There are eight systems in human body: motor system, nervous system, endocrine system, circulatory system, respiratory system, digestive system, urinary system and reproductive system. These systems coordinate with each other, so that all kinds of complex life activities in the human body can be carried out normally.
digestive system
The digestive system consists of digestive tubes and digestive glands. Responsible for food intake and digestion, so that we can get nutrients such as sugar, fat, protein and vitamins.
nervous system
The nervous system is the main system in the body. All kinds of information of internal and external environment are received by receptors, transmitted to the centers of brain and spinal cord through peripheral nerves for integration, and then controlled and regulated by peripheral nerves to maintain the relative balance between the body and internal and external environment. The nervous system consists of nerve cells (neurons) and glia. The nervous system is divided into central nervous system and peripheral nervous system.
respiratory system
The respiratory system includes respiratory tract (nasal cavity, pharynx, larynx, trachea, bronchus) and lung.
In the process of metabolism, animals constantly consume oxygen and produce carbon dioxide. The process of gas exchange between human body and external environment is called breathing. There are two places for gas exchange. One is the gas exchange between the outside world and respiratory organs such as lungs and gills, that is, lung respiration or gill respiration (or external respiration). The other is gas exchange (internal respiration) between blood and tissue fluid and between body tissues and cells.
circulatory system
The circulatory system is a system composed of body fluids (including blood, lymph and interstitial fluid) and their circulation pipes. Since the formation of the heart, the circulatory system of animals has been divided into two parts: heart and blood vessels, which is called cardiovascular system. The circulatory system is a transport system in organisms, which transports nutrients absorbed by digestive tract and oxygen inhaled through gills or lungs to various tissues and organs, and inputs the metabolites of various tissues and organs into blood through the same way, and then discharges them through lungs and kidneys.
motor system
Motion system: the bone surface is dense and hard, which is called bone compactness; The interior of the bone is honeycomb, which is called cancellous bone; The cavity in the bone is called marrow cavity, and the center is filled with bone marrow. The bone marrow of fetus and baby is red bone marrow, which is a hematopoietic organ. With the increase of age, the red bone marrow in the long bone marrow cavity is gradually replaced by adipose tissue and becomes yellow bone marrow.
endocrine system
Endocrine glands are some glands in the human body that have no outlet ducts. Its secretions are called hormones. It plays a regulatory role in the growth, development, metabolism and reproduction of the whole body.
The main endocrine glands in human body are: thyroid gland, parathyroid gland, adrenal gland, pituitary gland, pineal gland, islet, thymus gland and gonad.
urinary system
The urinary system consists of kidney, ureter, bladder and urethra. Its main function is excretion. Excretion refers to the physiological process in which various substances that are not utilized or harmful to the body are transported to the outside world during the metabolism of the body. Part of the discharged substances are metabolites of nutrients; The other part is the product of the destruction of aging cells. In addition, excreta also includes some unnecessary substances ingested with food, such as excess water and inorganic salts.
genital system
Reproductive system is the general name of organ components closely related to reproduction in organisms.
The function of reproductive system is to produce germ cells, reproduce new individuals, secrete sex hormones and maintain quasi-sexual characteristics.
There are two types of human reproductive system: male and female. According to the position of genitalia, it is divided into two parts: internal genitalia and external genitalia.
Many organs in multicellular organisms are connected together, and * * * completes some continuous basic victory functions. These organs form a system. Humans and higher animals have eight systems, namely digestive system, respiratory system, circulatory system, urinary system, exercise system, reproductive system, endocrine system and nervous system. The above-mentioned systems constitute the human body and the animal body, which are interrelated and restricted with each other under the regulation of the nervous and endocrine systems, so as to complete all the life activities of the whole organism and ensure the individual survival and racial continuity of the organism.