Just like other systems in the body, blood pressure has to be controlled in a homeostatic manner. Baroreceptors are pressure sensors that help detect blood pressure in the heart and the arteries. Obviously, a certain level of blood pressure needs to be maintained, and it is affected by factors such as blood vessel dilation and constriction, as well as blood volume. For instance, having a higher blood volume can generate greater pressure. Conversely, constricting blood vessels can create greater pressure even with a lower blood volume. There are many different mechanisms to essentially tweak and fine-tune to achieve the optimal blood volume and pressure. For example, the heart can increase cardiac output in response to low blood pressure. If the blood pressure is low, it will pump more blood to counteract that effect. Additionally, if the body is experiencing low blood volume, or for other reasons as well, blood can be diverted to important tissues. During a fight or flight response, blood is diverted away from digestive tissues because in such scenarios, digesting a meal is less crucial. This is accomplished by constricting specific arterioles to ensure that more blood goes to more critical tissues, like muscles during a fight or flight scenario. This tweaking can also be beneficial when experiencing a lower blood volume, ensuring that critical areas such as the brain still receive sufficient blood supply. By constricting blood vessels, the body can regulate blood delivery to various tissues.

Moreover, veins can constrict to divert more blood volume towards the heart and arteries. These effects do not have to apply across all blood vessels. For example, veins can constrict to provide less space for blood, ensuring more blood is present in the heart and arteries, which is critical as arteries deliver blood to the tissues, whereas veins bring it back to the heart. Furthermore, if the blood pressure becomes too high, dilating blood vessels can initiate a drop in blood pressure by creating less resistance to the flow of blood.

Additionally, there are several types of regulators connected to the heart, represented by various neuronal or nervous system connections that can modify the pumping of blood and influence blood pressure. Aside from these connections, there are numerous other mechanisms that provide a homeostatic system to fine-tune blood pressure and blood volume.

When things go wrong, we refer to diseases that affect the heart or vasculature as cardiovascular disease. One of the most common conditions is arteriosclerosis, the hardening of the arteries due to an accumulation of fat deposits. Cholesterol plays a significant role in this; it is a crucial molecule used in producing steroid hormones and in maintaining membrane fluidity in cells. Cholesterol is commonly described in layman terms as "good" and "bad." Low-density lipoprotein (LDL) is often referred to as 'bad cholesterol' because it delivers cholesterol in the body, leading to those harmful deposits. High-density lipoprotein (HDL), on the other hand, is termed 'good cholesterol' because it scavenges excess cholesterol, acting like a cleanup crew and helping prevent arteriosclerosis. A myocardial infarction, known commonly as a heart attack, occurs when one of the coronary arteries is blocked, leading to the damage of heart muscle tissue. Lastly, a stroke, which is damage to nervous tissue in the brain, is often caused by a lack of oxygen being delivered to the brain due to a blocked or ruptured artery in the brain. All these issues are severe and underline the necessity of maintaining heart health to prevent such outcomes.

That's all for this video. I hope it doesn't give you nightmares. Keep your hearts healthy, guys.