SUBOCCIPITAL REGION

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I. SUBOCCIPITAL MUSCLES ‑ (Atlas Fig. 4.36, 4.37; Figure above Table 4.2)

MUSCLE	ORIGIN	INSERTION	ACTION	NERVE
Rectus Capitis Posterior Major	Vertebra - axis (C2)	Occipital bone	Extends head, rotates skull in unilateral action	Suboccipital n. (dorsal ramus of C1)
Rectus Capitis Posterior Minor	Vertebra - atlas (C1)	Occipital bone	Extends head	Suboccipital n. (dorsal ramus of C1)
Obliquus Capitis Inferior	Vertebra - axis (C2)	Vertebra - atlas (C1)	Rotates head	Suboccipital n. (dorsal ramus of C1)
Obliquus Capitis Superior	Vertebra - atlas (C1)	Occipital bone	Extends head	Suboccipital n. (dorsal ramus of C1)

II. SUBOCCIPITAL TRIANGLE ‑ bounded by muscles; inferiorly by obliquus capitis inferior, medially by rectus capitis posterior major, laterally by obliquus capitis superior.

A. Nerves (Atlas Fig. 4.36)

1. Suboccipital nerve ‑ dorsal ramus of C1 spinal nerve; motor to suboccipital region.

2. Greater Occipital nerve ‑ dorsal ramus of C2 spinal nerve; sensory to skin of back of head and neck.

B. Arteries (Atlas Figure above Table 4.2; Fig. 4.40)

1. Occipital artery ‑ branch of External Carotid artery; pierces fascia of trapezius muscle to supply back of head and suboccipital region.

2. Vertebral artery ‑ ascends neck through foramina transversaria of vertebrae C1‑C6 and enters skull through foramen magnum; passes through suboccipital triangle.