11 Heart Anatomy and the Function of the Cardiovascular System Blood Vessels and Circulation...

11

Heart Anatomy and the Function of the Cardiovascular System

Blood Vessels and Circulation

Regulation of the Heart

Heart Diseases & Disorders

The Cardiovascular System

Lesson 11.1

Heart Anatomy and the Function of the

Cardiovascular System

Chapter 11: The Cardiovascular System

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• thoracic cavity• above diaphragm; between lungs• size of a clenched fist• weighs 8–12 ounces

The Heart: Location and Size


The Heart: Location and Size


• right atrium• right ventricle• left atrium• left ventricle

The Four Chambers of the Heart


• atrioventricular (AV) valves– tricuspid– bicuspid (mitral)

• semilunar valves– pulmonary– aortic

The Heart Valves


• (1) deoxygenated blood flows from the body to the inferior and superior vena cavae to right atrium

• (2) right atrium contracts, forcing blood through the tricuspid valve to right ventricle

• (3) right ventricle contracts, forcing blood through the pulmonary valve, to the pulmonary artery

• (4) blood exits to the lungs

Blood Flow through the Heart


• (5) oxygenated blood from lungs travels through the pulmonary veins to the left atrium

• (6) left atrium contracts, forcing blood through the mitral valve to the left ventricle

• (7) left ventricle contracts, forcing blood through the aortic valve

• (8) blood passes to the aorta• (9) blood travels out to parts of the body

Blood Flow through the Heart (continued)


Blood Flow through the Heart


• epicardium– outermost layer

• myocardium– middle layer

• endocardium– inner layer

Walls of the Heart


• diastole– ventricle relax, atria contract

• systole– ventricles contract, atria relax

• mean arterial pressure– overall pressure within cardiovascular system

Cardiac Cycle


• amount of blood pumped by heart in 1 minute measured in liters/minute

• stroke volume– amount of blood pumped in 1 beat

• heart rate– number of beats per minute

Cardiac Output

Lesson 11.2

Regulation of the Heart



• Sinoatrial (SA) node– Pacemaker; sends electrical impulse– tells heart to beat 60–100 bpm

Internal Control of the Heart


• cardiac center– sympathetic nerve system speeds up– parasympathetic nerve system slows down

• endocrine system– some hormones speed up

External Control of the Heart


• SA node• AV node• bundle of His• bundle branches–

right and left• Purkinje fibers

The Conduction System


• ECG or EKG– electrical activity of the heart– depolarize–contract– repolarize–relax

Electrocardiogram


• normal contractility condition– sinus rhythm

– arrhythmia• ventricle or atria contraction is

abnormal

Cardiac Arrhythmias


• bradycardia– slow heart beat

• tachycardia– fast heart beat

• premature atrial contraction (PACs)– atria contracts before

SA node

Cardiac Arrhythmias


• automatic external defibrillator (AED)– electric shock, stops heart– allows heart to start normal rhythm – anyone can use one

Defibrillators and Life-Threatening Arrhythmias


Fill in the blanks with: Tachycardia, Atrial fibrillation, Bradycardia, or Defibrillator.

1. _______________ is fast heart beat.

2. _______________ is slow heart beat.

3. _______________ is atria beating more than 350 bpm.

4. A(n) _______________ stops the heart so it can reset.

Review and Assessment

Lesson 11.3

Blood Vessels and Circulation



• Vasoconstriction vs. vasodilation

Blood Vessels: The Transport Network


Differences between Arteries and Veins


• exchange vessels– gas moves between tissue and blood

• capillary bed– network of exchange vessels

Capillaries


• cardiopulmonary circulation– between heart and lungs

• systemic circulation– between heart and body

Circulation: Moving Blood around the Body


Circulation: Moving Blood around Body


• coronary arteries– left – right

• coronary sinus

Cardiac Circulation


Arteries


Veins


• taking your pulse– find radial, carotid or brachial artery – count beats for 15 seconds, multiply by 4

• measuring blood pressure– stethoscope, sphygmomanometer– systolic/diastolic pressure

Taking Vital Signs

Joseph Dilag/Shutterstock.com, Ilya Andriyanov/Shutterstock.com


• weight– body mass index–weight to height

• blood pressure– systolic/diastolic–110/70 mmHg

• cholesterol– LDLs and HDLs

Know Your Numbers

Lesson 11.4

Heart Disease & Disorders



• heart murmurs– valves do not close properly

• valvular stenosis– narrowed, stiff heart valve

• mitral valve prolapse– mitral valve does not fully close

• palpitations

Valve Abnormalities


• pericarditis– inflammation of heart sac

• myocarditis– “ “ heart muscle

• endocarditis– “ “ heart lining and valves

Diseases Ending in -itis


• heart cannot pump blood• fluid backs up in

– Lungs, liver, limbs, GI tract

Heart Failure


• aneurysms– weakened artery bulges,

may break

• coronary artery disease– atherosclerosis– angina pectoris– ischemia

Diseases of the Arteries


• myocardial infarction– plaque blocks a cardiac artery

• treatment– aspirin as soon as symptoms appear– 20–60 minute window for treatment

Heart Attack


Heart Attack


• hypertension– blood pressure above 140/90 mmHg

• peripheral vascular disease– lack of circulation in legs

• stroke– blockage of brain blood flow

• ischemic stroke• hemorrhagic stroke• transient ischemic attack (TIA)

Heart Disease


True or False?

1. Hypertension is 120/80 mmHg.

2. Aspirin helps in a heart attack.

3. An aneurysm is a weakened artery.

4. Myocarditis affects the heart wall.

5. In a heart murmur the valves do not close properly.

Review and Assessment

11 Heart Anatomy and the Function of the Cardiovascular System Blood Vessels and Circulation...

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