Cardiovascular System Overview

These flashcards cover key vocabulary and concepts related to the cardiovascular system as outlined in the lecture notes.

Arteries

Vessels that carry blood away from the heart, generally high in oxygen.

Capillaries

Thin-walled vessels that serve as sites for cellular exchange between blood and tissues.

Veins

Vessels that return blood to the heart; they have high capacitance.

Systolic Pressure

The pressure in the arteries during the contraction of the heart.

Diastolic Pressure

The pressure in the arteries when the heart is at rest between beats.

Mean Arterial Pressure (MAP)

The average blood pressure in a person's arteries during one cardiac cycle.

Vasomotor Tone

The degree of constriction of blood vessels, influenced by the autonomic nervous system and hormones.

Hypertension

A condition defined by persistently high blood pressure, which increases the risk of arteriosclerosis.

Edema

Swelling caused by excess fluid trapped in the body's tissues due to increased filtration or decreased reabsorption.

Atherosclerosis

A condition characterized by the build-up of fatty deposits on the artery walls, making them less pliable.

Arteries

Vessels that carry blood away from the heart, generally high in oxygen. They branch into smaller arterioles and lead to capillaries.

Capillaries

Thin-walled vessels that serve as sites for cellular exchange between blood and tissues. They allow nutrients, gases, and waste products to pass between blood and surrounding cells.

Veins

Vessels that return blood to the heart; they have high capacitance. They have valves that prevent backflow and are typically lower in oxygen compared to arteries.

Systolic Pressure

The pressure in the arteries during the contraction of the heart. It is the higher of the two readings in a blood pressure measurement.

Diastolic Pressure

The pressure in the arteries when the heart is at rest between beats. It is the lower of the two readings in a blood pressure measurement.

Mean Arterial Pressure (MAP)

The average blood pressure in a person's arteries during one cardiac cycle. It is a useful measure for assessing the perfusion of organs.

Vasomotor Tone

The degree of constriction of blood vessels, influenced by the autonomic nervous system and hormones. Changes in vasomotor tone can affect blood flow and blood pressure.

Hypertension

A condition defined by persistently high blood pressure, which increases the risk of arteriosclerosis. It can lead to serious health issues, including heart disease and stroke.

Edema

Swelling caused by excess fluid trapped in the body's tissues due to increased filtration or decreased reabsorption. It can occur in response to inflammation or injury.

Atherosclerosis

A condition characterized by the build-up of fatty deposits on the artery walls, making them less pliable. This can lead to reduced blood flow and increase the risk of heart attacks

Arteries

Vessels that carry blood away from the heart, generally high in oxygen. They branch into smaller arterioles and lead to capillaries. The walls of arteries are thick and elastic to withstand high pressure.

Capillaries

Thin-walled vessels that serve as sites for cellular exchange between blood and tissues. They allow nutrients, gases, and waste products to pass between blood and surrounding cells. Capillaries form networks known as capillary beds to increase surface area for exchange.

Veins

Vessels that return blood to the heart; they have high capacitance. They have valves that prevent backflow and are typically lower in oxygen compared to arteries. Veins have thinner walls than arteries but can accommodate larger volumes of blood.

Systolic Pressure

The pressure in the arteries during the contraction of the heart. It is the higher of the two readings in a blood pressure measurement and reflects heart activity.

Diastolic Pressure

The pressure in the arteries when the heart is at rest between beats. It is the lower of the two readings in a blood pressure measurement and reflects the resistance in the blood vessels.

Mean Arterial Pressure (MAP)

The average blood pressure in a person's arteries during one cardiac cycle. It is a useful measure for assessing the perfusion of organs and is calculated using the formula: MAP = DBP + \frac{1}{3}(SBP - DBP).

Vasomotor Tone

The degree of constriction of blood vessels, influenced by the autonomic nervous system and hormones. Changes in vasomotor tone can affect blood flow and blood pressure, and it plays a critical role in regulating systemic vascular resistance.

Hypertension

A condition defined by persistently high blood pressure, which increases the risk of arteriosclerosis. It can lead to serious health issues, including heart disease and stroke. Lifestyle factors such as diet, exercise, and stress management can help control hypertension.

Edema

Swelling caused by excess fluid trapped in the body's tissues due to increased filtration or decreased reabsorption. It can occur in response to inflammation or injury and is commonly observed in conditions like heart failure and kidney disease.

Atherosclerosis

A condition characterized by the build-up of fatty deposits on the artery walls, making them less pliable. This can lead to reduced blood flow and increase the risk of heart attacks. Risk factors include high cholesterol, smoking, and lack of exercise.

Arteries

Vessels that carry blood away from the heart, generally high in oxygen. They branch into smaller arterioles and lead to capillaries. The walls of arteries are thick and elastic to withstand high pressure.

Capillaries

Thin-walled vessels that serve as sites for cellular exchange between blood and tissues. They allow nutrients, gases, and waste products to pass between blood and surrounding cells. Capillaries form networks known as capillary beds to increase surface area for exchange.

Veins

Vessels that return blood to the heart; they have high capacitance. They have valves that prevent backflow and are typically lower in oxygen compared to arteries. Veins have thinner walls than arteries but can accommodate larger volumes of blood.

Venules

Small vessels that collect blood from capillaries and converge to form veins. Venules have thin walls and help transport deoxygenated blood back toward the heart

Resistance in the context of blood circulation

Resistance is defined by three primary factors: blood vessel diameter, blood viscosity, and vessel length.

Blood Vessel Diameter

Resistance is inversely related to the diameter of the blood vessels; smaller diameters increase resistance, while larger diameters decrease it.

Blood Viscosity

This refers to the thickness of the blood; higher viscosity (e.g., due to increased red blood cell count or certain diseases) increases resistance.

Vessel Length

Longer blood vessels create more resistance; therefore, increased vessel length leads to higher resistance against the blood flow

Cardiac Output

The amount of blood the heart pumps in one minute. It is calculated by multiplying the heart rate by the stroke volume (the amount of blood pumped by the heart with each beat). Cardiac output is a critical measure of heart function and is essential for ensuring adequate blood flow to meet the body's metabolic demands

Stroke Volume

The amount of blood pumped by the heart with each beat. Stroke volume is a key component of cardiac output and is influenced by factors such as preload, afterload, and contractility.

Preload

The degree of stretch of the cardiac muscle fibers at the end of diastole, which is influenced by the volume of blood returning to the heart (venous return). It is a major determinant of stroke volume.

Afterload

The pressure the heart must work against to eject blood during systole. It is influenced by the resistance of the blood vessels and affects cardiac output, particularly in conditions like hypertension

Venous Return

The flow of blood back to the heart through the veins. It is influenced by factors such as the pressure gradient between the veins and the heart, the skeletal muscle pump, respiratory pump, and the compliance of the veins.

Total Peripheral Resistance (TPR)

The total resistance to blood flow offered by all of the systemic vasculature, excluding the pulmonary circulation. TPR is influenced by factors such as blood vessel diameter, blood viscosity, and the total length of the blood vessels, affecting overall systemic blood pressure.

Orthostatic Hypertension

A condition characterized by a sudden increase in blood pressure when a person stands up from a sitting or lying position. This can happen due to inadequate regulation of blood pressure upon changes in body position, leading to symptoms such as dizziness or lightheadedness