Detrusor Muscle

Definition

The detrusor muscle is a smooth muscle layer in the wall of the urinary bladder that is responsible for the contraction and relaxation of the bladder, allowing it to store and expel urine. It is a key component of the urinary system and plays a crucial role in the regulation of bladder function.

5 Must Know Facts For Your Next Test

1. The detrusor muscle is composed of smooth muscle fibers that are arranged in a complex network within the bladder wall.
2. Contraction of the detrusor muscle during the voiding phase of the micturition cycle increases the pressure within the bladder, allowing for the expulsion of urine.
3. Relaxation of the detrusor muscle during the storage phase of the micturition cycle allows the bladder to expand and accommodate increasing volumes of urine.
4. Dysfunction of the detrusor muscle, such as overactivity or underactivity, can lead to various urinary disorders, including overactive bladder and urinary incontinence.
5. Pharmacological agents that target the detrusor muscle, such as antimuscarinic drugs, are commonly used to treat urinary conditions by modulating its contractility.

Review Questions

• Explain the role of the detrusor muscle in the storage and voiding phases of the micturition cycle.
  • The detrusor muscle plays a crucial role in the micturition cycle. During the storage phase, the detrusor muscle relaxes, allowing the bladder to expand and accommodate increasing volumes of urine. This relaxation is facilitated by the parasympathetic nervous system. During the voiding phase, the detrusor muscle contracts, increasing the pressure within the bladder and enabling the expulsion of urine. This contraction is also mediated by the parasympathetic nervous system.
• Describe how dysfunction of the detrusor muscle can lead to urinary disorders.
  • Dysfunction of the detrusor muscle can lead to various urinary disorders. Overactivity of the detrusor muscle, where it contracts inappropriately, can result in an overactive bladder, characterized by symptoms such as urgency, frequency, and incontinence. Underactivity of the detrusor muscle, where it fails to contract adequately, can lead to urinary retention and incontinence. These conditions can significantly impact a person's quality of life and may require pharmacological interventions targeting the detrusor muscle to manage the symptoms.
• Analyze the importance of the detrusor muscle in the context of the introduction to the renal system and the urinary system, as well as its relevance in the pharmacological management of urinary disorders.
  • The detrusor muscle is a critical component of the urinary system, as it is responsible for the storage and expulsion of urine from the bladder. Its proper functioning is essential for maintaining normal bladder function and urinary continence. In the context of the introduction to the renal system, the detrusor muscle plays a key role in the final stage of urine production and elimination. Furthermore, the detrusor muscle is a target for pharmacological interventions in the management of urinary disorders, such as overactive bladder and urinary incontinence. Antimuscarinic drugs, for example, work by modulating the contractility of the detrusor muscle, thereby improving bladder function and alleviating the symptoms associated with these conditions.

Related terms

Urothelium: The innermost layer of the bladder wall that lines the interior of the bladder and acts as a barrier to prevent the leakage of urine.

Autonomic Nervous System: The part of the nervous system that controls involuntary bodily functions, including the regulation of the detrusor muscle in the bladder.

Parasympathetic Nervous System: The division of the autonomic nervous system that is responsible for the contraction of the detrusor muscle, enabling the bladder to empty.