View source for Sacral plexus

{{Short description|Nerve plexus}}
{{Infobox nerve
| Name        = Sacral plexus
| Latin       = plexus sacralis
| Image       = Gray828.png
| Caption     = Plan of sacral and [[Pudendal plexus (nerves)|pudendal plexus]]es.
| Image2      = Relations_of_the_sacral_plexus.png
| Caption2    = Relations of the sacral plexus. Dissection of side wall of pelvis showing sacral and pudendal plexuses.
| Innervates  =
| BranchFrom  = [[Lumbosacral trunk|L4-L5]], [[sacral nerves|S1-S4]]
| BranchTo    =
}}
In [[human anatomy]], the '''sacral plexus''' is a [[nerve plexus]] which provides motor and sensory nerves for the posterior thigh, most of the lower leg and foot, and part of the [[pelvis]]. It is part of the [[lumbosacral plexus]] and emerges from the [[lumbar vertebrae]] and [[sacral vertebrae]] (L4-S4).<ref name="Thieme-Atlas-470">''Thieme Atlas of Anatomy'' (2006), pp 470-471</ref>  A '''sacral [[plexopathy]]''' is a disorder affecting the nerves of the sacral plexus, usually caused by trauma, nerve compression, vascular disease, or infection. Symptoms may include pain, loss of motor control, and sensory deficits.

==Structure==
The sacral plexus is formed by:
* the [[lumbosacral trunk]]
* the [[anterior division]] of the first [[sacral nerve]]
* portions of the anterior divisions of the second and third sacral nerves
The nerves forming the sacral plexus converge toward the lower part of the [[greater sciatic forame]]n, and unite to form a flattened band, from the anterior and posterior surfaces of which several branches arise.
The band itself is continued as the [[sciatic nerve]], which splits on the back of the thigh into the [[tibial nerve]] and [[common fibular nerve]]; these two nerves sometimes arise separately from the plexus, and in all cases their independence can be shown by dissection. Often, the sacral plexus and the [[lumbar plexus]] are considered to be one large nerve plexus, the [[lumbosacral plexus]].  The [[lumbosacral trunk]] connects  the two plexuses.

===Relations===
The sacral plexus lies on the back of the pelvis in front of the [[piriformis]] muscle and the [[pelvic fascia]]. In front of it are the [[internal iliac artery]], [[internal iliac vein]], the [[ureter]], and the [[sigmoid colon]]. The [[superior gluteal artery]] and vein run between the [[lumbosacral trunk]] and the first sacral nerve, and the [[inferior gluteal artery]] and vein between the second and third sacral nerves.

==Nerves formed==
All the nerves entering the plexus, with the exception of the third sacral, split into ventral and dorsal divisions, and the nerves arising from these are as follows of the table below:
[[File:Sacral plexus.JPG|thumb|400px|Sacral plexus]]
{| class="wikitable" align="center"
|+ Nerves of the sacral plexus<ref name="Thieme-Atlas-476+478+482">''Thieme Atlas of Anatomy'' (2006), pp 476, 478, 482</ref>
|-
 ! Nerve !! Segment !! Innervated muscles !! Cutaneous branches
|-
| [[Superior gluteal nerve|Superior gluteal]]
 | L4-S1
 | [[Gluteus medius muscle|Gluteus medius]]<br />[[Gluteus minimus muscle|Gluteus minimus]]<br />[[Tensor fasciae latae]]
 | 
|-
| [[Inferior gluteal nerve|Inferior gluteal]]
 | L5-S2
 | [[Gluteus maximus muscle|Gluteus maximus]]
 | 
|-
| [[Posterior cutaneous nerve of thigh|Posterior cutaneous femoral]]
* [[Inferior cluneal nerves]]
* [[Perineal branches of posterior femoral cutaneous nerve|Perineal branches]]
 | S1-S3
 | 
 |
|-
| [[Perforating cutaneous nerve|Perforating cutaneous]]
 | S2-S3
 | 
 |
|-
| colspan=4 | Direct branches from plexus
|-
| 
* [[Nerve to piriformis|Piriformis]]
 | S1-2
 | [[Piriformis muscle|Piriformis]]
 | 
|-
| 
* [[Nerve to obturator internus|Obturator internus]]
 | L5, S1-2
 | [[Obturator internus muscle|Obturator internus]] and [[superior gemellus muscle|Superior gemellus]]
 | 
|-
|
* [[Nerve to quadratus femoris|Quadratus femoris]]
 | L4-5, S1
 | [[Quadratus femoris muscle|Quadratus femoris]] and [[inferior gemellus muscle|Inferior gemellus]]
 | 
|-
! colspan=4 | Sciatic
|-
| [[Sciatic nerve|Sciatic]]
 | L4-S3
 | [[Semitendinosus muscle|Semitendinosus]] (Tib)<br />[[Semimembranosus muscle|Semimembranosus]] (Tib)<br />[[Biceps femoris muscle|Biceps femoris]]
* Long head (Tib)
* Short head (Fib)
[[Adductor magnus muscle|Adductor magnus]] (medial part, Tib)
 | 
|-
| [[Common fibular nerve|Common fibular]]
 | L4-S2
 | 
 | [[Lateral sural cutaneous nerve|Lateral sural cutaneous]]<br />[[Sural communicating branch of common fibular nerve|Communicating fibular]]
|-
|
* [[Superficial fibular nerve|Superficial fibular]]
 | 
 | [[Fibularis longus]]<br />[[Fibularis brevis]]
 | [[Medial dorsal cutaneous nerve|Medial dorsal cutaneous]]<br />[[Intermediate dorsal cutaneous nerve|Intermediate dorsal cutaneous]]
|-
|
* [[Deep fibular nerve|Deep fibular]]
 | 
 | [[Tibialis anterior muscle|Tibialis anterior]]<br />[[Extensor digitorum longus muscle|Extensor digitorum longus]]<br />[[Extensor digitorum brevis muscle|Extensor digitorum brevis]]<br />[[Extensor hallucis longus muscle|Extensor hallucis longus]]<br />[[Extensor hallucis brevis muscle|Extensor hallucis brevis]]<br />[[Fibularis tertius]]
 | [[Medial terminal branch of deep fibular nerve|Lateral cutaneous nerve of big toe]]<br />[[Intermediate dorsal cutaneous nerve|Intermediate dorsal cutaneous]]
|-
| [[Tibial nerve]]
 | L4-S3
 | [[Triceps surae]]([[Gastrocnemius muscle|Gastrocnemius]], [[Soleus muscle|Soleus]])<br />[[Popliteus muscle|Popliteus]]<br />[[Plantaris muscle|Plantaris]]<br />[[Tibialis posterior muscle|Tibialis posterior]]<br />[[Flexor digitorum longus muscle|Flexor digitorum longus]]<br />[[Flexor hallucis longus muscle|Flexor hallucis longus]]
 | [[Medial sural cutaneous nerve|Medial sural cutaneous]]<br />[[Medial calcaneal branches of the tibial nerve|Medial calcaneal]]<br />[[Lateral dorsal cutaneous nerve|Lateral dorsal cutaneous]]
|-
|
* [[Medial plantar nerve|Medial plantar]]
 | 
 | [[Abductor hallucis muscle|Abductor hallucis]]<br />[[Flexor digitorum brevis muscle|Flexor digitorum brevis]]<br />[[Flexor hallucis brevis muscle|Flexor hallucis brevis]] (medial head)<br />[[Lumbrical muscle (foot)|Lumbrical]] (first and second)
 | [[Proper plantar digital nerves of medial plantar nerve|Proper digital plantar]]
|-
|
* [[Lateral plantar nerve|Lateral plantar]]
 | 
 | [[Flexor hallucis brevis muscle|Flexor hallucis brevis]] (lateral head)<br />[[Quadratus plantae muscle|Quadratus plantae]]<br />[[Abductor digiti minimi muscle (foot)|Abductor digiti minimi]]<br />[[Flexor digiti minimi brevis muscle (foot)|Flexor digiti minimi]]<br />[[Lumbrical muscle (foot)|Lumbrical]] (third and fourth)<br />[[Plantar interossei muscles|Plantar interossei]] (first to third)<br />[[Dorsal interossei muscles (foot)|Dorsal interossei]] (first to fifth)<br />[[Adductor hallucis muscle|Adductor hallucis]]
 | [[Proper plantar digital nerves of lateral plantar nerve|Proper plantar digital]]
|-
 ! colspan=4 | Pudendal and coccygeal
|-
| [[Pudendal nerve|Pudendal]]<br />([[Pudendal plexus (nerves)|Pudendal plexus]])
 | S2-S4
 | Muscles of the [[pelvic floor]]:<br />[[Levator ani]]<br />[[Superficial transverse perineal muscle|Superficial transverse perineal]]<br />[[Deep transverse perineal muscle|Deep transverse perineal]]<br />[[Bulbospongiosus muscle|Bulbospongiosus]]<br />[[Ischiocavernosus muscle|Ischiocavernosus]]<br />[[Sphincter ani externus muscle|Sphincter anus externus]]<br />[[Urethral sphincter]]
 | [[Inferior anal nerves|Inferior rectal]]<br />[[Perineal nerve|Perineal]]
* [[Posterior scrotal nerves|Posterior scrotal]]/[[Posterior labial nerves|labial]]
* [[Dorsal nerve of the penis|Dorsal penis]]/[[Dorsal nerve of clitoris|clitoris]]
* [[The nerves of prostatic utricle or vagina masculina or vesicula prostatica|prostatic urethra.]]/[[Inferior vaginal nerves|vagina]]
|-
| [[Coccygeal nerve|Coccygeal]]<br />([[Coccygeal plexus]])
 | S5-Co1
 | [[Coccygeus muscle|Coccygeus]]
 | [[Anococcygeal nerves|Anococcygeal]]<br />Dorsal branches
|}

==Additional images==
<gallery>
File:Gray838.png|The right sympathetic chain and its connections with the thoracic, abdominal, and pelvic plexuses. 
 File:Sacral plexus schematic.svg|A schematic depiction.
<!-- Deleted image removed:  Image:Sacral plexus.JPG|Sacral plexus. -->

File:Sacral plexus.gif| Diagram of the sacral plexus
</gallery>

==See also==
* [[Cervical plexus]]
* [[Brachial plexus]]
* [[Lumbar plexus]]
* [[Coccygeal plexus]]
* [[Lumbosacral plexus]]
* [[Nerve plexus]]
* [[Sciatic nerve]]
* [[Pudendal nerve]]
* [[Posterior femoral cutaneous nerve]]
* [[Superior gluteal nerve]]
* [[Inferior gluteal nerve]]

== Notes ==
{{Reflist}}

== References ==
{{one source|date=January 2009}}
{{Gray's}}
* {{cite book
| title     = Thieme Atlas of Anatomy: General Anatomy and Musculoskeletal System
| publisher = Thieme | year = 2006 | isbn = 1-58890-419-9
}}

==External links==
{{Commons category|Sacral plexus}}
* {{MeshName|Lumbosacral+Plexus}}
* {{ViennaCrossSection|pembody/body15a}}
* {{MedicalMnemonics|3544|2382|}}

{{Spinal nerves}}
{{Lumbosacral plexus}}
{{Portal bar|Anatomy}}
{{Authority control}}

[[Category:Nerve plexus]]
[[Category:Spinal nerves]]
[[Category:Nerves of the lower limb and lower torso]]