Physiology, Health & Exercise

Physiology and diseases of the cardiovascular systemEnergy balance and obesityPathophysiology of Diabetes MellitusPathophysiology of Osteoporosis

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Introduction

Exercise has wide ranging effects on the body and the mind.

In particular, it can reduce your risk of major diseases such as coronary heart disease (CHD), stroke, obesity, Diabetes Mellitus and Osteoporosis.

An active lifestyle will not only reduce your risk of developing these diseases but also give you a sense of well being and confidence.

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Structure & Function of the cardiovascular system

The heart is the central organ of the CVS pumping blood to the lungs and the other tissues of the body.

The primary purpose is to move substances around the bodyThe blood can only reach these tissues by passing through

blood vessels, the other vital component of the CVS.The CVS supplies all the cells of the body with nutrient and

oxygen-rich blood and removes carbon

dioxide which would otherwise kill cells.

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Heart Structure

4 chambersAtria at topVentricles at bottomMuscular pump composed of cardiac muscleCan beat without input from the nervous system

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Heart Structure

The cardiovascular system is closed as blood is transported within blood vessels.

It is also described as a double circulatory system because in one complete circulation of the body blood goes through the heart twice.

The left ventricle wall of the heart is thicker than the right as it is pumping blood around the whole body compared to only the lungs.

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Heart Structure

Having a double circulation reduces the time taken for the blood to circulate the whole body and allows mammals to have a higher basal metabolic rate (BMR)

The right side (RA) of the heart receives deoxygenated blood from the body and it passes it to the lungs to be oxygenated.

The left side (LA) receives oxygenated blood from the lungs and passes it to the rest of the body.

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Pulmonary circuit

RV

Pulmonary artery

lungs

Pulmonary vein

LA

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Systemic Circuit

RA

Vena Cava

Major organs

Aorta

LV

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Valves of the Heart

The valves between the atria and ventricles are known as atrio-ventricular valves (AV valves) as they prevent the back flow of blood into the atria when the ventricles contract.

Between RA & RV- tricuspid valve (3 flaps)Between LA & LV- bicuspid valve (2 flaps)-

also called mitral valve

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Valves of the Heart

The semi-lunar valves are found at the origins of the pulmonary artery and aorta.

Between RV and pulmonary artery- pulmonary valve

Between LV and aorta- aortic valveOpen when ventricles contract to allow blood flow

into the arteriesClose when arterial pressure falls to prevent blood

flowing back into the ventricles when they relax.

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Valves of the Heart

The heart valves closing cause the lub-dub sound heard with a stethoscope

A “heart murmur”-

“sloshing sound” as

valves not closing properly

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Heart Dissection

Heart dissection