1. The components of a circulatory system include the heart, blood vessels (arteries, veins, and capillaries), and blood.
- The heart is a muscular organ responsible for pumping blood throughout the body. It consists of four chambers: two atria and two ventricles. The atria receive blood while the ventricles pump blood out of the heart.
- Arteries are vessels that carry oxygenated blood away from the heart to the various organs and tissues. They have thicker and more elastic walls to withstand the higher pressure from the heart.
- Veins are vessels that carry deoxygenated blood back to the heart. They have thinner walls compared to arteries and contain valves to prevent the backflow of blood.
- Capillaries are tiny, thin-walled vessels that connect arteries and veins. They facilitate the exchange of oxygen, nutrients, and waste products between the blood and tissues.
- Blood is a fluid connective tissue consisting of red blood cells, white blood cells, platelets, and plasma. Red blood cells carry oxygen, white blood cells defend against infections, platelets aid in blood clotting, and plasma transports nutrients, hormones, and waste products.
2. The functions of the circulatory system include:
- Transporting oxygen, nutrients, hormones, and waste products to and from the cells and organs of the body.
- Facilitating the exchange of gases (such as oxygen and carbon dioxide) between the lungs and body tissues.
- Regulating body temperature through blood circulation.
- Distributing immune cells and antibodies to fight against infections.
- Assisting in the clotting process to prevent excessive bleeding.
3. Blood circulates through the heart in the following way:
- Deoxygenated blood enters the right atrium of the heart from the superior and inferior vena cava.
- The right atrium contracts, pushing the blood into the right ventricle.
- The right ventricle contracts, pumping the deoxygenated blood into the pulmonary artery.
- The pulmonary artery carries the blood to the lungs, where oxygen is picked up, and carbon dioxide is released.
- Oxygenated blood returns to the heart through the pulmonary veins, entering the left atrium.
- The left atrium contracts, pushing the blood into the left ventricle.
- The left ventricle contracts, pumping the oxygenated blood into the aorta.
- The aorta distributes the oxygenated blood to the rest of the body.
4. When selecting a venipuncture site, several factors need to be considered:
- Accessibility and visibility: The site should be easily accessible and visible, allowing for proper insertion of the needle and monitoring during the procedure.
- Vein condition: The chosen vein should be healthy and suitable for venipuncture. Factors such as size, depth, and palpability of the vein are important considerations.
- Patient comfort: The site should be chosen in a way that minimizes discomfort for the patient.
- Specific requirements: Certain tests or procedures may require specific vein selection, such as selecting a peripheral vein for intravenous infusion or a superficial vein for blood sampling.
5. Veins of the lower extremities (legs) are generally avoided as venipuncture sites due to several reasons:
- Increased risk of complications: Veins in the lower extremities are more prone to complications like hematoma formation, arterial puncture, nerve damage, and infection.
- Difficulty in maintaining pressure: The veins in the lower extremities are often under higher pressure due to gravity, making it harder to control bleeding after venipuncture.
- Increased risk of clot formation: Blood flow in the lower extremities is slower compared to the upper body, which increases the risk of clot formation (deep vein thrombosis) around the puncture site.
6. The palm side of the wrist (ventral aspect) is not an ideal site for venipuncture because:
- It contains numerous nerves: The ventral aspect of the wrist is densely populated with nerves, making it more risky to perform venipuncture due to the potential for nerve damage.
- Increased pain sensitivity: The palm side of the wrist is generally more sensitive to pain, and venipuncture in this area may cause discomfort or pain to the patient.
7. The best insertion sites for venipuncture include:
- Antecubital fossa: This area on the inner side of the elbow is commonly used for venipuncture. It includes veins like the median cubital vein, cephalic vein, and basilic vein.
- Dorsum of the hand: Veins on the back of the hand, such as the dorsal venous network, can be used for venipuncture.
- Forearm: Select veins on the forearm, like the cephalic and basilic veins, can be used as insertion sites.
8. When administering medication to an elderly person, several precautions should be taken:
- Assessing the condition: It is important to assess the overall health, medical history, and current medications of the elderly person to avoid potential drug interactions or contraindications.
- Proper dosage adjustment: The dosage of medications may need to be adjusted based on factors such as renal function and potential age-related changes in drug metabolism.
- Slow administration: Medications should be administered slowly to prevent adverse reactions or discomfort, considering the potential decline in organ function.
- Monitoring for side effects: Close monitoring for any adverse reactions or side effects is crucial in elderly individuals, as they may be more susceptible to medication-related complications.
- Ensuring patient comfort and safety: Elderly patients may have reduced mobility, frailty, or cognitive impairment, so it is important to ensure their comfort and safety during the administration process.
9. The purposes of intravenous infusion include:
- Fluid replacement: Intravenous infusion is commonly used to replace fluids in patients who are dehydrated or unable to take oral fluids due to various medical conditions.
- Medication administration: Intravenous infusion allows for the delivery of medications directly into the bloodstream, ensuring rapid and accurate absorption.
- Nutritional support: Intravenous infusion can be used to provide essential nutrients and electrolytes to patients who are unable to consume them orally.
- Blood transfusion: Intravenous infusion is used to deliver blood products, such as red blood cells or platelets, to individuals in need of transfusion.
10. The locations commonly used for intravenous injection in radiography include:
- Antecubital fossa: This area on the inner side of the elbow is often used for intravenous injection as it provides easy access to the veins, particularly the median cubital vein.
- Dorsum of the hand: Veins on the back of the hand can be used for intravenous injection, especially if the antecubital fossa is inaccessible or unsuitable.
- Forearm: Certain veins on the forearm, like the cephalic and basilic veins, can be used for intravenous injection if other sites are not feasible.
It is important to note that the specific choice of venous access site may vary based on individual patient factors, medical condition, and the preference or expertise of the healthcare professional performing the procedure.
