What is the sacrum? The sacrum (Os sacrum) is the penultimate segment of the spine. It consists of the five fused sacral vertebrae and their rib remnants, which together form a large, strong and rigid bone. This has a wedge shape: it is broad and thick at the top and becomes narrow and thin toward … Sacrum: Structure and Function
How the pulmonary circulation works The pulmonary circulation, together with the great or systemic circulation, forms the human circulatory system. It begins in the right heart: the blood, which is low in oxygen and loaded with carbon dioxide, coming from the body is pumped via the right atrium and the right ventricle into the truncus … Pulmonary Circulation: Structure and Function
What are blood vessels? Blood vessels are hollow organs. With a length of around 150,000 kilometers, these tubular, hollow structures create an interconnected network that runs through our entire body. Connected in series, it would be possible to circumnavigate the earth almost 4 times. Blood vessels: structure The vessel wall encloses a cavity, the so-called … Blood Vessels: Structure and Function
What is serotonin? Serotonin is a so-called neurotransmitter: it is a messenger substance that transmits information from one nerve cell to another in our nervous system. Serotonin is found in both the central and peripheral nervous systems. It is also found in blood platelets (thrombocytes) and in large quantities in special cells of our gastrointestinal … Serotonin: Effects and Structure
What is the cerebrum? The cerebrum or endbrain makes up the main part of the human brain. It consists of a right and a left half (hemisphere), the two connected by the bar (corpus callosum). Apart from the bar, there are other (smaller) connections (commissures) between the two halves of the brain. External division of … Cerebrum: Function, Structure, Damages
What is the cornea (eye)? The cornea of the eye is the translucent, anterior part of the outer skin of the eye. The much larger part of this eye skin is the sclera, which can be seen as the white part of the eye. The cornea is a flat protrusion at the front of the … Cornea (Eye): Structure and Function
What is the esophagus? The esophagus is a stretchable muscular tube that connects the pharynx to the stomach. Primarily, the esophagus ensures the transport of food and fluids through the throat and chest into the abdomen. An outer layer of connective tissue ensures the mobility of the esophagus in the chest cavity during swallowing. Blood … Esophagus: Structure and Function
What is the blood-brain barrier? The blood-brain barrier is a barrier between the blood and the brain substance. It is formed by the endothelial cells on the inner wall of the blood capillaries in the brain and the astrocytes (a form of glial cells) surrounding the vessels. The endothelial cells in the capillary brain vessels … Blood-Brain Barrier: Structure and Function
Venous versus arterial Arteries carry blood away from the heart, veins towards the heart. The proportion of the two types of vessels in the circulatory system is very different: compared to the veins, which make up the majority of blood vessels at around 75 percent, arteries are outnumbered at only around 20 percent (capillaries five … Artery: Structure and Function
What is a scrotum? The scrotum (scrotum) is a skin pouch, more precisely a pouch-like protrusion of the anterior abdominal wall. It is formed by the fusion of the embryonic sexual protrusions – which occur in both sexes. The seam can be recognized by a darker coloured line (raphe scroti). The scrotum is divided into … Scrotum (Testicles): Structure and Function
What is the portal vein circulation? The portal vein circulation is a part of the large blood circulation. The main vessel is the portal vein (Vena portae hepatis). It transports deoxygenated blood from the stomach, intestines and other abdominal organs to the liver. The blood contains numerous substances that have been absorbed from the digestive … Portal Circulation: Structure and Function
What is the medulla oblongata? The medulla oblongata (myelencephalon, afterbrain) is the lowest and rearmost area of the brain. After transition from the spinal cord, it thickens in an onion shape and ends at the bridge. The myelencephalon contains cranial nerve nuclei and is thus the origin of cranial nerves VII to XII, which emerge … Medulla Oblongata: Structure and Function
