Endocrine System
Maintains proper chemical balance inside the organism and stimulates reproduction and development. These functions are carried out thanks to the action of hormones which are substances secreted by endocrine glands.
They include: hypothalamus, pituitary gland, thyroids, parathyroids, pancreas, suprarenal glands and gonads. Hormones are liberated into the bloodstream, acting on specific organs and controlling their functions.
Excretory System
It is in charge of eliminating liquid and solid waste from the organism. It comprises:
– Urinary tract: comprises the kidneys, ureters, bladder and urethra.
Its main function is to filter substances in the bloodstream that are eliminated through the urine.
– Rectum and anus: these structures are located at the end of the digestive system and are in charge of eliminating solid waste (feces).
Immune and Lymphatic System
The immune system protects the organism against pathogens.
There are two types of immune responses in the event of such attacks: innate and adaptive or acquired.
The first response protects a person from the moment of birth and is in charge of phagocyte cells; the second response develops when the body is repeatedly exposed to harmful substances, which the body is prepared to respond to because an immune response has already been developed. The cells that participate in this type of immune system are lymphocytes.
The lymphatic system is also in charge of protecting the organism from pathogenic agents. The organs are divided into:
– Primary or central organs: thymus gland and bone marrow.
– Secondary or peripheral organs: the nodes, lymphatic tissue and the spleen.
