Cremaster muscle
Cremaster muscle | |
---|---|
Internal oblique | |
Insertion | Tunica vaginalis |
Artery | Cremasteric artery |
Nerve | Genital branch of genitofemoral nerve |
Actions | raise and lower the scrotum |
Identifiers | |
Latin | musculus cremaster |
TA98 | A04.5.01.018M A09.3.04.003 |
TA2 | 2374, 3617 |
FMA | 21531 |
Anatomical terms of muscle] |
The cremaster muscle is a paired structure made of thin layers of
Structure
In human males, the cremaster muscle is a thin layer of striated muscle found in the inguinal canal and scrotum between the external and internal layers of spermatic fascia, surrounding the testis and spermatic cord. The cremaster muscle is a paired structure, there being one on each side of the body.[1]
Anatomically, the lateral cremaster muscle originates from the
Blood supply
The cremaster muscle is supplied by the cremasteric artery, a branch of the inferior epigastric artery, along with anastomotic flow from the other arteries supplying the scrotum.[1]
Nerve supply
The cremaster muscle is innervated from the sensory and motor fibers of the
Development
The cremaster muscle develops to its full extent only in males; in females, the muscle is smaller and is found on the round ligament, where it is represented by only a few muscle loops.
In rats, it has been shown that cremaster muscles developed from the gubernacular bulb.[2]
Function
Retraction
The cremaster muscle's function is to raise and lower the testes in order to regulate scrotal temperature for optimal spermatogenesis and survival of the resultant spermatozoa. The ideal temperature for human sperm development is around 34 degrees Celsius, which is about 4 degrees Celsius below body temperature.[3] Temperature is regulated by increasing or decreasing the exposed surface area of the surrounding tissue, allowing faster or slower dissipation of body heat. The amount of retraction or relaxation is directly related to how far the environmental temperatures are from the ideal.[3] Cremaster works alongside the dartos muscle in order to maintain homeostasis for the reproductive organs and protect them from physical damage. When a man is cold or sexually stimulated, the dartos muscle causes the scrotum to become more wrinkled and smaller as it is retracted closer to the body. In warmer conditions, the dartos allows for less wrinkling and the scrotum becomes looser.[4]
The cremaster muscle is an
Clinically, a
The cremaster can also be contracted voluntarily, by performing
Clinical significance
The cremaster muscle occasionally experiences painful spasms or cramps in adult males which can be chronic and debilitating. Treatment for these spasms ranges from minor surgery to injection with Botulinum A toxin to the regular application of heat to relax the muscle. Surgery, including the excision of the cremaster muscle, has apparently been able to provide complete relief from this condition without significant side effects.[7][8]
Etymology
The name of the cremaster muscle is derived from the Ancient Greek noun κρεμαστήρ (kremastḗr), meaning "suspender"; its plural, κρεμᾰστῆρες (kremastēres), was used by Galen in the sense of "cremaster muscle".[9]
Additional images
-
The scrotum
-
The right testis, exposed by laying open the tunica vaginalis
References
- ^ PMID 30020720.
- PMID 11997885.
- ^ a b c d Snodgrass, Christie. "What is the Cremaster Muscle?". study.com. Retrieved 2022-12-25.
- ^ "Dartos muscle of scrotum - e-Anatomy - IMAIOS". www.imaios.com. Retrieved 2022-12-25.
- ^ Shafik, A. et al. J. Sexual Medicine 4:1022-1027, 2007
- PMID 30020720, retrieved 2022-12-25
- PMID 13304412.
- PMID 21601247. Retrieved 11 March 2012.
- ^ κρεμαστήρ, in Liddell & Scott (1940), A Greek–English Lexicon, Oxford: Clarendon Press.
External links
- Anatomy photo:36:07-0102 at the SUNY Downstate Medical Center - "Inguinal Region, Scrotum and Testes: Layers of the Spermatic Cord"