12. The Cardiovascular System Flashcards
blood is pumped out of where and moves through which vessel
left ventricle of heart
moves through aorta
what does the aorta do and what vessels does it give rise to
supplies body
splits into smaller arteries than branch into arterioles and then into capillaries
once in the capillaries the blood is collected into what
venules
what doe venules lead to
larger veins
the veins join up to form what vessels and where do these vessels empty
form inferior and superior vena cava
empty into right atrium
in the pulmonary circulation blood is pumped from right ventricle to/via what vessels
to capillaries of lung via pulmonary arteries
where does oxygenation of blood take place
in capillaries of the lung
blood returns from lungs back to heart via which vessel
pulmonary vein
when does systole occur
ventricles contract
when does diastole occur
when the atria contract and rest of heart is relaxed
contraction of the heart is controlled by what
autonomic nervous system
what controls the heart contraction specifically and where is it located
sinoatrial node in the right atrium
how does the sinoatrial node initiate heart contractions
node spreads contraction to the surrounding muscles via electrical impulses
impulses from SA node spread to where and what is the significance of this
spreads to the atrioventricular node between the atria
AV node slower to contract creating delay so atria can contract and push blood into ventricles before they contract
impulses spread through heart via what
purkinje fibres
what are arteries
elastic vessels that stretch when filled with blood
what are arteries wrapped in
smooth muscle
what are arterioles in terms of their structure and their role
small vessels that are wrapped in smooth muscle and constrict/dilate to regulate blood pressure
what are capillaries in terms of structure and what do they do
blood vessels that are one cell thick
nutrient and gas exchange occurs in capillaries
what are veins in terms of structure and what do they do
contain greater volume of blood than arteries
blood is pumped at a lower pressure in veins so have valve system that prevents backflow of blood
arteries and veins carry blood in what direction
arteries = away from heart
veins = towards heart
what is the blood responsible for
transporting nutrients, waste products and hormones around the body
what are the 4 major components of blood
plasma
white blood cells
red blood cells
platelets
what is plasma and its components
contains matrix of the blood which includes water, urea, ammonia, inorganic compounds and proteins
