ST segment
The portion of a line that falls between two points is called a line segment.
If you are tracing your father's ancestry, you are looking at your paternal ancestry.
mesopyll
The portion of the kidney that extends between the renal pyramids is called the renal columns. They are composed of cortical tissue and serve to separate the renal pyramids.
A portion of butter is called a Pat of butter
provenance
electrocardiogram
septum of the heart divides heart into right and left, that portion of the septum between right and left atria is called (interatrial) septum, while the portion of septum between right and left ventricles is called (interventricular) septum.
septum of the heart divides heart into right and left, that portion of the septum between right and left atria is called (interatrial) septum, while the portion of septum between right and left ventricles is called (interventricular) septum.
Portion of the area of a circle is called a sector.
The upper portion of a fraction is called the numerator.
A Punnett square.