Anatomical Terms, Body Planes, and Microscopy

Vocabulary and terminology from Laboratory 1: Anatomical Terms, Body Planes, and Microscopy.

Anatomic position

A common reference position characterized by an upright stance, feet parallel and flat on the floor, upper limbs at the sides with palms facing anteriorly, and eyes looking forward with a level head.

Section

An actual cut or slice that exposes internal anatomy.

Plane

An imaginary flat surface passing through the body.

Coronal (frontal) plane

A vertical plane dividing the body into anterior (front) and posterior (back) parts.

Transverse (cross-sectional) plane

A horizontal plane dividing the body into superior (top) and inferior (bottom) parts.

Midsagittal (median) plane

A vertical plane dividing the body into equal left and right halves.

Sagittal (parasagittal) plane

A plane parallel to the midsagittal plane but to the left or right, dividing the structure into unequal portions.

Oblique plane

A plane that passes through a structure at an angle.

Axial region

The main vertical axis of the body, consisting of the head, neck, and trunk.

Appendicular region

The portions of the body consisting of the upper and lower limbs.

Dorsal (posterior) cavity

The internal space completely encased in bone, subdivided into the cranial cavity and the vertebral canal.

Cranial cavity (endocranium)

The part of the dorsal cavity formed by the bones of the cranium which houses the brain.

Vertebral canal

The part of the dorsal cavity formed by the bones of the vertebral column which houses the spinal cord.

Ventral cavity

The larger, anteriorly placed cavity that does not completely encase organs in bone and is separated by the diaphragm into thoracic and abdominopelvic cavities.

Mediastinum

The central region of the thoracic cavity between the lungs, containing the thymus, esophagus, trachea, and major blood vessels.

Parietal layer

The layer of a serous membrane that lines the internal surface of the body wall.

Visceral layer

The layer of a serous membrane that covers the external surface of organs (viscera).

Serous fluid

A lubricant liquid secreted by cells in the serous membrane that reduces friction between organs and the body wall.

Pleura

The two-layered serous membrane associated with the lungs, consisting of parietal and visceral layers and a pleural cavity.

Pericardium

The two-layered serous membrane associated with the heart, consisting of the parietal pericardium (sac around the heart) and visceral pericardium (external heart surface).

Peritoneum

The two-layered serous membrane lining the abdominopelvic cavity and covering most of its organs.

Umbilical region

The middle region of the nine abdominopelvic compartments, named for the navel at its center.

Epigastric region

The abdominopelvic region located superior to the umbilical region.

Hypogastric region

The abdominopelvic region located inferior to the umbilical region.

Hypochondriac regions

The right and left abdominopelvic regions located inferior to the costal cartilages and lateral to the epigastric region.

Iliac regions

The right and left abdominopelvic regions located lateral to the hypogastric region.

Parfocal

The property where a microscope stays in focus when magnification is increased, requiring only minimal adjustments with the fine adjustment knob.

Resolution

The ability to differentiate between two close objects as separate or not.

Working distance

The distance between the mechanical stage and the tip of the objective lens; this distance decreases as magnification increases.

Field of view

The circular area visible when looking through the microscope eyepiece.

Scanning objective

The focus lens with a magnification of $4\times$, typically marked with a red band.

Oil immersion objective

The focus lens with a magnification of $100\times$, typically marked with a white band.

Total magnification formula

$$\text{Total Magnification} = \text{Power of Ocular Lens} \times \text{Power of Objective Lens}$$