Anatomy Lecture 24

  1. Ureter gross anatomy
    • long muscular tubes connecting the kidneys to the bladder
    • they begin as a continuation of the renal pelvis at the level of L2
    • retroperitoneal and secured to the posterior abdominal
    • wall
    • when they enter the pelvis the penetrate the posterior
    • wall of the bladder at an oblique angle
  2. lecture notes
  3. histology of the ureter
    • three layers
    • mucosa: transitional epithelium on a lamina propria
    • muscularis: two layers of smooth muscle (inner longitudinal, outer circular)
    • adventitia: fibrous layer of connective tissue
    • peristaltic contractions of the muscularis in response to stimulation of stretch receptors
  4. lecture notes
  5. Urinary bladder gross anatomy:
    • collapsible, muscular sac
    • temporary storage for urine
    • retroperitoneal
    • in males it is located behind the pubic symphysis and in front of the rectum
    • in females it lies under the uterus and in front of the vagina
    • rugae
    • can hold up to one liter of urine
    • trigone: no rugae, apex
    • neck of the bladder: internal urethral sphincter, smooth muscle and involuntary
  6. lecture notes
  7. histology of ther urinary bladder
    • three layers:
    • mucosa: transitional epithelium on a lamina propria
    • muscularis: very thick layer of smooth muscle
    • adventitia: fibrous connective tissue except on the top of the bladder where it is covered with peritoneum
    • muscularis is called the detrusor muscle:
    • composed of three layers of smooth muscle: inner longitudinal, middle circular, outer longitudinal
  8. lecture notes
  9. Urethra gross anatomy:
    • thin walled muscular tube
    • in females it is about 3-4 cm long and is bound to the anterior vaginal wall
    • external opening is called the external urethral meatus
    • in males the urethra is about 20 cm long
    • prostatic urethra: 2.5 cm long and passes through the prostate gland
    • membranous urethra: 2 cm long, extends from the prostate to the beginning of the penis, passes through the muscular pelvic floor called the urogenital diaphragm
    • penile urethra: about 15 cm long, extends from the urogenital diaphragm and passes through the penis to open to the exterior at the external urethral meatus

    external urethral sphincter
  10. lecture notes
  11. histology of the urethra
    • in males the histology varies along the length of the urethra:
    • prostatic urethra: transitional epithelium
    • membranous urethra: stratified columnar with patches of pseudostratified columnar epithelium
    • penile urethra: stratified columnar with patches of pseudostratified columnar to stratified squamou
    • in females the epithelium is transitional near the bladder to stratified squamous
  12. lecture notes
  13. Micturition:
    • reflex arc
    • afferent sensory impulses to the spinal cord
    • efferent parasympathetic impulses to the bladder
    • afferent impulses to the brain
    • incontinence
    • urinary retention
  14. lecture notes
Card Set
Anatomy Lecture 24
excretory system