Blood Pressure Lab

What you will learn today… When the ventricles of the heart contract, pressure is increased throughout all the arteries, causing blood pressure Blood pressure is measured with a sphygmomanometer The systolic number is indicated by the first sounds heard through a stethoscope The diastolic number is the onset of silence in the stethoscope

What is blood pressure? 1. Hydrostatic pressure exerted on the walls of the arteries so that blood can circulate to the body 2.Blood pressure is much lower once the blood is delivered to the capillaries; consequently, the pressure in the veins is much lower.

What is blood pressure? 3.To insure that there is enough force to get the blood back to the heart, veins will have additional mechanisms to work against gravity and a low pressure. a.Nearby skeletal muscle physically pushes on the veins. b.Breathing increases the pressure in the abdominal cavity to force blood into the chest area. c.The smooth muscle in the veins themselves contract in a process known as vasoconstriction.

What is blood pressure? 4. Blood pressure causes some fluids (water) to be absorbed from the tissues of the body. This fluid is called lymph. a. The lymph travels through the lymphatic system, which is a system of vessels that runs alongside the veins b. The lymph passes through lymph nodes to filter out harmful microbes, and to pick up lymphocytes if needed

Lymphatic System

Two readings in blood pressurereadings 1. Systolic: contraction of ventricles 2. Diastolic: relaxation of ventricles The diastolic number is the more important to determine health. Systolic=120 (average) Diastolic 70

Two readings in blood pressure 3. Blood pressure is measured with a sphygmomanometer

HowHow to take a blood pressure reading …

Hypothesis 1. How does “fitness” affect blood pressure and heart rate? 2. How is “return rate to normal” of heart rate after exercise affected by “fitness”?

References /generalbiology/Physiology/CirculatorySystem/Circulator ySystem/Vertebrate/bloodvessels_3.gif /Lumologie/images/img_lymphDiagram.jpg measure-blood-pressure-using-a-sphygmomanometer /