BIOS 255 A&PIII Final Review Questions and Answers 100% Pass

BIOS 255 A&PIII Final Review Questions and Answers 100% Pass Describe the structure and functions of the four heart chambers and associated valves and provide the name of their associated great vessel(s). - ANSWER -The chambers of the heart include two upper atria and two lower ventricles. External features of the heart include the auricles ( pouch-like extensions found in the atria), the coronary sulcus - a deep sulcus that externally shows the separation of the atria and ventricles, and the anterior and posterior sulci - grooves that externally mark the boundaries between the 4 heart chambers. The right atrium receives blood from the superior vena cava, inferior vena cava, and coronary sinus. It is separated internally from the left atrium by the interatrial septum, which contains the fossa ovalis. Blood exits the right atrium through the tricuspid valve. The right ventricle receives blood from the right atrium. Separated internally from the left ventricle by the interventricular septum, it pumps blood through the pulmonary valve into the pulmonary trunk. Oxygenated blood enters the left atrium from the pulmonary veins and exits through the bicuspid (mitral) valve. 2 | P a g e Created by Grace Amelia © 2025, All Rights Reserved. The left ventricle pumps oxygenated blood through the aortic valve into the aorta. right atrium - ANSWER -receives blood from the superior vena cava, inferior vena cava, and coronary sinus. It is separated internally from the left atrium by the interatrial septum, which contains the fossa ovalis. Blood exits the right atrium through the tricuspid valve right ventricle - ANSWER -receives blood from the right atrium. Separated internally from the left ventricle by the interventricular septum, it pumps blood through the pulmonary valve into the pulmonary trunk left atrium - ANSWER -Oxygenated blood enters this atrium from the pulmonary veins and exits through the bicuspid (mitral) valve left ventricle - ANSWER -This ventricle pumps oxygenated blood through the aortic valve into the aorta auricles - ANSWER -pouch like extensions found in the atria (look like flaps with wrinkled edges from the exterior) sulci - ANSWER -grooves that externally mark the boundaries between the four heart chambers coronary sulcus - ANSWER -deep sulcus that externally shows the separation of the atria and ventricles anterior and posterior interventricular sulcus - ANSWER -shallow grooves that depict the surface boundaries between the 2 ventricles. 3 | P a g e Created by Grace Amelia © 2025, All Rights Reserved. Name the components of the conduction system of the heart, trace the conduction pathway. - ANSWER -The conduction starts at the pacemaker region called the Sinoatrial Node (SA node) which is just under where the superior vena cava enters the right atrium. From here the conduction passes to the Atrioventricular Node (AV node) which is just to the right of the septum. From here the stimulation is passed through the Atrioventricular (AV) Bundle (Bundle of His) which carries the conduction to the septum where two Bundle Branches pick it up. These branches carry the conduction to the base of the septum where they separate into the Purkinje Fibres. These fibers carry the conduction all around the heart. What is the role of the autonomic nervous system in regulating cardiac output? - ANSWER -Cardiac output is the amount of blood pumped by the heart each minute. The most important system outside of the heart that controls this is the ANS. The vagus nerve brings down the heart rate. The parasympathetic releases acetylcholine, which brings the heart rate down (inhibitory). The sympathetic releases norepinephrine and epinephrine to bring the heart rate up (excitatory). Describe the timing and events of the cardiac cycle, identifying the normal heart sounds, which events do they represent? - ANSWER -The cardiac cycle consists of systole (contraction) and diastole (relaxation) of both atria, plus the systole and diastole of both ventricles. The average heartbeat is 75 beats/min. A complete cardiac cycle is 0.8 seconds. Divided into three stages: 1.Diastole: the chambers of the heart (atria and ventricles) are relaxed and filling up with blood from the veins. The atrioventricular valves (bicuspid on the left and tricuspid on the right) are open and the semilunar valves (pulmonary and aortic) are closed. This stage lasts for about 0.4 second. 4 | P a g e Created by Grace Amelia © 2025, All Rights Reserved. 2.Atrial systole: the atria are contracting and the ventricles are relaxed. This takes about 0.1 second. 3.Ventricular systole: the ventricles contract and pump blood out of the heart into the arteries. During this stage the atrioventricular valves are closed and the semilunar valves are open. This takes about 0.3 second. S1, the first heart sound (lubb), is caused by blood turbulence associated with the closing of the atrioventricular valves. S2, the second sound (dupp), is caused by blood turbulence associated with the closing of semilunar valves. Distinguish among arteries, capillaries, and veins on the basis of their structure and function. - ANSWER - Arteries 2 types: elastic (conducting) & muscular (distributing