Human Circulatory System Quiz

The separation that divides the heart into two halves, preventing the mixing of oxygenated and deoxygenated blood.

Red blood cells are responsible for carrying oxygen throughout the body. This is due to their unique structure and the presence of hemoglobin. Hemoglobin binds to oxygen and releases it into the tissues.

Blood vessels are tubes that carry blood throughout the body. The inside of a blood vessel is called a lumen, which acts as a channel for blood flow.

Plasma is a fluid component of blood, consisting mostly of water, with dissolved substances like sugars, proteins, and salts.

Urea is a waste product produced by the liver during the breakdown of proteins. It is transported by the blood to the kidneys for excretion.

The system that transports substances like nutrients, oxygen, carbon dioxide, and waste products throughout the body.

The primary reason humans need a circulatory system is because our large size makes diffusion alone insufficient for transporting substances throughout the body.

Blood in arteries carries a lower level of carbon dioxide and higher level of digested food substances compared to blood in veins.

Blood in veins carries a higher level of carbon dioxide and a lower level of digested food substances compared to blood in arteries.

The human heart is the central pump that circulates blood throughout the body, ensuring the delivery of oxygen and nutrients and removal of waste.

The pulmonary artery carries blood low in oxygen to the lungs, while the pulmonary vein carries oxygen-rich blood back to the heart.

The hepatic vein carries blood with high levels of urea and glucose to the liver, where it is processed.

Blood in the renal vein has the lowest level of urea because it is filtered and excreted by the kidneys.

The red pigment found in red blood cells that binds to oxygen and carries it throughout the body.

Hemoglobin has a strong attraction to oxygen, allowing it to efficiently bind and carry oxygen from the lungs to the body's tissues.

The binding of oxygen to hemoglobin is reversible, meaning oxygen can be easily released to tissues that need it and picked up again from the lungs.

Hemoglobin is a protein molecule composed of four polypeptide chains, each containing a heme group. The heme group contains an iron atom that binds to oxygen.

Red blood cells transport oxygen from the lungs to the body's tissues.

Blood vessels that carry blood away from the heart, under high pressure, usually carrying oxygenated blood.

Blood vessels that carry blood back to the heart, under low pressure, usually carrying deoxygenated blood.

The thick muscular layer in arteries that helps maintain blood pressure and elasticity.

The central space inside a blood vessel where blood flows.

A type of muscle found in the walls of arteries and veins that helps regulate blood pressure.

Red blood cells are shaped like discs with an indentation in the middle, increasing their surface area relative to their volume. This allows for faster diffusion of gases, like oxygen and carbon dioxide.

They lack a nucleus, allowing for more space to carry oxygen, increasing their oxygen-carrying capacity. This is crucial for their primary function.

The presence of hemoglobin gives red blood cells their characteristic red color. Hemoglobin is a protein that binds to oxygen.

Red bone marrow, found in the center of bones, generates red blood cells through a process called hematopoiesis.

White blood cells, unlike red blood cells, have irregular shapes and possess a nucleus.

White blood cells are the body's defense system. They patrol the blood and tissues looking for invaders like bacteria and viruses. They are often called 'soldiers' of the immune system.

Blood platelets are tiny fragments of cells that lack a nucleus. Their primary function is to help stop bleeding, forming clots to seal wounds.

They are produced in the red bone marrow, just like red blood cells and white blood cells.

Arteries have thicker walls to withstand the high blood pressure generated by the heart's pumping action.

Arteries have more elastic tissue which helps them stretch and recoil, maintaining blood flow.

Arteries have more muscle tissue than veins, allowing them to contract and relax to regulate blood flow.

Veins have valves to prevent backflow of blood, especially when blood is flowing against gravity.

Veins have a larger lumen, which reduces resistance to blood flow and increases flow rate.

Capillaries have thin walls, which allow for rapid diffusion of substances between blood and tissue cells.

The network of capillaries in tissues provides a large surface area, facilitating efficient exchange of materials.

Capillaries are densely spread throughout tissues, minimizing the distance substances have to travel.

The narrow lumen of capillaries slows blood flow, allowing more time for exchange of materials between blood and tissue cells.

The total cross-sectional area of capillaries is larger than that of arterioles, decreasing blood flow velocity and promoting efficient exchange.

The contraction of skeletal muscles adjacent to veins helps move blood towards the heart. The squeezing action pushes blood forward.

The negative pressure in the chest cavity during inhalation helps draw blood towards the heart. This is similar to how a straw works.

Veins have valves that prevent blood from flowing backward. These valves act like one-way doors, ensuring blood moves in the right direction.

The smooth muscle in the walls of arterioles can contract or relax, changing the diameter of the vessel. This regulates blood flow and pressure.

The arteriole smooth muscle helps withstand the pressure of blood flowing through arteries. It acts like a strong wall.