The cardiovascular system consists of the heart and blood vessels that get bifurcated further into veins, capillaries, and arteries. Lungs and airways make the most of the respiratory system; these, coupled with other structures help in the inhalation and exhalation process. Muscles are the other part of the system that helps the lungs to expand and contract in sync with inhalation and exhalation.
Absorption starts in the body after the food is broken down into its building blocks. The process of absorption starts in the abdomen with the direct consumption of simple substances( e.g. water and alcohol) into the bloodstream. However, small intestine is the place where the maximum absorption process occurs; it is densely folded that prolongs the contact of the walls with the digested food. . Lymphatic and small blood vessels in the wall of small intestine pick up the molecules from the food and transport them to other body parts. The large intestine absorbs water and vitamin B and K.
Excretion is the concluding function of the digestive system. After absorption, waste is excreted from the body through a process known as defecation. It throws indigestible substances out of the body and prevents them from being accumulated in the gut. Defecation time, to an extent, is guided by the brain; it must be done on regular basis to prevent the indigestible material from getting stuck inside the body.
Apparently, transportation plays a crucial role in the human body as nutrients, respiratory gases, and waste products need to be transported both in and out of the body. Cells require different nutrients and materials to perform their specific tasks. As energy flows, these materials also flow in the cells thereby sustaining cell growth and replacement. The transportation system in the body may occur through various ways.
Passive transport or diffusion occurs by which materials get transported through membranes and within cells. Diffusion occurs to move materials from the areas of high concentration to the areas of lower concentration. In passive transportation, cells don't use energy to move molecules. By contrast, the cell uses energy to transport molecules in and out of the cell. This is done by active transportation mechanism. Materials move against the gradient, unlike passive transportation in which materials move with the gradient.
Clearly, all body systems are significant to carry out specific tasks and to keep the body in good health and shape. While the digestive system breaks down food and removes waste, the immune system protects the body against harmful viruses and pathogens. The endocrine system comprises eight major glands and secretes hormones in the blood. The nervous system, having transmitted proper signals to different organs, guides our voluntary(mindful movements) and involuntary actions( breathing). Skeletal system consists of 206 bones that are conjoined by tendons, ligaments, and cartilage. This system assists the human body in storing calcium and producing blood cells.
Integumentary system, the largest body organ, protects us from the bacteria and viruses. Skin helps the human body maintain its temperature and eliminates waste via perspiration. Muscular system, consisting of 650 muscles, assists the human body in blood flow and other body movements. While cardiac muscle helps the heart in pumping the blood, skeletal muscle facilitates mindful movements by being properly connected to the bone.
References
Aaronson, P. J., Jeremy, W., & Connolly, M. (2012). The Cardiovascular System at a Glance. John Wiley & Sons.
Anatomy and Physiology of Organ Systems. (2015). Retrieved May 5, 2016, from austincc.edu: http://www.austincc.edu/mlt/phb/phb_unit2LecAnatomyAndPhysiology_Jan31_2013.pdf
Civardi, G. (2001). Drawing The Human Body: An Anatomical Guide. Sterling Publishing Company.
Insel, P., Ross, D., & McMohan, K. (2013). Nutrition. Burlington: Jones & Bartlett Publishers.
