Module 2: The Back - Surface Anatomy, Vertebral Column, and Back Muscles

Vocabulary flashcards reviewing surface anatomy of the back, vertebral column regions and structures, curvatures, intervertebral discs, and layers of back muscles.

Surface Anatomy

The branch of anatomical study focusing on features that can be seen and touched from the external surfaces of the body.

Palpable Structure

An anatomical feature or structure that is able to be touched and felt through the skin.

Palpable Bony Structures of the Back

spinous process of$C7$ , spine of the scapula, medial border of the scapula, inferior angle of the scapula, ribs, and iliac crest.

Axial Skeleton

The skeletal division comprising the bones of the head and trunk, which form the central axis of the body.

Appendicular Skeleton

The skeletal division comprising the bones of the arms and legs, which make up the appendages.

Spine (Vertebral Column)

A column of stacked vertebrae that distributes body weight downwards, forms joints for movement, and creates the spinal canal to enclose and protect the spinal cord.

Cervical Region

The neck region of the spine, composed of seven cervical vertebrae designated $C1$ through $C7$.

Thoracic Region

The thorax region of the spine, composed of twelve thoracic vertebrae ($T1$--$T12$) that articulate with $12$ pairs of ribs.

Lumbar Region

The lower back region of the spine, composed of five large lumbar vertebrae ($L1$--$L5$) designed to bear heavy body weight.

Sacrum

A single triangular bone formed by five fused sacral vertebrae ($S1$--$S5$) that articulates with the hip bones to form the pelvis. Weight is distributed from spine to pelvis

Coccyx

The tailbone, typically composed of $3$ to $5$ small fused vertebrae, most often 4 ($Co1$--$Co4$), which represents an evolutionary remnant of a tail.

Lordotic Curvature

A spinal curvature in which the concavity faces posteriorly (back), present in the cervical and lumbar regions.

Kyphotic Curvature

A spinal curvature in which the concavity faces anteriorly (front), present in the thoracic and sacral regions.

Primary Curvature

A spinal curvature present at birth, specifically the thoracic and sacral curvatures.

Secondary Curvature

A spinal curvature that develops after birth, including the cervical curvature (as a child holds up its head) and lumbar curvature (as a child stands upright).

Scoliosis

An abnormal condition in which the spine exhibits a lateral curvature, deviating away from the midline of the body.

Vertebral Body

The thick, anterior, weight-bearing region of a vertebra.

Vertebral Arch

The posterior bony arch of a vertebra that, together with the vertebral body, encloses the vertebral foramen.

Vertebral Foramen

The central aperture in a vertebra bounded by the body and vertebral arch, occupied by the spinal cord.

Vertebral Canal

The continuous canal formed by stacking the vertebral foramina of adjacent vertebrae, housing and protecting the spinal cord.

Intervertebral Foramen

A opening formed between two articulating vertebrae through which a spinal nerve exits the vertebral canal laterally.

Spinous Process

A posterior projection from the vertebral arch that serves as an attachment site for muscles and ligaments.

Transverse Process

A lateral projection extending from a vertebra that serves as an attachment point for muscles and ligaments.

Superior Articular Process

A bony process pointing superiorly that forms a joint with the inferior articular process of the vertebra above it.

Inferior Articular Process

A bony process pointing inferiorly that forms a joint with the superior articular process of the vertebra below it.

Atlas ($C1$)

The first cervical vertebra, which articulates directly with the skull to primarily allow flexion and extension of the head.

Axis ($C2$)

The second cervical vertebra, which acts as a pivot allowing rotation of the head and $C1$.

Vertebra Prominens ($C7$)

The seventh cervical vertebra, characterized by a long, easily palpable spinous process that serves as a major surface landmark.

Nuchal Ligament

A strong ligament extending from the skull to the long spinous processes of the cervical vertebrae that helps support the head upright.

Transverse Foramina

Openings located within the transverse processes of cervical vertebrae through which the vertebral artery passes toward the skull.

Sacro-Iliac Joint

The stable, broad joint formed between the sacrum and the ilium of the hip bone to bear and transmit body weight into the pelvis.

Intervertebral Disc

A rubbery pad with a fibrocartilage outer layer and jelly-like center situated between adjacent vertebral bodies for shock absorption and flexibility.

Slipped Disc

A painful condition occurring when excess weight-bearing compression forces parts of an intervertebral disc into the vertebral canal, compressing the spinal cord.

Superficial Back Muscles

The muscle group located just deep to the skin (trapezius, latissimus dorsi, levator scapulae, rhomboid major, and rhomboid minor) that moves the scapula and arm.

Intermediate Back Muscles

The middle layer of back muscles (serratus posterior superior and serratus posterior inferior) that weakly act on the ribs during respiration.

Transversospinales

The deepest back muscle group connecting adjacent vertebrae, primarily responsible for lateral bending and spinal rotation.

Rotatores

Small deep muscles belonging to the transversospinal group that aid in spinal rotation and lateral bending.

Costal Facets

Only thoracic vertebrae have costal facets on bodies and transverse processes. Smooth area where a joint is formed with another bone.

Lumbar Vertebra unique features

They have robust spinous, transverse, and articular processes where big muscles attach.

Erector spinae muscles

Run up and down length of spine on posterior aspects of vertebrae and ribs. Inferiorly, they fuse into a single muscle belly. Extend spine and hold body upright.