Anatomy and Physiology The Cardiovascular System

https://www.youtube.com/watch?v=qWti317qb_w

BLOOD PRESSURE http://amg.adam.com/content.aspx?productId=26&pid

=26&gid=000001&keyword=high%20blood%20pressure&searchScope=Article&count=20

CVS http://umm.edu/health/medical/ency/animations/cardi

ovascular-system http://media.hhmi.org/biointeractive/click/circulatorium

/?_ga=1.100921737.981100844.1458683497

The cardiovascular system contains the heart, blood vessels (BVs), and blood.

Its function is to transport oxygen and nutrients throughout the body. It does this by circulating blood.

An average body contains ~5-5.5 liters of blood but the heart pumps ~7,000 liters of blood daily while the heart contracts ~2.5 billion times in an average lifetime.

The Heart: This is a powerful

pump

It is found in the thoracic (chest) cavity behind the sternum and mediastinum

Average heart size is 14 X 9 cm

It is separated into chambers: 2 right and 2 left (or 2 upper and 2 lower)

It is covered by the pericardium (a membrane) which has 2 layers:

◦ Visceral pericardium (covers the heart; inner layer); a.k.a. epicardium

◦ Parietal pericardium (covers the visceral pericardium; outer layer)

◦ The pericardial cavity is the space between these layers which contains serous fluid

◦ Pericarditis is inflammation of the pericardium usually caused by viral or bacterial infection.

The Heart Walls

This is composed of 3 layers:

◦ Epicardium protects the heart (reduces friction); this contains connective tissue & adipose

◦ Myocardium is the middle layer; contains mostly cardiac tissue

◦ Endocardium is the innermost layer; contains epithelium & connective tissue and elastic & collagenous fibers

Heart Chambers and Valves:

There are 4 chambers: ◦ The atria (sing. atrium) receive blood

◦ The ventricles send blood (from the atria)

The right & left chambers are separated by a wall called the septum.

There are several valves in the heart that provide the main function of regulating blood flow in ONE direction only (prevents backflow).

The Heart Walls

and Chambers:

http://www.texasheartinstitute.org/HIC/Topic

s/images/myocard.jpg

Heart Valves:

◦ Atrioventricular valves (a.k.a. A-V valves b/c they are between the atria and ventricles): there is 1 on the right & 1 on the left.

Tricuspid valve is between the right atrium and ventricle; blood flows from the right atrium to the right ventricle.

Bicuspid valve (MITRAL VALVE)is between the left atrium and ventricle; blood flows from the left atrium to the left ventricle.

◦ Pulmonary valve: at the base of the pulmonary trunk; this enables blood to leave the heart (and flow to the lungs thru the pulmonary arteries); blood flows out of the right ventricle

◦ Aorta valve: at the base of the aorta (a large artery); blood flows out of the left ventricle

Heart Valves:

http://www.google.com/imgres

Pulmonary Circulation: (heart to lungs)

Pulmonary arteries: carry blood to lungs

Pulmonary veins: return blood from lungs to heart (left side)

Systemic Circulation: (heart to rest of body)

Aorta: main artery (largest) that pumps blood from heart to all body tissues (except lungs)

Superior & Inferior Vena Cava: bring blood back into heart from body tissues.

http://www.google.com/imgres

Blood Flow Path: begins with O2 poor blood:

Right Atrium Right Ventricle Pulmonary Trunk Pulmonary Arteries Alveoli of lungs for O2 Pulmonary Veins Left Atrium Left Ventricle Aortic Valve Aorta

Body

http://www.google.com/imgres

The Cardiac Conduction System:

This coordinates the cardiac cycle

Contains the sinoatrial node (a.k.a. S-A node) located beneath the epicardium:

◦ This acts as the pacemaker of the heart b/c it is rhythmic (meaning it starts impulses, thereby generating the heart’s rhythm).

Contains the atrioventricular node (a.k.a. A-V node) located beneath the endocardium

This acts as the impulse conduction pathway between the atria and ventricles

Cardiac Cycle & Sounds:

The cardiac cycle is 1 heart contraction AND 1 heart relaxation, or a complete heartbeat.

Atrial systole is atrial contraction while atrial diastole is atrial relaxation.

When listening to the heartbeat with a stethoscope, it sounds like lubb-dupp. The lubb is ventricular contraction while the dupp is ventricular relaxation.

http://www.google.com/imgres

A murmur is a sound that is heard when there is slight damage to a valve of the heart.

◦ The damage is the leaking of blood through a valve b/c the valve does not completely close.

http://www.google.com/imgres

An electrocardiogram (a.k.a. ECG) is a recording of electrical charges in the myocardium during a cardiac cycle.

Heart problems can be detected with the use of an ECG.

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Heart Regulation: The heart rate can change(temporarily) by certain factors:

Neural (ANS) controls: stress

Hormones & ions: changes or imbalances in electrolytes (Ca++, Na+, K+), thyroxine, or epinephrine

Physical factors: temperature, age, gender

http://www.google.com/imgres

Blood Vessels (BVs):

These include the arteries, arterioles, capillaries, venules and veins.

The arteries take blood away from the heart; vasoconstriction & vasodilation (opening & closing of an artery) controls blood flow and blood pressure.

Oxygenated

Blood (red)

http://cache.eb.com/eb/image?id=92806&rendTypeId=34

Arteries (& Veins) have 3 layers:

◦ Tunica intima is the innermost layer containing endothelium (internal epithelium) which helps prevent blood clotting

◦ Tunica media is the middle layer

◦ Tunica externa is the outermost layer

The arterioles come from the arteries (they are smaller arteries)

http://www.medicalook.com/systems_images/Veins.jpg

Capillaries are the smallest BVs

◦Found between arterioles and venules

◦Gases & nutrients are exchanged thru their membranes (semipermeable)

This occurs by diffusion, filtration & osmosis

The amount of capillaries found within a tissue varies according to the tissue’s O2 requirement (more O2 required=more capillaries)

http://biology.bangor.ac.uk/images/bsx1009/fig15-3

Venules are small veins

Veins carry blood to the heart from the body; these run parallel to arteries.

◦ Veins have 3 layers (like arteries) but not as distinct

◦ Thinner walls than arteries

◦ Less elastic but greater diameter than arteries

◦ Many contain valves which act as flaps preventing backflow of blood

http://www.brvsa.com/venous.htm

Varicose Veins:

http://www.wakeradiology.com/Portals/0/Varicose1.jpg

http://www.brvsa.com/images/varicose2.jpg

http://www.brvsa.com/venous.htm

Physiology of Circulation:

Vital Signs: Arterial pulse, blood pressure, rate of respiration, and body temperature.

Pulse: each beat of the left ventricle as it travels through the arterial system.

A pulse is felt at certain points on the body. This is due to an artery close to the surface of the skin.

This is the contraction and relaxation of an arterial wall.

http://www.google.com/imgres

Testing carotid artery

https://www.nhlbi.nih.gov/health/health-topics/topics/cu/

http://www.nlm.nih.gov/medlineplus/ctscans.html

http://www.nlm.nih.gov/medlineplus/ency/article/003799.htm

http://www.nlm.nih.gov/medlineplus/ency/article/007269.htm

Blood Pressure: Blood pressure can be

defined as the force of blood against BVs.

When the ventricles contract with the maximum pressure is the systolic pressure.

When the ventricles relax with the lowest pressure is the diastolic pressure.

http://www.google.com/imgres

Factors that Influence Blood Pressure:

Heart action: this determines the total volume of blood entering the arterial system.

Blood volume: this is ~5k-5.5 liters or 8% of body weight. This equals the sum of the elements and plasma.

Blood volume is proportional to bp (normally). When blood volume decreases, bp drops; dehydration will also influence bp b/c it affects blood volume.

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Peripheral Resistance: this is the force of the friction between blood and blood vessels. This can hinder blood flow.

Blood viscosity: this is the ease with which blood particles move past each other. Greater viscosity=greater resistance.

Thicker blood (meaning it has more parts) creates higher bp.

Factors that Influence Blood Pressure:

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Factors that Influence Blood Pressure:

Additional Factors that may influence blood pressure: ANS (autonomic nervous system) –

STRESS! Renal Factors (kidneys) Temperature Hormones Diet

Balloon angioplasty & stent: https://www.youtube.com/watch?v=e13TGGccvT4 Cerebral aneurysm: https://www.youtube.com/watch?v=oA1j1xWlHoU https://www.youtube.com/watch?v=AfXxq387EOc Stroke: http://www.pennmedicine.org/encyclopedia/em_Di

splayAnimation.aspx?gcid=000123&ptid=17 Stroke warning signs: http://www.strokeassociation.org/STROKEORG/Wa

rningSigns/Stroke-Warning-Signs-and-Symptoms_UCM_308528_SubHomePage.jsp

HIGH BLOOD PRESSURE/Hypertention: http://amg.adam.com/content.aspx?productId=26&pi

d=26&gid=000001&keyword=high%20blood%20pressure&searchScope=Article&count=20

Heart attack symptoms: http://www.heart.org/HEARTORG/Conditions/HeartA

ttack/WarningSignsofaHeartAttack/Warning-Signs-of-a-Heart-Attack_UCM_002039_Article.jsp#.WL7Ctjh9kss

In women:

http://www.heart.org/HEARTORG/Conditions/HeartAttack/WarningSignsofaHeartAttack/Heart-Attack-Symptoms-in-Women_UCM_436448_Article.jsp#.WL7DfDh9kss

http://www.medicinenet.com/heart_attack_symptoms_and_early_warning_signs/article.htm

VIRTUAL LAB:

http://www.hhmi.org/biointeractive/cardiology-virtual-lab

CIRCULATORY SYSTEM DISEASES:

http://www.md-health.com/Circulatory-System-Diseases.html

THE END!

This slide show was developed by Dana Halloran,

Cardinal Mooney High School, Sarasota, FL.

Used with her personal permission,

adapted and amended by Rosa Whiting,

Manatee School for the Arts, Palmetto, FL.