Nitrogenase is a complex consisting of the MoFe protein (dinitrogenase or component I) a heterotetramer, and the Fe protein (dinitrogenase reductase or component II) a homodimer.

TLS Online TPP Program

#Id: 5218

#Unit 7. System Physiology – Animal

In vivo, a plasma Ca 2+ level low enough to interfere with blood clotting is incompatible with life. In vitro, clotting can be prevented if Ca 2+ is removed from the blood by the addition of substances such as oxalates or chelating agents.

TLS Online TPP Program

#Id: 3959

#Unit 7. System Physiology – Animal

The heart consists of two kinds of muscle cells: 

Contractile cells 

Conducting cells

TLS Online TPP Program

#Id: 3960

#Unit 7. System Physiology – Animal

Contractile cells constitute the majority of atrial & ventricular tissues.

TLS Online TPP Program

#Id: 3961

#Unit 7. System Physiology – Animal

Conducting cells constitute tissues of the SA node, the atrial internodal tracts, the AV node, the bundle of His, & the Purkinje system.

TLS Online TPP Program

#Id: 3964

#Unit 7. System Physiology – Animal

Conducting cells are specialized muscle cells which function to rapidly spread action potentials over the entire myocardium.

TLS Online TPP Program

#Id: 3973

#Unit 7. System Physiology – Animal

The action potential spreads throughout the myocardium in the following sequence: SA node  Atrial internodal tracts and atria  AV node  Bundle of His  Purkinje system  Ventricles