Related Concept Videos

The Carbon Cycle01:14

The Carbon Cycle

Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.
The Sulfur Cycle01:22

The Sulfur Cycle

Sulfur, an important element in the chemical makeup of proteins, is recycled through the atmosphere and aquatic and terrestrial environments. Found in the atmosphere as sulfur dioxide (SO2), sulfur is released by decaying organisms, weathered rocks, geothermal vents, volcanos, and burning fossil fuels. It is deposited into the ecosystem, cycled through the biotic community, and either released back into the atmosphere as gas or deposited in marine sediment for long-term storage and eventual...
Assessment of Diffusion and Perfusion01:17

Assessment of Diffusion and Perfusion

Understanding and evaluating diffusion and perfusion is critical in assessing a patient's respiratory and circulatory health. These processes play key roles in maintaining the body's internal environment, ensuring that tissues receive adequate oxygen while waste products are efficiently removed.
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this principle...
External and Internal Respiration01:24

External and Internal Respiration

External respiration occurs in the lungs, and it is the first step in the journey of oxygen inside the body. When we inhale, oxygen enters our lungs and diffuses across the thin alveolar membrane. The alveoli are tiny, air-filled sacs that provide a vast surface area for gas exchange. Oxygen in the alveoli has a higher partial pressure (105 mmHg) than in the adjacent pulmonary capillaries (40 mmHg), establishing a pressure gradient. As a result, oxygen molecules move from the alveoli into the...
Carbon Dioxide Transport in the Blood01:19

Carbon Dioxide Transport in the Blood

Carbon dioxide (CO2) transport in the blood is critical to human physiology. On average, our body cells produce around 200 mL of CO2 per minute, precisely the quantity expelled by the lungs. This process involves the transportation of CO2 from the tissue cells to the lungs in three primary forms.
Forms of CO2 Transport
1. Dissolved in plasma: A small percentage (7-10%) of CO2 is transported and dissolved directly in the plasma.
2. Carbaminohemoglobin: Just over 20% of CO2 is chemically bound to...
Microbes and the Carbon Cycle01:24

Microbes and the Carbon Cycle

The carbon cycle is a fundamental Earth process involving the transfer of carbon among the biosphere, lithosphere, atmosphere, and hydrosphere. It plays a critical role in regulating the planet’s climate and supporting life by cycling carbon through various chemical forms and reservoirs. Carbon primarily circulates as carbon dioxide (CO₂), representing its oxidized form, while reduced forms such as methane (CH₄) and organic compounds also play essential roles.Microbial activity is central to...