Diseases, Conditions, Syndromes

What's a pulse oximeter? Should I buy one to monitor COVID at home?

Having a low level of oxygen in the blood is an early sign of worsening COVID. But not everyone gets obvious symptoms. For instance, some people can have low oxygen levels without getting short of breath or feeling otherwise ...

Cardiology

Can damaged hearts heal themselves?

New research has found measuring a protein that forms to create new blood vessels after a heart attack or unstable angina, and determining the protein's genetics, could potentially help to predict long-term survival, specifically ...

Overweight & Obesity

Secretin hormone induces satiation by activating brown fat

Researchers from the Turku PET Centre and Technical University of Munich have discovered a new mechanism controlling satiation. According to the recently published study, the hormone secretin induces satiation by activating ...

page 1 from 18

Circulatory system

The circulatory system is an organ system that passes nutrients (such as amino acids and electrolytes), gases, hormones, blood cells, nitrogen waste products, etc. to and from cells in the body to help fight diseases and help stabilize body temperature and pH to maintain homeostasis. This system may be seen strictly as a blood distribution network, but some consider the circulatory system as composed of the cardiovascular system, which distributes blood, and the lymphatic system, which distributes lymph. While humans, as well as other vertebrates, have a closed cardiovascular system (meaning that the blood never leaves the network of arteries, veins and capillaries), some invertebrate groups have an open cardiovascular system. The most primitive animal phyla lack circulatory system. The lymphatic system, on the other hand, is an open system.

The main components of the human circulatory system are the heart, the blood, and the blood vessels. The circulatory system includes: the pulmonary circulation, a "loop" through the lungs where blood is oxygenated; and the systemic circulation, a "loop" through the rest of the body to provide oxygenated blood. An average adult contains five to six quarts (roughly 4.7 to 5.7 liters) of blood, which consists of plasma, red blood cells, white blood cells, and platelets. Also, the digestive system works with the circulatory system to provide the nutrients the system needs to keep the heart pumping.

Two types of fluids move through the circulatory system: blood and lymph. The blood, heart, and blood vessels form the cardiovascular system. The lymph, lymph nodes, and lymph vessels form the lymphatic system. The cardiovascular system and the lymphatic system collectively make up the circulatory system.

This text uses material from Wikipedia, licensed under CC BY-SA