Circulatory System Flashcards
What is the function of the circulatory system?
Transports nutrients throughout the body and removes waste products.
How does the heart function in a double circulatory system?
Blood flows through the heart twice in one circuit:
• Deoxygenated blood is pumped to the lungs.
• Oxygenated blood is pumped around the body.
What are coronary arteries and why are they important?
Coronary arteries supply blood to the heart muscle, providing it with oxygen needed for respiration.
What is the role of the pulmonary artery and pulmonary vein?
Pulmonary Artery: Carries deoxygenated blood from the heart to the lungs.
Pulmonary Vein: Carries oxygenated blood from the lungs back to the heart.
How does the aorta function in the circulatory system?
The aorta carries oxygenated blood from the heart to the body, under high pressure to ensure distribution to all tissues.
What is the role of the vena cava in the circulatory system?
The vena cava returns deoxygenated blood from the body to the heart.
How do the renal arteries and veins function in the circulatory system?
Renal Artery: Carries oxygenated blood from the aorta to the kidneys.
Renal Vein: Carries deoxygenated blood from the kidneys back to the heart.
What is the primary function of arteries?
Arteries transport blood away from the heart to the organs.
Describe the structure of artery walls.
Artery walls have thick layers of muscle, elastic fibres for stretching, and a folded endothelium to maintain high pressure and stretch.
What are arterioles and their function?
Arterioles are smaller vessels that arteries split into when reaching organs. They control blood flow by contracting to restrict or relaxing to allow blood flow.
What is the main function of veins?
Veins transport blood back to the heart.
Compare the structure of veins to arteries.
Veins have a wider lumen, thinner muscle walls, and elastic tissue compared to arteries. They also have valves to ensure blood flows towards the heart.
What are capillaries and their function?
Capillaries are very small vessels that branch from arterioles, have thin walls (one cell thick), and allow efficient exchange between blood and body cells.
How does the thin wall of capillaries facilitate exchange?
Capillary walls are one cell thick, minimizing diffusion distance for efficient exchange of substances like oxygen.
Describe the location and function of capillaries.
Capillaries pass very close to body cells, allowing rapid exchange due to the short diffusion distance between the capillaries and cells.
How do capillary networks benefit tissue exchange?
Capillary networks (capillary beds) provide a large surface area for substance exchange between the bloodstream and tissues.
What is tissue fluid?
Tissue fluid is a combination of oxygen, water, and nutrients that surrounds cells and is used for substance transport from capillaries.
What is pressure filtration in the context of tissue fluid?
Pressure filtration is the process where substances move out of capillaries into tissue fluid due to high pressure at the capillary entrance.
How does pressure gradient affect fluid movement in capillaries?
High pressure at the entrance of a capillary bed creates a pressure gradient that causes fluid to flow into the surrounding space, forming tissue fluid.
How does pressure change as fluid moves out of capillaries?
The pressure inside capillaries decreases as fluid moves out, resulting in lower pressure at the capillary exit compared to the entrance.
What role do plasma proteins play in the water potential gradient?
Plasma proteins remain in the capillaries, increasing plasma protein concentration and decreasing water potential, causing water to move back into the capillaries via osmosis.
What is the function of the lymphatic system in relation to tissue fluid?
The lymphatic system collects excess tissue fluid and recycles it back into the bloodstream.
