Tears are secretions of the lacrimal glands or tear glands flowing from the main excretory ducts into the eyeball and eyelids. Tears lubricate the eyes and keep it clean. Tears also flow when the individual experiences extreme emotions like happiness and sadness. There are two lacrimal glands or...
Conjunctiva lubricates the eyes and is a barrier against infectious microbes. It is a thin and transparent mucous membrane over the white part of the eyes and inside the eyelids. There are three kinds of conjunctiva: the bulbar or ocular conjunctiva lines the sclera over the white of the eye; the...
Micturition is the process of excreting excess fluid and substances that have potential harm to the body through the acts of urination and voiding. The renal system is involved in micturition. The kidneys filter excess water and waste products to produce urine. The ureters connect each kidney to...
Fatty tissue is composed of mostly adipocytes, which are fat cells. Fatty tissue aids in the maintenance of the body’s temperature. However, too much fatty tissue is detrimental to health as it can lead to cardiovascular disease, stroke and some types of cancers. To decrease and maintain a low...
Yolks do not only occur in eggs, but are also a part of the first stages of an embryo’s development. By five weeks of gestation, the yolk sac is the first part of the embryo that is visible on the ultrasound. When looking at the ultrasound during the first weeks, doctors can use the yolk sac to...
Psychological human universals is an anthropological and evolutionary psychology term referring to behavioral or cognitive traits which are common for all neurologically normal human beings. Human universalism partially challenges cultural relativism which exaggerates the variations amongst people....
The major organs of the body are simply the most well known organs but may not be important if they work alone, as they need to work in co-ordination with all other organs in the body. Starting at the top of the human body, the brain processes information and is the body’s control center. It...
The three main sections of the brain are the forebrain, midbrain and the hindbrain. All the different parts of the brain process information and provide responses in terms of what we say, think, feel and do. The cerebrum, responsible for thought and action is in the forebrain. The cerebrum is...
Hematopoietic stem cells (HSCs) are cells that are capable of producing all blood type cells. The process through which blood is replenished in the body is called hematopoiesis. In this process, the HSCs create the necessary blood cells, which include lymphocytes, granulocytes, and red blood cells,...
The IUD, or intrauterine device, is an object that is inserted into the uterus. It is one of the most effective forms of birth control, guaranteeing more than 99 percent effectiveness. There are two general kinds of IUDs. One is the copper IUD and the other is the hormone-releasing IUD. In the...
