脈

1. Origins, structure, and basic meaning

• Structure: 脈 is read as みゃく and is a noun for a pulse, and in other contexts can refer to a vein or vascular line.
• Basic usage: Use 脈を確かめる when checking a pulse and 脈が速くなる when the pulse itself quickens.

2. Common pitfalls and similar expressions

• Relationship to 脈拍
  • 脈拍 precisely names the pulse produced by the heartbeat; the examples use the shorter 脈 in that same sense.
• Contrast with 血管
  • 血管 is the blood vessel as an anatomical structure, whereas 脈を確かめる・脈が速くなる refers to the pulse that can be felt or become faster.