Mama vs. pecho vs. seno
In Spanish, the words 'mama', 'pecho' and 'seno' are commonly used to refer to a woman's breast or bosom. Each of these terms has its own nuances and contexts in which it is more appropriate or commonly used.
Mama
'Mama' is a clinical or anatomical term often used in medical contexts to refer specifically to the mammary gland or breast tissue.
La radiografía muestra un tumor en la mama izquierda.
(The X-ray shows a tumor in the left breast.)
Pecho
'Pecho' generally refers to the chest area as a whole, but can also refer to the breast, especially in more general, non-medical contexts. It's often used in a broader sense than 'mama'.
Se quejaba de dolor en el pecho.
(She was complaining of chest pain.)
Le puso al bebé en el pecho para alimentarlo.
(She put the baby to her breast to feed him.)
Seno
'Seno' is used to refer to the breast with an emphasis on femininity, sensuality, or maternal aspects. It can also mean 'bosom' or 'the part of a garment that covers the breasts'. It's more poetic and less clinical than 'mama'.
El vestido tenía un escote que revelaba parte de su seno.
(The dress had a neckline that revealed part of her bosom.)
El bebé dormía tranquilo en el seno de su madre.
(The baby slept peacefully in his mother's bosom.)
Summary
While 'mama', 'pecho' and 'seno' can all refer to a woman's breasts, they have different connotations and uses. Mama' is more medical, referring specifically to the breast tissue; 'pecho' is broader, often referring to the chest area but can include the breasts; and 'seno' emphasises femininity, sensuality or maternal warmth. Choosing the right word depends on the context and what aspect of the breast you want to emphasize.