Question

Name the two cardiac centers and state their location. Sympathetic impulses to the heart have what effect? Parasympathetic impulses to the heart have what effect? Name the parasympathetic nerves to the heart. (p. 287)

Short answer

Question: Identify the two cardiac centers, their location, and the effects of sympathetic and parasympathetic impulses on the heart. Additionally, name the parasympathetic nerves to the heart. Answer: The two main cardiac centers are the cardioaccelerator center and the cardioinhibitory center, both located in the medulla oblongata. Sympathetic impulses, sent through the cardioaccelerator center, increase the heart rate and strength of contraction. Parasympathetic impulses, sent through the cardioinhibitory center, decrease the heart rate and strength of contraction. The parasympathetic nerves to the heart are called the vagus nerves (cranial nerve X).

Step-by-step solution

1. Cardiac Centers

There are two main cardiac centers in the human body, the cardioaccelerator center and the cardioinhibitory center.

2. Location of Cardiac Centers

Both of these cardiac centers are located in the medulla oblongata, which is a part of the brainstem.

3. Sympathetic Impulses to the Heart

Sympathetic impulses to the heart are sent through the cardioaccelerator center and have the effect of increasing the heart rate and the strength of contraction. This is the body's "fight or flight" response, preparing the body for action.

4. Parasympathetic Impulses to the Heart

Parasympathetic impulses are sent through the cardioinhibitory center and generally have the effect of decreasing the heart rate and the strength of contraction. This is more of a "rest and digest" response, as it helps to conserve energy and restore the body's resources.

5. Parasympathetic Nerves to the Heart

The parasympathetic nerves that reach the heart are called the vagus nerves (cranial nerve X). These nerves play a crucial role in regulating the body's heart rate in response to various stimuli and conditions.