Learning Objectives

Know the structures of the heart, their function, and the path of blood flow (circulation)
Understand how pacemaker cells (of the SA node) are autorhythmic (AP self-generating) due to hyperpol trigger (slow voltage-gated Na⁺-channels).
- Each AP causes 1 heartbeat - AP Frequency = HR
Understand the neural control of the heart
- Sympathetic → NE → ↑ HR & ↑ contraction force
- Paraympathetic → ACh → ↓ HR & ↓ contraction force
Know the spread of APs
- through intercalated discs (GAP junctions which are also anchored together)
- SA node → atria → AV node (pause) (→ bundle of His → Purkinje fibers) → ventricles
Know the AP of contractile cells
- extra plateau phase caused by voltage-gated Ca²⁺-channels (simulatenously with voltage-gated K⁺-channels)
- Causes extended consistent contractions
ID the points of sinus rhythm and what they indicate
Know bradycardia (BP < 60bpm) & Tachycardis (BP >100bpm)
Know the factors affecting peripheral blood flow
- Pressure gradients
- Resitance
  - blood vessel diameter (constriction / dilation)
  - length
  - Viscosity
Know how smooth muscles at arterioles control blood flow to different organs
Know the structures of blood vessels
know the different types of capillaries
Know what the lymphatic system is and what it does

Cardio - Heart Anatomy & Pacemaker Cells

Cardio - Electrocardiogram (ECG / EKG)

Cardio - Blood Flow

Types of Circulatory Systems