Nerves Learning Materials

Nerves Cervical Nerves Nerve C1, C2 and C3 Function help control the head and neck, including movements forward, backward, and to the sides - C2 is for the upper head sensation - C3 is for the sides of the face and the upper parts of the head Upward shoulder movements Control deltoid and biceps muscles Controls wrist extensors and provides some innervation to the biceps Controls the triceps and wrist extensor muscles Controls finger flexion C4 C5 C6 C7 C8 Thoracic nerves Nerve T1 and T2 T3, T4 and T5 T6, T7 and T8 T9, T10, T11 and T12 Function feed into nerves that go into the top of the chest as well as into the arm and hand feed into the chest wall and aid in breathing feed into the chest and/or down into the abdomen feed into the abdomen and/or lower in the back. Lumbar nerves Nerve Function L1 sensation to the groin and genital regions and may contribute to the movement of the hip muscles provide sensation to the front part of the thigh and inner side of the lower leg and control movements of the hip and knee muscles provides sensation to the outer side of the lower leg, the upper part of the foot, and the webspace between the first and second toe and controls hip, knee, foot, and toe movements. L2, L3 and L4 L5 Sacral Nerves Nerve S1 S2 S3 S4 and S5 Function innervation for the ankle jerk Back and thighs Medial buttock area perineal area Dermatomes and Myotomes Dermatomes Cervical Component C2 C3 C4 C5 C6 C7 C8 Function Behind the ear and the base of the skull Back of the head and behind the neck Across the lower neck and top of the shoulders Across the collarbones and upper shoulders Shoulders, down the outside of the arm, and the thumb The upper back, down the back of the arm, index, and middle fingers Upper back, down the inside of the arm, ring and pinkie fingers Thoracic Component T1 T2 T3 T4 T5, T6 and T7 T8 and T9 T10 T11 T12 Function Across the upper back and chest, through the armpit, and down the front of the arm Across the upper back and chest, just below the armpit Across the upper back and chest, just above the nipples Across the upper back and chest, including the nipples Narrow bands across the mid-back and chest, starting below the nipples Naval Mid-back and abdomen, including the navel Mid-back and abdomen just below the navel, dipping toward the pelvis in front Mid-back and lower abdomen, dipping more sharply toward the pelvis in front Lumbar Component Function L1 Across the lower back, around the hips, then dipping down to the groin L2 and L3 Across the lower back, angling down across the front and inside of the thigh L4 Across the lower back, angling down the front of the thigh, knee, and calf, and wrapping around the inside of the ankle L5 Across the lower back, angling down the front and outside of the calf, the foot (top and bottom), and the first four toes Sacral Component Function S1 Across the lowest part of the back, then arching steeply and traveling down the back of the thigh, back and inside of the calf, and to the little toe S2 The genitals in front, across the buttocks in the back, then arching sharply to run down the back of the thigh and calf S3 An egg-shaped area of the buttocks in back, the genitals in front S4 A smaller egg-shaped area of the buttocks S5 A tiny dot in the buttocks Coccygeal The final dermatome and single spinal nerve in the coccygeal region affect an area of the buttocks and the tailbone area. Importance: In clinical practice, dermatomes are important for helping doctors identify where nerve problems originate and diagnose certain conditions.