← Back to Session

Time Completed: 01:42:54

Final Score 86%

154
26

Questions

  • Q1. Correct
  • Q2. Correct
  • Q3. Correct
  • Q4. Correct
  • Q5. Correct
  • Q6. Correct
  • Q7. X Incorrect
  • Q8. Correct
  • Q9. Correct
  • Q10. X Incorrect
  • Q11. Correct
  • Q12. Correct
  • Q13. X Incorrect
  • Q14. Correct
  • Q15. Correct
  • Q16. Correct
  • Q17. Correct
  • Q18. Correct
  • Q19. Correct
  • Q20. Correct
  • Q21. Correct
  • Q22. Correct
  • Q23. Correct
  • Q24. Correct
  • Q25. Correct
  • Q26. Correct
  • Q27. Correct
  • Q28. Correct
  • Q29. Correct
  • Q30. Correct
  • Q31. Correct
  • Q32. Correct
  • Q33. Correct
  • Q34. Correct
  • Q35. Correct
  • Q36. Correct
  • Q37. Correct
  • Q38. Correct
  • Q39. Correct
  • Q40. Correct
  • Q41. Correct
  • Q42. Correct
  • Q43. Correct
  • Q44. Correct
  • Q45. Correct
  • Q46. X Incorrect
  • Q47. X Incorrect
  • Q48. X Incorrect
  • Q49. X Incorrect
  • Q50. Correct
  • Q51. Correct
  • Q52. Correct
  • Q53. Correct
  • Q54. X Incorrect
  • Q55. X Incorrect
  • Q56. Correct
  • Q57. Correct
  • Q58. Correct
  • Q59. Correct
  • Q60. Correct
  • Q61. X Incorrect
  • Q62. Correct
  • Q63. Correct
  • Q64. Correct
  • Q65. Correct
  • Q66. Correct
  • Q67. Correct
  • Q68. Correct
  • Q69. Correct
  • Q70. Correct
  • Q71. Correct
  • Q72. Correct
  • Q73. Correct
  • Q74. Correct
  • Q75. X Incorrect
  • Q76. Correct
  • Q77. Correct
  • Q78. Correct
  • Q79. Correct
  • Q80. Correct
  • Q81. Correct
  • Q82. X Incorrect
  • Q83. Correct
  • Q84. Correct
  • Q85. Correct
  • Q86. Correct
  • Q87. Correct
  • Q88. Correct
  • Q89. Correct
  • Q90. Correct
  • Q91. Correct
  • Q92. Correct
  • Q93. Correct
  • Q94. X Incorrect
  • Q95. Correct
  • Q96. X Incorrect
  • Q97. Correct
  • Q98. Correct
  • Q99. Correct
  • Q100. Correct
  • Q101. X Incorrect
  • Q102. Correct
  • Q103. Correct
  • Q104. Correct
  • Q105. Correct
  • Q106. Correct
  • Q107. X Incorrect
  • Q108. X Incorrect
  • Q109. Correct
  • Q110. Correct
  • Q111. Correct
  • Q112. X Incorrect
  • Q113. Correct
  • Q114. X Incorrect
  • Q115. Correct
  • Q116. Correct
  • Q117. X Incorrect
  • Q118. Correct
  • Q119. Correct
  • Q120. Correct
  • Q121. Correct
  • Q122. X Incorrect
  • Q123. Correct
  • Q124. X Incorrect
  • Q125. Correct
  • Q126. Correct
  • Q127. Correct
  • Q128. Correct
  • Q129. Correct
  • Q130. Correct
  • Q131. Correct
  • Q132. Correct
  • Q133. Correct
  • Q134. Correct
  • Q135. Correct
  • Q136. Correct
  • Q137. Correct
  • Q138. Correct
  • Q139. Correct
  • Q140. Correct
  • Q141. Correct
  • Q142. Correct
  • Q143. Correct
  • Q144. Correct
  • Q145. Correct
  • Q146. Correct
  • Q147. Correct
  • Q148. Correct
  • Q149. Correct
  • Q150. Correct
  • Q151. Correct
  • Q152. X Incorrect
  • Q153. Correct
  • Q154. Correct
  • Q155. Correct
  • Q156. Correct
  • Q157. X Incorrect
  • Q158. Correct
  • Q159. Correct
  • Q160. Correct
  • Q161. Correct
  • Q162. Correct
  • Q163. Correct
  • Q164. Correct
  • Q165. X Incorrect
  • Q166. Correct
  • Q167. Correct
  • Q168. Correct
  • Q169. Correct
  • Q170. Correct
  • Q171. X Incorrect
  • Q172. Correct
  • Q173. Correct
  • Q174. Correct
  • Q175. Correct
  • Q176. Correct
  • Q177. Correct
  • Q178. Correct
  • Q179. Correct
  • Q180. Correct

Anatomy

Abdomen

Question 160 of 180

The bladder receives its efferent parasympathetic fibres derived from spinal cord segments:

Answer:

The bladder receives efferent parasympathetic fibres from the pelvic splanchnic nerves (S2 to S4). Parasympathetic stimulation causes the detrusor muscle of the bladder to contract and the internal sphincter muscle to relax.

Urinary Bladder

The bladder is the most anterior viscera in the pelvic cavity. When empty it is entirely situated in the pelvic cavity, but when full expands superiorly into the abdominal cavity. The bladder is a retroperitoneal structure and when full lies adjacent to the anterior abdominal wall.

Structure

The empty bladder is shaped like a three-sided pyramid that has tipped over to lie on its side and has an apex, a base, a superior surface and two inferolateral surfaces.

  • The apex of the bladder is directed towards the top of the pubic symphysis.
  • The triangular-shaped base (or fundus) of the bladder faces posteroinferiorly. The two ureters enter the bladder at each of the upper corners of the base, and the urethra drains inferiorly from the lower corner of the base.
  • The inferolateral surfaces of the bladder are cradled between the levator ani muscles of the pelvic diaphragm and the adjacent obturator internus muscles above the attachment of the pelvic diaphragm.
  • The superior surface is slightly domed when the bladder is empty and balloons upwards as the bladder fills.

By OpenStax College [CC BY 3.0 , via Wikimedia Commons

Structure of the Urinary Bladder. (Image by OpenStax College [CC BY 3.0 , via Wikimedia Commons)

Relations

In the male the bladder is related:

  • anteriorly to the pubic symphysis
  • posteriorly to the rectovesical pouch and rectum
  • inferiorly to the prostate and the pelvic floor
  • superiorly to the peritoneum.

In the female the bladder is related:

  • anteriorly to the pubic symphysis
  • posteriorly to the vesicouterine pouch, the uterus, the cervix and the vagina
  • superiorly to the uterus and the peritoneum
  • inferiorly to the pelvic floor.

By OpenStax College [CC BY 3.0 , via Wikimedia Commons

Relations of the Urinary Bladder. (Image by OpenStax College [CC BY 3.0 , via Wikimedia Commons)

Innervation

The bladder receives efferent sympathetic fibres from the hypogastric plexuses and nerves (T12 - L2).

The bladder receives efferent parasympathetic fibres from the pelvic splanchnic nerves (S2 to S4).

The voluntary external urethral sphincter is innervated by the pudendal nerve (S2 - S4).

Control of Micturition

General visceral afferent fibres from the bladder, which are stimulated by distension (approximately 300 mL for adults), are conveyed in both the sympathetic and parasympathetic nervous system (the latter being the most important in micturition).

Storage Phase:

At low bladder volumes, afferent firing is low. Sympathetic stimulation keeps the detrusor muscle relaxed and keeps the involuntary internal sphincter closed, inhibiting bladder emptying.

Voiding Phase:

At high bladder volumes, afferent firing increases, causing a conscious sensation of urinary urge. During micturition, parasympathetic stimulation causes the detrusor muscle to contract and the involuntary internal sphincter muscle to relax, facilitating emptying of the bladder. The somatic external urethral sphincter is consciously relaxed during micturition.

Neurogenic Bladder

The bladder stretch reflex is a primitive spinal reflex where a full bladder, detected by stretch receptors in the bladder wall, activates visceral afferents resulting in activation of parasympathetic efferents and contraction of the detrusor muscle with resultant micturition. Normally this spinal reflex is overridden by the higher centres of the brain to give voluntary control over micturition via the external urethral sphincter.

In spinal cord injury, two types of clinical syndromes are seen:

  • In injuries above the conus medullaris (above vertebra T12), the S2 - S4 levels of the spinal cord are intact and there is a functioning spinal reflex. In this case a reflex bladder will occur, where there is loss of higher control and so the bladder stretch reflex takes over, and the detrusor muscle is stimulated to contract as the bladder fills.
  • In injuries affecting the S2 - S4 sacral nerve roots (below vertebra T12) a flaccid bladder will occur, where there is loss of both higher control and of the spinal reflex. In this case when the bladder fills, it becomes abnormally distended until the internal and external sphincters are stretched, allowing urine to pass.

Report A Problem

Is there something wrong with this question? Let us know and we’ll fix it as soon as possible.

Loading Form...

Close
  • Biochemistry
  • Blood Gases
  • Haematology
Biochemistry Normal Value
Sodium 135 – 145 mmol/l
Potassium 3.0 – 4.5 mmol/l
Urea 2.5 – 7.5 mmol/l
Glucose 3.5 – 5.0 mmol/l
Creatinine 35 – 135 μmol/l
Alanine Aminotransferase (ALT) 5 – 35 U/l
Gamma-glutamyl Transferase (GGT) < 65 U/l
Alkaline Phosphatase (ALP) 30 – 135 U/l
Aspartate Aminotransferase (AST) < 40 U/l
Total Protein 60 – 80 g/l
Albumin 35 – 50 g/l
Globulin 2.4 – 3.5 g/dl
Amylase < 70 U/l
Total Bilirubin 3 – 17 μmol/l
Calcium 2.1 – 2.5 mmol/l
Chloride 95 – 105 mmol/l
Phosphate 0.8 – 1.4 mmol/l
Haematology Normal Value
Haemoglobin 11.5 – 16.6 g/dl
White Blood Cells 4.0 – 11.0 x 109/l
Platelets 150 – 450 x 109/l
MCV 80 – 96 fl
MCHC 32 – 36 g/dl
Neutrophils 2.0 – 7.5 x 109/l
Lymphocytes 1.5 – 4.0 x 109/l
Monocytes 0.3 – 1.0 x 109/l
Eosinophils 0.1 – 0.5 x 109/l
Basophils < 0.2 x 109/l
Reticulocytes < 2%
Haematocrit 0.35 – 0.49
Red Cell Distribution Width 11 – 15%
Blood Gases Normal Value
pH 7.35 – 7.45
pO2 11 – 14 kPa
pCO2 4.5 – 6.0 kPa
Base Excess -2 – +2 mmol/l
Bicarbonate 24 – 30 mmol/l
Lactate < 2 mmol/l

Join our Newsletter

Stay updated with free revision resources and exclusive discounts

©2017 - 2024 MRCEM Success