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117 Cards in this Set
- Front
- Back
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What are the 5 classes of blood vessels? And what do they do?
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1. Arteries:carry blood away from heart
2. Arterioles:smallest branches of arteries 3. Capillaries: smallest blood vessels, location of exchange between blood and interstitial fluid 4. Venules: collect blood from capillaries Veins: return blood to heart |
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What are the largest blood vessels? And what do they do?
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Pulmonary trunk: carries blood from right ventricle to pulmonary circulation
Aorta: carries blood from left ventricle to systemic circulation |
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What are the smallest blood vessels?
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Capillaries
Have small diameter and thin walls Chemicals and gases diffuse across walls |
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Arteries and veins have 3 wall laters, what are they?
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tunica intima: inner layer
tunica media: middle layer tunica externa: outer layer |
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What are the differences between arteries and veins?
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They run side by side
Arteries have thicker walls and higher blood pressure Arteries have small, round lumen...Vein has a large, flat lumen Arteries more elastic Vein lining contracts, artery lining doesn't Veins have valves |
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What is vasoconstriction?
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The contraction of arterial smooth muscle by the ANS
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What is vasodilation?
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Relaxes smooth muscle
Enlarging the lumen |
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What do vasoconstriction and vasodilation affect?
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1. afterload on heart
2. peripheral blood pressure 3. capillary blood flow |
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How do arteries change from heart to capillaries?
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from elastic arteries, to muscular arteries, to arterioles
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What are elastic arteries?
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Also called conducting arteries
Large vessels Tunica media has many elastic fibers and few muscle cells Elasticity evens out pulse force |
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What are muscular arteries?
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Also called distribution arteries
medium-sized (most arteries) Tunica media has many muscle cells |
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What are arterioles?
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small
Have little or no tunica externa Have thin or incomplete tunica media |
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What is resistance? And what vessels do this?
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The force opposing blood flow
Arterioles do this |
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What is an aneurysm?
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A bulge in an arterial wall that is caused by weak spot in elastic fibers.
Pressure may rupture vessel |
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What are capillaries?
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Are smallest vessels with thin walls
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What is the function of capillaries?
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Location of all exchange functions of cardiovascular system
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What is the structure of a capillary?
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Endothelial tube, inside thin basal lamina
No tunica media No tunica externa Diameter is similar to red blood cell |
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What are the types of capillaries?
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Continuous capillaries
Fenestrated capillaries |
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What are continuous capillaries and where are they found?
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Have complete endothelial lining. Found in all tissues except epithelia and cartilage.
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What are the functions of continuous capillaries?
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Permit diffusion of:
water small solutes Lipid-soluble materials Block: blood cells plasma proteins |
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What are fenestrated capillaries? And where are they found?
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Have pores in endothelial lining
Found in: choroid plexus endocrine organs kidneys intestinal tract |
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What are the functions of fenestrated capillaries?
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Permit rapid exchange of water and larger solutes
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What is a Capillary Sphincter?
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Guards entrance to each capillary
Opens and closes, causing capillary blood to flow in pulses |
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What are the 3 categories of veins?
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1. Venules: very small veins
collect blood from capillaries 2. Medium-sized veins: thin tunica media 3. Large veins: have all 3 tunica layers |
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What are vein valves?
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Folds of tunica intima
Prevent blood from flowing backward |
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What percent blood volume does the heart, arteries, and capillaries make up?
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30-35%
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The venous system makes up what percent of blood?
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60-65%
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What is capacitance?
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The ability to stretch
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Which stretch more, veins or arteries?
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Veins
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How do veins respond to blood loss?
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Vasomotor centers stimulate sympathetic nerves...
-systemic veins constrict - veins in liver, skin and lungs redistribute venous reserve |
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What is the term for when systemic veins constrict?
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venoconstriction
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What is capillary blood flow?
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Equals cardiac output
Is determined by: pressure and resistance in the cardiovascular system |
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What is pressure?
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What the heart generates to overcome resistance
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What is the pressure gradient?
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the difference between pressure at the heart and pressure at peripheral capillary beds
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What are the different kinds of measuring pressures?
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Blood pressure (BP): arterial pressure
Capillary hydrostatic pressure (CHP): pressure within the capillary beds Venous pressure: pressure in the venous system |
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What is vascular resistance?
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Resistance of blood vessels due to friction between blood and vessel walls
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What is viscosity?
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Resistance caused by molecules and suspended materials in a liquid
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What is turbulance?
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Swirling action that disturbs smooth flow of liquid
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What are the different kinds of pressures in the systemic circuit?
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Systolic pressure, Diastolic pressure, Pulse pressure, Mean arterial pressure
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What is systolic pressure?
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peak arterial pressure during ventricular systole
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What is Diastolic pressure?
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minimum arterial pressure during diastole
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What is Pulse pressure?
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difference between systolic pressure and diastolic pressure
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What is Mean arterial pressure?
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MAP = diastolic pressure + 1/3 pulse pressure
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What is Hypertension?
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abnormally high blood pressure
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What is Hypotension?
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abnormally low blood pressure
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What happens to arterial walls during elastic rebound?
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stretch during systole
rebound during diastole keep blood moving during diastole |
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Blood pressure decreases with what?
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Friction
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Pulse pressure increases or decreases due to elastic rebound?
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decreases
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What is the venous return?
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Amount of blood arriving at right atrium each minute
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Compression of skeletal muscles....
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pushes blood toward heart
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What cavity is the Respiratory Pump in? What affect does inhaling and exhailing have?
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Thoracic cavity
Inhaling decreases thoracic pressure Exhaling raises thoracic pressure |
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What is Capillary Exchange?
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Moves materials across capillary walls
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What is Diffusion?
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Movement of ions or molecules from high concentration to lower concentration
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What are the 5 diffusion routes?
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1. Water, ions, small molecules: diffuse between adjacent endothelial cells or fenestrated capillaries
2. Some other ions: diffuse through channels in cell membranes 3. Large, water-soluble compounds: pass through fenestrated capillaries 4. Lipids and lipid-soluble materials: diffuse through endothelial cell membranes 5. Plasma proteins: cross endothelial lining in sinusoids |
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What is Filtration?
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removal of large solutes through membrane
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What is Capillary Filtration?
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Water and small solutes forced through capillary wall, leaving larger solutes in bloodstream
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What is Reabsorption the result of?
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Osmosis
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What does Osmotic pressure do?
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equals pressure required to prevent osmosis
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What does Hydrostatic pressure do?
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forces water out of solution
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What does Osmotic pressure do?
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forces water into solution
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What is Net Hydrostatic Pressure the difference between? And what does it do to water/solutes?
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capillary hydrostatic pressure (CHP)
and interstitial fluid hydrostatic pressure (IHP) Pushes water and solutes out of capillaries and into interstitial fluid |
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During capillary exchange, what happens at the arterial end of capillary
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fluid moves out of capillary into interstitial fluid
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During capillary exchange, what happens at the venous end of capillary?
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fluid moves into capillary out of interstitial fluid
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The transition point is between filtration and reabsorption; which end is it closer to: venous or arterial?
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venous
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What is Fluid Recycling?
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When water moves out of capillaries and into bloodstream thru lymphatic system
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What are the 4 Functions of Blood and Lymph Cycle?
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1. Ensures plasma and interstitial fluid communication
2. Accelerates distribution of nutrients, hormones, and dissolves gases through tissues 3. Transports insoluble lipids and tissue proteins that can’t cross capillary walls 4. Flushes chemicals to immune system tissues |
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What is tissue perfussion and what is it affected by?
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It is: blood flow thru tissues
Affected by: blood pressure |
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What does Cardiovascular Regulation change?
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It changes blood flow to a specific area at an appropriate time without changing blood flow to vital organs
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What are the 3 Regulatory Mechanisms? And what do they do?
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Autoregulation: immediate adjustments
Neural mechanisms: respond quickly to changes at specific sites Endocrine mechanisms: control long-term changes |
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What do Vasodilators do?
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Dilate precapillary sphincters
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True or False: Local vasodilators accelerate blood flow at tissue level
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True
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What releases Local Vasoconstrictors? And how many capilarry beds does it affect?
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released by: damaged tissues.
affects: a single capillary bed |
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Cardiovascular centers consists of...
And what do they do? |
Consists of: cardiac and vasomotor centers of medulla oblongata
Function: adjust cardiac output and peripheral resistance |
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Cardioacceleratory center increases or reduces cardiac output?
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Increases
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What does the Cardioinhibitory center do?
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reduces cardiac output
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What is Vasomotor Tone produced by?
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constant action of sympathetic vasoconstrictor nerves
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What do baroreceptor reflexes respond to?
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changes in blood pressure
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What do chemoreceptor reflexes respond to?
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changes in chemical composition
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Baroreceptor Reflexes: When blood pressure rises, CV centers...
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decrease cardiac output
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Baroreceptor Reflexes: When blood pressure falls, CV centers....
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increase cardiac output
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Where do Baroreceptors stretch walls?
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carotid sinuses: maintain blood flow to brain
aortic sinuses: monitor start of systemic circuit right atrium:monitor end of systemic circuit |
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Chemoreceptors: Where is blood monitered?
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carotid bodies and aortic bodies:
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True or false: Chemoreceptors control bloodflow to brain
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True
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Explain Antidiuretic Hormone (ADH)
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Released by posterior lobe of pituitary
Elevates blood pressure Reduces water loss at kidneys |
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What does Angiotensin II respond to?
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fall in renal blood pressure
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Explain Erythropoietin (EPO)
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Released at kidneys
Responds to low blood pressure Stimulates red blood cell production |
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Atrial natriuretic peptide (ANP) is produced where?
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cells in right atrium
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Brain natriuretic peptide (BNP) is produced where?
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ventricular muscle cells
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What do ANP and BNP have in common?
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Respond to diastolic stretching
Lower blood volume/blood pressure Reduce stress on heart |
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What do blood, heard, and cardiovacular system have in common?
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Work together, respond to physical changes, maintain homeostasis
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What are 3 effects of light exercise?
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1. extensive vasodilation occurs: increase circulation
2. venous return increases: muscle contractions 3. cardiac output rises: due to rise in venour return and atrial stretching |
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What are 5 effects of heavy exercise?
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1. activates sympathetic nervous system
2. cardiac output increases to max. 3. restricts blood flow to nonessential organs 4. redirects blood flow to skeletal muscles, lungs, heart 5. blood supply to brain is unaffected |
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What are effects of regular moderate exercise?
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lowers total blood cholesterol levels
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What are the effects on intense exercise?
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can cause severe physiological stress
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What is hemorrhaging?
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severe blood loss
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What are responses to hemorrhaging?
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cardiovascular system adjusts to maintain blood pressure and restore blood volume
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What are 3 short term responses to hemorrhage?
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1. to prevent drop in blood pressure
2. sympathetic nervous system triggers hypothalamus, constricts arterioles, and improves venous return 3. hormonal effecs increase cardiac output |
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What is shock a result of?
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Failure to restore blood pressure
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what are 4 long term responses to hemorrhage?
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1. recall of fluids from interstitial spaces
2. aldosterone and ADH promote fluid retention and reabsorbtion 3. increase of thirst 4. red blood cells production are stimulated by EPO |
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Which organs have seperate mechanisms to control blood flow?
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brain, heart, lungs
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Where is blood flow top priority and has a high oxygen demand?
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the brain
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What is another term for a stroke?
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cerebrovascular accident (CVA)
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What is a stroke?
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blockage in cerebral artery that stops blood flow
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How is blood transported to the heart?
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by coronary arteries
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What is a heart attack?
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blockage of coronary blood flow that can be fatal
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What is blood flow to the lungs regulated by?
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oxygen levels in alveoli
High oxygen: vessels dilate Low oxygen: vessels constrict |
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Are embryonic lungs and digestive tracts funtional during fetal circulation?
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No
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What is the function of the placenta?
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to provide respiratory functions and nutrition
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Explain how blood flows thru the placenta
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Blood flows thru a pair of umbilical arteries, which arise from internal iliac arteries, and enter umbilical cord
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How does blood return from the placenta?
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in an umbilical vein
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What happens at birth?
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Newborn breathes air, lungs expand, oxygen is circulated
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What is foramen ovale?
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interatrial opening covered by valve-like flap that directs blood from right to left atrium
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What is ductus arteriosus?
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short vessel that connects pulmonary and aortic trunks
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How does the cardiovascular change at birth?
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pulmonary vessels expand
blood flows rising oxygen levels cause ductus arteriosus constriction rising left atrium pressure closes foramen ovale |
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What are 3 age related changes in blood?
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1. decreased hematocrit
2. blood clots 3. blood pooling in legs |
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What are 5 age related changes in the heart?
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1. reduced cardiac output
2. changes in cell behavior 3. reduced elasticity of fibrous skeleton 4. progressive atherosclerosis 5. replacement of damaged cells by scar tissue |
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What are 3 age related changes in blood vessels?
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1. arteries become less elastic
2. calcium deposits on vessel walls 3. thrombi can form |
