1.
Water functions as
Correct Answer
C. A solvent in the blood
Explanation
Water functions as a solvent in the blood because it has the ability to dissolve various substances, such as gases, nutrients, and waste products. As a solvent, water helps transport these dissolved substances throughout the body, allowing for the proper functioning of cells and organs. Additionally, water's solvent properties enable it to facilitate chemical reactions and maintain the balance of electrolytes and ions in the blood.
2.
Which of the following is the pacemaker of the heart?
Correct Answer
A. Sinoatrial node
Explanation
The pacemaker of the heart is the sinoatrial node. It is responsible for initiating the electrical impulses that regulate the heart's rhythm and coordinate its contractions. The sinoatrial node is located in the right atrium of the heart and generates electrical signals that travel through the atria, causing them to contract and pump blood into the ventricles. From there, the electrical signals are conducted to the atrioventricular node, which further regulates the timing of the heart's contractions. The purkinje fibers and autonomic nerves also play important roles in the heart's electrical system, but they are not the primary pacemaker.
3.
Which of the following factors affect blood pressure?
Correct Answer
D. All of the above
Explanation
The viscosity of the blood refers to its thickness or resistance to flow. When blood becomes more viscous, it requires more pressure to flow through the blood vessels, leading to an increase in blood pressure. Blood flow resistance in the arteries is another factor that affects blood pressure. If the arteries are narrow or constricted, it increases the resistance and requires higher pressure for blood to flow through them, resulting in elevated blood pressure. The elasticity of blood vessel walls also plays a role in blood pressure regulation. If the blood vessels lose their elasticity, they become stiff and less able to expand and contract, causing an increase in blood pressure. Therefore, all of these factors can affect blood pressure.
4.
The superior vena cava drains blood from the
Correct Answer
A. Head, neck, upper limbs and thoracic wall
Explanation
The superior vena cava is a large vein that carries deoxygenated blood from the upper body back to the heart. It specifically drains blood from the head, neck, upper limbs, and thoracic wall. This means that blood from these areas is collected by the superior vena cava and returned to the heart to be pumped to the lungs for oxygenation.
5.
Wher in the body is the axillary vein located?
Correct Answer
C. Armpit
Explanation
The axillary vein is located in the armpit. This vein runs alongside the axillary artery and is responsible for draining blood from the upper limb back to the heart. It is an important vessel in the circulatory system, as it carries deoxygenated blood from the arm and shoulder region.
6.
Where in the body is the great saphenous vein located?
Correct Answer
C. Leg
Explanation
The great saphenous vein is located in the leg. It is the longest vein in the body and runs along the inside of the leg, from the groin to the foot. It is responsible for carrying deoxygenated blood from the lower extremities back to the heart.
7.
Which of the following is NOT a type of white blood cell/
Correct Answer
C. Erythrocyte
Explanation
Erythrocytes, also known as red blood cells, are not a type of white blood cell. White blood cells play a crucial role in the immune system, defending the body against infections and diseases. Neutrophils, lymphocytes, and basophils are all types of white blood cells that have different functions in the immune response. Neutrophils are the most common type and are responsible for fighting bacterial infections. Lymphocytes are involved in both the innate and adaptive immune responses. Basophils release histamine and other chemicals during allergic reactions. Erythrocytes, on the other hand, are responsible for carrying oxygen to the body's tissues.
8.
Where is the spleen located?
Correct Answer
B. Behind and to the left of the stomach
Explanation
The spleen is located behind and to the left of the stomach. This positioning allows it to be in close proximity to the stomach, which is important for its functions in filtering the blood and storing red blood cells. Additionally, this location also helps to protect the spleen from direct trauma, as it is partially covered by the ribcage.
9.
Which of the following is NOT a lymph node of teh pelvis or lower limbs?
Correct Answer
D. Supratrochlear or cubital
Explanation
The supratrochlear or cubital lymph node is not a lymph node of the pelvis or lower limbs. The popliteal, inguinal, and iliac lymph nodes are all located in the pelvis or lower limbs. The supratrochlear lymph node is located in the upper limb, specifically in the region of the elbow. Therefore, it is not a lymph node of the pelvis or lower limbs.
10.
Which of the following is NOT a function of the lymphatic system?
Correct Answer
C. Production of erythrocytes
Explanation
The lymphatic system is responsible for various functions in the body, including transportation of dietary lipids, drainage of excess tissue fluid, and production of lymphocytes. However, the production of erythrocytes, or red blood cells, is not a function of the lymphatic system. Erythrocytes are produced in the bone marrow, specifically in the spongy bone. The lymphatic system primarily plays a role in the immune system and fluid balance, rather than blood cell production.
11.
Which organ destroys worn-out erythrocytes?
Correct Answer
D. Spleen
Explanation
The spleen is responsible for destroying worn-out erythrocytes, also known as red blood cells. It filters the blood and removes old or damaged red blood cells from circulation. The spleen plays a crucial role in maintaining the overall health and functionality of the blood by eliminating these worn-out cells.
12.
Which type of tissue is blood?
Correct Answer
B. Connective
Explanation
Blood is classified as connective tissue because it consists of cells suspended in a liquid extracellular matrix called plasma. Connective tissue is characterized by its ability to support, connect, and protect other tissues in the body. In the case of blood, it transports oxygen, nutrients, hormones, and waste products throughout the body, and plays a vital role in immune responses and maintaining homeostasis.
13.
The heart chamber receiving blood from the lungs is the
Correct Answer
C. Left atrium
Explanation
The left atrium receives oxygenated blood from the lungs through the pulmonary veins. It then contracts to push this blood into the left ventricle, which pumps it out to the rest of the body. The right atrium, on the other hand, receives deoxygenated blood from the body and sends it to the right ventricle to be pumped to the lungs for oxygenation. Therefore, the correct answer is the left atrium, as it is the heart chamber that receives blood from the lungs.
14.
The triple-layered sac that surrounds and protects the heart is the
Correct Answer
D. Pericardium
Explanation
The correct answer is Pericardium. The pericardium is a triple-layered sac that surrounds and protects the heart. It consists of an outer fibrous layer, a middle serous layer, and an inner layer that directly covers the heart. The pericardium helps to prevent the heart from overexpanding, provides lubrication for smooth heart movements, and acts as a barrier against infection and inflammation.
15.
Which valves prevent backflow of blood into the atria when the ventricles contract?
Correct Answer
A. Atrioventricular
Explanation
The atrioventricular valves prevent backflow of blood into the atria when the ventricles contract. These valves, namely the tricuspid valve on the right side and the mitral valve on the left side, close during ventricular contraction to prevent blood from flowing back into the atria. This ensures that blood is forced to flow forward into the arteries and prevents any regurgitation into the atria.
16.
Which side of the heart receives deoxygenated blood from the body and pumps it to the lungs?
Correct Answer
A. Right
Explanation
The right side of the heart receives deoxygenated blood from the body and pumps it to the lungs. The deoxygenated blood enters the right atrium from the body through the superior and inferior vena cava. It then passes through the tricuspid valve into the right ventricle. From there, it is pumped through the pulmonary valve and into the pulmonary artery, which carries the blood to the lungs for oxygenation.
17.
Which type of blood vessels carry blood away from the tissues towards he heart?
Correct Answer
D. Veins
Explanation
Veins carry blood away from the tissues towards the heart. Unlike arteries, which carry oxygenated blood away from the heart, veins carry deoxygenated blood back to the heart. Veins have thinner walls and larger lumens compared to arteries, allowing them to accommodate the lower pressure of deoxygenated blood. Additionally, veins contain valves that prevent backflow of blood and assist in the upward flow towards the heart.
18.
Which type of blood vessel has walls composed of a single layer of endothelium and a basement membrane?
Correct Answer
B. Capillaries
Explanation
Capillaries have walls composed of a single layer of endothelium and a basement membrane. This structure allows for the exchange of gases, nutrients, and waste products between the blood and surrounding tissues. Capillaries are the smallest blood vessels in the body and are responsible for delivering oxygen and nutrients to cells, as well as removing waste products. Their thin walls and small size facilitate efficient diffusion of substances across the vessel walls. Arterioles, venules, and veins have thicker walls and are not composed solely of endothelium and basement membrane.
19.
Which of the following vessels carries blood from the digestive tract to the liver?
Correct Answer
C. Hepatic portal vein
Explanation
The hepatic portal vein carries blood from the digestive tract to the liver. This vein collects blood from the stomach, intestines, pancreas, and spleen, and transports it to the liver for processing and detoxification. The hepatic portal vein is responsible for delivering nutrients and absorbed substances from the digestive system to the liver, allowing the liver to regulate and metabolize these substances before they enter the systemic circulation.
20.
What is the name of the route blood follows from the heart to the tissues and organs of the body and back to the heart?
Correct Answer
D. Systemic circulation
Explanation
Systemic circulation refers to the pathway that blood takes from the heart to the tissues and organs of the body, and then back to the heart. This process involves the pumping of oxygenated blood from the left side of the heart to the rest of the body through the arteries. The oxygen is then exchanged for carbon dioxide in the tissues, and the deoxygenated blood returns to the heart through the veins to be reoxygenated. Therefore, systemic circulation is responsible for delivering oxygen and nutrients to the body's cells and removing waste products.