The endocrine system is made up of glands, which are located throughout the body and secrete hormones into the blood (Herlihy, 2014). Hormones in the body are secreted to control particular organs and tissues, being secreted by feedback control loops, the central nervous system or biorhythms (Herlihy, 2014). For example they regulate metabolic processes, assist in growth and reproduction, during times of need such as trauma or illness and with regulation of water and electrolytes in the body (Herlihy, 2014). Hormones are either classified as proteins, which are the most common or steroids, which are only secreted by the adrenal cortex and sex glands (Herlihy, 2014). They attach to tissues or organs, which are known as targets (Herlihy, 2014). These targets are receptor cells, which are either external and located on cell membranes or internal, within the cell (Herlihy, 2014). There are many glands throughout the body, with the main glands being the, hypothalamus, pineal gland, pituitary gland, thyroid gland, parathyroid gland, thymus gland, adrenal gland, pancreas and the gonads (Herlihy, 2014). The endocrine system is a vital system needed to function optimally to secrete hormones into the blood to be carried around the body to particular sites to then control tissues and organs (Herlihy, …show more content…
Conditions, which affect the sensory system, include colour blindness and glaucoma. Glaucoma is a disorder of the eye where vision loss occurs (Scanlon & Sanders, 2010, p. 223). It is commonly caused by pressure build up due to the aqueous humor, which is watery fluid in the anterior cavity of the eye (Herlihy, 2014). This fluid has 2 main roles, allows the eye to maintain shape and allows the cornea to stay healthy (Herlihy, 2014). When the pressure builds up it cuts off the supply of blood to the retina and the optic nerve becomes damaged (Herlihy, 2014). While Glaucoma causes blindness another condition of the senses is colour blindness. Colour blindness is due to genetics being passed on by either the mother or the father (Scanlon & Sanders, 2010, p. 225). Colour blindness is most commonly associated with the colours red and green where individuals are unable to distinguish between the two colours, resulting in both colours looking the same (Scanlon & Sanders, 2010, p. 225). The retina contains three cones which contain the colours red, green and blue, which when working together form different colours (Herlihy, 2014). Individuals who are colour blind often lack one of these cones (Scanlon & Sanders, 2010, p. 225). Although, individuals who experience these conditions have reduced or no vision they need to ensure they maintain their mental health. Through physical activity they are able