Question: 258 EXERCISE IS SPINAL NERVES C. Spinal Nerve Divisions And The Four Spinal Plexuses Of The 31 Pairs Of Spinal Nerves, There Are 8 Cervical, 12 Thoracic, 5 Lumbar, 5 Sacral, And 1 Coccygeal. Many Spinal Nerves Join With Other Spinal Nerves To Form A Braided Network Or Plexus (braid) Before They Innervate Body Struc Tures. This Occurs In Four Regions …

Question: 258 EXERCISE IS SPINAL NERVES C. Spinal Nerve Divisions And The Four Spinal Plexuses Of The 31 Pairs Of Spinal Nerves, There Are 8 Cervical, 12 Thoracic, 5 Lumbar, 5 Sacral, And 1 Coccygeal. Many Spinal Nerves Join With Other Spinal Nerves To Form A Braided Network Or Plexus (braid) Before They Innervate Body Struc Tures. This Occurs In Four Regions …

258 EXERCISE IS SPINAL NERVES C. Spinal Nerve Divisions and the Four Spinal Plexuses of the 31 pairs of spinal nerves, there260 EXERCISE 18 SPINAL LAVES E. Major Nerves from the Lumbar and Sacral Plexuses The lumbar plexus is made up of anterior (ve

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258 EXERCISE IS SPINAL NERVES C. Spinal Nerve Divisions and the Four Spinal Plexuses of the 31 pairs of spinal nerves, there are 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. Many spinal nerves join with other spinal nerves to form a braided network or plexus (braid) before they innervate body struc tures. This occurs in four regions of the body where the networks form the cervical, brachial, lumbar, and sacral plexuses. The thoracic (intercostal) spinal nerves (T2-T12) do not participate in forming plexuses. ACTIVITY 3 Spinal Nerve Divisions and Spinal Plexuses 1 Label the cervical, thoracic, lumbar, sacral, and coccygeal nerves in Figure 154. 2 Label the four spinal plexuses also in Figure 15.4. 3 Identify the spinal nerve divisions and plexuses from Figure 154 on a model or chart. 4 Pronounce the terms as you point to them. Modular oblongate Atlas (irst cervical vertebra) T2 T3 T4 T5 TO T7 те T9 ΤΙΟ T11 brachial plexus (PLEX) cervical nerves • cervical plexus coccygeal nerve (cox sh-GEAL) lumbar nerves . lumbar plexus • sacral nerves • sacral plexus thoracic nerves T12 L2 L3 2 3 FIGURE 15.4 Posterior view of the four spinal plexuses. 260 EXERCISE 18 SPINAL LAVES E. Major Nerves from the Lumbar and Sacral Plexuses The lumbar plexus is made up of anterior (ventral) rami from L.-L.The lumbar plexus supplies the skin and mus- cles of the abdominal wall, external genitalia, and part of the lower limbs. The major nerves are the femoral and obturator nerves. The sacral plexus is formed from the anterior (ventral) rami from L-S This plexus supplies the buttocks, per ineum, and most of the lower limbs. Its major nerves are the pudendal and sciatic. The sciatic is composed of the tibial and common fibular (peroneal) nerves ACTIVITY 5 Major Nerves from the Lumbar and Sacral Plexuses 1 Label the nerves listed on Figure 15.6 using the name of the nerve, plexus of origin, and muscle innervation Muscle innervation is described in Table 15.2. 2 Identify the nerves from Figure 15.6 on models or charts. femoral nerve (FEM-o-rul obturator nerve (OB-turator) • common fibular (peroneal pudendal (pyoo DEN-dal) sciatic (sci A-tic) • tibial 3 Pronounce the terms as you point to them ANTERIOR POSTERIOR 3 4 FIGURE 15.6 Major nerves of the lumbar and sacral plexuses. TABLE 15.2 Motor Function of Nerves from the Lumbar and Sacral Plexuses NERVE MUSCLES INNERVATED BY NERVES Femoral lliacus, quadriceps femoris, sartorius, pectineus Obturator Adductor longus, adductor brevis, and part of adductor magnus, gracilis Common fibular Fibularis longus muscle tibialis anterior, extensor digitorum longus Pudendal Muscles of perineum Sciatic Biceps femoris, semimembranosus, semitendinosus (hamstrings) Tibial Gastrocnemius, soleus, tibialis posterior, flexor digitorum longus, plantaris, flexor hallucis longus