It is worth comparing the definitions of these elements in the two languages, because there are slight differences in usage:

• Descender: a vertical stem below the baseline in some lowercase letters; examples: p, q.
• Extender: a stroke that reaches above the x-height or below the baseline. Ascenders and descenders are extenders.
• Stem: the main stroke of a letter. Not all letters have stems (c, C, s, S) and some might have two (H, M, N). Examples: b, B, l, L and Y.
• Stroke: the main diagonal part of a letter, for example the thicker diagonal part in M, N, V, w, Y. Arms, crossbars, bowls and stems are considered strokes.
• Tail: the end of the descending stroke in g, j, K, p, q, R, y.
• Terminal: the connection, usually curved, between a stroke and a serif, for example, the bottom part of j, but also inside a letter (g).
• X-height: the distance between the baseline and the top of a lowercase letter’s body. All the letters of the word xenia would be within x-height, except the dot of the i.
http://bookpublishing.suite101.com/article.cfm/typesetting_e...

Anillo: Es el asta curva cerrada que forman las letras "b, p y o".
Ascendente: Asta que contiene la letra de caja baja y que sobresale por encima de la altura x, tales como las letras "b, d y k".
Asta: Rasgo principal de la letra que la define como su forma o parte mas esencial.
Astas montantes: Son las astas principales o oblicuas de una letra, tales como la "L, B, V o A".
Asta ondulada o espina: Es el rasgo princial de la letra "S" en mayúscula o "s" en minúscula.
Asta transversal: Rasgo horizontal de las letras "A, H, f o t".
http://www.fotonostra.com/grafico/partescaracter.htm


--------------------------------------------------
Note added at 14 hrs (2010-03-18 10:23:36 GMT)
--------------------------------------------------

typography strokes!