The foetal circulation and the changes which that circulation undergoes during and shortly after birth

Fetal circulation is a unique system that facilitates the exchange of gases, nutrients, and waste products between the developing fetus and the mother. This intricate process takes place through a special organ called the placenta.
Two umbilical arteries transport blood from the fetus to the placenta. At the placenta, the blood absorbs oxygen and nutrients while simultaneously eliminating waste products. This oxygen-enriched and nutrient-rich blood then returns to the fetus through one...

The development of the vascular system in a fetus is a complex and intricate process that begins as early as 15 to 16 days post-conception. This process starts outside the embryo, specifically in the mesoderm of the yolk sac, chorion, and connecting stalk. Approximately two days later, the formation of blood vessels occurs within the embryo itself.
The initial formation of this system is facilitated by the small amount of yolk present in the ovum and yolk sac. Blood vessels originate from...

The systemic and pulmonary circuits are crucial components of the circulatory system, working together to transport blood between the heart, lungs, and the rest of the body. The process begins with pulmonary circulation, where deoxygenated blood is pumped from the right ventricle to the lungs via the pulmonary trunk and arteries. Upon reaching the lungs, the blood becomes oxygenated and returns to the heart, specifically to the left atrium, via the pulmonary veins.
The oxygenated blood is sent...

The cardiovascular system is a vital transportation system in the body. It comprises the heart and blood vessels and facilitates the exchange of gases, nutrients, and waste products.
Heart
The heart is the central pump of the cardiovascular system that circulates blood throughout the body. It comprises two atria receiving the blood and two ventricles pumping blood out of the heart. Their rhythmic contractions, called heartbeats, ensure that blood flow remains continuous.
Blood Vessels
Blood...

The development of the human heart, a crucial organ, commences from the mesoderm on the 18th or 19th day after fertilization. This process initiates in the cardiogenic area, a group of mesodermal cells at the embryo's head end, which evolves into elongated strands known as cardiogenic cords. These cords undergo a transformation to form hollow-centered endocardial tubes.
As the embryo undergoes lateral folding, these paired tubes approach each other, merging into a single primitive heart tube by...

The human circulatory system consists of blood, blood vessels that carry blood away from the heart, around the body, and back to the heart, and the heart itself, which acts as a central pump. The systemic circuit supplies blood to the whole body, the coronary circuit supplies blood to the heart, and the pulmonary circuit supplies blood flow between the heart and lungs.