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Flashcards in Heart And Blood Vessels Deck (16):

What is the role of diffusion ?

Diffusion is sufficient transport of materials in small animals, large animals need a circulatory system


What is an open circulatory system and a closed circulatory system ?

An open circulatory system means the blood leaves the blood vessels

A closed circulatory system means blood is always in the blood vessels
- blood moves around the body quicker
- allows alterations in blood flow to body organs


Describe arteries

Carry blood away from the heart

Have low blood pressure

Have thick walls

Do not have valves

Have narrow lumens

Carry oxygen rich blood


Describe veins

Carry blood to the heart

Have low pressure

Have thin walls

Have valves

Have large lumens

carry oxygen poor blood except for pulmonary vein


What are capillaries

Capillaries connect arteries to veins, have thin walls and allow exchange of materials


What are valves

Valves prevent the black flow of blood


What is double circulation

Double circulation means that blood flows...

- from the heart to the lungs and then back to the heart (pulmonary circuit)

- from the heart to the rest of the body and back to the heart (systemic circuit)


How how is the heartbeat controlled

The heart beat is controlled by......

- the pacemaker (SA Node ) in the wall of the right atrium, which cause atria to contract

- the atrio-ventricular (AV) node, which send electrical impulses down the septum

- the ventricles, which contract


What is diastole and systole

Diastole is when the heart is relaxed

Systole is when the heart contracts


Stages of the heart beat

Diastole: Blood enters the atria

Atrial systole : Blood is pumped to the ventricles

Ventricular systole : Blood is pumped out of the heart


What is a pulse

Caused by the expansion and contraction of an artery as blood is forced through it

Caused by ventricular systole


What are the effects of excersise

The effects of excessive on heartbeat are investigated by comparing the pulse rate at rest and after exercise


What is blood pressure

Blood pressure his the force of the blood against the walls of the arteries

Higher value is measure of systolic pressure

Lower value is a measure of diastolic pressure


How does smoking effect the heart

Increasing heart rate

Increasing blood pressure

Increasing the risk of blood clots


Main dietary factors affecting the circulatory system

Saturated fats - causing blocked arteries

High Salt intake - raising blood pressure

Being greatly overweight -raises blood pressure and causes heart attacks


Aerobic exercise

Strengthens the heart

Improves blood circulation

Reduces body weight