cardiovascular system flashcards

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What are the 3 parts of the cardiovascular system?

The Heart (pump), Blood (transport medium), and Blood Vessels (transport tubes).

Why is human circulation called a "Closed System"?

Blood is always contained within vessels and does not directly bathe the organs.

What is the primary goal of this closed system?

To maintain Homeostasis by regulating pH, temperature, and osmotic pressure.

Define Vasodilation vs. Vasoconstriction in Thermoregulation.

Vasodilation: Widening of vessels near the skin to release heat (cooling).

Vasoconstriction: Narrowing of vessels to the core to conserve heat (warming).

What is Plasma and what are its contents?

Plasma is a pale straw-colored liquid that makes blood watery so it can flow.The liquid portion (55%). Contains water, proteins (like Fibrin), salts, lipids, hormones, and waste (CO2 and Urea).

What are the cellular adaptations of an Erythrocyte (RBC)?

Biconcave disc shape (high surface area) and no nucleus (more room for hemoglobin).

What is Phagocytosis in WBCs?

The process where Leukocytes engulf and "consume" microorganisms/pathogens.

What are Thrombocytes (Platelets) and Platelet Activation?

Cell fragments that facilitate clotting. Activation triggers them to stick together to stop blood loss and prevent infection.

Name the 4 chambers and the Septum.

Right/Left Atria (receiving/top) and Right/Left Ventricles (pumping/bottom). The Septum is the muscular wall preventing oxygenated/deoxygenated blood from mixing.

Define the Auricle, Pericardium, and Apex.

Auricle: External flap of the atrium that increases filling capacity.

Pericardium: The double-walled sac that protects/anchors the heart.

Apex: Apex: The pointed bottom tip of the heart that points to the left hip.

Identify the 4 valves and their purpose.

Tricuspid (Right AV), Mitral/Bicuspid (Left AV), Pulmonary, and Aortic.

Purpose: To prevent backflow. The Chordae Tendineae (heart strings) hold the AV valves in place

What is the Ligamentum Arteriosum?

The small ligament that is a remnant of fetal circulation, connecting the arch of the aorta and the pulmonary artery.

Define Double Circulation.

Blood passes through the heart twice: Pulmonary Circuit (to lungs) and Systemic Circuit (to body).

Trace the path of blood returning from the BODY.

Vena Cava → Right Atrium → Tricuspid Valve → Right Ventricle → Pulmonary Valve → Pulmonary Artery → Lungs.

Trace the path of blood returning from the LUNGS.

Pulmonary Vein → Left Atrium → Mitral/Bicuspid Valve → Left Ventricle → Aortic Valve → Aorta → Body.

What are Coronary Arteries and Veins?

The heart's own blood supply; coronary arteries branch off the aorta to deliver oxygen/glucose to the heart muscle.

Compare Arteries, Veins, and Capillaries.

Arteries: Away from heart; thick walls; high pressure.

Veins: Toward heart; thin walls; low pressure; contain valves.

Capillaries: Smallest vessels; site of Gas Exchange

Rank vessels by blood pressure (Highest to Lowest).

Artery > Arteriole > Capillary > Venule > Vein.

Define Systole vs. Diastole and the 1/3-2/3 rule.

Systole: Ventricles squeeze (work/high pressure).

Diastole: Ventricles relax (fill/low pressure).

Timing: The heart spends 1/3 of the time in Systole and 2/3 in Diastole.

Where is blood pressure measured and what is the definition of blood pressure?

In the Brachial Artery of the upper arm using millimeters of mercury (mmHg).

Definition: Pressure is defined as the Force of the cells and plasma pushing against the Surface Area of the vessel walls.

Calculation: Pressure = Force/Area

The Pulmonary Exception

In the body, arteries carry oxygenated blood. BUT, the Pulmonary Artery is the only artery that carries deoxygenated blood.

The Muscle Wall

The Left Ventricle has a significantly thicker myocardium (muscle) than the right because it must pump blood to the entire body, not just the lungs.

Atrial Septal Defect

If the septum has a hole, oxygenated and deoxygenated blood mix, reducing the efficiency of oxygen delivery.

Artificial Blood

A salt-water substitute that adds volume to keep the heart pumping but cannot transport oxygen because it lacks RBCs.

Blood Transfusion

Giving a patient real, donated blood; this is the only way to replace lost oxygen-carrying capacity.

Arterioles

Small branches of arteries that lead to capillaries.

Venules

Small vessels that gather blood from capillaries to lead back into veins.

Beyond gases, what 4 specific substances does blood transport?

Nutrients (glucose/amino acids), Waste (CO_2/Urea), and Chemical Messengers (hormones).

What is Oxyhemoglobin and what color is it?

The bright red complex formed when the iron-containing protein hemoglobin binds to oxygen.

What are 2 ways WBCs defend the body besides phagocytosis?

1. Producing Antibodies (bind to pathogens to destroy them) and 2. Producing Antitoxins (neutralize poisons).

What is the Pulmonary Vein exception?

While most veins carry deoxygenated blood, the Pulmonary Veins are the only veins that carry oxygenated blood (returning from the lungs).