The infinitive is the most basic form of a verb. In Spanish, infinitives always end in -ar, -er or -ir, with -ar being the most common. An infinitive by itself does not indicate tense nor who or what is performing the action of the verb. In both English and Spanish, the infinitive can often function as a noun. In Spanish, such a noun is always masculine and is usually used in the singular form. The Spanish word for infinitive is infinitivo. Other examples of infinitives in Spanish are hablar, viajar, comprender, and resistir.
1 The kidneys are a pair of bean-shaped organs that lie on either side of the spine in the lower middle of the back. 2  Each kidney weighs about 5 ounces and contains approximately one million filtering units called nephrons.  Each nephron is made of a glomerulus and a tubule.
Kidneys are bean shaped organs approximately 11 to 14 centimeters long, 6 centimeters wide and 4 centimeters thick. Located in the abdominal cavity, they lie retroperitoneally. The right kidney is placed lower than the left, with the latter being slightly more medial than the former. The left kidney is at the level of T12 to L3, and its counterpart slightly lower.[ 2 ]. The image shows the location of both kidneys: the left at the T12 to L3 level and the right lower than the other.