Download Respiratory Levels of Organization

Respiratory Levels of Organization
Our bodies exchange oxygen for carbon dioxide at a number of different
levels. The exchange of air from the outside environment into the lungs
is driven by the mechanics of ventilation. At a molecular level oxygen
binds to hemoglobin in the red blood cells in the capillaries of the lungs.
Some of this oxygen displaces carbon dioxide that was transported from
peripheral cells. The exchange of gases occurs in red blood cells (where
hemoglobin is concentrated) at the interface of the circulatory system
and respiratory system, called the respiratory membrane. Oxygen
diffuses from the inhaled air in the lungs across the aveolar and capillary
membranes and into the blood plasma. It then enters the red blood cells
where it will be carried on hemoglobin molecules to the other tissues of
the body. Gas exchange at the respiratory membrane is known
as external respiration. Gas exchange at between the tissues and the
blood is internal respiration. At the molecular level carbon dioxide
created during cell metabolism diffuses across the cell membrane into
the interstitial spaces and extracellular fluid. When it crosses the
capillary and red blood cell membrane some carbon dioxide is picked up
hemoglobin by molecules inside the red blood cell. Inside the cells of the
body tissues, oxygen will be used during the process of aerobic cellular
respiration. Cellular respiration is a process used by our cells to
convert nutrients into energy. The process of aerobic cellular respiration
requires oxygen and produces carbon dioxide as a waste product.
To understand these system-level functions, you will be further
exploring
structures
and
processes
occurring
at
all
levels
of
organization. Some examples of major respiratory structures assigned to
their structural level of organization of the respiratory system include:
•
Chemical level – oxygen, carbon dioxide, bicarbonate and hydrogen
ions
•
Macromolecular level – hemoglobin, mucus, and surfactant
•
Cellular level – ciliated cells, goblet cells, alveolar cells, and
macrophages
•
Tissue level – stratified to pseudostratified to simple squamous
epithelium
•
Organ level – upper respiratory tract, bronchial tree and lungs
•
Organ system level - integration of organs for gas exchange