The Circulatory System

Página 1

Blood

4 parts of blood-

plasma,

red blood cells,

white blood cells,

platelets

Plasma:

liquid part of blood

carries chemicals(food and waste) around the body

Red blood cells:

formed in bone marrow

contains a red, iron based pigment called haemoglobin

transport oxygen

white blood cells:

made in the bone marrow

fight infections

platelets:

are made in bone marrow

form blood clots

Blood vessels

3 types:

arteries

veins

capillaries

Arteries:

carries blood away from the heart(A for arteries and A for Away)

carry blood under high pressure

have thick,strong walls to resist the pressure

Veins:

carry blood towards the heart

carry blood under low pressure

have thin walls

have valves to prevent blood flowing backward

capillaries:

connect arteries to veins

tiny and very numerous

very thin walls

allow substances to pass in and out(to and from body cells)

Vena cava:carries low oxygen blood from body to the heart

right atrium: pumps low-oxygen blood to the right ventricle

valves: prevent backflow of blood

right ventricle:pumps low oxygen blood to the lungs

pulmonary artery:carries low oxygen blood from heart to lungs

septum:seperates low oxygen and rich oxygen blood

pulmonary veins: carry oxygen rich blood from lungs to heart

left atrium: pumps oxygen rich blood to left ventricle

left ventricle: pumps oxygen rich blood around the body

aorta: carries oxygen rich blood from the heart to all other parts of the body

Blood flow circuits

from heart to lungs and back

from heart to body and back again

pulse rates and exercise

pulse is caused by the surge of blood in an artery due to a heartbeat

average pulse rate for adult is 70 per minute

exercise increases heartbeat and pulse rate

exercise makes the heart stronger and reduces weight

Heart disease can be prevented by:

exercise

healthy diet

no smoking

Chp. 6

the heart