A normal PR interval measures 0.12-0.20 seconds which is 3 to 5 small boxes on the EKG strip. When you measure a PR interval, you start measuring at the BEGINNING of the p-wave until the BEGINNING of the QRS complex. Here are some simple steps on how to measure the PR interval: Find the P-wave on the EKG strip. Determine where the PR interval is, and to do this you start measuring at the beginning of the p-wave until the beginning of the QRS complex. Count the SMALL boxes between there measurements. Remember each box represents 0.04 seconds.
The role of the excretory system is to rid the body of toxic waste products. Which of these body systems also plays a direct role in removing waste products from the body? A) endocrine B) nervous C) respiratory D) skeletal.
The excretory system is a system of organs that removes waste products from the body. When cells in the body break down proteins (large molecules that are essential to the structure and functioning of all living cells), they produce wastes such as urea (a chemical compound of carbon, hydrogen, nitrogen, and oxygen).he excretory system is a system of organs that removes waste products from the body. When cells in the body break down proteins (large molecules that are essential to the structure and functioning of all living cells), they produce wastes such as urea (a chemical compound of carbon, hydrogen, nitrogen, and oxygen).