Give the three main parts of the bladder
Give the histological layers of the bladder wall
MUCOSA • Transitional epithelium • Lamina propria • Submucosa NOT MUCOSA • Detrusor muscle • Adventiia
What is the body/fundus of the bladder?
• Temporary store of urine
What is the trigone?
• Ureteric orifices and internal urethral orifice are at the angles of a triangle
What is the neck of the bladder?
• Connects the bladder to the urethra
Outline the structure of the detrusor urinae muscle
• Made from a meshwork of muscle fibres in roughly 3 layers
○ Inner longitudinal
○ Middle circular
○ Outer longitundinal
Why does the bladder have three layers of muscle?
• Arrangement of muscle gives the bladder strength regardless of direction it is being stretched in
What is detrusor muscle supplied by?
• Autonomic nervous system, not under voluntary control
Spinal nerve supply is bilateral
What is the internal urethral sphincter?
What is a physiological sphincter?
• A sphincter which is indistinguishable from surrounding tissue at autopsy
What is the primary muscle of continence?
• Internal Urethral Sphincter
What is the external urethral sphincter
• Anatomical sphincter
○ Localised circular muscle thickening to facilitate action
What is the external urethral sphincter derived from?
• Pelvic floor muscles
What type of muscle is the external sphincter?
* Contracts to constrict urethra and hold in urine
What are the two innervations of the detrusor?
* Sympathetic
Outline the parasympathetic innervation of the detrusor
Contraction
Outline the sympathetic innervation of the detrusor?
What is the innervation of the internal urethral sphincter?
What is the innervation of the external urethral sphincter?
What are the four main functions of the nervous system in relation to the bladder?
• Provide sensation of bladder filling and pain
• Allow the bladder to relax and accomodate to increasing volumes of urine
• To initiate and maintain voiding so bladder empties completely, with minimal residual volume
• To provide an integrated regulation of the smooth muscle
and skeletal muscle sphincters of the urethra
What prevents retrograde ejaculation in men?
• Prostatic urethra
Give the nerve roots which control urine storage
• L1 & L2
Give the nerve roots which control bladder voiding
S2-S4
What are the two phases of the bladder?
* Filling