Physiology

Blood Vessel Physiology

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This laboratory investigates the physical mechanisms by which our blood vessels function in allowing the circulatory system to do its job.  Blood vessels are not simply rigid tubes that conduct blood to our tissues like copper pipes carrying water to our houses, nor are they infinitely extensible balloons that can accommodate any amount of blood pressure or volume.  In fact, blood vessels have a complex composition that allows them to do several different jobs and change their function depending on the situation.  In essence, blood vessels are a dynamic tissue rather than a static one.  Just as with other organs of the body, blood vessels are complex in nature because of the demand for their complex function.  When a disease state changes these properties, it can have devastating and often fatal effects.  In this exercise students will use models of blood vessels to determine the effects of normal blood vessel distensibility on the dynamics of blood flow, and investigate the nature of aneurysms.

Diffusion across Biological Membranes:  A Simulation

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This lab uses two different sizes of dialysis tubing to represent cellular and organelle membranes.  Students design experiments in which they place solutions of iodine, starch, and glucose on different sides of a membrane.  The movement of these materials is monitored with the use of indicator solutions.

Students are given a list of tasks, a description of supplies and equipment, and some instructions on how to get started.  They are then asked to design a set of experiments that will allow them to accomplish as many of the tasks as they can in the allotted time.

Electrocardiogram and Control of Heart Rate

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The electrocardiogram, or ECG, is a device used to document patterns of cardiovascular activity.  By analyzing the waves produced by the ECG we can see how various stimuli effect heart function.  This activity provides a visual representation of the heart beat and clearly demonstrates how heart rate is controlled.  Students will learn how to operate and ECG and interpret the heart monitor strips.  They will also begin to understand the relationship between blood pressure, heart rate, and the strength of contraction, as well as learn how the brain controls each of these functions.

Photosynthesis and Spectrophotometry

PDF File, 72K

The first part of this lab makes use of a spectrophotometer to study the rate of photosynthesis in a suspension of spinach chloroplasts.  The chloroplasts are subjected to varying light and temperature conditions.  As the blue dye, DPIP, is reduced, it becomes colorless, a change which can be measured quantitatively by following the % transmittance of the suspension.

The second part of the lab measures the absorption spectrum of a solution of pigments isolated from spinach leaves.

Physics of "Phoot"

PDF File, 100K

In this lab students will investigate the application of physical principles to a living organism.  Students will analyze the foot and its function as a machine by applying lever mechanics to the "walking" foot.  Analysis will incorporate anatomical terms for some of the muscles and bones involved in plantigrade motion.

Respirometry 1:  Lung Volumes and Capacities

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What Are Your Volumes and Capacities?

: By use of a Collins respirometer, students measure their inspiratory reserve volume, expiratory reserve volume, tidal volume, and determine vital capacity.  Resting measurements compared with values obtained after exercise may reveal individual homeostatic mechanisms.  This exercise may be extended by pooling and analyzing class data.

Respirometry 2:  Determining Metabolic Rate

PDF File, 76K

This module uses the Collins respirometer to measure oxygen consumption and relates this volume to rate of metabolism when the subject is at rest.