Factors that maintain normal blood pressure.

1. Healthy diet: Eating a diet rich in fruits, vegetables, whole grains, and lean proteins can help maintain normal blood pressure. Avoiding excessive salt, sugar, and processed foods can also help regulate blood pressure.

2. Regular exercise: Engaging in regular physical activity, such as walking, jogging, swimming, or cycling, can help lower blood pressure and improve overall cardiovascular health.

3. Maintaining a healthy weight: Being overweight or obese can increase the risk of high blood pressure. Losing weight through a combination of healthy eating and regular exercise can help lower blood pressure.

4. Limiting alcohol consumption: Drinking excessive amounts of alcohol can raise blood pressure. Limiting alcohol intake to moderate levels can help maintain normal blood pressure.

5. Managing stress: Chronic stress can contribute to high blood pressure. Finding healthy ways to manage stress, such as meditation, yoga, or deep breathing exercises, can help lower blood pressure.

6. Getting enough sleep: Lack of sleep or poor quality sleep can contribute to high blood pressure. Aim for 7-9 hours of quality sleep each night to help maintain normal blood pressure.

7. Avoiding tobacco products: Smoking and using other tobacco products can raise blood pressure and increase the risk of heart disease. Quitting smoking and avoiding secondhand smoke can help maintain normal blood pressure.

8. Regular monitoring: Regularly monitoring blood pressure levels can help identify any changes or abnormalities early on. This can help in managing blood pressure and preventing complications.

Intrinsic Factors:

- Cardiac output: The volume of blood pumped by the heart per minute. Increased cardiac output increases blood pressure.
- Peripheral resistance: Resistance to blood flow in the arteries. Increased peripheral resistance increases blood pressure.
- Blood volume: The amount of blood in the circulatory system. Increased blood volume increases blood pressure.
- Blood viscosity: The thickness of blood. Increased blood viscosity increases blood pressure.

Extrinsic Factors:

- Vasomotor tone: The degree of constriction or dilation of blood vessels. Increased vasomotor tone (constriction) increases blood pressure.
- Baroreceptor reflex: Pressure-sensitive receptors in the carotid sinus and aortic arch. These receptors detect changes in blood pressure and send signals to the brain to regulate it.
- Renin-angiotensin-aldosterone system (RAAS): A hormonal pathway that regulates blood pressure by controlling water and salt balance.
- Sympathetic nervous system: The part of the nervous system that controls the "fight or flight" response. Activation of the sympathetic system leads to increased heart rate, peripheral resistance, and blood pressure.

Other Factors:

- Age: Blood pressure tends to increase with age due to arterial stiffening.
- Gender: Men typically have higher blood pressure than women before menopause.
- Race: Certain racial groups, such as African Americans, have a higher risk of hypertension.
- Lifestyle factors: Obesity, smoking, excessive alcohol consumption, and lack of physical activity can increase blood pressure.
- Genetic factors: Some people are more genetically predisposed to developing hypertension.