A9- Blood and Blood Vessels Flashcards
You have an expansive network of tubes inside your body designed to transport blood to and from the body and lungs
Blood Vessels
aorta
the largest blood vessel in the
body, connected directly to the heart; the
aorta branches into arteries that carry
oxygenated blood to the body tissues
A blood vessel that carries blood away from the heart towards the body tissues is called an…
artery
When are arteries nto carrying oxygenated blood?
The one exception to this rule is your pulmonary artery because it carries deoxygenated blood from right atrium to the lungs
The walls of the arteries are made of 3 layers of tissue
An outer layer of connective tissue
A middle layer of smooth muscle
A inner layer of epithelial (Endothelim) cells
What does the feeling of your pulse really mean?
you are actually feeling blood being forced through your arteries due to the contraction of your heart
TRUE OR FALSE: Arteries have valaves?
FALSE
Arteries do NOT contain valves!
As arteries branch off, they get smaller and smaller along the way
These smaller vessels are called the…
arterioles
What happen to artieris when heart conmtratcs and send blood around body?
Arteries expand
TRUE OR FALSE: Outer layer of arteries has elastain fibers that gives vessels elasticity
TRUE
arteriole
the smallest artery, with smooth
muscle in its walls
vasodilation
an increase in the diameter
(dilation) of arterioles that increases the
blood flow to tissues
vasoconstriction
a decrease in the
diameter of arterioles that decreases the
blood fl ow to tissues
What type of muscle does arterioles have in their walls?
Smooth muscle in the walls
How do arterioles regulate their diamter?
nerves
What gives our faces a flushed look?
Nerve impluses in the smooth muscle in the arterioles in the skin can relax, which increases diamteter of blood vessles to give a flushed look
When smooth muscle inarterioles are relaxed…
diameter of bkood vessels increase which open the vessel
When body is cold what happenes to the vessels?
Vessels can close to restrict blood flow to skin to prevetn loss of heat
When an arteriole reaches the body tissue, it branches into the smallest vessel called …
capillaries
The walls of capillaries are only…
one cell layer thick and wide
What do caplilaires do?
provide oxygen and nutrients to every cell in the body
Where are capilaries found?
often are found in networks called capillaries beds
Capillaires facilitie exchange of…
waste, nutrients, gases, hormones between blood and body cells
How do nutrients and gasses like CO2 and O2 diffuse in capillaires?
Through the membrane
How do larger materails move through capillaries?
move through fluid filled spaces with capiliar cell mebranes
Interstial fluid contains…
-water
-nuittents
-gases
-wastes
-small protiens
Why is it a good thing that speed of bloodflow drops quickly while blood is forced into capalliaries?
Enchances diffusion
Higher fluid pressure on arterial side of capillary netwirk cause water to…
diffuse from blood into tissue fluid
Reduced concentration of water in blood increases the…
concentration of discolved substances and protiens in the blood increases the concentration of dissolved substanes and protiens in the blood as it corsses the capiliary network
Pre-capillary spinchinter
Is where the arteriole branches into a capillary. Th ese sphincter
muscles serve the same function as the dilation and constriction of arterioles.
What does the pre-capillary sphincter do when blood is not needed?
the pre-capillary sphincters contract
and reduce blood fl ow
What does the pre-capillary sphincter do when blood is needed?
arterioles and
sphincters are fully relaxed, and the blood fl ow to the muscles is increased.
venule
the smallest vein; formed by the
merging of capillaries
After the oxygen has diffused out of and the carbon dioxide has diffused into the blood, it needs to return to heart and lungs
After the capillary bed, it will enter…
venules
Venules and veins carry…
wastes and carbon dioxide back to the heart and lungs where it can be expelled
Veins almost always carry…
deoxygenated blood away from the tissues and towards the heart
The one exception in veins is…
the pulmonary vein because it carries oxygenated blood away from the lungs and towards the heart (i.e. the left atrium)
Veins have the same three layer structure as arteries but…
but have a thinner layer of muscle and a wider opening
Valves and skeletal muscle contractions helps the blood…
fight gravity and push back towards the heart
Most veins contain valves that can…
open and close