Anatomy II Quiz 1 Part 2

Neutrophils are the most abundant white blood cells in the body. They play a crucial role in the immune system by engulfing and destroying bacteria and other foreign substances. They are highly mobile and are the first responders to sites of infection or inflammation. Neutrophils are characterized by their multi-lobed nucleus and granular cytoplasm. Their abundance and rapid response make them an essential component of the body's defense against infections.

Hemoglobin is a protein found in red blood cells that is responsible for carrying oxygen throughout the body. Each heme ring in hemoglobin contains an iron atom, which is essential for the binding and transport of oxygen. Iron binds to oxygen in the lungs and releases it to tissues that need oxygen for cellular respiration. Without iron, hemoglobin would not be able to perform its crucial role in oxygen transport, leading to severe health problems such as anemia. Therefore, the correct answer is iron.

The pulmonary arteries carry blood to the lungs.

When the left ventricle contracts, it squeezes the blood out of the chamber and into the aorta. This contraction causes the walls of the ventricular chamber to come closer together, resulting in a decrease in diameter. This decrease in diameter helps to increase the pressure inside the ventricle, allowing for efficient ejection of blood into the aorta.

The left ventricle has a greater workload than the right ventricle. This is because the left ventricle is responsible for pumping oxygenated blood to the rest of the body through the systemic circulation, while the right ventricle only pumps deoxygenated blood to the lungs for oxygenation.

The correct answer is "between the left atrium and left ventricle." The bicuspid or mitral valve is located between the left atrium and left ventricle of the heart. It is responsible for preventing the backflow of blood from the left ventricle into the left atrium during ventricular contraction.

The atrioventricular valves permit blood flow in one direction only. These valves are located between the atria and ventricles of the heart and prevent backflow of blood. When the ventricles contract, the valves close to prevent blood from flowing back into the atria. This ensures that blood flows in a forward direction, from the atria to the ventricles, and then out of the heart to the rest of the body.

The pulmonary veins carry blood from the lungs back to the heart.

The sinoatrial node is the normal pacemaker of the heart. It is located in the wall of the right atrium. It generates electrical impulses that regulate the heart's rhythm and initiate the contraction of the atria. These impulses then travel through the atrioventricular node and the Purkinje fibers to stimulate the contraction of the ventricles. The sinoatrial node is responsible for initiating each heartbeat and ensuring that the heart beats at a regular and coordinated pace.

Bradycardia refers to a slow heart rate, while tachycardia refers to a fast heart rate. Cardiac tamponade and cardiomyopathy are conditions that can affect the heart, but they do not specifically relate to heart rate. Therefore, the correct answer is "Bradycardia; tachycardia."

Plasma is closest in composition to interstitial fluid because both contain similar concentrations of electrolytes, hormones, and nutrients. Interstitial fluid surrounds and bathes cells, providing them with necessary substances and removing waste products. Plasma, on the other hand, is the liquid component of blood that carries nutrients, hormones, and waste products throughout the body. Both fluids are essential for maintaining homeostasis and ensuring proper functioning of cells and tissues.

The pus associated with infected wounds contains cellular debris, dead neutrophils, and tissue fluids. This is because when a wound becomes infected, the body's immune system sends white blood cells, mainly neutrophils, to fight off the infection. These neutrophils die in the process and along with other cellular debris and tissue fluids, they form pus. Therefore, all of the options mentioned in the answer are correct.

A digestive disorder that impairs a person's ability to absorb vitamin K will result in low levels of Factor X, low levels of prothrombin, low levels of thromboplastin, and prolonged bleeding. Vitamin K is essential for the production of these clotting factors, and without adequate levels of vitamin K, the body's ability to form blood clots is compromised. This can lead to prolonged bleeding and low levels of these clotting factors. Therefore, all of the above options are correct.

The heart is innervated by both parasympathetic and sympathetic nerves. The parasympathetic nervous system slows down the heart rate and reduces the force of contractions, while the sympathetic nervous system increases the heart rate and enhances the force of contractions. These two systems work together to maintain the balance and regulation of the heart's activity.

When the semilunar valves close, it means that the ventricles have finished contracting and the blood has been pumped out of the heart into the arteries. At this point, the AV valves open to allow blood to flow from the atria into the ventricles, preparing for the next cycle of the heartbeat. Therefore, the correct answer is "open".

Starling's law of the heart states that an increase in end-diastolic volume, which is the volume of blood in the ventricles at the end of diastole, leads to an increase in stroke volume. This means that the heart will pump out a greater volume of blood with each contraction when the ventricles are filled with a larger volume of blood. This law explains the relationship between the volume of blood in the heart and the force of contraction, highlighting the heart's ability to adapt to changes in blood volume.

The correct answer is tricuspid. The tricuspid valve is located between the right atrium and right ventricle of the heart. It prevents the backflow of blood from the ventricle into the atrium during ventricular contraction.

Plasma makes up about 55 percent of whole blood, while water makes up about 92 percent of the plasma volume.

Neutrophils are the most numerous white blood cells (WBCs) in a differential count of a healthy individual. They play a crucial role in the immune system's response to bacterial infections. Neutrophils are highly mobile and quickly migrate to the site of infection, where they engulf and destroy bacteria through a process called phagocytosis. Their abundance in the differential count indicates a healthy immune system capable of effectively combating bacterial pathogens.

The bicuspid valve, also known as the mitral valve, is located between the left atrium and the left ventricle of the heart. Its main function is to prevent the backward flow of blood into the left atrium when the left ventricle contracts and pumps blood out to the rest of the body.

The visceral pericardium refers to the innermost layer of the pericardium, which is the protective sac surrounding the heart. It is also known as the epicardium. The epicardium is a thin, smooth layer that covers the surface of the heart and is composed of connective tissue and a layer of mesothelial cells. It provides protection to the heart and also helps in reducing friction between the heart and the surrounding structures. Therefore, the correct answer is epicardium.

The connective tissue fibers of the myocardium serve multiple functions. They help distribute the forces of contraction, ensuring that the heart contracts efficiently. They also add strength and prevent overexpansion of the heart, maintaining its structural integrity. Additionally, these fibers provide elasticity, allowing the heart to return to its normal size after each contraction. Lastly, they provide physical support for the cardiac muscle, helping to maintain the shape and position of the heart. Therefore, all of the given options are correct.

After donating a unit of blood, the number of reticulocytes would be expected to increase in a peripheral blood sample. Reticulocytes are immature red blood cells that are released by the bone marrow into the bloodstream in response to an increase in demand for oxygen-carrying cells. Therefore, after donating blood, the body would need to produce more red blood cells to replenish the loss, leading to an increase in reticulocyte count.

The right ventricle pumps blood to the right and left lungs. This is because the right ventricle receives deoxygenated blood from the right atrium and pumps it to the lungs through the pulmonary artery. In the lungs, the blood is oxygenated and then returned to the left atrium through the pulmonary veins. From the left atrium, the oxygenated blood is then pumped into the left ventricle and eventually to the rest of the body through the aorta.

The atrium has two main functions: to collect blood and to pump blood to the ventricle. It receives blood from either the body (in the case of the right atrium) or the lungs (in the case of the left atrium) and then contracts to push the blood into the ventricle. Therefore, option "both A and D" is correct as it includes both of these functions.

The pulmonary semilunar valve is located between the right ventricle and the pulmonary trunk. Its main function is to prevent the backward flow of blood from the pulmonary trunk into the right ventricle. This ensures that oxygenated blood flows from the right ventricle into the pulmonary trunk and then to the lungs for oxygenation. Therefore, the correct answer is the right ventricle.

The T wave on an ECG tracing represents ventricular repolarization. This is the phase of the cardiac cycle where the ventricles are relaxing and resetting their electrical charge in preparation for the next contraction. The T wave is a positive deflection on the ECG graph, indicating the repolarization of the ventricles. It follows the QRS complex, which represents ventricular depolarization.

The correct answer is A or B or C because all three conditions listed (pulmonic valve insufficiency, aortic valve stenosis, and mitral valve insufficiency) can cause a heart murmur. A heart murmur is an abnormal sound heard during a heartbeat, and it can be caused by various factors including valve problems.

The coronary sulcus is a groove that marks the border between the atria and ventricles. This groove separates the upper chambers of the heart (atria) from the lower chambers (ventricles). It is an important landmark that helps to distinguish the different regions of the heart and plays a role in the circulation of blood.

The cusps (leaflets) of atrioventricular valves attach directly to chordae tendineae. Chordae tendineae are thin, fibrous cords that connect the cusps of the AV valves to the papillary muscles in the ventricles. These tendons help to anchor the valves and prevent them from prolapsing or flipping into the atria when the ventricles contract.

A normal range for red blood cell (RBC) count in adults is typically between 4.5 to 5.5 million cells per microliter of blood. A value of 3.5 million RBCs would be lower than the normal range, indicating a lower than normal RBC count. This can be a sign of anemia, a condition characterized by a decrease in the number of red blood cells or a decrease in the amount of hemoglobin in the blood. Anemia can result in symptoms such as fatigue, weakness, and shortness of breath.

Calcium channel blockers like nifedipine can produce a negative inotropic effect, which means they decrease the force of cardiac contraction. They can also decrease blood pressure by relaxing the smooth muscles in the walls of blood vessels, leading to vasodilation. Additionally, these drugs can dilate the coronary arteries, improving blood flow to the heart. Therefore, all of the given options are correct.

Blood returning to the heart from the systemic circuit first enters the right atrium. The right atrium receives deoxygenated blood from the body through the superior and inferior vena cava. From the right atrium, the blood flows into the right ventricle through the tricuspid valve, and then it is pumped into the pulmonary circuit to be oxygenated in the lungs.

A moving blood clot is called an embolus. An embolus is a clot that breaks away from its original location and travels through the bloodstream to another part of the body, where it can block blood flow and cause various complications depending on where it lodges.

The surgical removal of the stomach can lead to pernicious anemia. Pernicious anemia is a condition where the body is unable to absorb enough vitamin B12 from the gastrointestinal tract. The stomach plays a crucial role in the absorption of this vitamin. Without a stomach, the body's ability to absorb vitamin B12 is greatly reduced, leading to pernicious anemia. This condition can cause fatigue, weakness, shortness of breath, and other symptoms due to a deficiency in vitamin B12.

Intercalated discs serve to transfer action potentials, the force of contraction, and ionic currents from cell to cell. These discs are specialized cell junctions found in cardiac muscle, and they play a crucial role in coordinating the electrical and mechanical activities of the heart. Action potentials are the electrical signals that initiate muscle contraction, while the force of contraction refers to the strength of the muscle contraction. Ionic currents are the movement of ions across the cell membrane, which is essential for generating and propagating action potentials. Therefore, all of these functions are facilitated by intercalated discs.

The volume of blood ejected from each ventricle during a contraction is referred to as stroke volume. It represents the amount of blood pumped out with each heartbeat. Cardiac reserve refers to the ability of the heart to increase its output during times of increased demand. End-diastolic volume is the volume of blood in the ventricles at the end of diastole, while end-systolic volume is the volume of blood in the ventricles at the end of systole. Cardiac output is the total volume of blood pumped by the heart per minute.

Coronary veins empty into the right atrium. The coronary veins collect deoxygenated blood from the heart muscle and return it to the heart. The right atrium is one of the four chambers of the heart and receives deoxygenated blood from the body through the superior and inferior vena cava. From the right atrium, the blood is then pumped into the right ventricle and then to the lungs for oxygenation. Therefore, the correct answer is right atrium.

All of the proteins mentioned in the options (luteinizing hormone, insulin, and prolactin) are found in plasma. Plasma is the liquid component of blood and contains various proteins, including hormones like luteinizing hormone, insulin, and prolactin. These proteins play important roles in regulating various physiological processes in the body. Therefore, the correct answer is all of the above.

A hematocrit measures the percentage of red blood cells in the total blood volume. Red blood cells are one of the formed elements in the blood, along with white blood cells and platelets. By determining the abundance of formed elements, a hematocrit provides information about the overall cellular composition of the blood. It does not provide information about plasma composition, clotting factors, blood type, or sedimentation rate.

The right atrium receives blood from the coronary sinus, inferior vena cava, and superior vena cava. The coronary sinus collects deoxygenated blood from the heart muscle itself, while the inferior vena cava brings deoxygenated blood from the lower body and the superior vena cava brings deoxygenated blood from the upper body. Therefore, all three options (A, B, and C) are correct.

Albumin is a plasma protein that transports fatty acids and some hormones. It is the most abundant protein in the blood and plays a crucial role in maintaining osmotic pressure, pH balance, and transporting various substances throughout the body. Due to its ability to bind to fatty acids and hormones, albumin acts as a carrier molecule, ensuring their safe transport to different tissues and organs.

The foramen ovale is a small opening in the interatrial septum of the fetal heart that allows blood to flow from the right atrium to the left atrium. This structure is present in fetal circulation to bypass the non-functioning lungs, as the oxygenated blood from the placenta needs to be distributed to the rest of the body. After birth, when the baby takes its first breath, the pressure in the left atrium increases, causing the foramen ovale to close and form the fossa ovalis, which is a remnant of the foramen ovale.

After donating blood, the body needs to replace the lost red blood cells. Reticulocytes are immature red blood cells that are released into the bloodstream to replace the lost ones. Therefore, it is expected that the reticulocyte count will increase after donating blood.

Eosinophils are a type of white blood cell that are often elevated in allergic individuals. They play a role in the immune response to parasitic infections and are involved in the inflammatory response associated with allergies. They release chemicals that help to destroy parasites and are also involved in the regulation of inflammation. Therefore, the description "often elevated in allergic individuals" best matches the term eosinophils.

Pacemaker cells isolated from the SA node generate action potentials at a rate of 80-100 beats per minute. These cells are responsible for initiating the electrical signals that regulate the heart's rhythm and determine the heart rate. This range of beats per minute is considered normal for a healthy adult at rest.

The correct answer is that the refractory period lasts until the muscle relaxes. During a muscle contraction, the muscle fibers become temporarily unresponsive to further stimulation. This is known as the refractory period. In cardiac muscle, the refractory period lasts until the muscle relaxes, which prevents tetanic contractions from occurring. This is important for the proper functioning of the heart as it allows for adequate filling and emptying of blood between contractions.

The left ventricle pumps a greater volume of blood compared to the right ventricle. This is because the left ventricle is responsible for pumping oxygenated blood to the rest of the body, while the right ventricle pumps deoxygenated blood to the lungs. The left ventricle has a thicker wall, round cross section, and produces more pressure when it contracts, all of which contribute to its ability to pump a greater volume of blood.

The long plateau phase of the cardiac muscle action potential is due to calcium channels remaining open. This allows an influx of calcium ions into the cell, which prolongs the depolarization phase and delays repolarization. This is important for the proper functioning of the heart, as it allows for sufficient time for the heart to contract and pump blood effectively.

The P wave of the electrocardiogram represents the depolarization of the atria. Depolarization refers to the electrical activation and contraction of the heart muscle. The SA node, known as the natural pacemaker of the heart, initiates the electrical signal that causes the atria to contract. Therefore, the P wave represents the spread of this electrical signal through the atria, leading to their contraction.