Level 2 - Cardiovascular, Respiratory & Lymphatic Systems

Explanation
The heart is made out of muscle. It is composed of cardiac muscle tissue, which is a specialized type of muscle that contracts and relaxes to pump blood throughout the body. The muscular walls of the heart allow it to generate the force necessary to pump blood and maintain circulation.

Explanation
Capillaries are the smallest blood vessels in the body and are responsible for the exchange of materials between the bloodstream and the body's tissues. Their thin walls allow for the diffusion of oxygen, nutrients, and waste products between the blood and the surrounding tissues. Arteries and veins are larger blood vessels that transport blood to and from the capillaries, but they do not directly participate in the exchange of materials.

Explanation
Valves are found in veins. Veins are blood vessels that carry deoxygenated blood back to the heart. Valves in veins help prevent the backflow of blood and ensure that blood flows in one direction, towards the heart. This is important because veins are under lower pressure compared to arteries, and the valves help to maintain the flow of blood against gravity.

Explanation
Arteries are the type of blood vessels that are under the most pressure. This is because arteries carry oxygenated blood away from the heart to the rest of the body, and the force exerted by the pumping of the heart causes the blood to flow with high pressure. In contrast, veins carry deoxygenated blood back to the heart, and capillaries are tiny, thin-walled vessels that connect arteries and veins, allowing for the exchange of nutrients and waste products.

Explanation
White blood cells, also known as leukocytes, are responsible for fighting infections in the body. They are a crucial part of the immune system and help to identify and destroy foreign invaders such as bacteria, viruses, and other pathogens. White blood cells can engulf and destroy these pathogens, produce antibodies, and coordinate immune responses to protect the body from infections.

Explanation
The cardiovascular system carries enzymes to the appropriate cells. This system consists of the heart, blood vessels, and blood. The heart pumps blood, which contains enzymes, to all the cells in the body through the blood vessels. This ensures that the enzymes reach the appropriate cells where they are needed for various biological processes. The lymphatic system, on the other hand, is responsible for carrying lymph fluid and immune cells, not enzymes.

Explanation
Hypotension is the correct answer because it refers to low blood pressure. Hypotension occurs when the force of blood against the artery walls is too low, resulting in inadequate blood flow to the organs and tissues of the body. This can lead to symptoms such as dizziness, fainting, and fatigue. Hypertension, on the other hand, refers to high blood pressure, which is the opposite of low blood pressure.

Explanation
Red blood cells, also known as erythrocytes, are responsible for carrying oxygen to the body's tissues. They contain a protein called hemoglobin, which binds to oxygen in the lungs and transports it to cells throughout the body. The red color of these cells is due to the presence of iron in hemoglobin. White blood cells, on the other hand, are involved in the immune response and platelets help in blood clotting.

Explanation
Platelets are responsible for preventing excess blood loss and microbe entry. They form clots to stop bleeding by sticking together and sealing off damaged blood vessels. Additionally, platelets release chemicals that attract white blood cells to the site of infection, helping to fight against microbes and prevent their entry into the body.

Explanation
Arteries are a type of blood vessel that carry oxygenated blood away from the heart to the various organs and tissues in the body. They are deeper in the body compared to veins and capillaries, which are closer to the surface. Arteries have thicker walls and a more muscular structure to withstand the high pressure of blood flow. Veins, on the other hand, carry deoxygenated blood back to the heart and have thinner walls. Capillaries are the smallest blood vessels and connect arteries to veins, allowing for the exchange of oxygen, nutrients, and waste products between the blood and surrounding tissues.

Explanation
Phlebitis is the inflammation of a vein, which can occur due to various factors such as infection, trauma, or the presence of a blood clot. This inflammation can cause pain, redness, and swelling in the affected area. Deep vein thrombosis, on the other hand, refers to the formation of a blood clot in a deep vein, which can also lead to inflammation but is not the primary cause. Anaemia and epitaxis do not directly cause inflammation inside a vein. Therefore, phlebitis is the correct answer as it specifically refers to the pathology causing inflammation inside a vein.

Explanation
Nodes are small, bean-shaped structures found throughout the lymphatic system. They act as filters, trapping and removing harmful microorganisms, as well as other foreign substances, from the lymph fluid. This helps to prevent the spread of infection and disease throughout the body.

Explanation
The popliteal lymph nodes are found at the back of the knee. These lymph nodes are responsible for filtering lymph fluid and helping to fight off infections in the lower leg and foot. They play an important role in the immune system by trapping and destroying harmful substances.

Explanation
The thoracic duct drains the most lymph in the body. It is the largest lymphatic vessel and collects lymph from the lower limbs, abdomen, left side of the thorax, left arm, and left side of the head and neck. It then empties into the left subclavian vein, where the lymph is returned to the bloodstream. The right lymphatic duct, on the other hand, drains lymph from the right side of the head and neck, right arm, and right side of the thorax, and empties into the right subclavian vein. However, the thoracic duct drains a larger portion of the body, making it the correct answer.

Explanation
Oxygen needs to be supplied to the blood.

Explanation
The correct name for the windpipe is trachea. The trachea is a tube-like structure that connects the larynx to the bronchi, allowing air to pass in and out of the lungs. It is lined with ciliated cells and cartilage rings to provide support and prevent collapse. The trachea plays a vital role in the respiratory system by transporting air to and from the lungs.

Explanation
Gaseous exchange takes place in the alveoli. These tiny air sacs are located at the end of the bronchioles in the lungs. They are surrounded by a network of blood vessels called capillaries. Oxygen from the inhaled air diffuses through the thin walls of the alveoli and enters the bloodstream, while carbon dioxide, a waste product, diffuses from the bloodstream into the alveoli to be exhaled. This exchange of gases is crucial for the respiratory system to provide oxygen to the body's cells and remove carbon dioxide.

Explanation
The larynx is the part of the respiratory system that contains the voicebox. It is located between the pharynx and the trachea. The larynx houses the vocal cords, which are responsible for producing sound and allowing us to speak. It also plays a crucial role in protecting the airway during swallowing by closing off the entrance to the trachea with the epiglottis.

Explanation
The external jugular vein is found in the neck. It is a prominent vein that runs diagonally across the side of the neck and is visible under the skin. It drains blood from the head, face, and neck region and carries it back to the heart. The external jugular vein is often used for medical procedures such as blood draws or intravenous access.

Explanation
The radial artery is found in the arm. It is one of the major arteries in the arm and is responsible for supplying oxygenated blood to the forearm and hand. It runs along the radius bone in the forearm and can be easily palpated at the wrist, making it a common site for measuring the pulse.

Explanation
The common carotid artery is found in the neck. This artery is a major blood vessel that supplies oxygenated blood to the head and neck region. It branches off into the internal and external carotid arteries, which further supply blood to the brain and face, respectively. The location of the common carotid artery in the neck allows for efficient and direct blood flow to these vital areas.