Bio 242 Test 3
Which of the following means relaxation of the atra?
Atria diastole
Select the correct statement about the heart valves.
The atrioventricular (AV) valves prevent backflow of blood into the atria during ventricular contraction.
Which of these hormones would have an affect on blood pressure? epinephrine ADH angiotensin II all of the above
all of the above
The P wave of a normal electrocardiogram indicates __________________________.
atrial depolarization
Which of the following is NOT part of the intrinsic conduction system of the heart?
atrioventricular (AV) valve
The baroreceptors in the carotid sinus and aortic arch are sensitive to which of the following?
changes in arterial pressure
Normal heart sounds are caused by which of the following events? excitation of the sinoatrial (SA) node closure of the heart valves friction of blood against the chamber walls opening of the heart valves
closure of the heart valves.
Which of the following is not true regarding fenestrated capillaries?
Fenestrated capillaries form the blood-brain barrier.
Which of the following best describes the net flow of fluid at the capillaries? fluid flows out an the venous end and in at the arterial end fluid flows in at the arterial and venous ends fluid flows out at the venous and arterial ends fluid flows out at the arterial end and in at the venous end
fluid flows out at the arterial end and in at the venous end
Compared to skeletal muscle, cardiac muscle ____________________.
has more gap junctions that allow it to act as a functional syncytium.
Which of the following is NOT an intrinsic control of blood flow? metabolic controls hormonal control autoregulation myogenic controls
hormonal control
The force exerted by fluid pressing against capillary walls describes:
hydrostatic pressure
Which of the following artery types are also known as distributing arteries and account for most of the name arteries in the body? elastic arterioles veins muscular
muscular
Which of the following transports oxygen-rich blood?
pulmonary vein
The left ventricular wall of the heart is thicker than the right wall in order to _________________________.
pump blood with greater pressure
The form of circulatory shock known as hypovolemic shock is _______________.
shock that results from large-scale losss of blood volume, or after severe vomiting or diarrhea.
Which vessel types are called capacitance vessels because they contain up to 65% of blood supply?
veins
The atrioventricular (AV) valves are closed _____________________.
when ventricles are in systole
Which of the following would have the least influence on blood pressure? white blood cell count cardiac output peripheral resistance blood volume
white blood cell count
Each of the following describes the action of aldosterone except one. Which of the following does not describe the activity of aldosterone hormone?
It will result in higher sodium levels in the urine.
The volume of blood flowing through vessels, organs, or the entire circulation in a given period describes:
blood flow
Which of the following is the most significant source of blood flow resistance? blood vessel type blood viscosity total blood vessel length blood vessel diameter
blood vessel diameter
The term for an abnormally slow heart rate is:
bradycardia
Which of the following vessel types is the site of material exchange? arteries capillaries veins arterioles
capillaries
The amount of blood pumped out of each ventricle in one minute is termed _____________________.
cardiac output
Which of the following vessels does NOT empty into the right atrium? coronary sinus cardiac veins superior vena cava inferior vena cava
cardiac veins
Which of the following increases heart rate? cardioacceleratory center via sympathetic trunk cardioacceleratory center via the vagus nerve cardioinhibitory center via sympathetic trunk cardioinhibitory center via the vagus nerve
cardiacceleratory center via sympathetic trunk
Which of the following is a structure that holds cardiac cells together? desmosomes pericardium valves gap junctions
desmosomes
Respiratory gases, which are lipid soluble molecules, cross the capillary walls by
diffusing through fenestrations
Which layer of the heart wall is continuous with the lining of blood vessels?
endocardium
Blood within the pulmonary veins returns to the ________________.
left atrium
Blood that is being pumped into the systemic circuit comes from which chamber of the heart?
left ventricle
Which of the following vessels types carry blood towards the heart?
veins
Which of the following factors does NOT influence heart rate?
skin color
The velocity of blood flow is ________________________.
slowest in the capillaries because the total cross-sectional area is the greatest
Failure of a valve to open is termed _________________.
stenotic valve
Which of the following areas of the brain does NOT have an influence on blood pressure? hypothalamus thalamus medulla oblongata cerebral cortex
thalamus
Peripheral resistance is a measurement of :
the amount of friction blood encounters with vessel walls
If the vagal nerves to the heart were cut, the result would be that ____________________.
the heart rate would increase by about 25 beats per minute
What tunic of an artery is most responsible for maintaining blood pressure and continuous blood circulation?
tunica media