What is an Anatomical Position in the Human Body?

Anatomical position refers to the position in which an individual faces forward with their upper limbs stretched to both sides with palms facing forward. The standard anatomical position of the body is used to reference other anatomical aspects of the body. 

Anatomical Positions

The anatomical position is a way of representing the human body and its anatomy in a descriptive manner such that the positions of different organs and other body parts can be clearly understood and studied. It is the positioning of a specific part of a body at any particular angle. The different comparative analysis is done under anatomical positions that help one to locate different structures inside the body so that anatomy studies can be done easily. Anatomical positions are studied in terms of comparative studies where body planes, cavities, and directional terms are used to explain the anatomy completely.

The importance of standardization in anatomical positions

The standardization of anatomical positions gives us clarity around different organs of different organisms. The anatomical position is universally studied for various organisms around including human beings and enabling the anatomical representation of different species. The standardization of anatomical position is accepted internationally and thereby making anatomical studies easier.

In human beings, the standard anatomical position is considered when the body is standing upright, whereas in quadruped animals the anatomical position is considered with a posture with all four feet stabilized on the ground and body structure lying parallel to feet.

Anatomical Positions and Body Plane

To study the anatomical positions, the human body is divided into three anatomical planes that separate different body organs. The three-body planes are the coronal plane, sagittal plane, and transverse plane. They are described as follows:

Coronal plane

This plane divides the body into anterior and posterior sides also known as dorsal and ventral sides. This is also called the frontal plane and it works perpendicular to the sagittal plane.

Sagittal plane

This plane of sagittal passes from top to bottom in the vertical direction and divided the body into two halves as left and right. This plane is also known as midsagittal or median as it divides a body into two halves through the midline. 

Transverse plane

This plane runs perpendicular to the caudal plane and separates the body into cranial and caudal sections. It is otherwise called the axial plane which cuts the body at right angles to the coronal and sagittal plane. 

Anatomical Positions and Role of Body Cavities

Body cavities are a very important part of the anatomical position that describes the management of internal organs in a body and the arrangement of various membranes and sheaths to segregate and compartmentalize various body parts from one another. These body cavities give the human body, a proper system for several organs to work without any disturbance. The body cavities are of 3 types as follows:

Cranial cavity

It is made by cranial bones and they are present in the central nervous system. This cavity contains the cerebrospinal fluid that helps in the functioning of the central nervous system including the brain and the spinal cord. It is part of the dorsal cavity.

Thoracic cavity

It is surrounded by the rib cage and contains the heart and lungs. This cavity gives support to the mediastinum area. The diaphragm supports the thoracic cavity from below and helps in the separation of the abdominopelvic cavity. The thoracic cavity is divided into superior, middle, anterior, and posterior mediastinum cavities along with pleural cavities.

Abdominopelvic cavity

It has two parts as abdominal and pelvic which together are termed abdominopelvic. This cavity is located below the diaphragm and holds the digestive system and reproductive system. The abdominal cavity specifically contains most of the region of the Gastrointestinal tract followed by the adrenal glands and kidneys. The pelvic cavity contains most of the region called the urogenital system and rectum.

Anatomical Terms used in the Description of Anatomical Positions

Regional terms used in the description of anatomical positions

Regional terms are also an important system for the separation of the body according to similar functions. This system includes axial and appendicular regions. The axial region involves the parts of the human body that make up the main axis including the head, neck followed by the chest, and trunk of the body. Similarly, the appendicular region of the human body connects the different body parts to the axial regions of the body. It includes the appendages and limbs. 

Directional terms used in the description of anatomical positions

The directional terms are very essential for anatomical studies as they are widely used in different ways for the description of locations of different body organs. The basic directional terms are as follows: 

• Anterior or ventral position describes the front portion of the human body. For example, the toes are anterior to the foot. Posterior or dorsal describes the back portion of the body. For example, the posterior pituitary gland secretes oxytocin and antidiuretic hormones, prolactin, and growth hormones are secreted by its posterior region.
• Superior or cranial describes the higher position of one organ than the other in the body. Inferior or caudal describes the position below to other parts of the body. For example, superior and inferior vena cava are the two branches of vena cava that carry blood from the upper half and lower half of the body respectively.
• Lateral position is the position or direction toward the side of the body. The medial position is the middle portion of a body. This position is named the midline that is a line drawn vertically from the central position of the forehead to the bottom. The arms and lungs exist as symmetrical and bilateral in the medial position in the human body.
• Proximal and Distal are studies together as per the reference point. The proximal position is the near place to a reference point, whereas the distal position is farther compared to the proximal. For example, the proximal convoluted tubule starts soon after glomerulus and is thus named proximal, whereas the distal convoluted tubule is present later and so they are named distal.
• Superficial is the position nearer to the surface of the body. For example, skin is superficial to the bones. Deep is the position that is very far from the surface of the body. For example, the brain is present deep within the skull in the human body.

Types of Movements 

Types of movements describe the feasibility of several movements in accordance with the bifurcation of the body concerning anatomical positions. Two important factors that are essential for joint movements are the axis, around which movement takes place and the plane of the movement. Rotation, extension, inversion, circumduction, deviation are some examples of important movements that take place in the body. Thus, the various anatomical positions can be easily studied and learn with the help of clear ideas about the plane of the axis, body cavities, and various directionalities. One should always study anatomical positions with diagrams as the diagrams give a visual understanding of inside functioning and the different anatomical terminology should be learned and used properly.

Practice Problem 

Which plane is defined as a horizontal line via the body?

Answer: Transverse plane is described as a horizontal plane that can divide any body region into lower and upper parts.

Context and Applications

This topic is significant in the professional exams for both undergraduate and graduate courses, especially for 

B.Sc. in Biology   

B.Sc in Microbiology   

M.Sc in Microbiology   

Masters in Microbial Biotechnology