Circulatory system Flashcards
What are the four components of blood?
Plasma, red blood cells, white blood cells, platelets
What is plasma rich in? What is suspended in it? (9)
Rich in protein. Blood cells, platelets, O2, proteins, glucose, vitamins, minerals, CO2, cellular respiration waste products are suspended in it
What is the role of fibrinogen?
Blood clotting: fibrinogen activates when platelets have clotted a blood vessel and forms a mesh to capture more platelets. This lets the injured site fully heal
What are red blood cells also known as?
Erythrocytes
The red blood cells have a _______ shape. What is the purpose of this?
biconcave shape
to increase S.A. for gas exchange
What protein do red blood cells contain? What is its main purpose?
hemoglobin
main purpose is to carry O2 and CO2 to and from the lungs
What are white blood cells also called?
Leukocytes
What is the main function of white blood cells?
To defend against harmful bacteria and viruses
Explain the process of phagocytosis.
- Leukocyte engulfs bacteria
- Leukocyte releases enzymes to destroy the bacteria and the leukocyte itself
- The remnants produce pus
What are platelets? What are they essential for?
Cell fragments
Essential for blood clotting
Explain the process of blood clotting.
Platelets stick to collagen fibres in the blood vessel wall.
As more platelets stick, the hole in the blood vessel in sealed
Then, fibrinogen in plasma is activated. It forms long fibrin strands which become a mesh the captures more platelets. This allows the injured site to fully heal.
Once the blood vessel is fully healed, the clot is absorbed by the body.
What happens in the tissues when a person is active?
Cellular respiration increases: more oxygen is used to make energy. As such there is an oxygen deficiency in these tissues.
The partial pressure of O2 falls in the tissue cells, letting oxygen from hemoglobin (higher P.P.) diffuse into the cells.
At the same time, PP for CO2 in the tissue cells is now higher than in capillaries. Hemoglobin binds with the CO2.
This is taken back to the heart through red blood cells via the venous system
Explain the flow of blood around the circulatory system, starting with the right atrium of the heart.
Deoxygenated blood arrives in the right atrium via the superior and inferior vena cava.
The right atrium contracts, opening the tricuspid valve and pumping blood into the right ventricle.
When the right ventricle is full, it contracts to push blood out the pulmonary artery to the lungs.
Gas exchange happens in the lungs.
The now oxygenated blood returns to the heart through the pulmonary vein and enters the left atrium.
The left atrium contracts, opening the bicuspid valve and pumping blood into the left ventricle.
The left ventricle contracts to push blood out into the ascending aorta. From there, it is distributed throughout the body.
What are some adaptations that occur in the circulatory system for someone who exercises frequently? (3)
Left ventricle increases in size and makes stronger contractions: more volume and more blood pumped out per contraction. This decreases heart rate.
More capillaries form in muscle cells. This increases the amount of blood that can get to the muscles, meaning more oxygen for cellular respiration.
More oxidative enzymes that produce ATP - the energy currency of the body
What is the difference between systolic and diastolic blood pressure?
Systolic: blood pressure in arteries when the heart contracts
Diastolic: blood pressure in arteries when the heart relaxes
