Blood Vessels & Circulation
Where are fenestrated capillaries located in the body?
capillaries of the hypothalamus, pituitary, pineal, and thyroid gland
Where are chemoreceptors located?
carotid and aortic bodies and ventrolateral surface of medulla oblongata
Identify the hormones responsible for short-term regulation of decreasing blood pressure and blood volume
epinephrine and norepinephrine
Capillaries with a perforated lining are called......
fenestrated capillaries
Angiogenesis refers to ......
growth of new blood vessels from preexisting blood vessels
Explain the equation R α 1/r4.
vessel diameter - change in radius (r) affects resistance (R) to the 4th power
What factors are involved in the formation of varicose veins?
when blood backs up through the valves and pools in the veins and distends
Under what general conditions would fluid move into a capillary?
when blood colloid osmotic pressure is greater than capillary hydrostatic pressure
Review all the fetal arteries and vein and their function.
--Umbilical arteries: Pair of arteries that carry blood from the fetus to the placenta --Umbilical vein: Carries blood from the placenta --Ductus venosus: •Vascular connection to veins within the liver •Collects blood from liver and from umbilical vein •Empties into inferior vena cava Foramen ovale, or interatrial opening: •Allows blood to pass from right atrium to left atrium -Bypasses pulmonary circuit •Has one-way valve to prevent backflow Ductus arteriosus: •Bypass between pulmonary trunk and aorta •Sends blood from right ventricle to systemic circuit -Foramen ovale: right atrium to left atrium -Ductus arteriosus: from right ventricle straight to aorta to circulate throughout body
If a person has a blood pressure of 120/90, his mean arterial pressure would be ________ mm Hg.
100 90+ ((first # - second #)/3 )= 90+ ((120-90)/3) 90+ 30/3 90+ 10 100
Describe the distribution of total blood volume in the body. Percentage
64%- systemic venous system 9%- pulmonary circuit 7%- heart 13%- systemic arterial system 7%- systemic capillaries
Calculate the mean arterial pressure for a person whose blood pressure is 125/70
88.3
Describe a capillary.
A capillary is a small blood vessel whose thin wall permits exchange between blood and interstitial fluid by diffusion.
Define edema
Abnormal accumulation of fluid in interstitial spaces of tissues.
How does body defend blood volume against dehydration?
Accelerates reabsorption of water at the kidneys, Experiences a recall of interstitial fluids, Experiences an increase in the blood colloidal osmotic pressure, and Increases water intake.
________ is the regulation of blood flow by local mechanisms within a capillary bed.
autoregulation
Name the location where metabolites exchange by diffusion with the tissues and the cells.
Capillaries
The vascular pressure that declines from roughly 35 mm Hg to about 18 mm Hg is the .........
Capillary hydrostatic pressure
________ are multiple arteries that fuse in order to serve a single capillary network
Collaterals
________ are the only blood vessels whose walls are thin enough to permit blood-tissue exchange
capillaries
The superior vena cava collect blood from the......
Head, chest, and upper limbs.
Names of fetal blood vessels post child birth.
Patent ductus arteriosus& Patent foramen ovale
Name the immediate and long-term problems related to hemorrhage.
The immediate problem related to hemorrhage is maintaining adequate blood pressure and peripheral blood flow. The long-term problems related to hemorrhage is to restore normal blood volume.
Describe the respiratory pump
The negative pressure created in the thoracic cavity aids venous return to the heart; drawing blood back
________ refers to all the factors that resist blood flow in the entire circulatory system.
Total peripheral resistance
How does the kidney respond to vasoconstriction of the renal artery?
Vasoconstriction of the renal artery would decrease both blood flow and blood pressure at the kidney. In response, the kidney would increase the amount of renin it releases, which in turn would increase the level of angiotensin II. The angiotensin II would bring about increased blood pressure and increased blood volume
Where is blood pressure highest? Hint: Blood vessels
aorta (arteries)
Which is greater: arterial pressure or venous pressure?
arterial pressure
List the five general classes of blood vessels.
arteries, arterioles, capillaries, venules, veins
The main control of peripheral resistance by the vasomotor centers occurs in the
arteriole; or medulla oblongata
Define tissue perfusion.
blood flow to tissues sufficient to deliver adequate oxygen and nutrients.
Describe the pulmonary circuit
blood to and from gas exchange surfaces in the lungs
The systemic circuit delivers oxygenated blood to ________ and returns blood to the ________.
body organs; right atrium
The blood colloid osmotic pressure mostly depends on the
concentration of plasma proteins
Capillaries that have a complete lining are called ......
continuous capillaries
Identify the two types of capillaries with a complete endothelium.
continuous capillary and fenestrated capillary
What effect does an increase in the respiratory rate have on CO2 levels?
decrease CO2 levels
As blood travels from arteries to veins, blood pressure......
decreases
Materials can move across capillary walls by .............(process)
diffusion, filtration, reabsorption (osmosis)
The hormone that produces cardiovascular effects similar to activation of the sympathetic nervous system is ...
epinephrine
Which would reduce peripheral resistance: an increase in vessel length or an increase in vessel diameter?
increase in vessel diameter
What will happen to pH due to decrease in blood CO2 levels in blood?
increase pH
Describe autoregulation as it relates to cardiovascular function
involves local factors changing the pattern of blood flow within capillary beds in response to chemical changes in interstitial fluids
Sinusoids can be found in the ......
liver!!! bone marrow, spleen
The difference between the systolic and diastolic pressures is called the ________ pressure.
pulse
Where does blood enter while returning from the systemic circuit?
right atrium
Which chamber of the heart receives blood from the systemic circuit?
right atrium
Why is it beneficial for capillary pressure to be very low?
to allow time for diffusion between the blood and surrounding interstitial fluid
Describe the systemic circuit.
transports blood to and from the rest of the body
Describe the roles of the natriuretic peptides.
trigger responses whose combined effects are to decrease blood volume and decrease blood pressure which decrease stress on heart walls
Which of the following is the innermost layer of a blood vessel?
tunica intima
The layer of the arteriole wall that can contains smooth muscle and can produce vasoconstriction is the ...
tunica media
The muscular layer of a blood vessel is the
tunica media
Which layer of a blood vessel contains concentric sheets of smooth muscle tissue?
tunica media
Explain the correct order of blood flow in the heart.
unoxygenated blood enters the RIGHT ATRIUM -> thru tricuspid valve to RIGHT VENTRICLE -> pulmonary artery -> lungs -> now oxygenated blood flows thru pulmonary veins to LEFT ATRIUM -> mitral valve to LEFT VENTRICLE -> blood through aortic valve to aorta to rest of body
The process of decrease in any vessel diameter that occurs due to smooth muscle contraction is called ...
vasconstriction
List the factors that contribute to total peripheral resistance.
vascular resistance, vessel length, vessel diameter, blood viscosity, and turbulence.
The large vessels that return blood to the heart are called
veins
Why are valves located in veins but not in arteries?
veins are more distensible/expandable then arteries and act as blood reservoirs to accommodate large volumes of blood
What part of brain contains sensory neurons that are part of chemoreceptor reflexes?
ventrolateral surface of the medulla oblongata
After blood leaves the capillaries, it enters the ......
venules
