✔️20 - Nervous System: Lumbosacral Plexus IN PROGRESS

cervical intumescence

-C6-T1-T2

-Spinal cord segments

-Thoracic limbs innervation

lumbar intumescence

-L3-L4-S3

-Spinal cord segments

-Pelvic limbs and pelvic viscera innervation

intumescentiae

The segments that gives origin to the nerves supplying the thoracic and pelvic limbs are called _____

dorsal

_____ branches of the thoracic spinal nerves are associated with the following:

-motor

-cutaneous sensory

-associated with the lateral branch

ventral

_____ branches of the thoracic spinal nerves are associated with the following:

-intercostal nerves

-thoracic spinal nerves 1-12

-motor

-cutaneous sensory

*lateral cutaneous brs.

*ventral cutaneous brs

lateral cutaneous branches of IC nerves T2 & T3

-Innervate tricipital and part of axillary regions of thoracic limb

-Intercostobrachial nerves

L3-S3 spinal nerves (lumbosacral plexus)

What are the ventral branches of lumbar and sacral spinal nerves ?

genitofemoral nerve

-Formed by ventral branches of L3 andL4 spinal nerves.

-Motor to cremaster m.

-Sensory from skin in inguinal region (inguinal mammary gland, prepuce), proximal medial thigh

obturator nerve

-Arises from L4, L5, L6 spinal nerves

-Innervates adductors of pelvic limb

*External obturator m.

*Pectineus m.

*Gracilis m.

*Adductors

femoral nerve

-Arises from L4, L5, L6 spinal nerves

-Emerges from iliopsoas m.

-Innervates:

*Iliopsoas m.

*Quadriceps femoris m.

*Sartorius m.

-Gives rise to saphenous n.

*Cutaneous innervation to skin of medial femoral, genual, tibial and pes regions

saphenous nerve

The femoral nerve gives rise to what?

Caudal cutaneous femoral nerve

-Follows caudal gluteal a. to level of ischiatic tuberosity

-Terminates in skin on proximal caudal half of thigh

-S1, S2, & S3

lumbosacral trunk

The following are associated with _____:

-Caudal gluteal n.

-Cranial gluteal n.

-Sciatic n. (ischiatic n.)

lumbosacral trunk

-Formed by ventral branches of L6,L7, S1, S2

-Near greater ischiatic notch

-Gives rise to:

*Caudal gluteal n.

*Cranial gluteal n.

*Sciatic n.

caudal gluteal nerve

What nerve is associated with the superficial gluteal muscle?

cranial gluteal nerve

What nerve is associated with the following muscles?

-Middle gluteal m.

-Piriformis m.

-Deep gluteal m.

-Tensor fasciae latae m

sciatic nerve

-Arises from L6, L7, S1, S2 spinal nerves

-Courses over greater ischiatic notch, dorsal and caudal to the coxal joint.

-Within pelvis, innervates (#9,10,11)

*Internal obturator m.

*Gemelli mm.

*Quadratus femoris m.

-Caudal to hip, innervates: (#12,13,14)

*Biceps femoris m.

*Semimembranosus m.

*Semitendinosus m.

lateral and caudal cutaneous sural nerves

_____ arise from fibular and tibial components of sciatic n. to supply cutaneous innervation to lateral and caudal surfaces of crus

-common fibular (peroneal) nerve

-tibial nerve

Proximal to the stifle, the sciatic nerve divides into what?

common fibular (peroneal) nerve

Innervates flexors of the tarsal joint and extensors of the digit

tibial nerve

Innervates extensors of the tarsal joint and flexors of the digit

common fibular (peroneal) nerve

-Divides into deep and superficial peroneal (fibular) nn.

-Branches innervate the flexors of the tarsal joint and extensors of the digits

tibial nerve

Branches innervate the extensors of the tarsal joint and flexors of the digits

deep fibular nerve

-Innervates:

*Cranial tibial m.

*Long digital extensor m.

*Peroneus longus m.

-Courses distally with the cranial tibial a.

superficial fibular nerve

Innervates the lateral digital extensor and peroneus brevis muscles

tibial nerve

-Arises from L7, S1 spinal nerves

-Innervates:

*Gastrocnemius m.

*Superficial digital flexor m.

*Deep digital flexor m.

*Popliteus m.

-Divides into medial and lateral plantar nn.

*Sensory to plantar surface of pes