Axillary sheath is derived from: (A) Preveebral fascia, (B) Pretracheal fascia, (C) Investing layer of deep cervical fascia, (D) Deep fascia of throacic wall
Answer is A. -The muscular floor of the posterior triangle is covered by preveebral layer of fascia colli. -It forms the axillary sheath around subclan aery and brachial plexus travelling from the root of neck to the upper limb. -reference: Textbook of anatomy, Head Neck, and brain, Vishram Singh, 2nd edition, page no.80