Where does oxygen enter the blood stream?

Answer 1

In the lungs. As we breathe, air travels down the pharynx (throat), into the trachea, and into the lungs. Its journey into the lungs begins with the trachea. The trachea branches off into two limbs called your bronchi. Two, because there is one for each of your lungs. Just like a tree, the limbs get smaller. These smaller limbs are called bronchioles. Now, we covered all that because at the very tips of the bronchioles are a collection of berry-like sac structures called avleoli. This is where the magic takes place (ok, I admit, it's not that dramatic). The air ( which contains oxygen) has traveled this far and it now fills the alveoli. The large pulmonary artery leading from the heart travels toward the lungs. As it progresses closer and closer it splits into smaller and smaller vessels, until it forms capillaries. These pulmonary capillaries are covering the alveoli. This can be visualised by thinking of a net or webbing around a round sac-like structure. The pulmonary capillaries are filled with blood that's been all around the body, and is now low in oxygen and rich in carbon dioxide. Back to the alveoli. The wall is so thin it's able to allow diffusion of oxygen into the capillaries. Diffusion is the tendency of the molecules of a substance to move from an area of high concentration to an area of low concentration. In this situation the alveoli are filled with oxygen rich air, and the blood in the pulmonary capillaries has very little. The oxygen diffuses into the capillaries replenishing those oxygen starved blood cells. Carbon dioxide moves the other way.

Answer 2

Oxygen enters the blood through the lungs. Every inhale taken by a human being provides oxygen to the blood moving through the walls of the lungs. Each exhale is comprised of carbon dioxide and other pollutants carried by the blood to the lungs.

Answer 3

Oxygen is absorbed into the blood from the capillaries which surround the tiny air sacs called alveoli (plural; alveolus is single) in the lungs.

When the air containing oxygen is breathed in, it is at a higher pressure within the lungs than the blood in the capillaries.

Therefore oxygen diffuses through the cell walls because of the pressure difference, into the blood stream, where it attaches to the haemoglobin in red blood cells for distribution to every cell in the body.

Answer 4

1. The oxygen then clings to red blood cells as they pass through the alveolar capillariaries The inhaled oxygen passes into the alveoli and then diffuses through the capillaries into the arterial blood. Meanwhile, the waste-rich blood from the veins releases its carbon dioxide into the alveoli. The carbon dioxide follows the same path out of the lungs when you exhale.

Answer 5

In air breathing animals, oxygen enters the blood stream through the alveoli, tiny sacs in the lungs. In water breathing animals oxygen enters the blood stream through the gills.

Answer 6

Lungs

If your in K12 in Biology it might give you a diagram then it would be in the bottom in D.

Answer 7

Oxygen follows the path [expression] to provide the body to work. It has to go through many body parts such as the bronchial tubes, the air sacs, the windpipe, and the lungs.