Human Anatomy Part 1 - K. A. Dyubenko, A. K. Kolomiytsev, Yu. B. Chaykovsky 2002

Special Part
Splanchnology, splanchnologia [the study of viscera] - General Overview

Splanchnology (from the Greek splanchna meaning viscera, and logos meaning study) is a branch of anatomy that examines the development, Structure, and topography of Internal Organs responsible for metabolic processes between the body and the environment, as well as reproductive Functions.

The viscera, or splanchna s. viscera, refer to the organs located within the internal cavities of The Human Body (abdominal, thoracic, and pelvic). They ensure METABOLISM, food intake, Digestion, absorption, and The excretion of waste products into the environment, along with hormone production and reproduction. Depending on their functional characteristics, internal organs are grouped into the following systems:

- Digestive System, systema digestorium;

- Respiratory system, systema respiratorium;

- Urinary System, systema urinarium;

- reproductive systems, systemata genitalia.

The internal organs of these systems share a common origin, similar structure, and close TOPOGRAPHIC AND ANATOMICAL relationships, with highly interconnected functions. The coordination among these organs and their interaction with the environment are regulated by The Nervous system.

The digestive system transforms food into substances (Proteins, fats, and CARBOHYDRATES) that can be assimilated by body Tissues, and also eliminates undigested food residues.

The respiratory system ensures the uptake of oxygen into the body and the elimination of carbon dioxide.

The urinary system excretes the End products of Metabolism from the body.

The reproductive systems ensure human procreation.

Internal organs in the human body are structured around three tubular formations:

- the digestive tract, extending along the entire body with two openings: the oral and anal orifices;

- the respiratory tract, featuring a single opening: the nasal orifice;

- the URINARY AND REPRODUCTIVE systems, which possess only outlet openings (in males, the urethral opening; in females, the urethral and vaginal openings).

Externally, some internal organs are covered by an adventitial membrane, while others are covered by a serous membrane, which protects them against excessive friction, enhances mobility, and ensures structural fixation.

The thoracic and abdominal cavities of the human body are lined with a serous membrane. This membrane not only lines the cavities (parietal layer) but also covers the organs situated within them (visceral layer). The free surface of the serous membrane facing the peritoneal cavity is smooth and glossy. A slit-like space, lubricated by a small amount of serous fluid, is formed between the parietal and visceral layers of the serous membrane.

Tubular organs resemble a tube with a cavity enclosed by walls. Glandular organs consist of parenchyma—accumulations of specific Cells—and a Connective Tissue framework known as stroma. Some of these organs possess excretory ducts, whereas others (such as Endocrine glands) lack them.

The walls of hollow organs are composed of three layers: an inner mucosal layer with a submucosa, a middle muscular layer, and an outer connective tissue or serous layer. Blood and Lymphatic vessels, which transport structural and energetic Materials, as well as nerve structures that regulate organ functions, are embedded within the walls of internal organs.