Anatomy - Section Planes Overview

Study Notes

Planes of Section Through an Organ

Planes of section in the small intestine resemble "glass" sheets and illustrate various shapes despite the organ being tubular.

Types of Section Planes

Sagittal Plane: Divides the body into right and left halves; the term derives from "the flight of an arrow," indicating direction from front to back.
Median Plane: A specific sagittal plane that bisects the body at midline, creating equal right and left portions.
Transverse Plane: Also known as the horizontal plane, it separates the body into superior (upper) and inferior (lower) sections parallel to the ground.
Frontal (Coronal) Plane: Divides the body into anterior (front) and posterior (back) sections; exemplified by the coronal suture, which resembles a crown across the skull.

Organ Sectioning Techniques

Longitudinal Section: A cut along the length of an organ, akin to slicing a hot dog bun.
Transverse (Cross) Section: A complete cut through an organ, similar to cutting a hot dog or banana into round pieces.
Oblique Section: A diagonal cut across the long axis of an organ.

Body Cavities

Body cavities are classified into two primary types: Dorsal and Ventral.
Both cavity types provide protection to internal organs, with the dorsal designation varying between anatomical texts.

Dorsal Body Cavity

Encases the organs of the nervous system, including the brain and spinal cord.
Divided into:
- Cranial Cavity: Houses the brain.
- Vertebral Canal: Encloses the spinal cord.
Protected by membranes known as meninges.

Ventral Body Cavity

Contains the majority of internal organs referred to collectively as viscera.
Major subdivisions include:
- Thoracic Cavity: Superior to the abdominopelvic cavity, mainly containing the heart and lungs.
- Abdominopelvic Cavity: Enclosed by abdominal muscles.

Thoracic Cavity

Subdivided into lateral pleural cavities (each contains a lung) and the mediastinum (contains the heart, major blood vessels, thymus, trachea, and esophagus).

Abdominopelvic Cavity

Comprises:
- Abdominal Cavity: Houses most digestive organs (stomach, intestines, liver, spleen).
- Pelvic Cavity: Contains the urinary bladder, urethra, rectum, and reproductive organs.

Serous Membranes in the Ventral Body Cavity

Line the walls of body cavities and cover the surfaces of internal organs.
Composed of two layers; the inner layer contacts the organs, providing lubrication and protection.

Description

Explore the various planes of section through organs, particularly focusing on the small intestine. This quiz delves into sagittal, median, transverse, and coronal planes, as well as techniques for organ sectioning. Test your understanding of anatomical terminology and sectioning methods.