unit 4 AI

Cardiovascular system

The system that distributes blood throughout the body, comprising the heart, blood vessels, and blood.

Heart

The pump that creates pressure to move blood through the cardiovascular system.

Blood vessels

Tubes through which blood flows, including arteries, arterioles, capillaries, venules, and veins.

Blood

The fluid that carries oxygen, nutrients, hormones, immune cells, and waste products.

Pulmonary Circuit

The path in which blood leaves the heart to go to the lungs to pick up oxygen and return to the heart.

Systemic Circuit

The pathway in which blood leaves the heart through arteries to deliver oxygen to the body.

Arteries

Blood vessels that carry blood away from the heart.

Veins

Blood vessels that carry blood back to the heart.

Atria

The upper chambers of the heart that receive blood.

Ventricles

The lower chambers of the heart that pump blood out of the heart.

Septum

The wall separating the left and right sides of the heart.

Superior vena cava

The largest vein in the body that transports deoxygenated blood from the upper body to the right atrium.

Right atrium

The chamber of the heart that receives blood from the body via the vena cava.

Right ventricle

The chamber of the heart that pumps deoxygenated blood to the lungs.

Pulmonary arteries

Arteries that carry deoxygenated blood from the right ventricle to the lungs.

Pulmonary veins

Veins that carry oxygenated blood back from the lungs to the left atrium.

Left atrium

The chamber of the heart that receives oxygenated blood from the lungs.

Left ventricle

The chamber of the heart that pumps oxygenated blood into the systemic circuit via the aorta.

Aorta

The largest artery in the body that carries oxygenated blood from the left ventricle to the body.

Valves

Structures in the heart that prevent the backflow of blood.

Aortic valve

The valve that prevents blood from flowing back from the aorta into the left ventricle.

Pulmonary valve

The valve that prevents blood from flowing back from the pulmonary arteries into the right ventricle.

Atrioventricular valves

Valves that prevent backflow into the atria during contraction of the ventricles.

Interventricular septum

The wall separating the left and right ventricles.

Cardiac muscle

Specialized muscle tissue found in the heart, responsible for contracting and pumping blood.

Cardiomyocytes

Heart muscle cells.

Myofibers

Skeletal muscle fibers.

Electrical stimulation

The process that triggers muscle contractions via action potentials.

Nodal cells

Cells responsible for generating and conducting the heart's electrical impulses.

Pacemaker potential

The gradual depolarization in the sinoatrial node that triggers action potentials.

Sinoatrial node

The heart's natural pacemaker located in the upper right atrium.

Atrioventricular node

A node that connects the atria and ventricles and slows down the electrical signal.

Baroreceptor reflex

A mechanism that helps maintain blood pressure by adjusting heart rate and blood vessel diameter.

ECG (Electrocardiogram)

A test that measures the electrical activity of the heart.

Systole

The phase of the cardiac cycle when the heart contracts and pumps blood.

Diastole

The phase of the cardiac cycle when the heart relaxes and fills with blood.

Cardiac output

The amount of blood the heart pumps in one minute.

Stroke volume

The amount of blood pumped by the heart in one contraction.

End diastolic volume (EDV)

The total volume of blood in the ventricle at the end of filling.

End systolic volume (ESV)

The volume of blood remaining in the ventricle after contraction.

Resistance vessels

Smaller blood vessels like arterioles that offer resistance to blood flow.

Capillaries

The smallest blood vessels where exchange of gases, nutrients, and wastes occurs.

Venous return

The flow of blood back to the heart through veins.

Vasoconstriction

The narrowing of blood vessels to decrease blood flow.

Vasodilation

The widening of blood vessels to increase blood flow.

Humoral regulation

Control of blood flow through substances traveling in the bloodstream.

Neural regulation

Control of blood flow through the nervous system.

Autonomic nervous system (ANS)

The part of the nervous system that regulates involuntary bodily functions.

Sympathetic nervous system (SNS)

The branch of the autonomic nervous system responsible for the fight-or-flight response.

Parasympathetic nervous system

The branch of the autonomic nervous system responsible for rest-and-digest activities.

Epinephrine

A hormone released during stress that increases heart rate and blood pressure.

Arrhythmias

Irregular heartbeats that can affect the heart's ability to pump effectively.

Heart murmur

An abnormal heart sound resulting from valve issues.

Hemostasis

The process that prevents and stops bleeding.

Calcium-induced calcium release

The process where calcium from extracellular fluid triggers the release of more calcium from the sarcoplasmic reticulum.

Gap junctions

Connections that allow electrical signals to pass between cells in the heart.

Intercalated discs

Structures that connect cardiomyocytes, allowing synchronized contraction.

Desmosomes

Proteins that link adjacent cardiomyocytes and provide structural support.

T wave

The part of the ECG representing ventricular repolarization.

QRS complex

The part of the ECG representing ventricular depolarization.

P wave

The part of the ECG representing atrial depolarization.

PR interval

The time between the start of the P wave and the start of the QRS complex; indicates conduction between atria and ventricles.

QT interval

The time from the beginning of the Q wave to the end of the T wave; reflects the time taken for ventricular depolarization and repolarization.

Metabolic theory

A theory that explains how local metabolic conditions can influence blood flow.

Myogenic theory

A theory that explains how blood vessels react to changes in pressure.

Atrial systole

The contraction of the atria to push blood into the ventricles.

Isovolumetric contraction

The phase of contraction where the ventricles contract without ejecting blood.

Ventricular ejection

The phase of the cardiac cycle when the ventricles expel blood.

Diastolic pressure

The pressure in the arteries when the heart rests between beats.

Systolic pressure

The pressure in the arteries during heart contraction.

Mean arterial pressure (MAP)

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

Blood flow regulation

The process of adjusting the distribution and velocity of blood to different parts of the body.

Fluid balance

The maintenance of proper amounts of fluids in the body's compartments.

Filtration

The movement of fluids and solutes out of capillaries into the surrounding tissue.

Reabsorption

The movement of fluids and solutes back into capillaries from the surrounding tissue.

Lymphatic system

The system responsible for returning excess interstitial fluid to the bloodstream and involved in immune responses.

Edema

Swelling caused by excess fluid trapped in the body's tissues.

Norepinephrine

A neurotransmitter that causes vasoconstriction when released by the sympathetic nervous system.

Arterioles

Small blood vessels that regulate blood flow to tissues by changing diameter.

Capacitance vessels

Veins that have the capacity to hold a large volume of blood.

Resistance vessels

Arterioles that provide the greatest resistance to blood flow.

Clinical relevance

The importance of understanding cardiovascular system concepts for diagnosing and treating heart-related conditions.

Adaptations to exercise

Physiological changes in the heart and cardiovascular system that occur with regular exercise.

Blood distribution to organs

The allocation of blood flow to different organs based on metabolic needs.

Fluid exchange in capillaries

The transfer of oxygen, nutrients, and waste between blood and tissue cells in capillaries.

Exchange vessels

Capillaries that facilitate the exchange of substances between blood and surrounding tissues.

Neurotransmitter

Chemicals released by neurons to transmit signals across synapses.

Resistance to blood flow

The opposition encountered by blood as it moves through the circulatory system.

Hormonal influence on blood flow

The effect of hormones on the constriction and dilation of blood vessels.

Physiological mechanisms

Processes through which the body maintains homeostasis and responds to changes.

Baroreceptors

Sensors located in blood vessels that detect changes in blood pressure.

Action potential

A rapid change in voltage across a cell membrane that triggers muscle contractions.

Echocardiogram

An ultrasound test that evaluates heart function and structures.

Coronary circulation

The flow of blood to and from the tissues of the heart.

Vascular resistance

The resistance to blood flow within the blood vessels.

Endothelial cells

Cells lining the interior surface of blood vessels.

Cardiac arrest

A medical emergency where the heart stops beating effectively.

Myocardial infarction

Also known as a heart attack, it occurs when blood flow to a part of the heart is blocked.

Thrombosis

The formation of a blood clot in a blood vessel, which can restrict blood flow.

Low cardiac output

A condition where the heart pumps less blood than necessary, affecting organ function.