Circulatory Physiology (Lab 10)

Some Key Review Concepts

Factors Influencing Heart Rate

Your heart rate changes with your body position. Your heart rate increases when you exercise. 

Blood Pressure

A blood pressure reading consists of two numbers: a systolic pressure and diastolic pressure. Normal blood pressure for a healthy adult is about 120/80. The numerator is the systolic pressure and the denominator is the diastolic pressure.

The  Movement of Blood

Blood moving through the blood vessels exerts pressure against the vessel walls. This blood pressure is highest in the aorta. It decreases as the blood moves through the arterioles, capillaries, venules, and veins.

With each contraction of the heart, you can feel the expansion and recoil of the elastic arteries where they pass near the surface of the skin. This is the pulse. When you take your pulse, you measure heart rate – the number of times the heart contracts per minute.

Concept of Q₁₀

Q₁₀ measures the increase in metabolic activity resulting from an increase in body temperature. Daphnia can adjust their temperature to the environment, as the temperature in the environment increases, their body temperature also increases. This in turn increases their heartbeat rate per minute.  

Cold Blooded Animals

Heat generated can increase the body temperature and heart rate of cold blooded animals.

Lab Design

Part I: Cardiovascular Activity

In your laboratory you will do five different tests of cardiovascular fitness and assign fitness points based on the results of each test. 

Part II: Heart Rate in Daphnia

Observe Daphnia in a petri dish of water at three different temperatures. Time their heart rate with a stop watching, counting the contractions of their diaphragm.

Analysis of Results

Part I: Cardiovascular Activity

A fit individual pulse and blood pressure are lower and will return more quickly to the resting condition after exercise than in a less fit individual. 

Part II: Heart Rate in Daphnia

Record and Graph the Data