Le cycle ovarien

The ovarian cycle is regulated by a whole series of antagonistic hormones whose quantity present in the blood varies throughout the 28 days of the cycle. How do the brain and the reproductive system control each other's functioning?

Sperm production in the seminiferous tubules of the testicle is regulated by testosterone, the production of which is itself controlled by hormones secreted by the hypothalamic-pituitary complex, located at the base of the brain. But testosterone itself acts in return on the brain...

Carrying the waste products produced by the cells, the 5 liters of blood in our body pass through the nephrons, small filtration units located in the kidneys, 36 times a day. The waste products isolated in this way are diluted in the water present in our body and evacuated in the urine.

An organ of 2 square meters, weighing 5 kg, at the same time flexible, extensible, resistant, and renewing itself every 30 days... Which one is it? The skin, of course! The only organ of our body that we can see and that protects us from radiation, micro-organisms and shocks. Let's travel to the discovery of the three layers that…

In a universe that tends towards ever greater disorder, living beings are able to maintain an internal order. To create this order, the cells of an organism carry out a series of chemical reactions: this is called metabolism. This series of chemical reactions, which leads to the degradation of food molecules in the presence of oxygen…

L'adage est bien connu : le sport, c'est bon pour la santé ! Alors que nos vies sont de plus en plus sédentaires, maintenir une pratique physique régulière s'avère primordial. On le sait aujourd'hui, mettre le corps en mouvement, c'est agir sur l'ensemble de notre métabolisme.

To practice a physical or sports activity, we know that nutrition is a determining factor. Eating well before and after exercise is essential. But what nutrients does our body need? According to what type of effort? What metabolic mechanisms do they trigger at the level of each of our organs, in our tissues, in our skeleton? To…

How are images formed in our brain? At the origin, there is light, the one that is sent back to us by the objects that surround us. It enters our eyes through the lens. But how is the light information captured, interpreted and transmitted? And in fact, do we all see the same thing?

The skin and mucous membranes form a physical barrier that effectively protects the body from external aggressions. However, following a trauma or an infection, foreign micro-bodies may manage to penetrate this shield. A complex defense mechanism is then put in place: the inflammatory reaction...

Throughout life, the immune system keeps a memory of past viral or bacterial attacks. Each time a new antigen appears, certain immune cells are responsible for determining its identity card and storing it in anticipation of a future attack. Vaccination relies on this mechanism to stop the most devastating antigens.

When viruses and bacteria have succeeded in breaking through the body's first defense barrier (the inflammatory reaction), a second line of defense is put into action: this is adaptive immunity. This second protective shield is specific to vertebrates. It implements a complex mechanism using specific white blood cells: the…