1. Chapter 12: Heart

2. Functions of the Heart Generating blood pressure Routing blood
Ensuring one-way blood flow
Regulating blood supply
Functions of the Heart

3. Size, Form, Location of Heart
Mediastinum (divides thoracic cavity)
Surrounded by pericardial sac
Pericardial fluid reduces friction as heart moves
Anchors heart
Slightly larger than a closed fist
Size, Form, Location of Heart

4. Two different Pumps Right atrium & ventricle Left atrium & ventricle
Blood is pumped TO the lungs and back to heart
Blood is pumped TO the body and back to heart
Two different Pumps

5. Two Circuits Pulmonary circuit To and from the lungs
“pulmonary” – of or relating to lungs
Systemic circuit
To and from the rest of the body
Two Circuits
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

6. Two pumps and two circuits
Two Sets of Pumping Chambers in Heart
Right atrium
Receives systemic blood
Right ventricle
Pumps blood to lungs (pulmonary)
Left atrium
Receives pulmonary blood from lungs
Left ventricle
Pumps blood to organ systems (systemic)
Two pumps and two circuits
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

7. Three Kinds of Blood Vessels Arteries
Carry blood Away from heart and carry it to the capillaries
Capillaries
Microscopic vessels where exchange between cells and blood takes place
Veins
Receive blood from capillaries and carry it back to the heart
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

8. Coronary Vessels Left and Right coronary arteries from base of aorta
Blood from coronary arteries gives up 70% of its blood to heart muscle
Coronary Vessels

9. A separation of the atria from ventricles, on surface of heart; “ditch”
Coronary Sulcus

10. Coronary Thrombosus Thrombosus = “blood clot”
A blood clot of the coronary blood vessels
Also called “heart attack”
Lack of oxygen to tissue
Tissue dies
Dead tissue = “Infarct”
Aspirin: reduces clumping action
of platelets
Some enzymes can break down
blood clots
Coronary Thrombosus

11. Artherosclerotic Lesions
Thickening in the wall of the artery
Can contain cholesterol/lipid deposits
Restrict blood flow
Fatigue, pain symptoms (angina pectoris)
Artherosclerotic Lesions

12. Atria & Ventricles Atria: receive blood from veins Reservoir for blood
Ventricles: major pumping chambers
Interventricular septum: separates the two ventricles
Atria & Ventricles

13. Pericardium Layers Epicardium (Visceral pericardium) Myocardium
Simple squamous epithelium
Myocardium
Cardiac muscle
Endocardium
Simple squamous
Heart contracts due to myocardium
Pericardium Layers

14. Cardiac Muscle Intercalated Disks
Reduce electrical resistance between the cells
Allows action potentials to pass easily
The cells of the atria or ventricles contract at nearly the same time
Cardiac Muscle

15. Action Potential Resting potential -85 mV “Depolarization”
Na channel opens
Na into cell
Ca channels open
Ca into the cell
Action Potential

16. Action Potential “Repolarization” Na channels close Na stops
K+ moves out
Action Potential

17. “Plateau”
Ca channels open
Ca into cell
Action Potential

18. Action Potential “Final repolarization” Ca close
K+ open and out of cell
Returns to resting potential
Action Potential

19. Conduction System of the Heart
Sinoatrial Node: pacemaker of the heart
Produces action potentials at a faster rate than other areas of heart
----- Meeting Notes (3/4/16 08:17) -----
Know the location of His bundle, location of nodes, location of Perkinje Fibers
Conduction System of the Heart

20. Purkinje fibers:
His bundle:

21. Cardiac Cycle refers to a complete heartbeat from its generation to the beginning of the next beat.
It includes the diastole, systole and pause.
The repetitive pumping process that begins with cardiac muscle contraction and ends with the beginning of the next contraction.
Cardiac Cycle

22. Cardiac Cycle 1. Ventricular systole: contraction of the ventricle
Atrioventricular (AV) valves close (first heart sound – LUBB)
Semi-lunar valves open and blood is ejected into pulmonary trunk and aorta
2. Ventricular diastole: ventricles relax
Semi-lunar valves close(second heart sound – DUPP)
AV valves opens
3. Atrial systole (at end of ventricular diastole): atria contract
Forces blood into ventricle so they finish filling
Great video on lub-dub
Cardiac Cycle

23. Arrhythmia: abnormal heart rhythm
EKG records the electrical activity of the heart
P = atria contracting
QRS = ventricular depolarization/contraction
PR interval = time for SA node to reach ventricles
T= ventricular relaxation/repolarization
Read EKGs
Arrhythmia: abnormal heart rhythm

24. Murmur: abnormal heart sounds
Incompetent Valve: doesn’t close all the way, swishing after closure
Stenosed Valve: narrowed, swishing before closure

25. Murmur: abnormal heart sounds
Cardiac output: volume of blood pumped each minute (by either ventricle)
Stroke volume: volume of blood per ventricle each time heart contracts
Heart rate: number of times the heart contracts each minute

26. ABI: ankle brachial index
Blood pressure: systolic (blood pressure as heart contracts) and diastolic (pressure during interval between heartbeats)
Evaluates circulation in your leg
Shoes and socks removed
Uses Doppler Ultrasound to assess blood flow through vessels of arm and ankle
ABI: ankle brachial index