Vascular Diseases Quiz

The learning objectives for vascular disease are to classify vascular diseases, describe the characteristics of atheroma and its complications, define, classify and describe the types of aneurysm, define varicose veins, define vasculitis, and classify vascular tumors.

Atheroma is another name for atherosclerosis, which is a vascular disease that affects large and medium-sized elastic and muscular arteries.

The risk factors for atherosclerosis include age, sex, hypertension, hyperlipidemia (particularly LDL), diabetes, smoking, obesity, sedentary lifestyle, and low socio-economic status.

Atheromatous plaque is patchy and raised, with a white to yellow appearance, and is composed of lipid deposition, fibrosis, and chronic inflammation.

The age-related vascular changes include fibrosis of intima and media, accumulation of ground substance, and fragmentation of elastic lamellae.

Complications of atherosclerosis include peripheral vascular disease, atheroma of distal aorta/iliac/femoral arteries, intermittent claudication, pain, ulcers, gangrene, and aneurysms.

The types of aneurysms include atherosclerotic, dissecting, berry, micro-aneurysms, syphilitic, and mycotic.

The clinical consequences of atherosclerotic aneurysms include thrombosis, embolism, rupture, obstruction of a branch vessel, ischemic injury, and impingement on an adjacent structure.

The clinical symptoms of dissecting aortic aneurysms include sudden onset of excruciating pain, radiating from the anterior chest to the back between the scapulae, and moving downward as the dissection progresses.

The risk factors for varicose veins include age, sex, heredity, posture, and obesity.

Force is produced in cardiac muscle through the contraction of individual cardiac muscle cells. Unlike skeletal muscle, cardiac muscle cells are connected by intercalated discs, allowing for coordinated contraction of the entire muscle mass.

Extrinsic sympathetic nerves can increase the force produced in cardiac muscle by releasing norepinephrine, which binds to beta-adrenergic receptors on the cardiac muscle cells. This triggers a series of intracellular events that lead to increased calcium influx and stronger contractions.

The electrical activity of the heart can be divided into several phases: the P wave represents atrial depolarization, the QRS complex represents ventricular depolarization, and the T wave represents ventricular repolarization. These electrical events correspond to mechanical events in the cardiac cycle, such as atrial and ventricular contraction and relaxation.

In cardiac volume/pressure diagrams, the left side of the heart typically has a higher pressure and a smaller volume compared to the right side. This is because the left side of the heart pumps blood to the systemic circulation, which requires higher pressure, while the right side pumps blood to the pulmonary circulation, which has lower resistance.

Excitation/contraction coupling in cardiac muscle refers to the process by which an action potential (excitation) leads to muscle contraction. It involves the opening of L-type dihydropyridine channels, influx of calcium ions, and release of calcium ions from the sarcoplasmic reticulum via ryanodine release channels.

The refractory period in cardiac muscle ensures that the muscle cells have enough time to relax and refill with calcium ions before the next contraction. This allows for proper coordination of contractions and prevents sustained muscle contractions that can lead to arrhythmias.

The events of the cardiac cycle include atrial and ventricular contraction (systole) and relaxation (diastole). These events are coordinated by electrical signals and result in the pumping of blood throughout the body.

The activation of L-type dihydropyridine channels in cardiac muscle allows for the influx of calcium ions from the extracellular space. This calcium influx triggers the release of calcium ions from the sarcoplasmic reticulum, leading to muscle contraction.

Intercalated discs in cardiac muscle play a crucial role in allowing for coordinated contraction of the entire muscle mass. They contain gap junctions, which allow for the passage of electrical signals between adjacent muscle cells, ensuring synchronous contraction.

The sequestration of calcium ions by mucopolysaccharides in cardiac T-tubules helps regulate the availability of calcium ions for muscle contraction. It allows for precise control of calcium release from the sarcoplasmic reticulum and ensures proper coordination of contractions.