Flashcards in Blood Vessels Deck (124):
What are the 3 types of blood vessels? Direction of fluid?
Arteries: away from the heart
Capillaries: sites of exchange
Veins: Toward the hear
State if the blood is oxygenated or deoxygenated in veins and arteries?
What is the pathway of the vessels beginning from the heart?
elastic arteries -> muscular arteries -> arterioles -> capillaries -> venules -> veins
What type of blood do the veins and arteries carry in the systemic circulation?
arteries carry oxygenated blood and the veins carry deoxygenated blood
What type of blood do the veins and arteries carry in the pulmonary circulation?
arteries carry deoxygenated blood to the lungs and the veins carry oxygenated blood from the lungs to the heart
What are the 3 layers in blood vessels from deep to superficial?
tunica intima, tunica media, and tunica externa
What is the space containing blood in the blood vessels?
Which layer of the blood vessel consist of smooth muscle and elastin, and muscle activity regulated by the vasomotor nerve fibers?
Which layer in the blood vessel walls are connective tissue (collagen), reinforces vessels, and anchors it to nearby organs?
Which layer in the blood contains blood in lumen, endothelium?
What is the purpose of the endothelium in the blood vessel walls?
Which layer in the blood vessels wall is responsible for vasodilation and vasoconstriction?
Which vessel consist of only the tunica intima?
Which vessel consist of a thin tunica media and thick tunica externa?
Which vessel consist of a thick tunica media and thin tunica externa?
What are the three types of arteries?
elastic, muscular, and arterioles
Also known as conducting arteries, these have a large, thick walls, arteries near the heart, tunica media with elastic tissue
Also known as the distributing arteries, these arteries distribute blood to specific organs.
Leads into capillary beds, control minute by minute blood flow by vasoconstriction or vasodilation and important in BP regulation
How do the elastic arteries act as pressure reservoirs?
expand during systole t receive blood and recoiling during diastole to push blood forward
What is the function of the capillaries?
exchange of materials between blood and interstitial fluid
What are the three structural types capillaries?
continuous, fenestrated, and sinusoid
Which type of capillary is the most common, primarily in the skin and muscles, and has intercellular clefts?
What is the function of intercellular clefts?
allow passage of fluids and small solutes
Which type of capillary is have endothelial cells that increase permeability, and found where absorption or filtrate formation occurs?
What is the location where absorption or filtrate occur in capillaries?
small intestine and kidneys
Which type of capillary has fenestrations, large intercellular clefts, and incomplete basement membrane, allows large molecules and blood cells t pass between blood and surrounding tissues?
What is the location that allows large molecules to pass between blood and surrounding tissues?
liver, bone marrow, and spleen
Which disorder has thicker and stiffer artery walls?
Which disorder has lipid plaques form and protrude into vessel lumen?
What id a network of capillaries called?
flow of blood from arteriole to venule
What directly connects arterioles and venule at opposite ends of bed?
What are true capillaries?
actual exchange vessels
What is the function of the precapillary sphincter?
acts as a valve to regulate blood flow into the capillaries
What occurs when the precapillary sphincter closes?
blood flows through metarteriole thoroughfare channel and bypasses true capillaries
What do capillaries unite to form?
What do venules join to form?
What do veins have that arteries DO NOT?
larger lumens and thinner walls, and valves
What's another name from veins?
Why do veins have such thin walls?
BP is relatively low and F is steady rather than pulsatile
What are varicose veins?
veins that are tortuous and dilated due to competent (leaky) valves. Promoted by conditions that impede venous return
What are interconnections between blood vessels?
Define Blood Flow (F).
volume of blood flowing through a vessel, organ, or entire circulation in a give time
What is a force that blood exerts against a vessel wall?
True or False. The greater the difference in blood pressure, between 2 ends of a vessel, the greater the F through that vessel.
What is the opposition to flow that results from friction of blood against vessel walls?
What are the three sources of resistance?
blood viscosity, total blood vessel length, and blood vessel diameter
For each source of resistance, state whether is increases or decreases resistance?
Viscosity: increases resistance
Blood vessel length: increases resistance
Blood vessel diameter: decreases resistance
What is systemic BP?
pumping action of heart generating F. Pressure results when flow is opposed by resistance
Where is Systemic BP highest and steepest?
highest in aorta and steepest in arterioles
What is the highest arterial BP of a cardiac cycle? Give name and number in mmHg
Systolic pressure. 120mmHg
What is the lowest arterial BP of a cardiac cycle? Give name and number in mmHg
Diastolic pressure. 70-80 mmHg
What is the pressure wave caused by alternating expansion and recoil of arteries during each cardiac cycle?
What is the difference between systolic and diastolic pressures?
What is the average arterial pressure during a single cardiac cycle?
Mean arterial pressure (MAP)
As the distance increases from the heart, MAP and Pulse pressure due to what?
friction between blood and vessel walls and loss of elastic recoil
What range of numbers does BP decline in capillary BP?
What range of numbers does BP decline in venous BP?
Which 2 functional adaptations are important to venous return?
Muscular and respiratory pumps
How does the muscular pump functions?
skeletal muscle activity "milks" blood toward the heart
How does the respiratory pump functions?
pressure changes in ventral body cavity during breathing move blood toward heart
What are the 2 ways BP is controlled?
short term and long term regulation
Describe short-term regulation
alters BP by changing peripheral resistance and resistance. Neural and hormonal
Describe long-term regulation
alters BP by adjusting blood volume (kidneys)
Where are the cardio centers located and their function?
in the medulla oblongata and the function is to regulate heart rate and force of contraction
What are the 2 cardiac centers?
cardioacceleratory and cardioinhibitory
What is the function of he vasomotor center?
regulates blood vessel diameter
The role of the vasomotor center involved vasomotor fibers and tone, describe both.
Vasomotor fibers: transmits impulses at steady rate
Vasomotor tone: keep arterioles in state of moderate constriction
Which receptors respond to changes in arterial pressure and stretch?
Where are baroreceptors located?
carotid sinuses and aortic arch
When stretched where do baroreceptors send impulses?
How do baroreceptors respond when BP rises?
cardioinhibitory center is stimulated, cardioacceleratory center and vasomotor are inhibited. Parasympathetic
When BP rises in baroreceptors how do the blood vessels respond?
How do baroreceptors respond when BP drops?
cardioinhibitory center is inhibited, cardioacceleratory center and vasomotor center are stimulated
When BP rises in baroreceptors how do the blood vessels respond?
Which hormones are involved in short-term hormonal controls?
ADH, ANP, adrenal medulla hormones, and angiotensin II
What are the effects of NE and EP in short-term regulation?
increase BP, CO, & R
What are the effects of Angiotensin II in short-term regulation?
increases R, BP, and promotes vasoconstriction
What are the effects of ADH in short-term regulation?
increases R & BP, vasoconstriction
What are the effects of ANP in short-term regulation?
lowers BP, inhibits NA+ reabsorption, promotes vasodilation. Usually occurs after consuming NaCl
What is another name for long-term regulation?
What is the function of the long-term regulation?
kidneys restore and maintain BP homeostasis by regulating blood volume
What does the Renin-Angiotensin-Aldosterone Mechanism affect?
desire to drink and urine production
What is the sequence of Renin-Angiotensin-Aldosterone Mechanism ?
When BP or blood volume drops, kidneys releases renin, which act as an enzyme acting on angiotensinogen converting it to angiotensis I circulating in the plasma -> angiotensin converting enzyme (ACE) converts Angiotensin I to Angiotensin II
What are the results of Angiotensin II in long-term regulation?
vasoconstriction, increase R, activated thirsts center (in hypothalamus), stimulates release of ADH and aldosterone
What is hypertension?
sustained increased in either systolic or diastolic BP
Which type of hypertension has no underlying identifiable cause?
Which type of hypertension is due to indentifiable disorders?
What is the BP of someone who has hypotension?
If Jack's BP suddenly rises from suddenly rising from reclining or sitting, what does he suffer from?
What is tissue perfusion?
F through body tissues
True or false. Velocity of F is directly related to total cross-sectional area of vascular bed
False. Velocity of F is inversely related...
What is the term defined as the ability of a tissue to automatically adjust its F to match its metabolic demands?
How is autoregulation controlled?
by modifying diameter of arterioles
Why does vasodilation of arterioles and relaxation of precapillary sphincters occur?
decrease in O2 levels, accumulation of ions, and inflammatory chemicals
How does capillary exchanges occur?
movement of substances between blood plasma and interstitial fluid
Which mechanisms does capillary exchange use?
diffusion and bulk flow
How do liquid solubles move in capillary exchange?
How do molecules that are not liquid soluble move in capillary exchange?
through fenestrations or intercellular clefts
How do large substances move in capillary exchange?
Define bulk flow.
movement of water and small solutes across capillary walls between blood and interstitial fluid
Filtration is movement inside or outside the capillaries?
Reabsorption is movement inside or outside capillaries?
Which type of pressure pushes water out by exerting force by pressing fluid against a wall?
Which type of pressure pulls water in by large indiffusible molecules that are unable to cross capillary walls?
colloid osmotic pressure
Capillary hydrostatic pressure. pushes fluid out of capillary into interstitial fluid
interstitial fluid hydrostatic pressure. tends to push fluid into capillary. Usually assumed to be 0
capillary colloid osmotic pressure. tends to pull fluid into capillary. Mainly albumin
Interstitial fluid osmotic pressure. tends to pull fluid out of capillary
What are the outward pressures?
HPc and OPif
What are the inward pressures?
HPif and OPc
What is the equation for NFP?
If NFP is positive what does this indicate?
If NFP is negative what does this indicate?
True or false. Slightly more fluid is filtered out than is reabsorbed.
What collects the excess fluid returning it to blood?
What is any condition in which blood vessels are inadequately filled and blood cannot circulate normally?
Large-scale loss of blood or body fluids
Inefficient heart cannot sustain adequate circulation
Extreme vasodilation and decreased peripheral resistance
This type of shock is due to anaphalaxis
This type of shock is due to dehydration ad excessive sweating?