20.7: Key Terms

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Glossary Entries

Word(s)	Definition	Image	Caption	Link	Source
abdominal aorta	portion of the aorta inferior to the aortic hiatus and superior to the common iliac arteries
adrenal artery	branch of the abdominal aorta; supplies blood to the adrenal (suprarenal) glands
adrenal vein	drains the adrenal or suprarenal glands that are immediately superior to the kidneys; the right adrenal vein enters the inferior vena cava directly and the left adrenal vein enters the left renal vein
anaphylactic shock	type of shock that follows a severe allergic reaction and results from massive vasodilation
angioblasts	stem cells that give rise to blood vessels
angiogenesis	development of new blood vessels from existing vessels
anterior cerebral artery	arises from the internal carotid artery; supplies the frontal lobe of the cerebrum
anterior communicating artery	anastomosis of the right and left internal carotid arteries; supplies blood to the brain
anterior tibial artery	branches from the popliteal artery; supplies blood to the anterior tibial region; becomes the dorsalis pedis artery
anterior tibial vein	forms from the dorsal venous arch; drains the area near the tibialis anterior muscle and leads to the popliteal vein
aorta	largest artery in the body, originating from the left ventricle and descending to the abdominal region where it bifurcates into the common iliac arteries at the level of the fourth lumbar vertebra; arteries originating from the aorta distribute blood to virtually all tissues of the body
aortic arch	arc that connects the ascending aorta to the descending aorta; ends at the intervertebral disk between the fourth and fifth thoracic vertebrae
aortic hiatus	opening in the diaphragm that allows passage of the thoracic aorta into the abdominal region where it becomes the abdominal aorta
aortic sinuses	small pockets in the ascending aorta near the aortic valve that are the locations of the baroreceptors (stretch receptors) and chemoreceptors that trigger a reflex that aids in the regulation of vascular homeostasis
arterial circle	(also, circle of Willis) anastomosis located at the base of the brain that ensures continual blood supply; formed from branches of the internal carotid and vertebral arteries; supplies blood to the brain
arteriole	(also, resistance vessel) very small artery that leads to a capillary
arteriovenous anastomosis	short vessel connecting an arteriole directly to a venule and bypassing the capillary beds
artery	blood vessel that conducts blood away from the heart; may be a conducting or distributing vessel
ascending aorta	initial portion of the aorta, rising from the left ventricle for a distance of approximately 5 cm
atrial reflex	mechanism for maintaining vascular homeostasis involving atrial baroreceptors: if blood is returning to the right atrium more rapidly than it is being ejected from the left ventricle, the atrial receptors will stimulate the cardiovascular centers to increase sympathetic firing and increase cardiac output until the situation is reversed; the opposite is also true
axillary artery	continuation of the subclavian artery as it penetrates the body wall and enters the axillary region; supplies blood to the region near the head of the humerus (humeral circumflex arteries); the majority of the vessel continues into the brachium and becomes the brachial artery
axillary vein	major vein in the axillary region; drains the upper limb and becomes the subclavian vein
azygos vein	originates in the lumbar region and passes through the diaphragm into the thoracic cavity on the right side of the vertebral column; drains blood from the intercostal veins, esophageal veins, bronchial veins, and other veins draining the mediastinal region; leads to the superior vena cava
basilar artery	formed from the fusion of the two vertebral arteries; sends branches to the cerebellum, brain stem, and the posterior cerebral arteries; the main blood supply to the brain stem
basilic vein	superficial vein of the arm that arises from the palmar venous arches, intersects with the median cubital vein, parallels the ulnar vein, and continues into the upper arm; along with the brachial vein, it leads to the axillary vein
blood colloidal osmotic pressure (BCOP)	pressure exerted by colloids suspended in blood within a vessel; a primary determinant is the presence of plasma proteins
blood flow	movement of blood through a vessel, tissue, or organ that is usually expressed in terms of volume per unit of time
blood hydrostatic pressure	force blood exerts against the walls of a blood vessel or heart chamber
blood islands	masses of developing blood vessels and formed elements from mesodermal cells scattered throughout the embryonic disc
blood pressure	force exerted by the blood against the wall of a vessel or heart chamber; can be described with the more generic term hydrostatic pressure
brachial artery	continuation of the axillary artery in the brachium; supplies blood to much of the brachial region; gives off several smaller branches that provide blood to the posterior surface of the arm in the region of the elbow; bifurcates into the radial and ulnar arteries at the coronoid fossa
brachial vein	deeper vein of the arm that forms from the radial and ulnar veins in the lower arm; leads to the axillary vein
brachiocephalic artery	single vessel located on the right side of the body; the first vessel branching from the aortic arch; gives rise to the right subclavian artery and the right common carotid artery; supplies blood to the head, neck, upper limb, and wall of the thoracic region
brachiocephalic vein	one of a pair of veins that form from a fusion of the external and internal jugular veins and the subclavian vein; subclavian, external and internal jugulars, vertebral, and internal thoracic veins lead to it; drains the upper thoracic region and flows into the superior vena cava
bronchial artery	systemic branch from the aorta that provides oxygenated blood to the lungs in addition to the pulmonary circuit
bronchial vein	drains the systemic circulation from the lungs and leads to the azygos vein
capacitance	ability of a vein to distend and store blood
capacitance vessels	veins
capillary	smallest of blood vessels where physical exchange occurs between the blood and tissue cells surrounded by interstitial fluid
capillary bed	network of 10–100 capillaries connecting arterioles to venules
capillary hydrostatic pressure (CHP)	force blood exerts against a capillary
cardiogenic shock	type of shock that results from the inability of the heart to maintain cardiac output
carotid sinuses	small pockets near the base of the internal carotid arteries that are the locations of the baroreceptors and chemoreceptors that trigger a reflex that aids in the regulation of vascular homeostasis
cavernous sinus	enlarged vein that receives blood from most of the other cerebral veins and the eye socket, and leads to the petrosal sinus
celiac trunk	(also, celiac artery) major branch of the abdominal aorta; gives rise to the left gastric artery, the splenic artery, and the common hepatic artery that forms the hepatic artery to the liver, the right gastric artery to the stomach, and the cystic artery to the gall bladder
cephalic vein	superficial vessel in the upper arm; leads to the axillary vein
cerebrovascular accident (CVA)	blockage of blood flow to the brain; also called a stroke
circle of Willis	(also, arterial circle) anastomosis located at the base of the brain that ensures continual blood supply; formed from branches of the internal carotid and vertebral arteries; supplies blood to the brain
circulatory shock	also simply called shock; a life-threatening medical condition in which the circulatory system is unable to supply enough blood flow to provide adequate oxygen and other nutrients to the tissues to maintain cellular metabolism
common carotid artery	right common carotid artery arises from the brachiocephalic artery, and the left common carotid arises from the aortic arch; gives rise to the external and internal carotid arteries; supplies the respective sides of the head and neck
common hepatic artery	branch of the celiac trunk that forms the hepatic artery, the right gastric artery, and the cystic artery
common iliac artery	branch of the aorta that leads to the internal and external iliac arteries
common iliac vein	one of a pair of veins that flows into the inferior vena cava at the level of L5; the left common iliac vein drains the sacral region; divides into external and internal iliac veins near the inferior portion of the sacroiliac joint
compliance	degree to which a blood vessel can stretch as opposed to being rigid
continuous capillary	most common type of capillary, found in virtually all tissues except epithelia and cartilage; contains very small gaps in the endothelial lining that permit exchange
cystic artery	branch of the common hepatic artery; supplies blood to the gall bladder
deep femoral artery	branch of the femoral artery; gives rise to the lateral circumflex arteries
deep femoral vein	drains blood from the deeper portions of the thigh and leads to the femoral vein
descending aorta	portion of the aorta that continues downward past the end of the aortic arch; subdivided into the thoracic aorta and the abdominal aorta
diastolic pressure	lower number recorded when measuring arterial blood pressure; represents the minimal value corresponding to the pressure that remains during ventricular relaxation
digital arteries	formed from the superficial and deep palmar arches; supply blood to the digits
digital veins	drain the digits and feed into the palmar arches of the hand and dorsal venous arch of the foot
dorsal arch	(also, arcuate arch) formed from the anastomosis of the dorsalis pedis artery and medial and plantar arteries; branches supply the distal portions of the foot and digits
dorsal venous arch	drains blood from digital veins and vessels on the superior surface of the foot
dorsalis pedis artery	forms from the anterior tibial artery; branches repeatedly to supply blood to the tarsal and dorsal regions of the foot
ductus arteriosus	shunt in the fetal pulmonary trunk that diverts oxygenated blood back to the aorta
ductus venosus	shunt that causes oxygenated blood to bypass the fetal liver on its way to the inferior vena cava
elastic artery	(also, conducting artery) artery with abundant elastic fibers located closer to the heart, which maintains the pressure gradient and conducts blood to smaller branches
esophageal artery	branch of the thoracic aorta; supplies blood to the esophagus
esophageal vein	drains the inferior portions of the esophagus and leads to the azygos vein
external carotid artery	arises from the common carotid artery; supplies blood to numerous structures within the face, lower jaw, neck, esophagus, and larynx
external elastic membrane	membrane composed of elastic fibers that separates the tunica media from the tunica externa; seen in larger arteries
external iliac artery	branch of the common iliac artery that leaves the body cavity and becomes a femoral artery; supplies blood to the lower limbs
external iliac vein	formed when the femoral vein passes into the body cavity; drains the legs and leads to the common iliac vein
external jugular vein	one of a pair of major veins located in the superficial neck region that drains blood from the more superficial portions of the head, scalp, and cranial regions, and leads to the subclavian vein
femoral artery	continuation of the external iliac artery after it passes through the body cavity; divides into several smaller branches, the lateral deep femoral artery, and the genicular artery; becomes the popliteal artery as it passes posterior to the knee
femoral circumflex vein	forms a loop around the femur just inferior to the trochanters; drains blood from the areas around the head and neck of the femur; leads to the femoral vein
femoral vein	drains the upper leg; receives blood from the great saphenous vein, the deep femoral vein, and the femoral circumflex vein; becomes the external iliac vein when it crosses the body wall
fenestrated capillary	type of capillary with pores or fenestrations in the endothelium that allow for rapid passage of certain small materials
fibular vein	drains the muscles and integument near the fibula and leads to the popliteal vein
filtration	in the cardiovascular system, the movement of material from a capillary into the interstitial fluid, moving from an area of higher pressure to lower pressure
foramen ovale	shunt that directly connects the right and left atria and helps to divert oxygenated blood from the fetal pulmonary circuit
genicular artery	branch of the femoral artery; supplies blood to the region of the knee
gonadal artery	branch of the abdominal aorta; supplies blood to the gonads or reproductive organs; also described as ovarian arteries or testicular arteries, depending upon the sex of the individual
gonadal vein	generic term for a vein draining a reproductive organ; may be either an ovarian vein or a testicular vein, depending on the sex of the individual
great cerebral vein	receives most of the smaller vessels from the inferior cerebral veins and leads to the straight sinus
great saphenous vein	prominent surface vessel located on the medial surface of the leg and thigh; drains the superficial portions of these areas and leads to the femoral vein
hemangioblasts	embryonic stem cells that appear in the mesoderm and give rise to both angioblasts and pluripotent stem cells
hemiazygos vein	smaller vein complementary to the azygos vein; drains the esophageal veins from the esophagus and the left intercostal veins, and leads to the brachiocephalic vein via the superior intercostal vein
hepatic artery proper	branch of the common hepatic artery; supplies systemic blood to the liver
hepatic portal system	specialized circulatory pathway that carries blood from digestive organs to the liver for processing before being sent to the systemic circulation
hepatic vein	drains systemic blood from the liver and flows into the inferior vena cava
hypertension	chronic and persistent blood pressure measurements of 140/90 mm Hg or above
hypervolemia	abnormally high levels of fluid and blood within the body
hypovolemia	abnormally low levels of fluid and blood within the body
hypovolemic shock	type of circulatory shock caused by excessive loss of blood volume due to hemorrhage or possibly dehydration
hypoxia	lack of oxygen supply to the tissues
inferior mesenteric artery	branch of the abdominal aorta; supplies blood to the distal segment of the large intestine and rectum
inferior phrenic artery	branch of the abdominal aorta; supplies blood to the inferior surface of the diaphragm
inferior vena cava	large systemic vein that drains blood from areas largely inferior to the diaphragm; empties into the right atrium
intercostal artery	branch of the thoracic aorta; supplies blood to the muscles of the thoracic cavity and vertebral column
intercostal vein	drains the muscles of the thoracic wall and leads to the azygos vein
internal carotid artery	arises from the common carotid artery and begins with the carotid sinus; goes through the carotid canal of the temporal bone to the base of the brain; combines with branches of the vertebral artery forming the arterial circle; supplies blood to the brain
internal elastic membrane	membrane composed of elastic fibers that separates the tunica intima from the tunica media; seen in larger arteries
internal iliac artery	branch from the common iliac arteries; supplies blood to the urinary bladder, walls of the pelvis, external genitalia, and the medial portion of the femoral region; in females, also provide blood to the uterus and vagina
internal iliac vein	drains the pelvic organs and integument; formed from several smaller veins in the region; leads to the common iliac vein
internal jugular vein	one of a pair of major veins located in the neck region that passes through the jugular foramen and canal, flows parallel to the common carotid artery that is more or less its counterpart; primarily drains blood from the brain, receives the superficial facial vein, and empties into the subclavian vein
internal thoracic artery	(also, mammary artery) arises from the subclavian artery; supplies blood to the thymus, pericardium of the heart, and the anterior chest wall
internal thoracic vein	(also, internal mammary vein) drains the anterior surface of the chest wall and leads to the brachiocephalic vein
interstitial fluid colloidal osmotic pressure (IFCOP)	pressure exerted by the colloids within the interstitial fluid
interstitial fluid hydrostatic pressure (IFHP)	force exerted by the fluid in the tissue spaces
ischemia	insufficient blood flow to the tissues
Korotkoff sounds	noises created by turbulent blood flow through the vessels
lateral circumflex artery	branch of the deep femoral artery; supplies blood to the deep muscles of the thigh and the ventral and lateral regions of the integument
lateral plantar artery	arises from the bifurcation of the posterior tibial arteries; supplies blood to the lateral plantar surfaces of the foot
left gastric artery	branch of the celiac trunk; supplies blood to the stomach
lumbar arteries	branches of the abdominal aorta; supply blood to the lumbar region, the abdominal wall, and spinal cord
lumbar veins	drain the lumbar portion of the abdominal wall and spinal cord; the superior lumbar veins drain into the azygos vein on the right or the hemiazygos vein on the left; blood from these vessels is returned to the superior vena cava rather than the inferior vena cava
lumen	interior of a tubular structure such as a blood vessel or a portion of the alimentary canal through which blood, chyme, or other substances travel
maxillary vein	drains blood from the maxillary region and leads to the external jugular vein
mean arterial pressure (MAP)	average driving force of blood to the tissues; approximated by taking diastolic pressure and adding 1/3 of pulse pressure
medial plantar artery	arises from the bifurcation of the posterior tibial arteries; supplies blood to the medial plantar surfaces of the foot
median antebrachial vein	vein that parallels the ulnar vein but is more medial in location; intertwines with the palmar venous arches
median cubital vein	superficial vessel located in the antecubital region that links the cephalic vein to the basilic vein in the form of a v; a frequent site for a blood draw
median sacral artery	continuation of the aorta into the sacrum
mediastinal artery	branch of the thoracic aorta; supplies blood to the mediastinum
metarteriole	short vessel arising from a terminal arteriole that branches to supply a capillary bed
microcirculation	blood flow through the capillaries
middle cerebral artery	another branch of the internal carotid artery; supplies blood to the temporal and parietal lobes of the cerebrum
middle sacral vein	drains the sacral region and leads to the left common iliac vein
muscular artery	(also, distributing artery) artery with abundant smooth muscle in the tunica media that branches to distribute blood to the arteriole network
myogenic response	constriction or dilation in the walls of arterioles in response to pressures related to blood flow; reduces high blood flow or increases low blood flow to help maintain consistent flow to the capillary network
nervi vasorum	small nerve fibers found in arteries and veins that trigger contraction of the smooth muscle in their walls
net filtration pressure (NFP)	force driving fluid out of the capillary and into the tissue spaces; equal to the difference of the capillary hydrostatic pressure and the blood colloidal osmotic pressure
neurogenic shock	type of shock that occurs with cranial or high spinal injuries that damage the cardiovascular centers in the medulla oblongata or the nervous fibers originating from this region
obstructive shock	type of shock that occurs when a significant portion of the vascular system is blocked
occipital sinus	enlarged vein that drains the occipital region near the falx cerebelli and flows into the left and right transverse sinuses, and also into the vertebral veins
ophthalmic artery	branch of the internal carotid artery; supplies blood to the eyes
ovarian artery	branch of the abdominal aorta; supplies blood to the ovary, uterine (Fallopian) tube, and uterus
ovarian vein	drains the ovary; the right ovarian vein leads to the inferior vena cava and the left ovarian vein leads to the left renal vein
palmar arches	superficial and deep arches formed from anastomoses of the radial and ulnar arteries; supply blood to the hand and digital arteries
palmar venous arches	drain the hand and digits, and feed into the radial and ulnar veins
parietal branches	(also, somatic branches) group of arterial branches of the thoracic aorta; includes those that supply blood to the thoracic cavity, vertebral column, and the superior surface of the diaphragm
perfusion	distribution of blood into the capillaries so the tissues can be supplied
pericardial artery	branch of the thoracic aorta; supplies blood to the pericardium
petrosal sinus	enlarged vein that receives blood from the cavernous sinus and flows into the internal jugular vein
phrenic vein	drains the diaphragm; the right phrenic vein flows into the inferior vena cava and the left phrenic vein leads to the left renal vein
plantar arch	formed from the anastomosis of the dorsalis pedis artery and medial and plantar arteries; branches supply the distal portions of the foot and digits
plantar veins	drain the foot and lead to the plantar venous arch
plantar venous arch	formed from the plantar veins; leads to the anterior and posterior tibial veins through anastomoses
popliteal artery	continuation of the femoral artery posterior to the knee; branches into the anterior and posterior tibial arteries
popliteal vein	continuation of the femoral vein behind the knee; drains the region behind the knee and forms from the fusion of the fibular and anterior and posterior tibial veins
posterior cerebral artery	branch of the basilar artery that forms a portion of the posterior segment of the arterial circle; supplies blood to the posterior portion of the cerebrum and brain stem
posterior communicating artery	branch of the posterior cerebral artery that forms part of the posterior portion of the arterial circle; supplies blood to the brain
posterior tibial artery	branch from the popliteal artery that gives rise to the fibular or peroneal artery; supplies blood to the posterior tibial region
posterior tibial vein	forms from the dorsal venous arch; drains the area near the posterior surface of the tibia and leads to the popliteal vein
precapillary sphincters	circular rings of smooth muscle that surround the entrance to a capillary and regulate blood flow into that capillary
pulmonary artery	one of two branches, left and right, that divides off from the pulmonary trunk and leads to smaller arterioles and eventually to the pulmonary capillaries
pulmonary circuit	system of blood vessels that provide gas exchange via a network of arteries, veins, and capillaries that run from the heart, through the body, and back to the lungs
pulmonary trunk	single large vessel exiting the right ventricle that divides to form the right and left pulmonary arteries
pulmonary veins	two sets of paired vessels, one pair on each side, that are formed from the small venules leading away from the pulmonary capillaries that flow into the left atrium
pulse	alternating expansion and recoil of an artery as blood moves through the vessel; an indicator of heart rate
pulse pressure	difference between the systolic and diastolic pressures
radial artery	formed at the bifurcation of the brachial artery; parallels the radius; gives off smaller branches until it reaches the carpal region where it fuses with the ulnar artery to form the superficial and deep palmar arches; supplies blood to the lower arm and carpal region
radial vein	parallels the radius and radial artery; arises from the palmar venous arches and leads to the brachial vein
reabsorption	in the cardiovascular system, the movement of material from the interstitial fluid into the capillaries
renal artery	branch of the abdominal aorta; supplies each kidney
renal vein	largest vein entering the inferior vena cava; drains the kidneys and leads to the inferior vena cava
resistance	any condition or parameter that slows or counteracts the flow of blood
respiratory pump	increase in the volume of the thorax during inhalation that decreases air pressure, enabling venous blood to flow into the thoracic region, then exhalation increases pressure, moving blood into the atria
right gastric artery	branch of the common hepatic artery; supplies blood to the stomach
sepsis	(also, septicemia) organismal-level inflammatory response to a massive infection
septic shock	(also, blood poisoning) type of shock that follows a massive infection resulting in organism-wide inflammation
sigmoid sinuses	enlarged veins that receive blood from the transverse sinuses; flow through the jugular foramen and into the internal jugular vein
sinusoid capillary	rarest type of capillary, which has extremely large intercellular gaps in the basement membrane in addition to clefts and fenestrations; found in areas such as the bone marrow and liver where passage of large molecules occurs
skeletal muscle pump	effect on increasing blood pressure within veins by compression of the vessel caused by the contraction of nearby skeletal muscle
small saphenous vein	located on the lateral surface of the leg; drains blood from the superficial regions of the lower leg and foot, and leads to the popliteal vein
sphygmomanometer	blood pressure cuff attached to a device that measures blood pressure
splenic artery	branch of the celiac trunk; supplies blood to the spleen
straight sinus	enlarged vein that drains blood from the brain; receives most of the blood from the great cerebral vein and flows into the left or right transverse sinus
subclavian artery	right subclavian arises from the brachiocephalic artery, whereas the left subclavian artery arises from the aortic arch; gives rise to the internal thoracic, vertebral, and thyrocervical arteries; supplies blood to the arms, chest, shoulders, back, and central nervous system
subclavian vein	located deep in the thoracic cavity; becomes the axillary vein as it enters the axillary region; drains the axillary and smaller local veins near the scapular region; leads to the brachiocephalic vein
subscapular vein	drains blood from the subscapular region and leads to the axillary vein
superior mesenteric artery	branch of the abdominal aorta; supplies blood to the small intestine (duodenum, jejunum, and ileum), the pancreas, and a majority of the large intestine
superior phrenic artery	branch of the thoracic aorta; supplies blood to the superior surface of the diaphragm
superior sagittal sinus	enlarged vein located midsagittally between the meningeal and periosteal layers of the dura mater within the falx cerebri; receives most of the blood drained from the superior surface of the cerebrum and leads to the inferior jugular vein and the vertebral vein
superior vena cava	large systemic vein; drains blood from most areas superior to the diaphragm; empties into the right atrium
systolic pressure	larger number recorded when measuring arterial blood pressure; represents the maximum value following ventricular contraction
temporal vein	drains blood from the temporal region and leads to the external jugular vein
testicular artery	branch of the abdominal aorta; will ultimately travel outside the body cavity to the testes and form one component of the spermatic cord
testicular vein	drains the testes and forms part of the spermatic cord; the right testicular vein empties directly into the inferior vena cava and the left testicular vein empties into the left renal vein
thoracic aorta	portion of the descending aorta superior to the aortic hiatus
thoroughfare channel	continuation of the metarteriole that enables blood to bypass a capillary bed and flow directly into a venule, creating a vascular shunt
thyrocervical artery	arises from the subclavian artery; supplies blood to the thyroid, the cervical region, the upper back, and shoulder
transient ischemic attack (TIA)	temporary loss of neurological function caused by a brief interruption in blood flow; also known as a mini-stroke
transverse sinuses	pair of enlarged veins near the lambdoid suture that drain the occipital, sagittal, and straight sinuses, and leads to the sigmoid sinuses
trunk	large vessel that gives rise to smaller vessels
tunica externa	(also, tunica adventitia) outermost layer or tunic of a vessel (except capillaries)
tunica intima	(also, tunica interna) innermost lining or tunic of a vessel
tunica media	middle layer or tunic of a vessel (except capillaries)
ulnar artery	formed at the bifurcation of the brachial artery; parallels the ulna; gives off smaller branches until it reaches the carpal region where it fuses with the radial artery to form the superficial and deep palmar arches; supplies blood to the lower arm and carpal region
ulnar vein	parallels the ulna and ulnar artery; arises from the palmar venous arches and leads to the brachial vein
umbilical arteries	pair of vessels that runs within the umbilical cord and carries fetal blood low in oxygen and high in waste to the placenta for exchange with maternal blood
umbilical vein	single vessel that originates in the placenta and runs within the umbilical cord, carrying oxygen- and nutrient-rich blood to the fetal heart
vasa vasorum	small blood vessels located within the walls or tunics of larger vessels that supply nourishment to and remove wastes from the cells of the vessels
vascular shock	type of shock that occurs when arterioles lose their normal muscular tone and dilate dramatically
vascular shunt	continuation of the metarteriole and thoroughfare channel that allows blood to bypass the capillary beds to flow directly from the arterial to the venous circulation
vascular tone	contractile state of smooth muscle in a blood vessel
vascular tubes	rudimentary blood vessels in a developing fetus
vasoconstriction	constriction of the smooth muscle of a blood vessel, resulting in a decreased vascular diameter
vasodilation	relaxation of the smooth muscle in the wall of a blood vessel, resulting in an increased vascular diameter
vasomotion	irregular, pulsating flow of blood through capillaries and related structures
vein	blood vessel that conducts blood toward the heart
venous reserve	volume of blood contained within systemic veins in the integument, bone marrow, and liver that can be returned to the heart for circulation, if needed
venule	small vessel leading from the capillaries to veins
vertebral artery	arises from the subclavian artery and passes through the vertebral foramen through the foramen magnum to the brain; joins with the internal carotid artery to form the arterial circle; supplies blood to the brain and spinal cord
vertebral vein	arises from the base of the brain and the cervical region of the spinal cord; passes through the intervertebral foramina in the cervical vertebrae; drains smaller veins from the cranium, spinal cord, and vertebrae, and leads to the brachiocephalic vein; counterpart of the vertebral artery
visceral branches	branches of the descending aorta that supply blood to the viscera