Cardiovascular System Flashcards
Artery
Carries blood away from the heart
Vein
Returns blood to the heart. They contain valves because of the low blood pressure (to prevent backwards flow of blood).
Capillary
Exchange vessels for the tissues that connects the arterial side to the venus side.
- They contain, endothelial cells, a basal lamina, and pericytes.
- They do not have smooth muscle
Pulmonary veins
Oxygenated
Pulmonary arteries
Deoxygenated
Systemic veins
Deoxygenated
Systemic arteries
Oxygenated
Systemic system
Carries oxygenated blood from the heart to the tissues and deoxygenated blood from the tissues back to the heart.
Pulmonary system
Carries deoxygenated blood from the heart to the lungs and oxygenated blood from the lungs back to the heart.
Pericytes
Structures in capillaries that can replace endothelial cells if they are damaged (maintain viability).
Continuous capillary
Most common type of capillary found in the muscle, CNS, lungs, and skin.
Fenestrated capillary
Capillary that contains numerous pores in lining endothelium that are spanned by a thin diaphragm. Found in the intestines and kidneys*
*No diaphragm, thick basement membrane.
Sinusoidal capillary
Discontinuous capillary that contains spaces/holes and a wider lumen. Found in the spleen, liver, and bone marrow.
Methods of capillary exchange
Open pores/gaps, diffusion, filtration, vesicular transport, and transendothelial channels
Vesicular transport
System of pinocytotic pits and vesicles that transports large molecules across the membrane of a capillary.
Transendothelial channels
An aggregation of large vesicles that span across the membranes of the endothelium of a capillary to form a channel. Provides much more rapid transport of molecules.
Function of endothelial cells (capillaries)
Diapedesis and regulation of circulation
Tunica intima
Innermost layer of blood vessels that contains a layer of endothelial cells, connective tissue, and an internal elastic lamina.
Tunica media
Middle layer of blood vessels that contains a layer of smooth muscle, elastic fibers, and an external elastic lamina.
- It is thicker in arteries, and thinner in veins
Tunica adventitia
Outermost layer of blood vessels that contains connective tissue, vasa vasorum, and nerves.
- It is thicker in veins, and thinner in arteries.
Vasa vasorum
Blood vessels located within the tunica adventitia of blood vessels.
Elastic arteries
They have 40-60 layers of smooth muscle in the tunica media. This layer contains multiple elastic fibers within because it needs to be able to withstand the pumping of blood.
Ex/ the aorta
Muscular arteries
Also called distributing arteries, they contain up to 6-40 layers of smooth muscle in the tunica media.
Arteriole
Contains 1-5 layers of smooth muscle.
Arteriole-capillary-venule microcirculation
Most common microcirculation. Blood flows from an arteriole to a capillary bed and then to a venule within an organ or tissue. Blood flow is controlled by precapillary sphincters.
Arteriovenous anastomosis
Blood flows directly from an arteriole to a venule to short circuit circulation
- Ex/ skin (reticular layer)
Arteriole-capillary-arteriole microcirculation
Blood flows from an arteriole through a capillary bed and back to an arteriole. This occurs because this is under high pressure.
- Ex/ glomerulus of kidney
Venule-capillary-venule microcirculation
Blood flows from a venule through a capillary and back to a venule. This is a portal system.
Ex/ liver
Precapillary sphincter
Ring of smooth muscle in a capillary bed that controls the flow of blood by contacting or relaxing.
Vena cava
Large vein that contains bundles of smooth muscle in the adventitia that runs perpendicular to the media. It contains several layers of media unlike smaller veins.
Endocardium
Homologous to the tunica intima, location of Purkinje fibers
Myocardium
Homologous to the tunica media, muscle layer of the heart.
Epicardium
Homologous to the tunica adventitia, contains adipose tissue.
Pericardium
Outer wall of the sac that the heart sits in
Artium
Sections of the heart that push the blood into the ventricles. They do not have as thick of layers of muscle as the ventricles do.
Ventricle
Sections of the heart that squeeze the blood into the systemic or pulmonary systems. They have the thickest layers of muscle.
Purkinje fibers
Specialized muscle cells of the heart located in the endocardium of the heart. They are responsible for conducting depolarization that stimulates the contraction of the myocardium of the heart.
Sinoatrial node
Continually generates an electrical impulse in the heart, connects to the AV node.
Bundles of His
Bundles of purkinje fibers
Lymphatic system
Returns an excess of 10% of interstitial fluid to the blood, transports lipids, and is involved in immunologic support/surveillance.
- All fluid lymph gets filtered once before re-entering the blood.
Lymphatic vessles
They are distinguished by their lymphocytes (nucleated cells) and the valves (because they are unidirectional).
Lymphatic capillaries
They have permeability characteristics and contain filaments that anchor to connective tissue
