Anatomy Lecture: Back Muscles, Nerves, and Suboccipital Region

Vocabulary flashcards covering back muscle layers, nerve innervations, deep vertebral muscles, and suboccipital triangle anatomy from the lecture notes.

Extrinsic Muscle

A term referring to outermost or superficial muscles in comparison to other tissue layers.

Intrinsic Muscle

A term referring to innermost or deeper muscles compared to other tissue layers.

Integumentary System

The system comprising the skin, which covers superficial muscle layers.

Fixators

Muscles that function to hold anatomical structures in place.

Levator Scapulae

A deep extrinsic muscle that elevates or pulls up on the scapula; innervated by the dorsal scapular nerve.

Rhomboids Minor and Major

Deep back muscles that perform medial rotation of the scapula by pulling its medial border closer to the vertebral column and help hold the scapula in place.

Serratus Posterior (Superior and Inferior)

Intermediate layer fan-shaped muscles innervated by intercostal nerves that play supportive roles in rib elevation (inhalation) and rib depression (exhalation), especially in individuals with COPD or emphysema.

Latissimus Dorsi

A superficial extrinsic back muscle, also known as the coughing muscle, innervated by the thoracodorsal nerve, which plays a role in upper limb movement.

Winged Scapula

A condition characterized by the scapula popping out or winging out, caused by a disruption in innervation to the rhomboids.

Trapezius

A superficial extrinsic muscle with ascending, transverse, and descending parts that aids in scapular elevation, retraction, rotation, and arm adduction; innervated by Cranial Nerve 11 (motor) and C3/C4 (sensory proprioception/pain).

Abduction

Movement of the upper limb away from the sides of the body.

Adduction

Movement bringing the upper limb back closer to the body.

Dorsal Scapular Nerve

A peripheral nerve formed by the convergence of C4 and C5 spinal nerves branching from the intervertebral foramen, innervating levator scapulae and rhomboids.

Intercostal Nerves

Nerves passing between the ribs ('inter' meaning between, 'costal' meaning ribs) that innervate the serratus posterior muscles.

Splenius

A superficial intrinsic back muscle split into splenius cervicis and splenius capitis.

Cervicis

An anatomical designation indicating that a muscle runs through the region of the neck.

Capitis

An anatomical designation indicating that a muscle has a direct attachment point to the skull/occipital bone.

Erector Spinae Muscles

A collective name for intermediate intrinsic back muscles acting as fixators and postural muscles, categorized into a lateral group (iliocostalis and longissimus) and a medial group (spinalis).

Iliocostalis

A long muscle belonging to the lateral group of erector spinae, passing through the lumbar, thoracic, and cervical regions.

Longissimus

A muscle belonging to the lateral group of erector spinae, passing through the thoracic and cervical regions and attaching to the mastoid process.

Spinalis

The medial group of erector spinae muscles situated directly on the vertebral column.

Intertransversari

Deep intrinsic back muscles situated between the transverse processes of vertebrae.

Multifidus

Deep intrinsic back muscles linking one vertebra to the superior articular processes of adjacent vertebrae.

Interspinalis

Deep intrinsic back muscles located between the spinous processes of adjacent vertebrae.

Longus and Brevis

Anatomical terms describing two muscles with identical actions working interdependently: 'longus' refers to a narrower and longer muscle, while 'brevis' refers to a shorter and wider muscle.

Suboccipital Triangle

A deep triangular region formed by the obliquus capitis superior, obliquus capitis inferior, and rectus capitis posterior major muscles.

Contents of the Suboccipital Triangle

The suboccipital nerve, suboccipital venous plexus, and the third part of the vertebral artery.

Vertebrobasilar Syndrome

A condition resulting from temporary ischemia to the posterior brain due to compression of the exposed third part of the vertebral artery when tilting the head back for extended periods.

Ischemia

A state of decreased or restricted blood flow to an anatomical region.