The bit
The bit is on the bridle, that goes on their head. Its the metal thing that goes in the horses mouth. (:
A bit is metal bar that is on the bottom of the bridle. This fits inside the horses mouth, behind the teeth, where there is a gap.
Their mouth....
The metal part of the bridle is called a bit. This goes into the horses mouth. You can buy several types of bits.
The part of the tack (harness) that fits in the mouth of a horse is the bit.
a river mouth
The noseband is a part of the bridle. It's the part that goes on the top of the horses muzzle.
A girth which goes under the horses belly and buckles up on the other side.
It means the visible part of the bit (when it is in your horses mouth) is in the shape of the letter D.
Reins is a type of horse tack.
esophagus
if you are referring to horses, it is not called a "cheek strap". It is called a "cheek piece". A cheek piece is part of the bridle. When on a horse, it is along the side of a horses face, basically where the horses cheek is (from the ears to the muzzle). It is joined to the Bit (in the horses mouth) and the head piece which is the part of the bridle that is at the top of the horses head, by the poll (behind its ears). I hope this was helpful information.