CIRCULATORY SYSTEM

The circulatory system is also referred to as the cardiovascular system. It comprises the heart and all the blood vessels: Arteries, Capillaries, And Veins. There are essentially two components of circulation, namely:  Systemic circulation   Pulmonary circulation

circulation

Diagram showing Pulmonary (Blue) And Systemic Circulation (Red)

Besides these two, there is a third type of circulation called Coronary circulation. Because blood is the body’s connective tissue, it helps to transport essential nutrients and minerals to the cells and waste byproducts away from it. Hence, it is also known as the Body’s “Transport System.” Anatomically, the human heart is similar to other vertebrate hearts in the animal kingdom and hence, is a homologous organ.

DIGESTIVE SYSTEM

A diagram of the human digestive system detailing various components

The digestive system breaks down food and assimilates nutrients into the body, which the body then uses for growth and cell repair.

The major components of the digestive system are:

• Mouth
• Teeth
• Tongue
• Oesophagus
• Stomach
• Liver
• Pancreas
• Gastrointestinal tract
• Small and large intestines
• Rectum

The process of digestion starts with mastication (chewing food). Then, the saliva mixes with food and forms a bolus, a small, rounded mass that can be easily swallowed. Once swallowed, the food travels down the Oesophagus and into the stomach. The stomach secretes strong acids and powerful enzymes that break the food down into a paste.

It then moves into the small intestine where the food is broken down even more because of The Bile Secreted by The Liver and Powerful, Digestive Enzymes from The Pancreas. This is the stage at which nutrients are absorbed from the food.

The leftover materials (stool) then move on to The Large Intestine where it transforms from liquid to solid, as water is removed. Finally, it gets pushed into the rectum, ready to be eliminated from the body.