Podcast
Questions and Answers
What is the origin of the nerve that innervates the latissimus dorsi muscle?
What is the origin of the nerve that innervates the latissimus dorsi muscle?
Which muscle is innervated by the dorsal scapular nerve?
Which muscle is innervated by the dorsal scapular nerve?
What is the source of the arterial supply to the intermediate back muscles?
What is the source of the arterial supply to the intermediate back muscles?
What is the primary function of the ventral rami of spinal nerves?
What is the primary function of the ventral rami of spinal nerves?
Signup and view all the answers
What is the term for the area of skin supplied by a particular spinal nerve segment?
What is the term for the area of skin supplied by a particular spinal nerve segment?
Signup and view all the answers
Which nerve innervates the serratus posterior superior muscle?
Which nerve innervates the serratus posterior superior muscle?
Signup and view all the answers
Which muscle is innervated by the thoracodorsal nerve?
Which muscle is innervated by the thoracodorsal nerve?
Signup and view all the answers
Which of the following nerves does NOT supply the rhomboid muscles?
Which of the following nerves does NOT supply the rhomboid muscles?
Signup and view all the answers
What is the source of the arterial supply to the superficial back muscles?
What is the source of the arterial supply to the superficial back muscles?
Signup and view all the answers
What is the term for the area of skin supplied by a single spinal nerve?
What is the term for the area of skin supplied by a single spinal nerve?
Signup and view all the answers
Which muscle is not innervated by the dorsal scapular nerve?
Which muscle is not innervated by the dorsal scapular nerve?
Signup and view all the answers
What is the term for the branches of spinal nerves that supply the skin?
What is the term for the branches of spinal nerves that supply the skin?
Signup and view all the answers
Which of the following statements is TRUE about the dorsal rami of spinal nerves?
Which of the following statements is TRUE about the dorsal rami of spinal nerves?
Signup and view all the answers
What is the term for a network of nerves formed by the union of ventral rami of spinal nerves?
What is the term for a network of nerves formed by the union of ventral rami of spinal nerves?
Signup and view all the answers
Which of the following spinal nerves DOES NOT contribute to the formation of the brachial plexus?
Which of the following spinal nerves DOES NOT contribute to the formation of the brachial plexus?
Signup and view all the answers
What is the primary function of the sensory/afferent neurons in spinal nerves?
What is the primary function of the sensory/afferent neurons in spinal nerves?
Signup and view all the answers
Which artery supplies the trapezius muscle?
Which artery supplies the trapezius muscle?
Signup and view all the answers
What is the innervation of the latissimus dorsi muscle?
What is the innervation of the latissimus dorsi muscle?
Signup and view all the answers
Which nerve plexus innervates the superficial back muscles such as rhomboids?
Which nerve plexus innervates the superficial back muscles such as rhomboids?
Signup and view all the answers
What is the source of arterial supply to the serratus posterior superior and inferior muscles?
What is the source of arterial supply to the serratus posterior superior and inferior muscles?
Signup and view all the answers
Which artery changes its name to the axillary artery?
Which artery changes its name to the axillary artery?
Signup and view all the answers
What is the venous drainage of the back muscles?
What is the venous drainage of the back muscles?
Signup and view all the answers
Which nerve innervates the skin of the back?
Which nerve innervates the skin of the back?
Signup and view all the answers
Which muscle is supplied by the thoracodorsal artery?
Which muscle is supplied by the thoracodorsal artery?
Signup and view all the answers
Which muscle is supplied by the dorsal scapular artery?
Which muscle is supplied by the dorsal scapular artery?
Signup and view all the answers
Which nerve supplies the latissimus dorsi muscle?
Which nerve supplies the latissimus dorsi muscle?
Signup and view all the answers
Which intercostal space is the triangle of auscultation located at?
Which intercostal space is the triangle of auscultation located at?
Signup and view all the answers
What is the function of the serratus posterior inferior muscle?
What is the function of the serratus posterior inferior muscle?
Signup and view all the answers
What is the origin of the dorsal scapular nerve?
What is the origin of the dorsal scapular nerve?
Signup and view all the answers
Which reference line is used to locate the triangle of auscultation?
Which reference line is used to locate the triangle of auscultation?
Signup and view all the answers
What is the boundary of the triangle of auscultation?
What is the boundary of the triangle of auscultation?
Signup and view all the answers
What is the direction of rotation produced by the rhomboids on the scapula?
What is the direction of rotation produced by the rhomboids on the scapula?
Signup and view all the answers
Which nerve supplies the trapezius muscle?
Which nerve supplies the trapezius muscle?
Signup and view all the answers
What is the source of innervation for the superficial back muscles?
What is the source of innervation for the superficial back muscles?
Signup and view all the answers
What is the function of the anterior rami of spinal nerves in relation to the trapezius muscle?
What is the function of the anterior rami of spinal nerves in relation to the trapezius muscle?
Signup and view all the answers
What is the relationship between the levator scapulae and rhomboid muscles to the trapezius?
What is the relationship between the levator scapulae and rhomboid muscles to the trapezius?
Signup and view all the answers
What is the consequence of atrophy of the right trapezius muscle?
What is the consequence of atrophy of the right trapezius muscle?
Signup and view all the answers
How many pairs of spinal nerves are there?
How many pairs of spinal nerves are there?
Signup and view all the answers
What is the origin of the accessory nerve that innervates the trapezius muscle?
What is the origin of the accessory nerve that innervates the trapezius muscle?
Signup and view all the answers
Study Notes
Innervation of Extrinsic Back Muscles + Skin
- Spinal nerves (SN) originate from the spinal cord and contain both motor (efferent) neurons and sensory/afferent neurons.
- SN divides into dorsal and ventral rami.
Key Concept: Spinal Nerves
- Ventral rami innervate skin, mm, joints of limbs, and anterolateral trunk.
- Dorsal rami innervate skin and deep mm of back (excluding superficial back mm).
Innervation of Superficial Back Muscles
- Latissimus dorsi is innervated by thoracodorsal n. (C6, 7, 8).
- Levator scapulae, rhomboid major, and rhomboid minor are innervated by dorsal scapular n. (C5).
Innervation of Intermediate Back Muscles
- Intercostal nerves originate from ventral rami of thoracic spinal nerves.
- Serratus posterior superior is innervated by T2-T5 intercostal nerves.
- Serratus posterior inferior is innervated by T9-T12 intercostal and subcostal nerves.
Dermatomes
- A dermatome is the area of skin supplied by a particular spinal nerve segment.
- Cutaneous branches (touch, pain, etc.) vary and overlap.
Arterial Supply to Superficial Back
- Superficial back muscles are supplied by branches from the subclavian artery.
- Intermediate back muscles are supplied by branches directly from the aorta.
Arterial Supply to Superficial Back Muscles
- Trapezius is supplied by a superficial branch of the transverse cervical artery.
- Rhomboids + levator scapulae are supplied by the dorsal scapular artery.
- Latissimus dorsi is supplied by the thoracodorsal artery (branch of subscapular artery).
Key Concept: Supply to Superficial Back Muscles
- Trapezius is innervated by the accessory nerve (CN XI) and supplied by a superficial branch of the transverse cervical artery.
- Latissimus dorsi is innervated by the thoracodorsal nerve (C6-C8) and supplied by the thoracodorsal artery.
Venous Drainage
- Posterior intercostal or regional veins drain into the IVC or SVC.
- Lymph vessels and nodes parallel veins.
Surface Anatomy
- The triangle of auscultation is located just medial to the inferior angle of the scapula at the 6th intercostal space.
- Borders: trapezius (medially), latissimus dorsi (inferiorly).
Neurovasculature: Check-In
- The trapezius muscle is innervated by the accessory nerve (CN XI).
- Skin of the back is innervated by dorsal or ventral rami of SN.
- Superficial back muscles are innervated by nerves from the brachial plexus.
- The subclavian artery changes names to the axillary artery.
- Posterior intercostal arteries travel with the ribs.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz covers the innervation of extrinsic back muscles and skin, including the formation and branches of spinal nerves and their functions in motor and sensory neurons.
