Chapter 15 A+P Word Bank

1. Action Potential

• Definition: Electrical signal that triggers muscle contraction in the heart.

• Key Ions: Sodium (Na⁺), Potassium (K⁺), Calcium (Ca²⁺).

2. Anterior Interventricular Artery

• Definition: A major branch of the left coronary artery that supplies blood to the interventricular septum and anterior walls of both ventricles.

3. Aorta

• Definition: Largest artery in the body, carries oxygenated blood from the left ventricle to the body.

4. Aortic Valve

• Definition: Prevents backflow of blood from the aorta into the left ventricle.

5. Arteries & Arterioles

• Arteries: Carry blood away from the heart.

• Arterioles: Small arteries that control blood flow to capillaries.

6. A-V Node (Atrioventricular Node)

• Definition: Delays the electrical impulse, allowing the atria to contract before the ventricles.

7. Capillaries

• Definition: Smallest blood vessels where gas and nutrient exchange occurs.

8. Capillary Networks

• Definition: Dense web of capillaries that connect arteries and veins in tissues.

9. Cardiac Anatomy

• Includes: Chambers, valves, blood vessels, conduction system, and muscle layers of the heart.

10. Cardiac Cycle

• Definition: Sequence of events in one heartbeat.

• Phases: Atrial systole → Ventricular systole → Diastole.

11. Cardiac Depolarization

• Definition: Electrical charge change that triggers heart contraction.

12. Cardiac Output Equation

• Formula: CO = HR × SV (Heart Rate × Stroke Volume).

13. Cerebellum

• Definition: Brain region that coordinates voluntary movements.

14. Chordae Tendineae

• Definition: Fibrous strings that anchor heart valves to papillary muscles.

15. Coronary Sinus

• Definition: Large vein that collects blood from the heart muscle and returns it to the right atrium.

16. Corpus Callosum

• Definition: Structure in the brain that connects the left and right hemispheres.

17. Cusps

• Definition: Flaps in heart valves that ensure one-way blood flow.

18. Endocardium

• Definition: Smooth inner lining of the heart chambers.

19. Endothelium

• Definition: Inner lining of blood vessels.

20. Epicardium

• Definition: Outer layer of the heart wall.

21. Frank-Starling Law

• Definition: The heart pumps more blood when it receives more blood.

22. Functional Syncytium

• Definition: The heart functions as a single coordinated unit.

23. Heart Sounds

• "Lubb": Closure of AV valves.

• "Dupp": Closure of semilunar valves.

24. Hydrostatic Pressure

• Definition: Pressure exerted by blood in vessels.

25. Inward Oncotic Pressure

• Definition: Osmotic pressure pulling fluid into blood vessels.

26. Ions Involved in Depolarization

• Key Ions: Sodium (Na⁺) enters, Calcium (Ca²⁺) maintains plateau, Potassium (K⁺) exits.

27. Isovolumic

• Definition: No volume change in heart chambers, but pressure changes.

28. Mediastinum

• Definition: Cavity in the thorax where the heart is located.

29. Medulla Oblongata

• Definition: Brainstem region that controls heart rate.

30. Mitral Valve (Bicuspid Valve)

• Definition: Valve between the left atrium and left ventricle.

31. Myocardium

• Definition: Thick muscle layer of the heart responsible for contraction.

32. Osmotic Pressure

• Definition: Pressure that draws water into capillaries.

33. Papillary Muscles

• Definition: Muscles in ventricles that control valve function.

34. Parasympathetic Nervous System

• Function: Slows heart rate (via Vagus nerve).

35. Pericardial Membrane/Cavity

• Definition: Protective sac surrounding the heart.

36. Pons

• Definition: Brain region that helps regulate breathing.

37. P-Q Interval

• Definition: Time delay between atrial and ventricular contraction.

38. Pulmonary Arteries

• Definition: Carry deoxygenated blood from the right ventricle to the lungs.

39. Pulmonary Valve

• Definition: Prevents backflow from pulmonary artery to right ventricle.

40. Pulmonary Veins

• Definition: Carry oxygenated blood from lungs to left atrium.

41. Purkinje Fibers

• Definition: Conduct impulses through ventricles for coordinated contraction.

42. P-Wave

• Definition: Represents atrial depolarization on an EKG.

43. QRS Complex

• Definition: Represents ventricular depolarization on an EKG.

44. Regulating BP

• Controlled by: Baroreceptors, RAAS system, sympathetic/parasympathetic input.

45. S-A Node (Sinoatrial Node)

• Definition: Pacemaker of the heart, initiates heartbeat.

46. Shunting Blood

• Definition: Redirecting blood to priority organs during stress.

47. Sulci

• Definition: Grooves on the heart’s surface that contain blood vessels.

48. SV (Stroke Volume)

• Definition: Amount of blood pumped per heartbeat.

49. Sympathetic Nervous System

• Function: Increases heart rate and contractility.

50. Thyroid Hormones

• Function: Increase heart rate and metabolic activity.

51. Tricuspid Valve

• Definition: Valve between the right atrium and right ventricle.

52. Tunica Media

• Definition: Middle layer of blood vessel wall; controls vasodilation & vasoconstriction.

53. T-Wave

• Definition: Represents ventricular repolarization on an EKG.

54. Vagus Nerve

• Function: Slows heart rate via parasympathetic input.

55. Veins

• Definition: Carry blood to the heart, contain valves to prevent backflow.

56. Ventricular Volume

• Definition: The amount of blood contained in the ventricles.