The heart and blood vessels Flashcards
Name types of circulatory systems
Open circulatory system and closed circulatory system
Open circulatory system
Heart pumps blood into open ended vessels, e.g. insects
Close circulatory system
Blood remains in a continuous system of blood vessels, e.g. humans
advantages of a closed circulatory system
blood can be pumped faster
-Nutrients can be delivered to cells quicker
-Allows organisms to be more active
Blood flow rate to different organs can be changed
-E.g. increased blood flow to leg muscles when running
Name blood vessels
Arteries, veins, capillaries
Arteries
Carry blood away from the heart
What are smaller arteries called?
Arterioles
Veins
Carry blood to heart
What are smaller veins called?
venules
Capillaries
tiny vessels that link arteries and veins
blood vessels differences (lumen)
artery - small
Vein - large
Capillaries - tiny
blood vessels differences (wall)
Artery - thick
Vein - thin
Capillary - thin (allows easy exchange of materials)
blood vessels differences (valves)
artery - none
Vein - present
Capillary - none
blood vessels differences (direction of blood flow)
Artery- away from heart
vein - to the heart
Capillary - links arteries and veins
blood vessels differences (oxygenation of blood)
arteries - oxygenated (except pulmonary artery)
veins - deoxygenated (except pulmonary vein )
capillaries -both
blood vessels differences (blood flow)
artery - rapid under high pressure
vein - slow under low pressure
capillary - slow, pressure falling (allowed time for material exchange to occur)
blood vessels differences (pulse)
artery - blood flows in pulses
vein - blood flows at steady rate
capillary - no pulse
order of relationship between blood vessels
Artery
Arteriole
Capillary
Venule
Vein
material exchange is facilitated by?
Thin walls - rapid entry/exit of materials
Large surface area - close contact with body cells
Narrow tubes - increases pressure
Blood flow in arteries has aided by?
thick, muscular layer - increases blood flow
elastic fibres - bring blood vessel back to shape
Location of the heart
Thoracic cavity - between lungs, above, diaphragm
function of the heart
Pump blood around the body
structure of the heart
hollow, made of cardiac muscle
surrounded by pericardium (double membrane)
atria in the heart
upper chambers
Pump blood to ventricles
thin walls due to short distance
ventricles in the heart
Lower chambers
Pump blood out of the heart
Left ventricle thicker than the right ventricle
Where is the right ventricle pump blood to?
lungs (shorter circuit)
Where does the left ventricle pump blood to?
Around body
Role of valves
Prevent backflow of blood
Semilunar valves
Prevent backflow of blood to the heart
Bicuspid valves
Prevents backflow of blood to left atrium
Tricuspid valves
Prevent backflow of blood to right atrium
Role of septum
separate heart left and right
Separates oxygenated and blood
blood flow of deoxygenated blood
Enters through veins (superior and inferior vena cava)
exit through arteries (pulmonary artery)
Blood flow of oxygenated blood
enters through veins (pulmonary vein)
Exit through arteries (aorta)
pulmonary circuit
Heart to lungs and back to heart
Systematic circuit
heart to the body and back to heart
Advantages of double circulation
separate oxygenated and deoxygenated blood
Blood pressure can be kept high
Portal system
Pathway that begins and ends in capillaries
Hepatic portal system
Connect to the stomach and intestines with liver
Where did coronary arteries store blood to? + location
cardiac muscle
branch from aorta just above semilunar valves
Coronary veins
Jane blood from the heart wall into right atrium
how is heartbeat made?
alternating contraction and relaxation of cardiac muscle
Another name for contraction in the heart
systole
Another name for relaxation in the heart
diastole
How is sound of heartbeat, mean?
Closing of heart valves
how is heartbeat controlled?
Pacemaker (SA node) in right atrium
What is the SA node do you?
Send electrical signal to cardiac muscle
What happens when an SA node emits a signal?
Atria contract
what is receives the signals of the SA node?
AV node
What is the AV node do?
Send signals to ventricles
what happens when an AV node emits a signal?
Send signals to ventricles, causing them to contract
Stages of heartbeat
recite from notes
Pathway of blood
(recite from notes)
