Bio — Introduction to Biological Energy and Transport + 6 more topics

Every living cell, from the smallest bacteria to the cells in your body, needs energy to survive and function. This energy powers everything from building complex molecules to moving things around.

Photo by Terrance Barksdale on Pexels

Photo by Jess Loiterton on Pexels

First, the main bronchi divide into lobar bronchi (also called secondary bronchi), which go to different lobes of your lungs. Then, these split into segmental bronchi (tertiary bronchi). As they get smaller, the tubes lose their cartilage support and become bronchioles. The tiniest bronchioles are called terminal bronchioles, and these then lead into respiratory bronchioles.

Let's break it down into its main parts:

Photo by Frank Cone on Pexels

Photo by Santhosh Kanthala on Pexels

When you breathe in through your nose, the air first encounters your nostrils, which are lined with hairs (vibrissae). These hairs act as a coarse filter, trapping larger particles. Deeper inside, the nasal cavity is complex, with bony structures called conchae (or turbinates) that create turbulence. This turbulence forces air to swirl, increasing its contact with the moist, sticky mucus lining.

Photo by Ann H on Pexels

Gas exchange is the process by which gases move across a membrane. For living organisms, this usually means taking in oxygen (O2) from the environment and releasing carbon dioxide (CO2), a waste product of cellular respiration. This movement always happens via diffusion, which is the net movement of particles from an area of higher concentration to an area of lower concentration.