Back Muscles, Vertebral Column & Spinal Cord Vocabulary

Vocabulary flashcards covering key anatomical structures, functions, and clinical terms related to back muscles, vertebral column, spinal cord, meninges, and spinal nerves.

Superficial back muscles

Extrinsic muscles connecting upper limb to shoulder girdle (e.g., trapezius, latissimus dorsi, rhomboids, levator scapulae).

Intermediate back muscles

Extrinsic muscles that move the thoracic wall (serratus posterior superior & serratus posterior inferior).

Deep back muscles

Intrinsic muscles associated with the vertebral column (primarily the erector spinae group).

Trapezius

Superficial back muscle innervated by cranial nerve XI (spinal accessory); moves scapula and supports shoulder girdle.

Latissimus dorsi

Large superficial back muscle innervated by the thoracodorsal nerve; extends, adducts, and medially rotates the humerus.

Levator scapulae

Muscle that elevates the scapula; innervated by the dorsal scapular nerve.

Rhomboid major

Muscle that retracts and rotates the scapula; innervated by the dorsal scapular nerve.

Rhomboid minor

Smaller rhomboid muscle performing scapular retraction; dorsal scapular nerve supply.

Serratus posterior superior

Thin intermediate muscle elevating ribs; aids respiration.

Serratus posterior inferior

Intermediate muscle depressing ribs; aids forced expiration.

Erector spinae

Primary intrinsic back muscle mass extending vertebral column; subdivided into iliocostalis, longissimus, and spinalis.

Iliocostalis

Lateral column of erector spinae; attaches to ribs and iliac crest.

Longissimus

Intermediate column of erector spinae; longest muscle running from sacrum to skull.

Spinalis

Medial column of erector spinae located closest to the spinous processes.

Triangle of auscultation

Back region bordered by trapezius, latissimus dorsi, and medial scapula; thinnest musculature for lung sounds.

Lumbar triangle

Weak posterior abdominal wall area bordered by latissimus dorsi, external oblique, and iliac crest.

Dermatome

Area of skin mainly supplied by a single spinal nerve.

Posterior rami

Branches of spinal nerves that innervate intrinsic back muscles and overlying skin.

Anterior rami

Branches of spinal nerves supplying skin and muscles of neck, trunk, and limbs.

Atlas (C1)

First cervical vertebra lacking body and spinous process; supports the skull.

Axis (C2)

Second cervical vertebra featuring the dens (odontoid process) for head rotation.

Dens (odontoid process)

Upward projection of C2 that articulates with the atlas, allowing rotation.

Normal spinal curves

Four curvatures: cervical & lumbar lordoses (anterior convexity) and thoracic & sacral kyphoses (posterior convexity).

Kyphosis

Exaggerated thoracic posterior convexity—“humpback.”

Lordosis

Exaggerated lumbar anterior convexity—“hollow back,” often in pregnancy.

Scoliosis

Abnormal lateral curvature of the vertebral column.

Intervertebral disc

Secondary cartilaginous joint between vertebral bodies composed of annulus fibrosus and nucleus pulposus.

Annulus fibrosus

Fibrocartilaginous outer ring of an intervertebral disc providing strength.

Nucleus pulposus

Gelatinous central part of a disc acting as shock absorber.

Facet (zygapophyseal) joint

Synovial joint between superior and inferior articular processes allowing gliding motions.

Herniated disc

Protrusion of nucleus pulposus through a ruptured annulus fibrosus, compressing nerve roots or spinal cord.

Spina bifida

Failure of vertebral arch fusion; ranges from occult gap to meningomyelocele with exposed spinal cord/meninges.

Conus medullaris

Tapered lower end of spinal cord at ~L1–L2 level.

Filum terminale

Fibrous extension of pia mater anchoring spinal cord to coccyx.

Meninges

Three protective coverings of spinal cord: dura mater, arachnoid mater, pia mater.

Pia mater

Innermost meningeal layer closely investing spinal cord; forms denticulate ligaments & filum terminale.

Arachnoid mater

Delicate middle meningeal layer creating subarachnoid space for CSF.

Dura mater

Tough outer meningeal layer forming a single spinal dural sac.

Denticulate ligament

Lateral extensions of pia that anchor spinal cord to dura, separating motor and sensory roots.

Epidural space

Space between dura mater and vertebral canal periosteum containing fat and internal venous plexus.

Subarachnoid space

CSF-filled space between arachnoid and pia mater, houses cauda equina.

Lumbar cistern

Widened subarachnoid space (L2–S2) containing cauda equina; site for CSF sampling.

Spinal tap (lumbar puncture)

Needle insertion (commonly L3–L4) to obtain CSF from lumbar cistern.

Dorsal root ganglion

Collection of sensory neuron cell bodies on the posterior root of a spinal nerve.

Cauda equina

Bundle of lumbar, sacral, and coccygeal nerve roots descending past the conus medullaris.