Concomitant Urinary Triple Phosphate and Cystine Crystals
A 37-year-old man with cystinuria was seen in the nephrology clinic for routine follow-up. He had received a diagnosis of cystinuria at 1 year of age, when he had presented with nephrolithiasis and pyelonephritis; subsequent workup had shown elevated 24-hour cystine urinary excretion and homozygous variants in the gene SLC3A1. Since then, he had been treated with urinary alkalinization, high fluid intake, and tiopronin. At the current presentation, he was asymptomatic. The serum creatinine level was normal, and a urinalysis showed a pH of 7.0, with no hematuria or bacteriuria. Microscopic examination of a spun urine specimen showed hexagonal cystine crystals (Panel A) and rhombohedral triple phosphate — or struvite — crystals (Panel B). In the same field of view elsewhere in the specimen (Panel C), triple phosphate crystals of a different shape (arrowhead) and cystine crystals (arrow) were seen. Under polarized light, these triple phosphate crystals showed polychromatic properties, and the cystine crystals showed moderate polarizing properties (Panel D). Triple phosphate crystals are associated with urease-producing organisms. The patient had been treated for urinary tract infection 2 weeks before this presentation, but the causative organism had been unknown. At follow-up 1 month later, the patient had no recurrent symptoms of urinary tract infection.
Stomach
Foot X-ray AnatomyAnatomy of liverAbdominal aortic aneurysmImage of trachea blocked by chewing gum### 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.