Biochemistry

Imran Arif BIO 203.03

Pre-lab 7

Vocabulary

Systole- The time at which ventricular contraction occurs.

Atrium- The upper chambers of the heart.

Ventricles- The lower chambers of the heart which pump blood to the body.

Pacemaker- An object or substance that influences the rate at which a certain phenomenon occurs, often used alone to indicate the natural cardiac pacemaker.

Sinoatrial Node- The impulse generating (pacemaker) tissue located in the right atrium.

Sinus Venosus- An enlarged region between the vena cava and the right atrium, which houses the pacemaker in the amphibian heart.

Electrocardiogram- An recording of the electrical activity of the heart on a moving strip of paper. The electrocardiogram detects and records the electrical potential of the heart during contraction.

Dipole- A molecule that has both negative and positive charges.

P wave- The start of the measure in electrical activity on the ECG of the heart.

QRS complex- The deflections in an electrocardiograph tracing and represent ventricular activity of the heart.

T wave- The part of the ECG which shows the repolarization stage.

Standard Limb Leads- Used to show the ECG activity by measuring the different rates at different parts of the body.

1.

2. In the amphibian heart with 2 atriums and one ventricle the deoxygenated blood from the body enters the heart through the right atrium and makes its way to the conus arteriosus in the ventricle. After this passage it is send through the skin/lungs to be reoxygenated and then sent into the left atrium through the vena cava and back into the ventricle which will pump it out towards the body.

In a 4 chamber heart the process is similar but not the same. It is slightly more complex with the addition