Anatomy and Physiology: Cell Structure, Vertebral Column, and Trunk Musculature

Practice vocabulary flashcards covering cell anatomy, spine and rib structures, vertebral landmarks, and trunk musculature.

Cell Wall

A rigid outer boundary found in plant cells, such as onion cells, that gives them a structured and organized shape, which human cells lack.

Cell Membrane

A thin layer surrounding human and plant cells that regulates what enters and leaves the cell.

Cell Stain

A substance applied to cell specimens under a microscope because cells are naturally transparent and require color to be visible.

Mitochondria

The organelle referred to as the powerhouse of the cell, directly involved in the ATP energy system.

Nucleus

The controller organelle of a cell that contains genetic material such as DNA and RNA.

Cervical Vertebrae

The seven vertebrae ($C1$ through $C7$) located in the neck region of the vertebral column.

Thoracic Vertebrae

The 12 vertebrae ($T1$ through $T12$) located in the upper and middle back that articulate with the ribs.

Lumbar Vertebrae

The five large vertebrae ($L1$ through $L5$) located in the lower back.

Atlas ($C1$)

The first cervical vertebra ($C1$), which sits at the top of the spine and rotates on top of the second cervical vertebra.

Axis ($C2$)

The second cervical vertebra ($C2$), which features the dens and acts as the axis of rotation for the atlas.

Dens

A distinct upward projection on the axis ($C2$) vertebra that acts as a pivot point for the atlas ($C1$).

True Ribs

Ribs 1 through 7, which have independent cartilaginous attachments directly connecting to the sternum.

False Ribs

Ribs 8 through 12, which do not attach directly to the sternum but instead merge together or end freely.

Floating Ribs

Ribs 11 and 12 ($T11$ and $T12$), classified as false ribs because they have no anterior attachment to the sternum.

Costal Cartilages

Flexible cartilage structures connecting ribs to the sternum that absorb shock and allow expansion and compression during breathing.

Manubrium

The superior landmark section of the sternum.

Xiphoid Process

The small, inferior projection and landmark located at the tip of the sternum.

Jugular Notch

A landmark located at the top of the sternum that can be palpated just below the hyoid region.

Pedicle

The bony bridge connecting the vertebral body to the posterior arch and processes of a vertebra.

Lamina

The posterior portion of the vertebral arch located between the transverse process and the spinous process.

Spinous Process

The posterior projection of a vertebra that angles downward when in standard anatomical position.

Transverse Process

A lateral projection extending from the side of a vertebra.

Superior Articular Process

A process extending superiorly from a vertebra that provides an articulation surface with the vertebra above it.

Inferior Articular Process

A process extending inferiorly from a vertebra that provides an articulation surface with the vertebra below it.

Vertebral Foramen

The main central opening in a single vertebra through which the spinal cord passes.

Intervertebral Foramen

An opening formed between stacked adjacent vertebrae that allows peripheral spinal nerves to exit.

Median Sacral Crest

A mid-line ridge landmark running down the posterior surface of the sacrum along the midsagittal plane.

Sacral Foramina

The plural term for the multiple neural holes present in the sacrum.

Sternocleidomastoid

An anterior neck muscle attaching to the sternum, clavicle, and mastoid process; bilateral contraction produces cervical flexion, whereas unilateral contraction produces contralateral rotation.

Erector Spinae

A group of deep muscles on the posterior side of the spine that performs spinal extension.

Rectus Abdominis

An anterior abdominal muscle with vertically aligned fibers that produces spinal flexion.

Transverse Abdominis

The deepest abdominal muscle layer, featuring horizontal fibers running in a transverse plane.

External Oblique

The superficial outer abdominal muscle layer; unilateral contraction produces contralateral rotation to the opposite side.

Internal Oblique

An abdominal muscle layer deep to the external oblique; unilateral contraction produces ipsilateral rotation to the same side.

Quadratus Lumborum

A posterior abdominal/lumbar muscle that performs lateral spine flexion to maintain upright walking balance and equilibrium.

Contralateral Rotation

Rotation of a joint or body part toward the side opposite of the contracting muscle.

Ipsilateral Rotation

Rotation of a joint or body part toward the same side as the contracting muscle.

Platysma

The most superficial muscle layer in the neck region, situated superficial to the sternocleidomastoid.