The SAN located in the right atrium spreads a wave of electrical excitation across the Bachmann’s bundle to the walls of the atria causing it to contract, inducing atrial systole. The pressure in both atria increases greatly causing the tricuspid valves in the right atrium and bicuspid valves in the left atrium to open. Although the majority of the blood enters the ventricles during atrial diastole, the contraction of the atria forces the remaining 20% of blood volume (Shrestha, 2011) to fill the ventricles. Contraction of the right atrium fills the right ventricles with deoxygenated blood from the systematic circulatory system, while the left atrium receives oxygenated blood from the lungs via the pulmonary vein and fills the left ventricle. During the P-R segment, the electrical impulse passes down to the atrioventricular node (AVN) via the internodal pathway.
The bag is then inflated until the air pressure in the cuff overcomes the arterial pressure and obliterates the arterial lumen. This is confirmed by palpating the radial pulse that disappears when the cuff-pressure is raised above the arterial pressure. The pressure is then raised further by 20 mm Hg and then slowly reduced. When the pressure in the cuff reaches just below the arterial pressure, blood escapes beyond the occlusion in to the peripheral part of the artery and the pulse starts reappearing. This is detected by the appearance of sound heard in the stethoscope and pressure at which the sounds are first heard is the systolic pressure.
Among other things, the right atrium is the attachment point for the sinoatrial node. The sinoatrial node or SA node is the primary pacemaker site for the heart. It is innervated by the parasympathetic nervous system from the vagus nerve. The parasympathetic nervous system controls the vegetative functions of the body. As it pertains to the parasympathetic nervous system, the SA node provides the control of the heart’s rate in distress through the release of acetylcholine.
Therefore, platelets undergo degranulation the exocytosis of their cytoplasmic granules and release of factors that promote hemostasis. Aggregation is occurs when serotonin (vasoconstrictor), ADP (attracts more platelets and stimulates their degranulation), and thromboxane A2 (stimulates degranulation and vasoconstriction) are released. Thus it can quickly seal a small break in blood vessel. Coagulation is the last process of the hemostasis. It has three ways; intrinsic, extrinsic and common pathways.
3-qualtiative platelet disorders. 4- Hypofibrinogenaemia. 4- vWD. Lab 2 Prothrombin time Introduction: The prothrombin time (PT) test is ordered to help diagnose unexplained bleeding, often along with a partial thromboplastin time (PTT) test. The PT test evaluates the extrinsic and common pathways of the coagulation cascade, while the PTT test evaluates
Repolarization is the recharging of the heart after each heartbeat (VanPutte, 2011). There are five main components of an electrocardiogram: P, Q, R, S and T. The p waves, corresponds to depolarization of the atria (VanPutte, 2011). The QRS complex represents the progressive wave of ventricular depolarization (VanPutte, 2011). The T wave represents the repolarization of the ventricles. In this lab experiment four leads were used: one each on the left and right wrist and one each placed above the ankle of the left and right foot.
A. While the ventricle is in diastole c. B. By the movement of blood from atrium to ventricle d. C. While atrium is contracting e. D. When the ventricle is in systole f. E. During all of the above Match the following A. A. Myocardium B.
The first pump pumps "oxygen poor" blood to the lungs from the right ventricle of the heart via the pulmonary artery where it returns as "oxygen rich blood" via the pulmonary vein to the left atrium. It flows through to the left ventricle, where the second pump of the heart pumps the oxygen-rich blood to all the other parts of the body, via the aorta. There are four valves that ensure blood flows in the correct direction, these are the pulmonary valve, the tricuspid valve, the mitral valve and the aortic valve. | | The number of times the heart beats per minute, otherwise known as the pulse rate, is affected by the age and fitness of a person and their current level of activity. The heart's muscle wall is called the myocardium.
1a. At 8 am, Ben’s blood pressure plummets. List the two body parts that respond to the problem with blood pressure according to the tutorial in the order that they respond and explain what each organ system does to correct this problem. The first to respond is Ben’s nervous system, which senses a change in Ben’s blood pressure due to his fast movement out of the chair. This sends a signal to the heart that Ben’s blood pressure is low, and the heart begins to pump at an increased rate to correct the problem.
The human heart pumps blood through the arteries, which connect to smaller arterioles and then smaller capillaries. In this assignment, we will discuss the arterial blood pressure from several aspects, include definition, normal values for blood pressure, the most important factors affecting it, the mechanism involved in arterial blood pressure regulation, and the relevance between the pressure and the eye. Definition of blood pressure, it’s Normal value, and the factors that determine arterial blood pressure under physiologic conditions. Blood pressure refers to the force exerted by the blood against the inner walls of the blood vessels . This pressure produces when the heart contracts during the heartbeat cycle, which forces blood out