Chapter 12 - Cardiovascular System Flashcards
Lumen Definition
the inside of the vessels, Blood vessels lined with epithelial cells
Vasoconstriction Definition
When muscle contracts and the diameter of
the lumen narrows, reducing blood flow
Vasodilation Definition
When muscle relaxes and the diameter of
the lumen increases, increasing blood flow
Osmotic Pressure Definition
Draws fluid back into the vessel from the tissue
(at the venous end)
Blood pressure Definition
Force fluid out of the capillary and into the tissue
(at the arterial end)
Septum Definition
Separates right and left sides of the heart
Capillaries Definition
Arterioles break down into small vessels
It is here that components (O2, CO2,
nutrients, waste) can pass from the blood
vessels to other tissues
*Capillaries do not have a smooth muscle
layer
The RBCs stay in the blood vessels but the
oxygen leaves the RBCs and the capillaries
and goes into the tissues.
The oxygen leaves the capillaries because
there is a gradient – there is more oxygen in
the capillaries than in the tissues.
- Blood flow in capillaries is slow.
- This is important because it allows time
for the exchange of substances between
the blood and surrounding tissues
smallest vessels
Arteries Definition
Always carry blood away from the
heart and usually carry O2-rich blood
Smallest arteries
Veins Definition
Always returns blood to the heart
and usually carry O2-poor blood
Arteriole Definition
There are sphincter muscles that contract
to reduce blood flow to the capillaries
or they dilate to increase blood flow to the
capillaries
Venule Definition
Take CO2, water, and wastes away from
the tissues. Forming together to form veins
Smallest veins
Vena Cava Definition
Largest veins in the body
Aorta Definition
Largest artery
Pericardium Definition
Thick membranous sac surrounding the heart (secretes serous fluid)
Myocardium Definition
consists of cardiac muscle tissue, which contracts to pump blood
