circulatory system
Pulmonary:
Heart → Lungs → Heart (to oxygenate the blood)
Systemic:
Heart → Body → Heart (to deliver O₂ and nutrients)
Heart:
4 chambers (Right atrium → Right ventricle → Lungs → Left atrium → Left ventricle → Body)
Arteries:
Carry blood away from the heart (usually oxygenated)
Veins:
Carry blood toward the heart (usually deoxygenated
Capillaries:
Tiny vessels where exchange of gases and nutrients happens
Heart valves:
Prevent backflow (e.g., tricuspid, bicuspid/mitral, pulmonary, aortic)
Blood components:
Red blood cells (carry oxygen), white blood cells (immune system), platelets (clotting), plasma (fluid with nutrients/hormones)
Blood pressure:
Systolic (when the heart beats) vs Diastolic (when the heart rests)
ways CO₂ is transported in the blood,
70% is converted into bicarbonate ions (HCO₃⁻) in plasma.
20–23% binds to hemoglobin (but not at the oxygen site — it forms carbaminohemoglobin).
7–10% dissolves directly in plasma.
Blood clumps is called
agglutination
Red Blood Cells (RBCs)
Contain hemoglobin
Function: Carry oxygen from lungs to body, and CO₂ back to lungs
White Blood Cells (WBCs)
Part of the immune system
Function: Fight infections and foreign invaders
Platelets
Small fragments, not full cells
Function: Help with blood clotting (form scabs, stop bleeding)
Plasma
Yellowish liquid, mostly water
Function: Carries nutrients, hormones, and waste; also suspends all the blood cells