Anatomy And Physiology Of Heart! Quiz

Explanation
The human heart has four chambers. These chambers include two atria (left and right) and two ventricles (left and right). The atria receive blood from the veins and pump it into the ventricles. The ventricles then pump the blood out of the heart to the rest of the body. The separation of the chambers allows for efficient and coordinated blood flow, ensuring that oxygenated and deoxygenated blood do not mix.

Explanation
The normal stroke volume per each heartbeat is typically between 50-80 ml. This refers to the amount of blood pumped out of the left ventricle of the heart with each contraction. It is important for maintaining proper blood circulation throughout the body.

Explanation
The normal range of human heart rate is typically between 60 and 90 beats per minute. This range is considered normal for adults at rest, indicating a healthy cardiovascular system. Heart rates below 60 or above 90 may indicate an underlying medical condition or physical exertion. Monitoring heart rate is important for assessing overall health and fitness levels.

Explanation
The SA node, or sinoatrial node, is considered the main pacemaker of the human heart. It is responsible for initiating the electrical signals that regulate the heart's rhythm and control the contraction of the atria. The SA node is located in the upper part of the right atrium and generates regular electrical impulses, setting the pace for the rest of the heart.

Explanation
If the heart's pacemaker stops working, it does not necessarily mean that the heart will stop beating. While the pacemaker is responsible for initiating the electrical signals that regulate the heart's rhythm, there are backup systems in place that can take over if the pacemaker fails. These backup systems, such as the AV node and the Purkinje fibers, can generate their own electrical impulses to keep the heart beating. Therefore, even if the pacemaker stops working, the heart can still continue to beat.

Explanation
The correct answer is "strieted with branches." Striated refers to the presence of stripes or bands, which is characteristic of skeletal and cardiac muscle. The heart is composed of cardiac muscle tissue, which is striated in nature. Additionally, the branching pattern of cardiac muscle fibers allows for coordinated contraction and efficient pumping of blood throughout the body.

Explanation
The human heart contains intercalated discs that have gap junctions. These intercalated discs are specialized structures found between cardiac muscle cells, and they play a crucial role in coordinating the contraction of the heart. Gap junctions are small channels that allow for direct electrical and chemical communication between adjacent cells, enabling the rapid spread of electrical impulses throughout the heart. This synchronized contraction ensures that the heart beats as a coordinated unit, allowing it to effectively pump blood throughout the body. Therefore, the statement is true.

Explanation
The human heart is indeed electrical excitable. This means that it has the ability to generate and conduct electrical impulses, which are responsible for regulating the heart's rhythm and coordinating its contractions. These electrical impulses are generated by specialized cells in the heart called pacemaker cells, and they travel through a network of pathways to ensure that the heart beats in a coordinated and efficient manner. This electrical activity can be measured and recorded using an electrocardiogram (ECG) to assess the heart's health and diagnose any abnormalities.

Explanation
The heart rate for athletes is typically lower than that of a normal human. This is because athletes have a higher level of cardiovascular fitness and their hearts are more efficient at pumping blood. Regular exercise and training can lead to a lower resting heart rate for athletes, as their hearts become stronger and more efficient. This allows them to achieve the same level of oxygenation and circulation with fewer beats per minute compared to a normal individual.