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Prothallus of the tree fern Dicksonia antarctica (note new moss plants for scale) Spore-bearing plants , like all plants, go through a life-cycle of alternation of generations . The fully grown sporophyte , what is commonly referred to as the fern , produces genetically unique spores in the sori by meiosis .
Real-time magnetic resonance imaging of the human thorax during breathing X-ray video of a female American alligator while breathing. Breathing (spiration [1] or ventilation) is the rhythmical process of moving air into and out of the lungs to facilitate gas exchange with the internal environment, mostly to flush out carbon dioxide and bring in oxygen.
There are oxygen sensors in the smaller bronchi and bronchioles. In response to low partial pressures of oxygen in the inhaled air these sensors reflexively cause the pulmonary arterioles to constrict. [32] (This is the exact opposite of the corresponding reflex in the tissues, where low arterial partial pressures of O 2 cause arteriolar ...
The cardiovascular system responds to changing demands on the body by adjusting cardiac output, blood flow, and blood pressure. Cardiac output is defined as the product of heart rate and stroke volume which represents the volume of blood being pumped by the heart each minute. Cardiac output increases during physical activity due to an increase ...
[106] [107] Blood or air with a high oxygen content is shown in red; oxygen-poor air or blood is shown in various shades of purple-blue. The lungs of birds are relatively small, but are connected to eight or nine air sacs that extend through much of the body, and are in turn connected to air spaces within the bones. On inhalation, air travels ...
Plaque can limit the supply of blood and oxygen to your heart tissue. Many people with early coronary artery disease don’t have any symptoms. If your heart doesn’t get enough oxygen, you might ...
The main reason for exhalation is to rid the body of carbon dioxide, which is the waste product of gas exchange in humans. Air is brought into the lungs through inhalation. Diffusion in the alveoli allows for the exchange of O 2 into the pulmonary capillaries and the removal of CO 2 and other gases from the pulmonary capillaries to be exhaled ...
The human body needs iron for oxygen transport. Oxygen (O 2) is required for the functioning and survival of nearly all cell types. Oxygen is transported from the lungs to the rest of the body bound to the heme group of hemoglobin in red blood cells. In muscles cells, iron binds oxygen to myoglobin, which regulates its release.