
Insufficient ADH secretion Large volumes of dilute urine
Diabetes mellitus Too much glucose in filtrate to be reabsorbed Large volume of urine containing glucose
What is the correct terminology for kidney stones?
What are they formed from?
How do they create pain?
Renal Calculi
They are formed from crystallised minerals e.g. calcium.
Large stones may become lodged in kidney
Smaller stones may be passed in urine or may lodge in ureters◦Disrupt urine flow – painful!
Kidney stones can RIP the epithelium.
Renal Calculi
Crystallised minerals e.g. calcium◦Large stones may become lodged in kidney◦Smaller stoned may be passed in urine or may lodge in ureters◦Disrupt urine flow – painful!
Steady stream/flow is possible due to the narrowing urethra
Common pathologies - male and female
Benign prostatic hyperplasia
•Commonest pathology in males•
Prostatic carcinoma
•7% of cancer in men (common)•Treatable with surgery, radiotherapy•
Commonest pathology in females:
•urinary tract infections, eg: cystitis Shorter urethra than males and more open to the environment and exposed to more. More ilkely for a pathogen to get in. Can get in via the kidneys or vagina.
Cats are prone to cystitis - inflammation of the uthethra (epithelium is inflamed),
Arrange the following items in the correct order from innermost to outermost:
Lumen
Adventitia
Transitional Epithelium
Muscle
Lamina propria
INNERMOST: Lumen (of the bladder)
Transitional epithelium (lines the lumen)
Lamina propria
Muscular layer (detrusor muscle)
Adventitia (with fat cells)
Where in the brain does the micturition centre lie?
Pons.
The bladder sends impulses to the spinal cord via sympathetic afferents - true or false?
False
A distended bladder sends impulses to the spinal cord via parasympathetic afferents.
Which structure below is voluntarily contracted in order to achieve mid-flow stop?
Internal urethral sphincter - detrusor muscle - abdominal muscle - external urethral sphincter
External urethral sphincter
What is the name of the muscle associate with the bladder wall?
Detrusor
What is the difference between the ureter and the urethra?
The ureter allows urine to enter the bladder.
The urethra allows urine to EXIT the bladder.
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