1. The Cardiovascular System: The Heart18

2. Coverings of the Heart: Anatomy & Physiology
Pericardium – a double-walled sac around the heart
Pericardial walls are separated by the fluid-filled pericardial cavity
Protects and anchors the heart
Prevents overfilling of the heart with blood
Reduces friction

3. Layers of the Heart: The Heart Wall
Epicardium – visceral layer of the pericardium
Myocardium – cardiac muscle layer forming the bulk of the heart
Endocardium – endothelial layer of the inner myocardial surface

4. Atria are the receiving chambers of the heart
Atria of the Heart
Atria are the receiving chambers of the heart
Blood enters right atrium from superior and inferior vena cava and coronary sinus (vein from the heart)
Blood enters left atrium from pulmonary veins
From the lungs

5. Ventricles of the Heart
Ventricles are the discharging chambers of the heart
Right ventricle pumps blood into the pulmonary artery
Left ventricle pumps blood into the aorta

6. Also called the interventricular septum
The left and right side of the heart is divided by a tissue wall called the septum
Also called the interventricular septum

7. How does the heart prevent blood from flowing backwards?
2/20
Open your notes to page 55. I will be checking for questions on page 54
Heart diagram: in space below diagram or on post it note
Take out a sheet of paper for new notes. Page 57 Copy the EQ at the top of the page.
EQ:
How does the heart prevent blood from flowing backwards?

8. Heart valves ensure unidirectional blood flow through the heart
Two types: atrioventricular and semilunar
Atrioventricular (AV) valves lie between the atria and the ventricles:
Tricuspid between the right atria and ventricle
Bicuspid/mitral between the left atria and ventricle
AV valves prevent backflow into the atria when ventricles contract

9. Semilunar valves prevent backflow of blood into the ventricles
Heart Valves
Semilunar valves prevent backflow of blood into the ventricles
Aortic semilunar valve lies between the left ventricle and the aorta
Pulmonary semilunar valve lies between the right ventricle and pulmonary trunk (artery)

10. New EQ: copy the following:
How is heart rate regulated and controlled?

11. Heart Physiology: Sequence of Excitation
The brain sends a message to the Sinoatrial (SA) node
The message is sent to the Atrioventricular (AV) node
Impulse passes from atria to ventricles via the atrioventricular bundle (bundle of His)
continued

12. Heart Physiology: Sequence of Excitation
AV bundle splits into two pathways in the interventricular septum (bundle branches)
Bundle branches carry the impulse toward the apex of the heart
Purkinje fibers carry the impulse to the heart apex and ventricular walls

13. Be prepared to flip to page 56 so show me your questions on this page
2/21
Open your notes to page 54. I will be stamping for a summary on this page.
Be prepared to flip to page 56 so show me your questions on this page
Put the following EQ on a new sheet of paper (Pg 59)
EQ:
How is blood flow through the heart and the rest of the body measured?

14. Used to determine Blood Pressure
Cardiac Cycle
Cardiac cycle refers to all events associated with blood flow through the heart
Systole – contraction of heart muscle
Diastole – relaxation of heart muscle
Usually associated with ventricle contraction
Used to determine Blood Pressure
(more in chapter 19)

15. The pulse measures the flow of blood in the arteries
As blood flows through, the pressure of the blood causes the artery to expand
Directly related to heart rate

16. Heart sounds (lub-dup) are associated with closing of heart valves
First sound occurs as AV valves close and signifies beginning of systole
Second sound occurs when SL valves close at the beginning of ventricular diastole

17. New EQ for a new page of notes(page 61)
2/22/19
Open notes to pages 56 and 58 for me to stamp summary and questions
Copy the EQ on a new sheet of paper (page 61)
EQ:
What is the structure and function of the blood vessels?

18. The Cardiovascular System: Blood Vessels19

19. Carry blood away from the heart Thick middle muscle layer
arteries
Carry blood away from the heart
Thick middle muscle layer
Must withstand more pressure

20. Carry blood back to the heart Thinner muscular layer
veins
Carry blood back to the heart
Thinner muscular layer
Contain valves to prevent back flow of blood

21. Capillaries- smallest blood vessels
Walls consisting of a thin internal layer , one cell thick
Allow only a single RBC to pass at a time
contact tissues and exchange materials with the cells

22. Cardiac Cycle (review)
Cardiac cycle refers to all events associated with blood flow through the heart
Systole – contraction of heart muscle
Diastole – relaxation of heart muscle
Usually associated with ventricle contraction
Used to determine Blood Pressure
Do not copy

23. Determined by heart soundsBP
Determined by heart sounds
Pressure cuts off blood flow in artery
Pressure is released and blood flow is restored
Creates a thumping sound
This is the systolic pressure
Eventually the sounds go away when flow is restored to 100%
This is the diastolic pressure
Continued on next slide

24. BP
Written as:
Systolic / Diastolic
Ex: 120 / 80

25. Alterations in Blood Pressure
Hypotension – low BP in which systolic pressure is below 100 mm Hg or diastolic under 60
Hypertension – condition of sustained elevated arterial pressure of 140/90 or higher
Acute elevation can be caused by fever, physical exertion, and emotional upset
Chronic elevation is a major cause of heart failure/attack, vascular (blood vessel) disease, renal failure, and stroke