Anatomy of Thorax Mcqs

Early doctors were researching arrhythmia in heart beat as a result of unknown abnormal neuro-cardio mechanisms of the heart, one of theories was that SA and AV nodes were interfering with each other’s bio-electrical impulses another theory was that the right side of the septum was hypersensitive to electrical impulse, all were more else on the right track because we know now that SVT is a result of a faulty electrical connections of the heart.

Heart valves ensure one way blood flow through heart. The atrioventricular (AV) valves lie between the atria and the ventricles prevents the back flow of blood in to the atria while the ventricles contract. Chordae tendinae anchor AV values to papillary muscles. The left AV valve, the mitral or bicuspid valve consists of two cusps of endocardium. The right atrioventricular valve, the tricuspid valve, has three cusps. The second sets of valve are the semilunar valves. The pulmonary semilunar valves lie between the right ventricle and pulmonary trunk. Aortic semilunar valves lie between ventricle and the aorta. Semilunar valves prevent the backflow of blood into the ventricle.

1. The pulmonary circuit is supplied by which ‘side” of the heart? The systemic circuit? The right atrium

The structure that furnishes the axis for the rotation of the head from side to side is the:

The effects of a ligature around the AV groove presented no difference in the contraction of atria or ventricle after the first tightening. After the string was tightened further, the ventricular contractions were lost and the atria beat alone at 60 BPM. The AV signal between the chambers was blocked.

What size fibers make up the preganglionic neurons? The postganglionic neurons? Why is the white ramus white, and the gray ramus gray? What does this mean for speed of conduction?

4. left ventricle 5. superior vena cava 6. inferior vena cava 7. ascending aorta 8. aortic arch 9. brachiocephalic artery 10. left common carotid artery 11. left subclavian artery 12. pulmonary trunk 13. right pulmonary artery 14. left pulmonary artery 15. ligamentum arteriosum 16. right pulmonary veins 17. left pulmonary veins 18. right coronary artery 19. anterior cardiac vein t s w x v 20. left coronary artery 21. circumflex artery 22. anterior

Oxygen poor blood fills the right atrium from either the superior or inferior vena cava.

The four quadrants that divide the abdomen are the right upper quadrant, left upper quadrant, right lower quadrant and left lower quadrant.

This week I rotated through CT. CT is computed tomography. CT uses special x-ray machines to show detailed images of the body planes. This machine splits the body into axial, sagittal, and coronal images on one scan. Some CT scans are done with contrast and some are done without contrast. Contrast in used to highlight the vessels in the body so they will show up bright on the image. The contrast is injected through an IV that is inserted by either a tech or a nurse. Most scans were done on the chest, abdomen or pelvis but I also seen a few soft tissue neck scans and head scans. CT does both out patients and inpatients. They have a busy schedule and is very hard for them to stay on track. It doesn’t take much for them to fall behind.

Remove the dorsal portion of the carapace to observe other organs in the head and thorax.

1.1 Discuss with the use of diagrams the main anatomical features of the human body

The wave spreads through the atria before reaching the atrioventricular node, or AV node, located just above the right ventricle. The AV node focuses the wave into the ventricles, contracting the ventricles. Should the SA node fail, the AV node can take over as the primary pacemaker at a rate of forty to sixty beats per minute.

The S-A node signal is delayed by the atrioventricular node to allow the full contraction of the atria that allows the ventricles to reach their maximum volume. A sweeping right to left wave of ventricular contraction then pumps blood into the pulmonary and systemic circulatory systems. The semilunar valves that separate the right ventricle from the pulmonary artery and the left ventricle from the aorta open shortly after the ventricles begin to contract. The opening of the semilunar valves ends a brief period of isometric (constant volume) ventricular contraction and initiates a period of rapid ventricular ejection.

Atrial Septal Defect(ASD) is a very large problem concerning the heart in its overall function. When the heart, being the core of the cardiovascular system, has issues; it effects the rest of the body as a result. The core of the problem resides in the atrial septum. Normally the heart is divided into four separate chambers. But a person with atrial septal defect has an atrial septum that allows the blood from the left side of the heart back into the right side. This results in increased pulmonary blood flow and diastolic overload of the right ventricle. By having this constant left-to-right shunt, it can alter the pulmonary vascular resistance leading to hypertension or even the reversal of the shunt itself.