🔴 1.1 Cardiovascular System Flashcards by Jack Lassiter

Diastole

Term used to describe the relaxation phase of the cardiac cycle. Heart ventricles are relaxed and fill with blood

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Systole

Term used to describe the contraction phase of the cardiac cycle - the ventricles contract and blood pumped to the arteries

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Stroke volume

The volume of blood that leaves the heart during each contraction

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Health

State of complete physical, mental and social well-being and not merely the absence of disease and infirmity

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Fitness

The ability to meet and cope with the demands of the environment

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Physical activity

Being active and taking part in exercise - can directly benefit your physical health and wellbeing

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Heart rate

Number of times the heart beats per minute

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Anticipatory rise

Slight increase in heart rate usually before activity starts due to the expectation of exercise

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Cardiac output

The amount of blood the heart pumps out. Measured in litres per minute

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What is the cardiovascular system made up of

The heart and the blood vessels

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Why is an efficient cardiovascular system important during exercise

deliever oxygen to working muscles
gather waste products
transporting heat (a by product of exercise) to the skin so the performer can cool down

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Cardiac muscles - what are they? Where has more?

Cardiac muscles and the muscles in the walls of the heart. These muscles help to push blood through the heart. The ventricles have thicker muscular walls as it takes much more force to push the blood out of the heart then to push the blood from the atrial to the ventricles

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What does the vena cava do ?

Brings deoxygenated blood to the right atrium

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What does the pulmonary vein do?

Delivers oxygenated blood to the left atrium

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What does the pulmonary artery do?

Transports deoxygenated blood from the right ventricle to the lungs to be oxygenated

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What does the aorta do

Transports blood from left ventricle to the working muscles

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What is the job of the valves of the heart

They open and close to allow blood to pass through but also to prevent back flow of blood

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Myogenic

The capacity of the heart to generate its own impulses

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Sinoatrial node

A small mass of cardiac muscles found in the wall of the right atrium that generates the heart beat. It is more commonly called the pacemaker

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Atrioventricular node

This node relays the impulse between the upper and lower sections of the heart

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Bundle of his

A collection of heart muscle cells that transmit electrical impulses from the AVN via the bundle branches to the ventricles

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Purkinje fibres

Muscle fibres that conduct impulses in the walls of the ventricles

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What is the largest chamber of the heart and why

Left ventricle because it needs to pump blood to the whole body so it requires the largest and more developed cardiac muscles. Whereas the right ventricle only needs to pump blood to the lungs

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the rate at which the impulses are fireed from the SAN cam be controlled by 3 main mechanisms:

sympathetic nervous system
parasympathetic nervous system
medulla oblongata

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sympathetic nervous system

part of the autonomic nervous system that speeds up the heart rate

parasympathetic nervous system

part of the autonomic nervous system that slows down the heart rate

medulla oblongata

the most important part of the brain as it regulates the processes that keeps us alive such as breathing and heart rate

ANS

autonomic nervous system, determines the rate at which the SAN sends out impulses

how does the sympathetic nervous system speed up HR

releases adrenaline which will then increase the strength of the ventricular contractions which then increases stroke volume.

noradrenaline

this aids the spread of electrical impulses throughout the heart increases the heart rate

how does the parasympathetic nervous system decrease the heart rate

releases ACETYLCHOLINE which slows the spread of impulses throughout the heart

2 parts of the nervous system

- central nervous system - peripheral nervous system

peripheral nervous system

consists of nerve cells which transmit information to and from the CNS

cardiac control centre is stimulated by

- chemoreceptors - baroreceptors - propioreceptors

where are chemoreceptors found

CAROTOID ARTERIES AORTIC ARTERIES

role of chemoreceptors

they sense chemical changes in the blood. they detect co2 levels changing and for example, when co2 levels increase, the sympathetic nervous system is activated and when the co2 levels decrease, the parasympathetic nervous system is activated decreasing heart rate

where are baroreceptors found

found in the arterial walls

role of baroreceptors

the baroreceptors will establish a set point for blood pressure. an increase or decrease from this set point results in baroreceptors sending signals to the medulla oblongata. increase in arterial pressure = increase in baroreceptors stretch = DECREASE in heart rate decrease in arterial pressure = decrease in baroreceptor stretch = INCREASE in heart rate

where are proprioceptors found

muscles, tendons and joints

role of proprioceptors

provides information about movement and body position. increase in muscular movement leads to sympathetic nervous system ... increase hr

adrenaline

a stress hormone that is released by the sympathetic nervous system and cardiac nerve during exercise causing increase in heart rate

vascular shunt mechanism

redirecting of blood to the areas it is most needed

why shouldnt sports performers eat less than an hour before competition

a full gut would result in more blood being directed to the stomach instead of the working muscles - results in detrimental effect on the performer, less oxygen available

why does blood flow to the brain have to remain constant

ensure the brain functions are maintained and the brain needs oxygen for energy to maintain

when exercising, why does more blood need to go to the heart

because the heart muscles (cardiac muscles) need oxygen for energy to beat faster

when exercising, why does more blood need to go to the skin

energy is needed to cool the body down

vasometer centre

located in the medulla oblongata of the brain, controls both blood flow and blood pressure

how do the receptors redistribute blood flow

These receptors will stimulate the vasometre centre which will redustribute blood flow through vascontrictikn and vasodilation. Vasodilation is when the blood vessels widen to increase blood flow to the capillaries . Vasoconstriction is when the blood vessels narrows to decrease blood flow

What other mechanism causes redistribution of blood flow

Stimulation of the sympathetic nervous system located in the walls of the blood vessels. When sympathetic stimulation increases, vasoconstriction occurs and blood flow reduces

During exercise, in the capillaries, what percentage of oxygen dissolves into plasma

During exercise, in the capillaries, what percentage of oxygen combines with haemoflobin

97%

When fully saturated, how many oxygen molecules will each haemoglobin carry

Why is oxygen released from oxyhemoglobin at the tissue?

Because of the low pressure of oxygen that exists there, oxygen diffuses from area of high concentration to low

Oxyhameoglobin dissociation

Release of oxygen from oxyhaemoglobin to the tissues

When oxygen is released into the tissue, what is it stored by and why

Myoglobin this is because myoglobin has a higher affinity for oxygen and will store the oxygen for the mitochondria

Plasma

The fluid part of blood that surrounds blood cells and transports them

Haemoglobin

An iron containing pigment found in RBC which combine with oxygen to form oxyhaemoglobin

Myoglobin

Often called ‘muscle haemoglobin’ it is a iron containing pigment in slow twitch muscle fibres which has a higher affinity for oxygen than haemoglobin. Its main function is to transport oxygen from the cell membrane to the mitochondria where aeoribic respiration takes place

What is the partial pressure of o2

The amount of o2 in your blood stream

What does the Bohr effect mean

It means that for the same amount of blood in your body, more oxygen is released from oxyhaemoglobin into the tissues. The Bohr shift will allow oxygen to dissociate from haemoglobin more easily becyase the haemoglobin will have lower affinity for oxygen

What factors cause the Bohr effect to occur

- increase acidity - lower ph - increase co2 - increase body temp

Bradycardia

A decrease in resting heart rate below 60bpm