1. Unit K – Heart Structure and Function
Heart Quiz
Unit K – Heart Structure and Function

2. Unit K – Heart Structure and Function
First baby step – anatomy of heart
heart review

3. Diagram (quiz…)
Diagram (quiz…)

4. Parts of the Heart
Left and Right Atria – Collecting Chambers
-- Right: Collects blood from Venae Cavae
-- Left: Collects blood from Pulmonary
Veins
Left and Right Ventricles – Pumps
-- Right: Sends blood to the lungs via the
Pulmonary Trunk.
-- Left: Sends blood to the body via the
Aorta

5. Atrioventricular-- Valves -- Valves between the atria and ventricles
-- Prevent backflow of blood
-- Right hand side “Tricuspids”— three
cusps, or flaps (also known as right atrioventricular valve
-- Left hand side “bicuspid”– two cusps
(also known as the mitral valve or left atrioventricular valve)
 Chordae Tendineae
–Strong, Fibrous strings that support the
A.V. valves
--Keeps the valves from inverting with
the force of blood flow.

7. Semi-Lunar Valves (no chordae tendineae)
-- Between the ventricles and the Aorta
(aortic valve)
-- Between the ventricles and the Pulmonary Trunk
(pulmonary valve)

8.  Pulmonary Trunk
-- Branches off to form the Pulmonary Artery
-- Receives blood from the right ventricles
Septum
-- The wall of the Heart
-- Separates the left and right sides of the Heart

9. heart beat!

10. Control of Heart Heart is muscle tissue
Beat of heart is INTRINSIC will beat independently of any nervous stimulation

11. Coordination of Heartbeat
2 nodes – SA node and AV node both located in the right atrium
1) SA node – sinoatrial node/ pacemaker – upper wall of right atrium.
Acts as a pacemaker
Activates muscle cells of both atria to contract almost simultaneously

12. Coordination of Heartbeat

13. Coordination of Heartbeat
2) AV node – atrioventricular node – base of r.a.
impulse from SA node travels via nerves called the bundle of HIS
AV node initiates contraction of both ventricles via Purkinje fibers

14. Coordination of Heartbeat
SA node connected to brain via the Vagus nerve – brain signals SA node through this nerve and sets heart rate
Medulla oblongata part of brain that monitors blood pressure
Regulation is autonomic (not under conscious control)

15. Electrocardiogram ekg- a way to measure electrical activity of heart
Measures the electrical activity of heart in millivolts (mV)
This forms a graph that is then labeled PQRST
P curve – atria contracting
QRS – contraction of the ventricles
T recovery
Heart beat approx beats/min.

16. ECG/EKG

17. The red line is the EKG. The blue line is aortic pressure
The red line is the EKG. The blue line is aortic pressure. The green line shows heart sounds.

18. Blood Pressure Is the force of blood against the blood vessels
Not constant & is greater when ventricles contract
2 parts – systolic pressure (systole) – pressure when ventricles contract – higher number – given first

19. Blood Pressure
Diastolic pressure – diastole – pressure when ventricles are not contracting – atrial contraction
Blood pressure is measured along a brachial artery
120/80 = normal
Hypertension – high blood pressure (diet, stress, exercise)

20. Blood Pressure – cont’d
Hypotension – low blood pressure
Hypothalamus –part of brain that monitors blood pressure and can cause the arteries to constrict or dilate
heart attack!