18-22 quizzes

Which of the following receives blood during ventricular systole?

?

An electrocardiogram (ECG) provides direct information about valve function.

False

Cardiac muscle has more mitochondria and depends less on a continual supply of oxygen than does skeletal muscle.

False

Osmotic pressure is created by the presence in a fluid of small diffusible molecules that easily move through the capillary membrane.

False

Vasodilation is a widening of the lumen due to smooth muscle contraction.

False

The aorta receives the full force of blood exiting the heart during ventricular systole. Which of the following statements best describes the adaptive anatomy of the aorta?

Elastic fibers are extensive in the tunica media of the aorta and dampen the pulse pressure generated by the heart.

A precapillary sphincter is a cuff of smooth muscle that regulates the flow of blood into the capillaries.

True

Tissues damaged by myocradial infarction are replaced by connective tissue

True

Normal heart sounds are caused by which of the following events?

closure of the heart valves

Peripheral resistance ________.

increases as blood viscosity increases

What is the expected heart rate when a heart is removed from a living body?

100 beats / minute

Which statement best describes arteries?

All carry blood away from the heart

Select the correct statement about the heart valves.

Answer: The atrioventricular (AV) valves prevent backflow of blood into the atria during ventricular contraction.

If cardiac muscle is deprived of its normal blood supply, damage would primarily result from ________.

Answer: decreased delivery of oxygen

Compared to skeletal muscle, cardiac muscle ________.

Answer: has gap junctions that allow it to act as a functional syncytium

Which of the following transports oxygen-rich blood?

Answer: pulmonary vein

Isovolumetric contraction ________.

Answer: refers to the short period during ventricular systole when the ventricles are completely closed chambers

If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells, ________.

Answer: tetanic contractions might occur, which would stop the heart's pumping action

When does the period of atrial repolarization occur?

Answer: ventricular depolarization

Select the correct statement about blood flow.

Blood flow through the entire vascular system is equivalent to cardiac output.

How would an attack by a mugger affect blood pressure? What is the physiological basis for your answer?

Blood pressure would increase due to sympathetic nervous system stimulation.

The condition where fluid accumulation in the pericardial cavity compresses the heart and limits its ability to pump blood is called ________.

Cardiac tamponade

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.

Damage to the ________ causes heart block.

atrioventricular (AV) node

Which of the following is NOT part of the intrinsic conduction system of the heart?

atrioventricular (AV) node bundle branches sinoatrial (SA) node Answer: atrioventricular (AV) valve

During the period of ventricular filling ________.

blood flows mostly passively through the atria and the open atrioventricular (AV) valves into the ventricles

Which of the following is the most significant source of blood flow resistance?

blood vessel diameter

Permitting the exchange of nutrients and gases between the blood and tissue cells is the primary function of ________.

capillaries

The baroreceptors in the carotid sinus and aortic arch are sensitive to which of the following?

changes in arterial pressure

The arteries that are also called distributing arteries are the ________.

muscular arteries

When viewing a dissected heart, it is easy to visually discern the right and left ventricles by ________

noticing the thickness of the ventricle walls

The left ventricular wall of the heart is thicker than the right wall in order to ________.

pump blood with greater pressure

In red bone marrow newly formed blood cells enter the circulation. You would expect to see many ________ type of capillaries in red bone marrow.

sinusoid capillaries

The pulse pressure is ________.

systolic pressure minus diastolic pressure

Which tunic of an artery is most responsible for maintaining blood pressure and continuous blood circulation?

tunica media