During respiration in human beings, the actual place of gaseous exchange is the alveoli. The alveoli are tiny air sacs located at the end of the bronchioles in the lungs. These sacs are surrounded by a network of blood capillaries.

When we breathe in, air enters the bronchi and travels through the bronchioles until it reaches the alveoli. The alveoli have thin walls that are lined with a layer of moisture. This moisture helps in the exchange of gases.

In the alveoli, oxygen from the inhaled air diffuses across the moist walls and into the bloodstream. At the same time, carbon dioxide, which is a waste product of cellular respiration, moves from the bloodstream into the alveoli. This exchange of gases occurs due to the difference in their partial pressures.

The oxygen-rich blood is then carried back to the heart, which pumps it to the various tissues and organs in the body. The carbon dioxide, on the other hand, is expelled from the body through exhalation.

Therefore, it is the alveoli where the actual gaseous exchange takes place during respiration in human beings.