· Pillai & Lichtman, 2015). · The reproductive
· The immune system: It defends the body against pathogenic microbes that are exposed to the human body on a daily basis. The body’s defensive mechanism is achieved through an immune response which attacks disease-causing microbes likely to invade the body’s system. Also, the immune system is composed of specialised cells, various tissues, organs and proteins that work together to protect the body. The organs and tissues involved in the actives of the immune system are known as lymphoid organs, consisting of the spleen, bone marrow, thymus, appendix, lymph nodes, tonsils and Peyer’s patches found throughout the small intestinal duct. One of the important cells involved are white blood cells, also known as leukocytes which come in two basic types (phagocytes & lymphocytes) that combine to seek out and destroy disease causing organisms (Abbas, Pillai & Lichtman, 2015).
· The reproductive system: Number of organs within an organism that works together for the purpose of new creation. The role of the reproductive system involves producing hormones, developing cells, producing sperms and egg cells as well as transporting and sustaining the cells.
The organs associated with the process of reproduction entail the male and female reproductive organs. The male reproductive system comprises the penis, testes, sperm duct, scrotum and the epididymis while the female reproductive system which consists of the fallopian tubes, ovaries, uterus, urethra, cervix and vagina. From this, reproduction happens when the two gametes fuse together, releasing sperms from the male reproductive organ to fertilise an egg from the female reproductive organ (NHS choices, 2016).
· The circulatory system: This comprises of the heart, blood vessels (arteries, veins and capillaries) as well as the blood. The heart acts like “an anatomical pump, with its intricate conduits (arteries, veins and capillaries) that traverse the whole human body carrying blood” (Medscape, 2014). The blood contains oxygen, nutrients and waste that help to provide homeostasis and other functions of human cells and organs.
According to Medscape (2014), the circulatory system is also a two-way system. It has two circulatory circuits called pulmonary circuit and systematic circuit. Pulmonary circuit carries blood to the lungs to be oxygenated and then carried back to the heart. This is where gas exchange takes place. Systematic circuit, on the other hand, transports blood around the body. It is also responsible for transporting oxygen and nutrients to the body tissues as well as carrying away de-oxygenated blood (Medscape, 2014).
· The Locomotor system: Enables movement to take place using two systems- the muscular system and the skeletal systems. This type of system consists the bones, muscles, tendons and ligaments. The primary functions of the locomotor system include allowing movement, producing heat, storing calcium and phosphorus, supporting and protecting vital organs as well as giving shape to the body. The locomotor system is also made of hard and soft tissues. The hard tissues of the locomotor system include the skeleton and cartilage, while the soft tissues involve muscles, tendons, ligaments, joints and synovial membrane (Lumen learning, 2017).
“The skeletal system provides supportive analogous to a reinforcement bar in concrete construction. Motion occurs when various bones are connected to articulating joints. Cartilage prevents the ends of bones from rubbing directly on each other while the muscles contract to move the bones associated with the particular joint” (Lumen Learning, 2017). The muscular system, on the other hand, keep bones in place as well as play an essential role in the body movement.
· The endocrine system: Made up of ductless glands which are responsible for producing and secreting hormones and chemical substances which are produced in the body to regulate the activity of cells and organs. The major glands of the endocrine system are the hypothalamus, pituitary gland, the thyroid gland, the parathyroid glands, adrenal glands, pineal gland, pancreas and the gonads. These secrete different types of hormones which are responsible for regulating metabolism, growth and development, tissue function, sexual function, sleep and mood. (Emedicine Health, 2017). “Hormones are chemical messengers that transfer information from one cell to another to coordinate the functions of different parts of the body” (Emedicine Health, 2017).
· The nervous system: Olesky (2001), the nervous system “sends messages from your brain through your body in the form of nerve signals to make it do certain things, like raising your hand in class or kicking a ball”. The nervous system consists of the brain, spinal cord, sensory organs and all the nerves connected to these organs. Together, they function by controlling and enabling communication to take place within the body. This involves the sensory function, the interpretative function and the motor function. The four body systems of the nervous system include: the central nervous system, the peripheral nervous system, the somatic nervous system and the autonomic nervous system (ibid, 2001, p.4-5)