|Original (French) Title||Le Sang|
|The Bone Marrow||The Tiny Platelets|
The Blood is the fifth episode of Once Upon a Time.. Life. It focuses on the properties and circulation of the titular liquid tissue.
The episode begins with the narrator showing the circulatory system in the background, stating that if all blood vessels were to combine into a unique chain it would measure more than Earth's diameter. She presents the blood which circulates through those vessels and its compositon. During the daily routine, Globin unintentionally throws a carbon dioxide molecule at Globus. As usual, Hemo is distraught having to carry carbon dioxide (a lot of it considering he is large). She mocks him in a friendly way by crawling up to the heap he is carrying which makes him sweat. She tries to cheer him up considering that they're close to entering the pulmonary circulation.
A bit later, an unknown pathogen approaches Globin and starts wrapping out in a flirty way, but soon starts to compress around her. Globus quickly brings a Neutrophil, who fights the pathogen and then takes a fatal swallow. Another Neutrophil directs the Red Corpuscles to keep moving. They reach the alveoli and Hemo is finally relieved.
As the circulation continues, some Red Corpuscles discuss about their experiences regarding their jobs, and Globus points out their short lives full of work. Globin finds a sugar molecule and grabs it to lick it, but stops when a member of police notices her. Very soon, the system orders all cells to export their sugar reserves to blood, to which Globin thinks it's her fault. Globus, however, tries to assure her that it's a normal thing.
In the nucleus of a nearby cell, Maestro quickly orders the Golgi Bodies to export sugar to blood. In team work, cells bring the end to the shortage. A bit later, the three arrive to the spleen where Globus says bids his farewell, but tells Hemo and Globin not to worry given the fact how many Red Blood Cells are created per day. Later, the two reach the cells where they receive their carbon dioxide. However, an Enzyme fails to find any Red Corpuscles and simply disposes of carbon dioxide in the intercellular space. This causes the another system message to occur, requesting a quick action to get rid of carbon dioxide; the rate of breathing's been increased.
In tracheal tissue, a policeman forces two Red Corpuscles to carry carbon dioxide after mocking a worked-up Hemo. He also tries to do the same when he sees two Red Corpuscles with visibly full-to-top pouches. Then, Lieutenant Jumbo requests help from Macrophages instead. Later on, he and his two colleagues find a few intruders and get attacked when they ask for their identity cards. Lieutenant Jumbo recognizes them as streptococci. Neutrophils arrive as reinforcements, while Captain Peter orders to cease fire being unable to distinguish friend from foe safely. Macrophages arrive and help in the battle and ultimately clean the battlefield.
The scene changes to the outside world where Peter exercises wrestling with Jumbo. During the break, Peter begins sneezing and it turns out that it's Viruses that had snuck in while Neutrophils were resting. They soon cause an infection. Maestro, alarmed, receives two Interferons reporting attack of Flu B Virus. In meantime, the Platelets almost clog the blood vessel and are dismissed by Lieutenant Claire, who assures them that they have an important role. She sets off with Captain Peter to fight the viruses.
L. Jumbo and his Neutrophils arrive to the battle site with Lymphocytes. The battle begins as the polinuclear police performs phagocytosis on the Viruses. L. Claire starts the Antibody dropping operation, but soon enough Jumbo finds his armies outnumbered.
As the last hope, Captain Peter carries out the next strategy: he orders all the Neutrophils to retreat, but only Jumbo stays to fight the Viruses. Then he demands the Lymphocytes and Neutrophils to perform the operation mitosis, which happens. The Neutrophils return with toxic guns, which they use to finish off the Viruses to every last one. Jumbo is then found lying on the tissue, exhausted, as Claire and Peter are worried. Soon, in the outside world, a recently sick Peter feels better.
- This is the first episode to feature a major battle between body's sentinels and pathogens.
- This episode introduces the routine of Red Corpuscles exchanging oxygen and carbon dioxide.
- This episode marks the first time the Viruses caused the infection that grew into the illness.
- Blood is the only liquid tissue in humans and other animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells.
- The blood composition in vertebrates:
- Blood plasma takes 55% of blood and is mostly water and contains proteins, fats, sugars, vitamins, minerals and many other organic molecules, including the blood cells themselves.
- The other 45% is made up of blood cells:
- Red blood cells (erythrocytes) are the most abundant cells in the bloodstream that give blood its red color and are responsible for carrying oxygen and carbon dioxide using hemoglobin, a protein substance with iron deposits that helps them in gas transportation. They lack nucleus.
- White blood cells (leukocytes) are less numerous than red blood cells, but are the most diverse. Their task is to fight and/or prevent any pathogen rampage in the body.
- Platelets (thrombocytes) are responsible for wound reparation and blood clotting procedures.
- The vertebrate blood is bright red when it's full of oxygen, but it turns darker when it has carbon dioxide instead.
- Males have slightly more red blood cells by a microliter of blood (around 4.7 to 6.1 million) compared to females (around 4.2 to 5.4 million).
- Karl Landsteiner discovered the ABO groups in 1900 while Jan Janský performed the first blood group classification in 1907. The first non-direct transfusion was performed on March 27, 1914. The Rhesus factor was discovered in 1937.