1.2 Blood vessels Flashcards
do a blood vessel carry BOTH (CO2/waste) and (O2/nutrients)
give an example
- no
- a blood that carries (CO2/waste) and (O2/nutrients) are carried by separate blood vessels
- The blood that leaves the heart through the aorta is rich in oxygen and nutrients. This blood must be pumped in separate vessels from the blood that is full of carbon dioxide and wastes
function of the blood vessels
transport the blood to all parts of the body
what pumps the blood
the heart
what are the 3 types of blood vessels
- artery
- veins
- capillaries
Artery vs Veins
3 info
ARTERY
- carries blood away from the heart
- a thick-walled blood vessel
- no valves
VEINS
- carries blood toward the heart
- thin-walled blood vessels
- has valves
why must every living cell have to be close to a capillary
capillaries are thin walled porous vessels that allow materials from the blood, such as gases and fluids, to be exchanged with the body cells.
= it is where cells get there food and get rid of their waste
Therefore, every living cell must be close to a capillary to remain alive and functioning
what is the smallest and narrowest blood vessel
capillaries
what happens within the capillaries
blood exchanges O2 and glucose for wastes like CO2 from the cells
- (CO2/wastes) diffuse FROM cells and INTO the blood
- (O2/nutrients) diffuse FROM blood and INTO the cells
talk about the capillaries walls
the walls are only one cell thick for exchange of gases to take place by diffusion exist in capillary bed
Capillary bed
a web of capillaries surrounding the cells of the body tissues
how do the arteries and veins effectively reach every part of the body
both arteries and veins both branch into smaller vessels called arterioles and venules to effectively reach every part of the body
what is the largest veins int the body
venae cavae
steps about the hearts right side in more detail
- deoxygenated blood arrives to the heart from the body’s major veins, which flows into the venae cavae, the largest veins in the body
- the blood from each venae cavae is carried to the hearts right side where it is pumped to the lungs through the pulmonary arteries
- Within the capillaries of the lungs, the blood exchanges CO2 for O2 = oxygenated blood
- the oxygenated blood then returns to the heart’s left side through the pulmonary veins
Pulmonary circulation
the movement of the blood into and out of the lungs
what is the largest artery in the body
aorta
where do the coronary artery appear?
on the surface of the (R) and (L) ventricles of the heart
Pulmonary vein
the large blood vessel that carries oxygenated blood away from the lungs and into the hearts left atrium
Pulmonary artery
the large blood vessel that carries O2 poor blood away from the heart’s right ventricle and into the lungs
why do arteries have thick elastic walls
to withstand (not be damaged) the high PRESSURE exerted by the pumping heart. Except in this case of the pulmonary artery
As arteries get farther away from the heart and aorta …
they branch out and get smaller in diameter and lower in pressure. These smaller branched arteries are called arterioles
Arterioles
- a small artery that joins a larger artery to a capillary
- smaller in diameter and lower in pressure
- attached to a capillary
arterioles are attached to
capillaries
Venule
a small vein that joins a larger vein to a capillary
why does the wall of the veins / venules does not need to be thick and elastic as the walls of the arteries
the blood in venules and the larger veins has much lower pressure than the blood pressure in an artery
how does the low-pressure blood get back to the heart against the pull of gravity
example
- one way valves in the veins that prevents back flow of the blood
- the action of the contracting muscles.
the moving muscles push on blood in the veins while one-way venous valves prevent a back flow of blood and direct the blood back toward the heart
what if the veins become stretched and the valves are damaged
blood in the veins pools and the veins become raised in a condition called varicose veins
Varicose Veins
an enlarged, twisted vein near the surface of the skin resulting from poorly functioning valves
Blood pressure (2)
- the pressure exerted by the blood against the walls of blood vessels
- the pressure exerted by the blood on the walls of a MAJOR artery
Gauge
explain how it works
measure pressure in terms of height that a column of mercury can be raised
- the greater the pressure, the higher the column of mercury rises in the tube
what forces the blood to flow through the body’s blood vessels
BP