Cardiovascular System: Heart Anatomy, Valves & Blood Vessels

Cell → Tissue → Organ → Organ System → Individual
- Shows the progressive increase in complexity.
- Cardiovascular discussion will focus on the organ (heart) and organ system (cardiovascular system) levels.

Muscular organ that pumps blood throughout the body.
Roughly fist-sized; situated centrally in thoracic cavity, slightly left-leaning.
Four chambers
- 2 Atria (receiving chambers)
- 2 Ventricles (pumping chambers)
Chambers separated longitudinally by a muscular wall: septum.

Major labels visually highlighted
- Right/Left Atrium (RA, LA)
- Right/Left Ventricle (RV, LV)
- Valves: Tricuspid, Pulmonary, Mitral (Bicuspid), Aortic
- Great vessels: Aorta, Pulmonary Artery, Pulmonary Veins, Superior & Inferior Vena Cava

Definition: “Receiving chambers of the heart.”
Right Atrium
- Receives oxygen-poor (deoxygenated) blood from the body via both vena cavae.
Left Atrium
- Receives oxygen-rich (oxygenated) blood from the lungs via pulmonary veins.

Definition: “Pumping chambers of the heart.”
Right Ventricle
- Pumps deoxygenated blood to lungs for oxygenation via pulmonary artery.
Left Ventricle
- Pumps oxygenated blood to the entire body via the aorta.
- Thickest myocardial wall ➜ generates highest pressure.

1. Vena Cava
- Superior Vena Cava: drains upper body → right atrium.
- Inferior Vena Cava: drains lower body → right atrium.
2. Pulmonary Artery
- Carries deoxygenated blood from right ventricle → lungs.
3. Pulmonary Veins
- Only veins carrying oxygen-rich blood.
- Transport from lungs → left atrium.
4. Aorta
- Largest artery; distributes oxygenated blood from left ventricle → systemic circulation.

Purpose: ensure unidirectional blood flow; prevent back-flow (regurgitation).
1. Tricuspid Valve
- Location: RA ↔ RV
- Function: stops back-flow into right atrium.
2. Pulmonary (Semilunar) Valve
- Location: RV ↔ Pulmonary Artery
- Function: stops back-flow into right ventricle.
3. Mitral (Bicuspid) Valve
- Location: LA ↔ LV
- Function: prevents back-flow into left atrium.
4. Aortic (Semilunar) Valve
- Location: LV ↔ Aorta
- Function: prevents back-flow into left ventricle.

Arteries
- Thick muscular & elastic walls; endure high pressure.
- Mostly carry oxygenated blood away from heart (exception: pulmonary artery).
- Branch into smaller arterioles.
Capillaries
- Microscopic, single-cell-thick walls.
- Site of gas & nutrient exchange between blood and tissues.
- Connect arterioles ↔ venules.
Veins
- Thinner, less elastic walls; larger lumens; often contain valves.
- Carry blood toward the heart (mostly deoxygenated; exception: pulmonary veins).
- Merge from venules; largest = Vena Cava.

\text{Body} \rightarrow \text{Superior/Inferior Vena Cava} \rightarrow \text{Right Atrium}
Through Tricuspid Valve → Right Ventricle
Through Pulmonary Valve → Pulmonary Artery → Lungs (gas exchange)
Lungs → Pulmonary Veins → Left Atrium
Through Mitral Valve → Left Ventricle
Through Aortic Valve → Aorta → Systemic Circulation

Cycle repeats continuously; coordinated by cardiac conduction system (not detailed in slides but essential foundation).

Videos for kinesthetic & visual learners (pig heart dissection, animations).
“Arrange Me” & summary charts as formative assessments.
Emphasis on memorization (3-min video) balanced with functional understanding (valve video).

Memorize names and directional flow.
Don’t confuse pulmonary artery vs. vein (oxygenation state is opposite of systemic pattern).
Know which side of heart handles oxygen-poor vs. oxygen-rich blood.
Be able to label diagrams quickly.
Compare vessel-wall thickness & pressure relationships.

Blood Pressure: \text{BP} = \text{Cardiac Output} \times \text{Peripheral Resistance}
Cardiac Output: \text{CO} = \text{Stroke Volume} \times \text{Heart Rate}
Mention here for completeness; verify inclusion with instructor.