Download Blood Vessels Notes Handout

Name _________________________
Function/Purpose
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Blood Vessels: The Vascular System
Notes
Transport blood to the tissues and back
– Carry blood ____________ from the heart
• _______________________
• _______________________
– Exchanges between tissues and blood
• _______________________
– Return blood _________________ the heart
• _______________________
• _______________________
Structural Differences
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Arteries have a ______________________________________________ than veins
Capillaries are only _______________________ (tunica intima) to allow for exchanges between blood
and tissue
Veins have a ______________________________________________ than arteries
– Veins also have ____________ to prevent backflow of blood
– __________________ of veins are larger than arteries
Venous Aids for Return of Blood to the Heart
• Veins:
– Have a thinner tunica media
– Operate under _______________________
– Have a larger lumen than arteries
• To assist in the movement of blood back to the heart:
– Larger veins have valves to prevent backflow
– ______________________________________________ blood in veins toward the heart
Movement of Blood Through Vessels
• Most ______________________________________________
• Veins use the milking action of muscles to help move blood
Capillary Beds
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Capillary beds consist of two types of vessels
– _______________________—vessel directly connecting an arteriole to a venule
– _______________________—exchange vessels
• Oxygen and nutrients cross to cells
• Carbon dioxide and metabolic waste products cross into blood
Problems in & with Blood Vessels
• ______________: builds up on the inner walls of arteries; can be made from
calcium, fat, cholesterol, and fibrin (used in blood clotting)
• ________________________: narrowing and hardening of the arteries cause
by plaque formation
Caused by high “bad” cholesterol & low “good cholesterol, high blood pressure, cigarette smoke, and
diabetes
• ________________________: hardening of the arteries that affects small arteries and blood vessels
• ________________: solid mass of platelets and/or fibrin that forms in a blood vessel
Common, internal & external carotids
• ________________: typically a piece of a thrombus that is carried toward the brain
Can also be caused by pieces of plaque, fat, or air
• ________________: swelling along part of a blood vessel and where there is weakness along the
swelling – can rupture and cause immediate death
• Stroke
Occurs when ___________________________________________
Stroke symptoms
• Spotting a stroke: ________________
Face drooping
Arm weakness
Speech difficulty
Time to call 911
• ___________ (tissue plasminogen activator): “___________________________” medication to break
down a clot that is blocking blood flow to the brain
Pulse
• Pulse
– ______________________________________________
• Monitored at “_______________________” in arteries where pulse is easily palpated
• Pulse averages _________________ beats per minute at rest
• Pulse oximeter: used to read _____________________ in blood; can also record pulse
• _______________ should be between 95-100% to be normal; under 90% indicates hypoxia (low O2 sat)
Blood Pressure
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Measurements by health professionals are made on the pressure in large arteries
– __________________—pressure at the peak of ventricular contraction
– __________________—pressure when ventricles relax
– Write systolic pressure first and diastolic last (120/80 mm Hg)
Pressure in blood vessels decreases as distance from the heart increases
Blood Pressure: Effects of Factors
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__________ is blood pressure
– BP is affected by ______________________________________________________________
___________________________________________________________________________
CO (_______________________) is the amount of blood pumped out of the left ventricle per minute
PR (_______________________) is the amount of friction blood encounters as it flows through vessels
– ___________________________________________________________________________
________________________________________ increases PR
Temperature
– Heat has a __________________ effect
– Cold has a ____________________________________ effect
Chemicals
– Various substances can cause increases or decreases
Diet
Variations in Blood Pressure
•
Normal human range is variable
– Normal
• _________________ mm Hg systolic
• _________________ mm Hg diastolic
– Hypotension
• Low systolic (below 110 mm Hg)
• Often associated with illness
– Hypertension
• High systolic (above 140 mm Hg)
• Can be dangerous if it is chronic
How to Take Blood Pressure
1. Deflate the air bladder of the cuff and place it around the
Blood pressure is measured in
upper arm so it fits snugly, but not too tight. If you’re right
millimeters of mercury (mm Hg). A
handed, you should hold the bulb/pump in your left hand to
typical blood pressure is 120/80 mm
inflate the cuff. Hold it in the palm so your fingers can easily
Hg, or "120 over 80." The first
reach the valve at the top to open and close the outlet to the air
number represents the pressure when
bladder.
the heart contracts and is called the
2. Put the head of the stethoscope just under the edge of the
systolic blood pressure. The second
cuff, a little above the crease of the person’s elbow. Hold it
number represents the pressure when
there firmly with the thumb or with the fingers of the right hand.
the heart relaxes and is called the
Listen.
diastolic blood pressure.
3. Inflate the cuff with brisk squeezes of the bulb. Watch the
pressure gauge as you do it, you should go to around 150 mmHg or until the pulse is no
longer heard. At this point blood flow in the underlying blood vessel is cut off by
pressure in the cuff.
4. At around 150, slightly open the valve on the air pump (held in your left hand). This part takes practice, it’s
important that you don’t let the air out too suddenly or too slowly.
5. Now, pay attention to what you hear through the stethoscope as the needle on the pressure gauge falls. You
will be listening for a slight “blrrp” or something that sounds like a “prrpshh”. The first time you hear this
sound; note the reading on the gauge and immediately following you should hear the sound of a pulse. This
value is the systolic blood pressure.
6. The sounds should continue and become louder in intensity. Note the reading when you hear the sound for
the last time. This is the diastolic blood pressure.
7. Afterwards, open the air valve completely to release any remaining pressure. You and your partner should
perform this operation twice.