Which of the following conditions gives a string of beads appearance and may look aneurysmal?
Fibromuscular dysplasia of the artery to the kidney (renal artery) is shown here, with a “string of beads” appearance. Fibromuscular dysplasia is a condition that causes narrowing (stenosis) and enlargement (aneurysm) of the medium-sized arteries in your body.
What is Fibromuscular intimal hyperplasia?
FMD involves fibrous or muscular hypertrophy of the vessel tunica media with fibrous intimal hyperplasia; accordingly, it is sometimes referred to as fibromuscular hyperplasia. Often, poststenotic dilatation is also present. The process may range from mild occlusion to complete occlusion of the vessel.
What is arterial beading?
Intracranial arterial beading represents alternating areas of constriction in the intracranial arteries that gives the appearance of beads strung together.
What is beads on a string?
Nucleosomes can be defined as structures with a basic unit of DNA packaging which consists of a segment of DNA wrapped in sequence around eight histone protein core. This is also known as beads on a string structure. So, the correct answer is ‘Nucleosomes’.
What causes FMD?
The cause of FMD is unknown. A number of theories have been proposed, including environmental factors, such as smoking and estrogen, as well as genetic factors. Approximately 10% of patients with FMD have an affected family member.
What is meant by beads on a string model of chromatin?
What is meant by the “beads on a string” model of chromatin? The beads are the nucleosomes, and the string is the linker DNA.
What are sometimes described as the beads on a string where each bead has a particular segment of DNA molecule?
The string is DNA, and each bead is a “nucleosome core particle” that consists of DNA wound around a protein core formed from histones. The beads on a string represent the first level of chromosomal DNA packing.