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A&P2 Lab Chapter 18.
Terms in this set (25)
The cerebral arterial (circle of Willis)
provides alternate routes of blood flow in the brain/
What are the layers of the blood vessel wall (superior to deep)
The tunica interna, tunica media, tunica advertitia.
What is the role of the smooth muscle cells in the blood vessel wall
It determines the amount of blood flowing to a tissue, important role in blood pressure and controls the diameter of the blood vessel.
Would a blood clot lodged in one of the anterior or posterior communicating arteries of the cerebral arterial circle be likely to cause significant symptoms? why or why not?
It would be unlikely to cause noticeable symptoms because the blood could flow along an alternate route to the brain.
Why do arteries require more elastic fibers than veins?
Arteries are under higher pressure and therefore need to be more distensible, which is provided by the elastic fibers.
The first heart sound is known as ______ and is caused by closure of the __________.
S1; AV valves.
The second heart sound is known as ________ and is caused by closure of the _______________.
S2; semilunar valves.
The process of listening to the heart sounds is know as?
A noise heard in an artery as a result of turbulent blood flow.
A noise heard in the heart due to defective valves.
An elevated heart rate above 100 beats per minute.
The patern and regularity with which the heart beats.
A decreased heart rate below 60 beats per minute.
What is the baroreceptor reflex?
A reflex mediated by the PSNS that lowers blood pressure to protect the brain from sudden, rapid increases in blood pressure.
The ____________ is the pressure in the arteries during ventricular systole and averages about __________.
Systolic pressure; 120 mmHg.
The _____________ is the pressure in the arteries during ventricular diastole and averages about _____________.
Diastolic pressure; 80 mmHg.
The sounds heard in an artery when measuring the blood pressure are called:
Sounds of Korotkoff.
The actions of the sympathetic nervous system ___________ blood pressure, and the actions of the parasympathetic nervous system ________________.
The ankle-brachial compares the:
Systolic pressure in the arm to the systolic pressure in the ankle.
What might it mean if a pulse were normal on the right limb, and absent on the left limb?
It could indicate a normal anatomical variation, a blocked artery, or vascular disease.
pPalpation of both carotid arteries at the same time initiates a reflex know as the barreceptor reflex. if this reflex is initiated in a healthy person with normal blood pressure, the person may temporarily lose consciousness. Explain why this happens.
The sudden, abnormal drop in blood pressure deprives the brain of blood temporarily, which results in a loss of consciousness.
The baroreceptor reflex can be used to our benefit in a procedure known as a carotid sinus massage, which is performed when the blood pressure or heart rate is pathologically high. Why would a "massage" of the carotid sinus help to treat these conditions?
Massaging the carotid sinus decreases blood pressure in a controlled way by activating the baroreceptor reflex and allowing the PSNS to control heart rate.
What might be signified if the capillary refill time measures 10 seconds in the digits of one hand and 2 seconds in the digits of the other hand? What might it mean if the capillary refill time measures 10 seconds in all digits?
This could indicate diminished circulation in the affected digits, particularly the microcirculation.
Predict the effects of a drug that activates the sympathetic nervous system on blood pressure and heart rate. How would this drug affect the three factors that determine blood pressure?
This would increase cardiac output and peripheral resistance, which would increase blood pressure. Over a long period of time it may increase blood volume/ pressure.
Predict the effects of a drug that activates the parasympathetic nervous system on blood pressure and heart rate. How would this drug affect the three factors that determine blood pressure?
It would decrease cardiac output, peripheral resistance and blood volume.