BLOOD VESSEL AND CIRCULATION Flashcards
- carry blood to within two or three cell diameters of nearly all the trillions of cells that make up the body.
BLOOD VESSEL AND CIRCULATION
transport blood from the right ventricle of the heart through the lungs and back to the left atrium.
Pulmonary vessels-
transport blood from the left ventricle of the heart through all parts of the body and back to the right atrium.
Systemic vessels
carry blood away from the heart; usually, the blood is oxygenated.
Arteries
- the largest-diameter arteries and have the thickest wall.
- Stretch when the ventricles of the heart pump blood into them.
- The elastic recoil of these arteries prevents blood pressure from falling rapidly and maintains blood flow while the ventricles are relaxed.
Ex. aorta and pulmonary trunk.
Elastic arteries
include medium-sized (distributing arteries) and small arteries; relatively thick compared to their diameter.
Muscular arteries
contraction of the smooth muscle in the blood vessel; decrease blood vessel diameter and blood flow.
Vasoconstriction
Relaxation of the smooth muscle in blood vessel; increases blood vessel diameter and blood flow.
Vasodilation
where exchange of substances such as oxygen nutrients, Carbon dioxide and other waste products occurs between the blood and the tissue fluid.
Capillaries
a smooth muscle where the blood flow through capillary networks is regulated.
Precapillary sphincters
very thin and consists only of endothelium; Thin walls of capillaries- facilitate diffusion between the capillaries and surrounding cells
Capillary walls
carry blood toward the heart; usually, blood is deoxygenated.
Veins
have a diameter slightly larger than that of capillaries and are composed of endothelium resting on delicate connective tissue layer.
Venules
slightly larger in diameter than venules.
Small veins
collect blood from small veins and deliver it to large veins.
Medium-sized veins
3 layers of Blood Vessel Walls
- Tunics Intima
- Tunica Media
- Tunica adventitia/ tunica externa
- innermost layer.
- Endothelium- composed of simple squamous epithelial cells, a basement membrane, and a small amount of connective tissues.
- Contains a layer of thin elastic connective tissue.
Tunica Intima
- middle layer.
- Consists of smooth muscle cells arranged circularly around the blood vessel.
- Contains variable amounts of elastic and collagen fibers.
- A layer of elastic connective tissue forms the outer margin of the tunica media.
Tunica media
- Composed of dense connective tissue adjacent to the tunica media.
- The tissue becomes loose connective tissue toward the outer portion of the blood vessel wall.
Tunica adventitia/tunica externa
The system of the blood vessels that carries blood from the right ventricle of the heart to the lungs and back to the left atrium of the heart.
BLOOD VESSELS OF THE PULMONARY CIRCULATION
Where blood from the right ventricle is pumped into a short vessel.
Pulmonary trunk
exit the lungs and carry the oxygenated blood to the left atrium.
Pulmonary veins
System of the blood vessels that carries blood from the left-ventricle of the heart to the tissues of the body and back to the right atrium.
BLOOD VESSELS OF THE SYSTEMIC CIRCULATION: ARTERIES
where all arteries of the systemic circulation branch directly or indirectly.
AORTA
part of the aorta that passes superiorly from the left ventricle.
Ascending aorta
where the aorta arches posteriorly and to the left.
Aortic arch
longest part of the aorta.
Descending aorta
localized dilation of an artery that usually develops in response to trauma or congenital weakness of the artery wall.
Arterial aneurysm
extends a short distance and then branches at the level of the clavicle to form right common carotid.
Brachiocephalic artery
transports blood to the right side of the head and neck.
Right common carotid artery
transports blood to the right upper limb.
Right subclavian artery
transports blood to the left side of the head and neck.
Left common carotid
transports blood to the left upper limb.
Left subclavian artery
the base of each internal carotid artery that is slightly dilated.
Carotid sinus