Answer:
compound light microscope
Explanation:
an amoeba is a microscopic unicellular protist
Answer: B. pressure changes in the thorax
Explanation:
The veins are the blood vessels which returns the deoxygenated blood from all the tissues and cells of the body back to the heart. The ventricular systole, venous valves, activity of the skeletal muscles and neural control over venoconstriction all influence the movement of the blood in the venous.
The pressure changes in the thorax occurs due to inspiration and expiration. During the process of inspiration, the diaphragm below the lungs contracts and moves downward while the muscles of the ribs pulls downward. When the size of the thoracic cavity increase the air pressure inside the cavity decreases and vice-versa. The pressure inside the thoracic cavity is not related with the movement of the venous blood as it regulates the exchange of the gases not the blood.
The right answer is false.
Angioplasty is a technique that can reopen narrowed or obstructed arteries in the heart (coronary arteries) without extensive surgery. First performed in 1977, angioplasty is now as common as coronary artery bypass graft surgery.
The treatment of arteriosclerosis is surgical or endovascular if there is a risk of life, significant functional impairment or major risk involving the life of an organ or limb.
Angioplasty is not the only surgery for this, Several surgical techniques aim at restoring the arterial lumen or irrigating the private territory or at suppressing the arterial aneurysm.
- Endoluminal angioplasty or dilation using a balloon with or without a stent to correct a stenosis or to recanalize a short arterial occlusion.
- The removal by endarterectomy which consists of removing the atheroma plug which obstructs an artery leaving only the weed.
- Bridging, which will "short circuit" the obliterated artery by allowing the passage of blood from the healthy artery upstream to the permeable artery downstream, made with venous, arterial or prosthetic material.
In case of an aneurysm two techniques are available: either bypass surgery in conventional surgery removing the aneurysm - or the stent covered excluding the aneurysm.
In all cases the risks must be compared to the benefits of each technique and correctly exposed beforehand. Each act must be adapted to each case according to the functional stage, the general state of the patient and his physiological age more than legal.
An open circulatory system simply
means that the blood flows out of vessels and into the spaces or sinuses. Invertebrates,
insects and crustaceans has an open circulatory system where pump blood goes
into a hemocoel and diffusing back to the circulatory system between cells. In
other animals, the heart pumps the blood into the body cavities, spaces or
sinuses, where the blood surrounds the tissues.
