Nurse.ali fadel abassover 3 years ago
Megakaryocytes are cells in the bone marrow responsible for making platelets, which are necessary for blood clotting. One mystery regarding megakaryocytes is how they achieve their enormous size and large number of nuclei.
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Oral Diuresis in Heart FailureHeart and Lung Auscultation### Anatomy of the Heart: Summary
The heart is a muscular organ responsible for pumping blood throughout the body, supplying oxygen and nutrients while removing waste products. It is located in the thoracic cavity, between the lungs, and is roughly the size of a fist.
#### 1. **Structure:**
- **Chambers:** The heart has four chambers:
- **Right Atrium:** Receives deoxygenated blood from the body via the superior and inferior vena cavae.
- **Right Ventricle:** Pumps deoxygenated blood to the lungs through the pulmonary arteries.
- **Left Atrium:** Receives oxygenated blood from the lungs via the pulmonary veins.
- **Left Ventricle:** Pumps oxygenated blood to the rest of the body through the aorta.
- **Valves:** The heart contains four main valves that ensure unidirectional blood flow:
- **Tricuspid Valve:** Located between the right atrium and right ventricle.
- **Pulmonary Valve:** Located between the right ventricle and pulmonary arteries.
- **Mitral (Bicuspid) Valve:** Located between the left atrium and left ventricle.
- **Aortic Valve:** Located between the left ventricle and the aorta.
#### 2. **Wall Layers:**
- **Epicardium:** The outer layer, also known as the visceral pericardium.
- **Myocardium:** The thick, muscular middle layer responsible for contraction.
- **Endocardium:** The inner layer that lines the chambers and valves.
#### 3. **Blood Supply:**
- The heart receives its blood supply from the coronary arteries, which branch off the aorta. The **right coronary artery** supplies the right side of the heart, while the **left coronary artery** branches into the left anterior descending and circumflex arteries, supplying the left side.
#### 4. **Electrical System:**
- The heart's rhythmic contractions are controlled by its electrical conduction system, which includes:
- **Sinoatrial (SA) Node:** The natural pacemaker located in the right atrium.
- **Atrioventricular (AV) Node:** Receives impulses from the SA node and transmits them to the ventricles.
- **Bundle of His and Purkinje Fibers:** Distribute the electrical impulse throughout the ventricles, leading to contraction.
#### 5. **Function:**
- The heart functions in two primary circulatory loops:
- **Pulmonary Circulation:** Moves deoxygenated blood from the right side of the heart to the lungs for oxygenation.
- **Systemic Circulation:** Distributes oxygenated blood from the left side of the heart to the rest of the body.
The anatomy of the heart is crucial for its role in maintaining effective circulation and overall cardiovascular health. Understanding its structure helps in diagnosing and treating various heart conditions.Meningitis is an infection and swelling, called inflammation, of the fluid and membranes around the brain and spinal cord. These membranes are called meninges.
The inflammation from meningitis most often triggers symptoms such as headache, fever and a stiff neck.
Viral infections are the most common cause of meningitis in the United States. Bacteria, parasites and fungi also can cause it. Sometimes meningitis improves in a few weeks without treatment. But meningitis also can cause death. It often needs quick treatment with antibiotics.
Seek medical care right away if you think that you or someone in your family has meningitis. For meningitis caused by bacteria, early treatment can prevent serious complications.Mental and physical health are interconnected. We, as a society, need to work on emphasizing the importance of the two. This would prevent people developing physical and mental diseases at earlier and earlier ages.Second Degree Heart BlockThird Degree Heart BlockEndocarditisMarfan syndromePhenylketonuria