The term “fundus” in anatomy refers to the bottom, base, or widest part of a hollow organ, often the portion furthest from its opening. This region typically bulges or expands. The fundus applies to several different organs, highlighting its diverse presence and significance in various physiological systems.
Where is the Fundus Found?
The fundus is found in several key organs, each with a distinct location and role. In the eye, the fundus oculi describes the inner back surface, including the retina, optic disc, and macula. This area is opposite the lens and contains light-sensitive cells for vision.
The stomach also features a fundus, known as the fundus gastricus, the dome-shaped upper part situated above the esophagus. This region typically rests against the diaphragm and can expand significantly. The uterus has a fundus uteri, the broad, rounded upper portion, positioned opposite the cervix and above the fallopian tubes.
Within the urinary system, the urinary bladder has a fundus vesicae urinariae, its posterior base. This area is where the ureters, tubes carrying urine from the kidneys, enter the bladder. The gallbladder also contains a fundus vesicae biliaris, the broad, blind-ended part that extends beyond the lower edge of the liver.
The Fundus’s Role in Body Function
The fundus of various organs contributes significantly to their overall function. The fundus of the stomach acts as a temporary reservoir for undigested food and gas. Its ability to distend allows the stomach to hold larger quantities of food, facilitating the digestive process.
In the eye, the fundus oculi is where light is converted into electrical signals by the retina, sent to the brain via the optic nerve. Its examination can reveal signs related to eye health. The uterine fundus plays a crucial role during pregnancy, as it is the region where a fertilized egg implants and the fetus grows. During childbirth, strong muscular contractions of the uterine fundus help to push the baby out.
The fundus of the urinary bladder forms the posterior wall and is involved in urine storage, with the ureters entering this region. The fundus of the gallbladder is the primary site for the accumulation and concentration of bile, essential for fat digestion. Across these diverse organs, the fundus is a key component, contributing to specific physiological processes and often indicating the organ’s state of health.