The adjustment of blood flow to each
tissue in proportion to its requirements at any point in time is termed autoregulation
Arterial pressure in the pulmonary circulation is much higher than in the systemic circulation because of its proximity to the heart
False - It's higher in the systemic
Osmotic pressure is created by the presence in a fluid of small diffusible molecules that easily move through the capillary membrane
False - Large, non-diffusible
The thick-walled arteries close to the heart are called muscular arteries
False - They are called Elastic Arteries (conducting vessels)
A precapillary sphincter is a cuff of smooth muscle that regulates the flow of blood into the capillaries.
The carotid sinus reflex protects the blood supply to the brain, whereas the aortic reflex is more concerned with maintaining adequate blood pressure in the systemic circuit as a whole
Vasodilation is a widening of the lumen due to smooth muscle contraction
False - Due to smooth muscle relaxation - and the lumen constricts during contraction.
An obstruction in the superior vena cava would decrease the flow of blood from the head and neck to the heart
Arteries supplying the same territory are often merged with one another, forming arterial anastomoses
Whereas diffusion is more important for solute exchange between plasma and interstitial fluid, bulk flow is more important for regulation of the relative volumes of blood and interstitial fluid
Which of the following is not one of the three main factors influencing blood pressure?
Permitting the exchange of nutrients and gases between the blood and tissue cells is the primary function of ________.
The circulatory route that runs from the digestive tract to the liver is called ________.
hepatic portal circulation
Which of the following signs of hypovolemic shock is a relatively late sign?
rapidly falling blood pressure
Which of the following is likely during vigorous exercise?
Capillaries of the active muscles will be engorged with blood.
Which of the choices below explains why the arterioles are known as resistance vessels?
The contraction and relaxation of the smooth muscle in their walls can change their diameter.
Which of the following is true about veins?
Veins are called capacitance vessels or blood reservoirs
Which of the following processes provides a long-term response to changes in blood pressure?
Which of the choices below reflects the balance (or imbalance) between the direction and amount of fluid that flows across the capillary walls?
hydrostatic and osmotic pressure
Which of the following is a type of circulatory shock?
vascular, due to extreme vasodilation as a result of loss of vasomotor tone
Which tunic of an artery is most responsible for maintaining blood pressure and continuous blood circulation?
The influence of blood vessel diameter on peripheral resistance is ________.
significant because resistance is inversely proportional to the fourth power of the vessel radius
The form of circulatory shock known as hypovolemic shock is ________.
shock that results from large-scale loss of blood volume, or after severe vomiting or diarrhea
In the dynamics of blood flow through capillaries, hydrostatic pressure ________.
is the same as capillary blood pressure
The term ductus venosus refers to ________.
a special fetal vessel that allows umbilical blood to bypass the liver
Which of the choices below does not explain why low capillary pressures are desirable?
Low blood pressure is more desirable than high blood pressure
Which of the following are involved directly in pulmonary circulation?
right ventricle, pulmonary artery, and left atrium
Histologically, the ________ is squamous epithelium supported by a sparse connective tissue layer.
Which of the following blood pressure readings would be indicative of hypertension?
170/96 in a 50-year-old man
Select the correct statement about factors that influence blood pressure.
Excess red cell production would cause a blood pressure increase
The velocity of blood flow is ________.
slowest in the capillaries because the total cross-sectional area is the greatest
Select the correct statement about blood flow.
Blood flow through the entire vascular system is equivalent to cardiac output
A thrombus (blood clot) in the first branch of the arch of the aorta would affect the flow of blood to the ________.
right side of the head and neck and right upper arm
A patient with essential hypertension might have pressures of 200/120 mm Hg. This hypertensive state could result in all of the following changes except ________.
increased size of the heart muscle
The short-term controls of blood pressure, mediated by the nervous system and bloodborne chemicals, primarily operate via all but which of the following?
altering blood volume
Where in the body would you find low oxygen levels causing vasoconstriction and high levels causing vasodilation?
If blood pressure is almost normal in a person who has lost blood, does that mean the tissues are receiving adequate blood flow?
What do the ductus arteriosus and the foramen ovale become at birth?
ligamentum arteriosum; fossa ovalis
Which of the following would not result in the dilation of the feeder arterioles and opening of the precapillary sphincters in systemic capillary beds?
a local increase in histamine
Arteriole blood pressure increases in response to all but which of the following?
falling blood volume
The embryonic mesodermal cells that will eventually form the endothelial lining of blood vessels are called ________.
A family of peptides called ________ are released by the endothelium and are among the most potent vasoconstrictors known.
The ________ in the carotid sinuses and aortic arch detect increases in blood pressure.
________ shock is due to abnormal expansion of blood vessels and a rapid drop in blood pressure.
Capillary found where active capillary absorption or filtrate formation occurs
Capillary found in endocrine organs that allows hormones to gain rapid entry into the blood
Large unpaired branch of the abdominal aorta that supplies the liver, stomach, and spleen
Runs through the armpit area, giving off branches to the axillae, chest wall, and shoulder girdle