Medical Knowledge 13

Medical Knowledge 13

1. Rheumatoid arthritis (RA) is an autoimmune disease.

Rheumatoid arthritis (RA) is indeed an autoimmune disease. Autoimmune diseases occur when the body's immune system, which is responsible for protecting the body against harmful substances like bacteria and viruses, mistakenly attacks its own healthy tissues. In the case of rheumatoid arthritis, the immune system primarily targets the joints, leading to inflammation, pain, and damage.

In a person with RA, the immune system mistakenly identifies the lining of the joints, called the synovium, as a threat and launches an immune response. This immune response involves the release of various inflammatory substances, such as cytokines, which lead to chronic inflammation in the joints. Over time, this persistent inflammation can result in joint damage, deformity, and functional limitations.

While the exact cause of rheumatoid arthritis is still unknown, it is believed to involve a combination of genetic and environmental factors. Certain genetic variations can make individuals more susceptible to developing RA, and environmental triggers, such as infections or hormonal changes, can potentially activate the immune response.

Treatment for rheumatoid arthritis aims to reduce inflammation, manage symptoms, prevent joint damage, and improve quality of life. This often involves a combination of medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), disease-modifying antirheumatic drugs (DMARDs), and biologic therapies. Additionally, lifestyle modifications, physical therapy, and regular exercise can also play a role in managing the condition.

2. Parts of the brain stem are - midbrain, pons and the medulla oblongata.

The brain stem is the lower part of the brain that connects the rest of the brain to the spinal cord. It is responsible for many vital functions of the body. The brain stem consists of three main parts:

Midbrain: The midbrain is the uppermost portion of the brain stem. It serves as a relay station for sensory and motor signals between the brain and the rest of the body. It is involved in controlling eye movements, auditory and visual processing, and the regulation of arousal, sleep, and temperature.

Pons: The pons is located below the midbrain and in front of the medulla oblongata. It acts as a bridge that connects the cerebrum, cerebellum, and medulla oblongata. The pons is involved in various functions, including regulating sleep, breathing, facial expressions, and relaying sensory information between the cerebrum and the cerebellum.

Medulla Oblongata: The medulla oblongata is the lowermost part of the brain stem, adjoining the spinal cord. It plays a crucial role in controlling involuntary functions necessary for survival, such as breathing, heart rate, blood pressure, and digestion. It also contains centers that regulate reflexes, swallowing, coughing, and vomiting.

Together, the midbrain, pons, and medulla oblongata are responsible for essential functions like consciousness, sensory and motor coordination, breathing, heart rate, and maintaining vital bodily functions.

3. Schwann cells form the myelin sheaths around nerve fibers that are found in the PNS.

Schwann cells are a type of glial cell that is found in the peripheral nervous system (PNS). Their primary function is to form myelin sheaths around nerve fibers in the PNS. The myelin sheath is a protective covering that wraps around the axons of nerve fibers, allowing for faster and more efficient conduction of electrical impulses.

Each Schwann cell wraps itself around a single axon, forming multiple layers of myelin. The myelin sheath is composed of lipid-rich material, which provides insulation and helps to increase the speed of nerve signal transmission. The gaps between adjacent Schwann cells along the axon are called the nodes of Ranvier, and they play a role in facilitating the saltatory conduction of nerve impulses.

In addition to myelination, Schwann cells also have other important functions. They provide metabolic support to the nerve fibers, aid in nerve regeneration following injury, and contribute to the maintenance of the nerve microenvironment.

It's worth noting that myelin sheaths in the central nervous system (CNS), which includes the brain and spinal cord, are formed by a different type of glial cell called oligodendrocytes. Oligodendrocytes functionally resemble Schwann cells but differ in their anatomical structure and distribution within the CNS.

4. Hormone produced and secreted by the pineal gland is melatonin.

The hormone produced and secreted by the pineal gland is melatonin. The pineal gland is a small, pinecone-shaped gland located deep within the brain, specifically in the epithalamus.

Melatonin plays a crucial role in regulating the sleep-wake cycle, also known as the circadian rhythm. It is primarily released in response to darkness and helps to promote sleep and regulate the body's internal clock. The pineal gland receives signals from the retina in the eyes, which detects changes in light and dark cycles, and adjusts melatonin production accordingly.

Melatonin levels typically rise in the evening, signaling to the body that it is time to sleep. It helps to induce drowsiness, decrease alertness, and promote restful sleep. As morning approaches and light levels increase, melatonin secretion decreases, allowing the body to awaken and become more alert.

In addition to its role in regulating sleep patterns, melatonin also has other functions. It acts as an antioxidant, protecting cells from oxidative stress. It may also have influences on immune function, reproductive processes, and the body's response to stress.

Supplemental melatonin is sometimes used to help with sleep disorders, such as insomnia or jet lag, by adjusting the circadian rhythm. However, it is important to consult with a healthcare professional before starting any new supplements or medications.

5. The client is admitted to the hospital with hypertensive crises. Diazoxide (Hyperstat) is ordered. During administration, the nurse should:

A. Utilize an infusion pump.

B. Check the blood glucose level.✔️

C. Place the client in Trendelenburg position.

D. Cover the solution with foil.

Explanation: Hyperstat is given IV push for hypertensive crises, but it often causes hyperglycemia. The glucose level will drop rapidly when stopped. 

Answer A is incorrect because the hyperstat is given by IV push. 

The client should be placed in dorsal recumbent position, not Trendelenburg position, as stated in answer C. 

Answer D is incorrect because the medication does not have to be covered with foil.

6. The six-month-old client with a ventral septal defect is receiving Digitalis for regulation of his heart rate. Which finding should be reported to the doctor?

A. Blood pressure of 126/80

B. Blood glucose of 110mg/dL

C. Heart rate of 60bpm✔️

D. Respiratory rate of 30 per minute

Explanation: A heart rate of 60 in the baby should be reported immediately. The dose should be held if the heart rate is below 100bpm. The blood glucose, blood pressure, and respirations are within normal limits; thus, answers A, B, and D are incorrect.

7. The client admitted with angina is given a prescription for nitroglycerine. The client should be instructed to:

A. Replenish his supply every three months.

B. Take one every 15 minutes if pain occurs.

C. Leave the medication in the brown bottle.✔️

D. Crush the medication and take it with water.

Explanation: Nitroglycerine should be kept in a brown bottle (or even a special air- and water-tight, solid or plated silver or gold container) because of its instability and tendency to become less potent when exposed to air, light, or water.

The supply should be replenished every six months, not three months, and one tablet should be taken every five minutes until pain subsides, so answers A and B are incorrect. If the pain does not subside, the client should report to the emergency room. The medication should be taken sublingually and should not be crushed, as stated in answer D.

8. The client is instructed regarding foods that are low in fat and cholesterol. Which diet selection is lowest in saturated fats?

A. Macaroni and cheese

B. Shrimp with rice

C. Turkey breast✔️

D. Spaghetti with meat sauce

Explanation: Turkey contains the least amount of fats and cholesterol. Liver, eggs, beef, cream sauces, shrimp, cheese, and chocolate should be avoided by the client; thus, answers A, B, and D are incorrect. The client should bake meat rather than frying to avoid adding fat to the meat during cooking.

9. The client is admitted with left-sided congestive heart failure. In assessing the client for edema, the nurse should check the:

A. Feet

B. Neck✔️

C. Hands

D. Sacrum

Explanation: The jugular veins in the neck should be assessed for distension. The other parts of the body will be edematous in right-sided congestive heart failure, not left-sided; thus, answers A, C, and D are incorrect.

10. The nurse is checking the client’s central venous pressure. The nurse should place the zero of the manometer at the:

A. Phlebostatic axis

B. PMI

C. Erb’s point

D. Tail of Spence

Explanation: The phlebostatic axis is located at the fifth intercostals space midaxillary line and is the correct placement of the manometer. The PMI or point of maximal impulse is located at the fifth intercostals space midclavicular line, so answer B is incorrect. Erb’s point is the point at which you can hear the valves close simultaneously, making answer C incorrect. The Tail of Spence (the upper outer quadrant of the breast) is the area where most breast cancers are located and has nothing to do with placement of a manometer; thus, answer D is incorrect.

11. The physician orders lisinopril (Zestril) and furosemide (Lasix) to be administered concomitantly to the client with hypertension. The nurse should:

A. Question the order.

B. Administer the medications.✔️

C. Administer separately.

D. Contact the pharmacy.

Explanation: Zestril is an ACE inhibitor and is frequently given with a diuretic such as Lasix for hypertension. Answers A, C, and D are incorrect because the order is accurate. There is no need to question the order, administer the medication separately, or contact the pharmacy.

12. The best method of evaluating the amount of peripheral edema is:

A. Weighing the client daily

B. Measuring the extremity✔️

C. Measuring the intake and output

D. Checking for pitting

Explanation: The best indicator of peripheral edema is measuring the extremity. A paper tape measure should be used rather than one made of plastic or cloth, and the area should be marked with a pen, providing the most objective assessment. Answer A is incorrect because weighing the client will not indicate peripheral edema. Answer C is incorrect because checking the intake and output will not indicate peripheral edema. Answer D is incorrect because checking for pitting edema is less reliable than measuring with a paper tape measure.

13. A client with vaginal cancer is being treated with a radioactive vaginal implant. The client’s husband asks the nurse if he can spend the night with his wife. The nurse should explain that:

A. Overnight stays by family members is against hospital policy.

B. There is no need for him to stay because staffing is adequate.

C. His wife will rest much better knowing that he is at home.

D. Visitation is limited to 30 minutes when the implant is in place.✔️

Explanation: Clients with radium implants should have close contact limited to 30 minutes per visit. The general rule is limiting time spent exposed to radium, putting distance between people and the radium source, and using lead to shield against the radium. Teaching the family member these principles is extremely important. Answers A, B, and C are not empathetic and do not address the question; therefore, they are incorrect.