Transport & Exchange of Materials Flashcards
The Circulatory System (38 cards)
What is blood?
Blood is the transport link between the cells of all body systems.
Why is important blood?
It is also very important in maintaining the constant internal environment of the body
What are the main functions of blood?
- Transport
- Regulation
- Protection
What does the blood transport?
- Oxygen and nutrients to all cells of the body
- Carbon dioxide and other waste products away from the cells
- Chemical messages, called hormones to the cells
How does blood provide regulation?
- Maintaining the pH of body fluids
- Distributing heat and maintaining body temperature
How does the blood provide protection?
- Protecting against disease-causing micro-organisms
- Clotting when vessels are damaged, thus preventing blood loss.
What percentage of oxygen is carried in plasma?
Oxygen is not very soluble in water, so only about 3% is carried in the blood plasma.
How is the other 97% of oxygen carried?
The other 97% is carried in combination with haemoglobin molecules found in red blood cells to form a loose compound called oxyhaemoglobin.
Why is oxyhaemoglobin a loose compound?
It is loose because oxyhaemoglobin can easily break down to release oxygen.
Why is haemoglobin important?
The haemoglobin in red blood cells increases the oxygen-carrying capacity of the blood about 60-70 times.
When does oxygen combine with haemoglobin?
When the oxygen concentration is relatively high in the capillaries in the lungs, where oxygen diffuse into the blood from the air in the alveolus.
What happens when the oxygen concentration is low?
When the concentration is relatively low, the oxyhaemoglobin breaks down to haemoglobin and oxygen.
What oxygen concentration does tissue fluid have?
As the cells of the body are continually using oxygen, the tissue fluid around the cells has a relatively low oxygen concentration.
What happens when the red blood cells flow through the capillaries between the blood cells?
They give up their oxygen, which diffuse into the tissue fluid and then into the cells.
What percentage of carbon dioxide is carried in plasma?
Approximately 7-8% is dissolved and carried in the plasma
What percentage of carbon dioxide is combined with haemoglobin?
Another 22% or so combines with the globin part of the haemoglobin molecule to form the compound carbaminohaemoglobin.
What percentage of carbon dioxide is carried in plasma as bicarbonate ions?
The remaining 70% is carried in the plasma as bicarbonate ions.
What happens as the blood is flowing through the capillaries between the body cells,
Carbon dioxide diffuses into the plasma due to the difference in carbon dioxide concentration.
What happens once the carbon dioxide diffuses into the plasma?
Some carbon dioxide dissolves in the plasma, some combines with haemoglobin, but most reacts with water to form carbonic acid.
What happens to carbonic acid?
Carbonic acid then ionises into hydrogen ions and bicarbonate ions.
What happens once at the capillaries?
The carbon dioxide dissolved in the plasma diffuses out of the blood into the air in the alveolus.
The carbaminohaemoglobin breaks down, and the carbon dioxide molecules released also diffuse into the alveolus.
What happens to hydrogen and bicarbonate ions at the capillaries?
Hydrogen ions and bicarbonate ions recombine to form carbonic acid, which then breaks down under enzyme action into water and carbon dioxide. This carbon dioxide also diffuses into the alveolus.
How are nutrients and wastes transported?
Nutrients and wastes are dissolved and transported in the blood plasma
What are nutrients?
Nutrients are essential elements and molecules that are obtained from the food we eat.
