Pertukaran Gas Dalam Alveolus & Jaringan Tubuh | Sistem Respirasi Pada Manusia

Summary

This video explains the intricate process of gas exchange and transport in the human body. Oxygen from the air enters the bloodstream, binds to hemoglobin, and is transported to body tissues where it's used for energy production. Meanwhile, carbon dioxide, a waste product of metabolism, is transported back to the lungs via the blood, either bound to hemoglobin, dissolved in plasma, or converted into bicarbonate ions. The video also highlights the factors that influence oxygen and carbon dioxide transport, including pressure gradients and diffusion, essential for maintaining homeostasis and cellular function.

Takeaways

• 😀 Oxygen in the air is dissolved in water on the alveolar surface and diffuses across epithelial and endothelial cells into the bloodstream.
• 😀 Oxygen binds to hemoglobin (Hb) in red blood cells, forming oxyhemoglobin (HbO2), which is then transported throughout the body.
• 😀 Hemoglobin can bind up to four molecules of oxygen, with the heme group containing iron responsible for the oxygen transport and the red color of blood.
• 😀 Oxygen is released from oxyhemoglobin in tissues where oxygen concentration is low, allowing it to diffuse into body cells for energy production.
• 😀 Carbon dioxide (CO2) is transported in the blood in three forms: as carbaminohemoglobin (2-3%), dissolved in plasma (7%), and as bicarbonate ions (HCO3, 70%).
• 😀 The conversion of CO2 to bicarbonate ions is facilitated by the enzyme carbonic anhydrase.
• 😀 The binding of oxygen to hemoglobin is influenced by factors such as oxygen and carbon dioxide levels, oxygen pressure, and diffusion rates.
• 😀 The diffusion of oxygen from alveoli into capillaries and carbon dioxide from capillaries into alveoli is influenced by partial pressures of gases in the body.
• 😀 Atmospheric pressure at sea level is approximately 760 mmHg, with oxygen partial pressure around 160 mmHg, while in the alveoli, it is around 104 mmHg.
• 😀 Oxygen-rich blood from the lungs is transported via the pulmonary veins to the left atrium of the heart, then to the left ventricle, and subsequently distributed throughout the body.

Q & A

How is oxygen transported from the air into the bloodstream?

Oxygen in the air dissolves in the thin layer of water on the alveolar walls. It then diffuses across the epithelial and endothelial cells into the blood plasma, where it binds with hemoglobin in red blood cells to form oxyhemoglobin.

What is the role of hemoglobin in oxygen transport?

Hemoglobin in red blood cells binds with oxygen to form oxyhemoglobin. This allows hemoglobin to transport oxygen from the lungs to body tissues, where it releases oxygen when concentrations are low.

What is the structure of hemoglobin and how does it aid in oxygen transport?

Hemoglobin is composed of globin proteins and heme groups, which contain iron. The heme groups are responsible for oxygen binding, and the globin proteins help carry the oxygen throughout the body.

How does the oxygen-binding capacity of hemoglobin vary?

Hemoglobin can bind up to four molecules of oxygen, forming oxyhemoglobin. The binding is reversible, allowing oxygen to be released in tissues where the oxygen concentration is low.

What factors influence the binding of oxygen to hemoglobin?

The binding of oxygen to hemoglobin is influenced by factors such as oxygen concentration, carbon dioxide levels, oxygen pressure, and the diffusion rates in the alveoli and capillaries.

How is carbon dioxide transported in the blood?

Carbon dioxide is transported in three ways: 2-3% is carried by hemoglobin as carbaminohemoglobin, 7% is dissolved directly in the plasma, and 70% is transported as bicarbonate ions (HCO3) in plasma.

What role does carbonic anhydrase play in carbon dioxide transport?

Carbonic anhydrase helps convert carbon dioxide into bicarbonate ions (HCO3) in the red blood cells, facilitating the transport of carbon dioxide in the blood.

How is oxygen pressure different in the lungs and body tissues?

Oxygen pressure is higher in the alveoli and blood plasma of the lungs (about 104 mmHg) compared to body tissues (0-40 mmHg), which promotes the diffusion of oxygen from the lungs into the bloodstream.

How does carbon dioxide leave the body?

Carbon dioxide is released from the red blood cells and plasma into the alveoli, where it is exhaled out of the body during breathing.

What is the significance of the difference in oxygen and carbon dioxide pressures in the body?

The differences in pressures ensure efficient gas exchange: oxygen moves from the lungs (high pressure) to the blood (low pressure) and carbon dioxide moves from the blood (high pressure) to the lungs (low pressure) for exhalation.