14.2.1 EXRETORY SYSTEM, jihaz bawli

The excretory system consists of the kidneys, ureters, bladder, and urethra. The system forms and voids urine and ensures fluid and electrolyte balance It ensures homeostatic control of the body by controlling and maintaining the volume, pH, and ionic composition of plasma. The kidney is the most important organ in homeostasis fulfilling the physical laws, sunan al kawn, relating to equilibrium and balance, tawazun & i’itidaal. Urine is filth, najasat. The Law teaches the importance of avoiding being soiled by urine and teaches measures to safeguard against urine. Washing of hands and the external excretory organs is required after urination. The use of the right hand is forbidden. Urine of breast-feeding infants is treated differently from that of adults in washing. The urine of female infants is also treated differently from that of males. Urination on the street or public places is forbidden.

14.2.2 GENITAL SYSTEM, jihaz tanasuli

The Qur’anic term farj is used to refer to the external genitalia of both males and females. External genitalia must be private and are considered part of ‘awrat. The uterus, rahim, had special mention in the Qur’an as the abode of the fetus. Fertilization and growth inside the uterus increase chances of survival of human fetii compared to frogs and fish whose ova are fertilized and grow outside and birds whose fetii grow partially inside. Female reproductive physiology manifests predictable cyclicity that is one of the signs of Allah, ayaat al llaah. The ovarian, menstrual, uterine, and vaginal cycles recur every month for 30-40 years of the woman’s life and are closely related to the human reproductive function. The menstrual flow lasts a few days and recurs in a cycle of 28 days on average. The menstrual cycle manifests one of the sunan of Allah because its duration of 28 days is the same as the duration of the lunar cycle. Menstruation is a normal process at the end of each ovarian cycle. Unlike Yahudiyyat, Islam does not make a menstruating woman a social outcast. Menstruation is a cause of physiological stress therefore fasting or prayers are excused. Copulation is a source of physical pleasure but has a deliberate reproductive function that is considered one of the Purposes of the Law, maqasid al shari’at. The Qur’anic term nutfat or mani refers to the male and female gametes that are the spermatozoa and ova respectively. Sex determination is not random but is determined by Allah. Sexual identity is a result of biology and socialization. Some deviant cultures encourage people of one gender to behave like those of another gender contrary to the teachings of Islam that emphasize very strong gender identity and a sharp demarcation between males and females. There are severe punishments for feminine men, al mukhanathin, and masculine females, mutarajilaat. Homosexuality is also severely punished.

14.2.3 THE HEART

The Qur’anic term qalb is not used in an anatomical sense. The heart is a pump that provides the energy to drive blood through the circulatory system. Parity of the heart is understandable from the embryological point of view. Separation of the left and right hearts ensures supply of well-oxygenated blood to the tissues. Control of the heart rate is by the electrical conduction system.

14.2.4 THE BLOOD CIRCULATORY SYSTEM

The prophet mentioned the flow of blood inside the body. Ibn Nafees was the first to describe circulation centuries before European writers. The circulatory system is an illustration of the sunan of equilibrium and control. Blood circulation follows biophysical principles and is another illustration of the unity of creation because physical and biological phenomena follow the same laws, sunan al kawn. The efficiency of the heart’s energy conversion is 20%, better than many machines. Blood flow to the skin increases in hot temperature to release heat. During digestion more blood flows into the GIT. During exercise cardiac output increases ten-fold and work done by the heart can increase 500-fold.

14.2.5. RESPIRATORY SYSTEM

The Qur’an mentioned the chest, sadr but not as an organ of respiration. The lungs are the main organs of respiration. The lungs provide a big opportunity for exchange between the internal and external environments. The term respiration can be used in 2 different ways to mean ventilation or tissue respiration. Coughing and sneezing expel irritants. In coughing the glottis is closed raising intra-ductal pressure to 100mm of mercury. When the glottis is opened suddenly, a jet of air under high pressure is released accompanied by the familiar sound of coughing. The glottis is not closed in sneezing but pressure still builds up. Sneeze is from Allah. Sneeze in salat is from shaitan. The prophet taught the etiquette of sneezing and yawning. The sneezer should praise Allah. It is obligatory for those present to respond to the sneezer. Respiratory movements have been used over the millennia as indicators of life. The Qur’an describes the last moments as sakrat al mawt as respiration begins to fail.