basic body constitution(prakriti) and birth signs

In ayurveda, vata, pitta and kapha(tridoshas) are considered as the 3 body humours or the vital energies, which together constitute the basic body constitution. This is called the prakriti of the body. This may vary and the state of body at any particular point of time, is called vikriti. (It may be same as prakriti or can vary depending on lot of physical factors and emotional factors.)

Mesha, Simha and Dhanus(Aries, Leo and Sagittarius signs) represent the fiery elements or the agni tatwa.

Rishabha, Kannya and Makara(taurus, virgo and capricorn) indicate the earth or prithvi tatwa.

Mithuna, Thula and Kumbha(gemini, libra and aquarius) indicate the vayu tatwa or the air element.

Karkataka, Vrischika and Meena(cancer, scorpio and pisces) indicate the water element or jala tatwa.

Vata = vayu.

Pitta = agni.

Kapha = prithvi + jala.

when you have a predominance of agni tatwa rasis (fiery signs namely, aries, leo and sagittarius) your pitta will get more accentuated.

like wise, other elements too.

also, each graha or planet has a vata-pitta-kapha nature.
eg. sun/surya, mars/kuja, and ketu/dragins tail are pitta.
chandra/moon, guru/jupiter, venus/shukra are kapha
sani/saturn and rahu/dragon's head are vata
whereas budha/mercury is a mix of all 3, but skewing towards sani as far as taste is considered.

for robust health, you need a balanced humour state of vata-pitta- kapha

You can find a skew in vata-pitta-kapha through your tastes too.

Surya (Sun) – Pungent tastes
Soma (Moon) - Salty tastes
Mangal (Mars) – Bitter tastes
Budha (Mercury) – Mixed tastes
Brihaspati (Jupiter) – Sweet tastes
Shukra (Venus) – Acid or Citric tastes
Shani (Saturn) – Astringent tastes

Now, lets see how vata-pitta-kapha rules over bones, blood, nerves etc.

Surya (Sun) – Asthi (Bones)
Soma (Moon) – Rakta (Blood)
Mangal (Mars) – Majja (Marrow or Nerves)
Budha (Mercury) – Rasa (Skin)
Guru (Jupiter) – Meda (Fat)
Shukra (Venus) – Shukra (Semen)
Shani (Saturn) – Mamsa (Muscles)

the fine art is about reading the combined effect of relative strengths and weaknesses.