Blood Vessels and Circulation Practice Flashcards

A set of 80 vocabulary-style flashcards covering the anatomy, physiology, and regulation of the cardiovascular system based on lecture notes.

Arteries

Blood vessels that carry blood away from the heart.

Arterioles

The smallest branches of arteries.

Capillaries

The smallest blood vessels and the location of exchange between blood and interstitial fluid.

Venules

Small vessels that collect blood from capillaries.

Veins

Blood vessels that return blood to the heart.

Pulmonary Trunk

Vessel that carries blood from the right ventricle to the pulmonary circulation.

Aorta

Vessel that carries blood from the left ventricle to the systemic circulation.

Tunica intima

The inner layer of a blood vessel wall, including the endothelial lining, a connective tissue layer, and internal elastic membrane.

Tunica media

The middle layer of a blood vessel wall containing concentric sheets of smooth muscle in loose connective tissue and the external elastic membrane.

Tunica externa

The outer layer of a blood vessel wall that anchors the vessel to adjacent tissues; in arteries it contains collagen and elastic fibers.

Vasa Vasorum

Small vessels within the walls of large arteries and veins that supply the cells of the vessel.

Endothelium

The innermost lining of the blood vessel, part of the tunica intima.

Vasoconstriction

The contraction of arterial smooth muscle, reducing the diameter of the lumen.

Vasodilation

The relaxation of arterial smooth muscle, enlarging the lumen.

Afterload

The tension the heart must exert to open the aortic valve and eject blood, which is affected by vasoconstriction and vasodilation.

Elastic Arteries

Also known as conducting arteries, these are large vessels where the tunica media has many elastic fibers.

Muscular Arteries

Also known as distribution arteries, these are medium-sized vessels where the tunica media has many muscle cells.

Resistance Vessels

A term for arterioles because their constriction opposes blood flow, causing resistance ($R$).

Aneurysm

A bulge in an arterial wall due to a weak spot in the elastic fibers which may rupture with catastrophic results.

Continuous Capillaries

Capillaries with a complete endothelial lining found in all tissues except epithelia and cartilage.

Specialized Continuous Capillaries

Located in the CNS and thymus, these have restricted permeability known as the blood brain barrier.

Fenestrated Capillaries

Capillaries with pores in the endothelial lining that permit rapid exchange of water and larger solutes.

Sinusoids

Capillaries with gaps between adjacent endothelial cells that permit free exchange of water and large plasma proteins.

Precapillary sphincter

A muscle that guards the entrance to each capillary and opens/closes causing blood to flow in pulses.

Thoroughfare Channels

Direct capillary connections between arterioles and venules controlled by metarterioles.

Metarterioles

Smooth muscle segments that control flow through thoroughfare channels.

Collaterals

Multiple arteries that contribute to one capillary bed, allowing circulation to continue if one artery is blocked.

Arterial anastomosis

The fusion of two collateral arteries.

Arteriovenous anastomoses

Direct connections between arterioles and venules that bypass the capillary bed.

Angiogenesis

The formation of new blood vessels.

Vascular endothelial growth factor (VEGF)

A factor that stimulates angiogenesis in the embryo or in response to hypoxic tissues.

Venous Valves

Folds of the tunica intima that prevent blood from flowing backward in the venous system.

Capacitance

The ability of a blood vessel to stretch, specifically the relationship between blood volume and blood pressure.

Venoconstriction

The contraction of systemic veins stimulated by the vasomotor center to redistribute blood volume after loss.

Venous reserve

The volume of blood contained in the liver, skin, and lungs that can be redistributed during venoconstriction.

Pressure ($P$)

Force generated by the heart to overcome resistance in the cardiovascular system.

Pressure Gradient ($\Delta P$)

The difference between the pressure at the heart and the pressure at the peripheral capillary bed.

Blood Pressure (BP)

Arterial pressure measured in $mm/Hg$.

Capillary Hydrostatic Pressure (CHP)

The pressure within the capillary beds.

Total Peripheral Resistance

The resistance of the entire cardiovascular system, which must be overcome by circulatory pressure.

Vascular Resistance

Friction between the blood and the vessel walls, depending on vessel length and diameter.

Blood viscosity

Resistance to flow caused by materials suspended in a liquid.

Turbulence

A swirling action that disturbs the smooth flow of blood, often caused by plaque deposits.

Systolic Pressure

The peak arterial pressure measured during ventricular systole.

Diastolic Pressure

The minimum arterial pressure measured during ventricular diastole.

Pulse pressure

The difference between the systolic and diastolic pressure.

Mean arterial pressure (MAP)

The average pressure calculated as diastolic pressure plus one-third of the pulse pressure.

Hypertension

Abnormally high blood pressure, typically greater than $140/80$.

Hypotension

Abnormally low blood pressure.

Elastic Rebound

The action where arterial walls stretch during systole and recoil during diastole to keep blood moving.

Respiratory pump

The mechanism where inhalation and exhalation influence thoracic pressure to draw venous blood toward the heart.

Diffusion

The movement of ions or molecules along a concentration gradient from high to low concentration.

Filtration

Process driven by hydrostatic pressure where water and small solutes are forced through capillary walls.

Reabsorption

The movement of fluid back into the capillary as a result of osmotic pressure.

Blood colloid osmotic pressure (BCOP)

The pressure required to prevent osmosis caused by suspended proteins that are too large to cross capillary walls.

Net hydrostatic pressure

The force that tends to push water and solutes out of capillaries and into the interstitial fluid.

Net osmotic pressure

The force that pulls water and solutes into a capillary from the interstitial fluid.

Net Filtration Pressure (NFP)

The difference between net hydrostatic pressure and net osmotic pressure, calculated as $(CHP - IHP) - (BCOP - ICOP)$.

Recall of fluids

An increase in reabsorption of interstitial fluid into the blood caused by a reduction in CHP and NFP during hemorrhaging.

Edema

The buildup of fluid in peripheral tissues caused by an increase in CHP or a decline in BCOP.

Autoregulation

Local regulation where chemical changes in interstitial fluids open or close precapillary sphincters.

Baroreceptors

Sensory receptors that sense changes in blood pressure to make adjustments via the ANS.

Chemoreceptors

Sensory receptors that sense changes in blood gas levels.

Antidiuretic hormone (ADH)

A hormone released as part of the endocrine response to influence cardiovascular performance and blood volume.

Erythropoietin (EPO)

A hormone that stimulates blood formation in response to low blood pressure or low oxygen.

Pulmonary circuit

The circuit where deoxygenated blood is sent to the lungs to remove $CO_2$ and add $O_2$.

Systemic circuit

The circuit that contains $84 \%$ of blood volume and supplies the rest of the body.

Ascending aorta

Part of the aorta that rises from the left ventricle and branches into the coronary arteries.

Aortic arch

The curved portion of the aorta between the ascending and descending sections.

Brachiocephalic trunk

A branch of the aortic arch that supplies the right side of the head and right arm.

Left common carotid artery

A branch of the aortic arch supplying the left side of the head.

Left subclavian artery

A branch of the aortic arch supplying the left arm.

Axillary artery

The continuation of the subclavian artery as it leaves the thoracic cavity.

Brachial artery

The continuation of the axillary artery that divides into the radial and ulnar arteries.

External carotid artery

A division of the common carotid that supplies the neck, lower jaw, and face.

Internal carotid artery

A division of the common carotid that supplies the brain.

Vertebral arteries

Arteries arising from the subclavian arteries that enter the cranium through the foramen magnum.

Circle of Willis

An anastomosis at the base of the brain formed by the interconnection of the internal carotid and basilar arteries.

Thoracic aorta

The part of the descending aorta that supplies the organs and wall of the chest.

Superior vena cava

The vein that receives blood from the head, neck, chest, shoulders, and upper limbs.

Inferior vena cava

The vein that collects blood from organs inferior to the diaphragm.