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What is the primary function of Purkinje fibers in the heart? A) To contract the heart muscle B) To trigger waves of contraction through both ventricles simultaneously C) To supply oxygen to the heart D) To regulate blood flow through the arteries E) To produce heart sounds
B) To trigger waves of contraction through both ventricles simultaneously Explanation: Purkinje fibers are specialized cardiac muscle fibers that play a crucial role in conducting electrical impulses, allowing for synchronized contraction of the ventricles.
What role do the elastic laminae in arteries play? A) They prevent blood flow B) They contribute to uniform blood flow C) They form valves D) They increase blood viscosity E) They decrease arterial pressure
B) They contribute to uniform blood flow Explanation: The numerous elastic laminae in arteries help make blood flow more uniform, allowing for effective blood transport during both systole and diastole.
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p.4
Cardiac Muscle and Heart Chambers

What is the primary function of Purkinje fibers in the heart?
A) To contract the heart muscle
B) To trigger waves of contraction through both ventricles simultaneously
C) To supply oxygen to the heart
D) To regulate blood flow through the arteries
E) To produce heart sounds

B) To trigger waves of contraction through both ventricles simultaneously
Explanation: Purkinje fibers are specialized cardiac muscle fibers that play a crucial role in conducting electrical impulses, allowing for synchronized contraction of the ventricles.

p.7
Structure and Function of the Heart

What role do the elastic laminae in arteries play?
A) They prevent blood flow
B) They contribute to uniform blood flow
C) They form valves
D) They increase blood viscosity
E) They decrease arterial pressure

B) They contribute to uniform blood flow
Explanation: The numerous elastic laminae in arteries help make blood flow more uniform, allowing for effective blood transport during both systole and diastole.

p.8
Pathophysiology of Cardiovascular Diseases

What predisposing factor is indicated by a ratio of LDL to HDL greater than 3:1?
A) Hypertension
B) Dyslipidemia
C) Hyperglycemia
D) Smoking
E) Obesity

B) Dyslipidemia
Explanation: A dyslipidemia characterized by a ratio of LDL to HDL greater than 3:1 is a significant predisposing factor for cardiovascular diseases, particularly atheromas.

p.2
Structure and Function of the Heart

Which chamber of the heart pumps oxygenated blood into the aorta?
A) Right atrium
B) Left atrium
C) Right ventricle
D) Left ventricle
E) Superior vena cava

D) Left ventricle
Explanation: The left ventricle is responsible for pumping oxygenated blood into the aorta, which then distributes it throughout the systemic circulation.

p.7
Vascular Wall Tissues

What are the three tunics of blood vessel walls?
A) Intima, media, adventitia
B) Endocardium, myocardium, epicardium
C) Lumen, tunica, valves
D) Elastic, muscular, fibrous
E) Arterial, venous, capillary

A) Intima, media, adventitia
Explanation: The walls of both arteries and veins consist of three tunics: the intima, media, and adventitia, which correspond to the heart's endocardium, myocardium, and epicardium.

p.6
Pathophysiology of Cardiovascular Diseases

What is the role of tissue plasminogen activator (tPA) in medical treatment?
A) To promote blood clot formation
B) To dissolve blood clots
C) To increase blood pressure
D) To enhance platelet aggregation
E) To reduce blood flow

B) To dissolve blood clots
Explanation: tPA is a serine protease that breaks down fibrin and quickly dissolves clots, making it a critical treatment for conditions involving thrombus formation.

p.5
Endothelial Function and Importance

What is the role of vascular endothelial growth factor (VEGF)?
A) It promotes blood clotting
B) It stimulates the formation of the vascular system
C) It inhibits inflammation
D) It breaks down fat
E) It regulates heart rate

B) It stimulates the formation of the vascular system
Explanation: VEGF is a growth factor that stimulates the formation of the vascular system from embryonic mesenchyme and promotes angiogenesis during growth, tissue repair, and in pathological conditions.

p.8
Arterial Sensory Structures

What is the role of carotid sinuses?
A) They increase blood flow
B) They act as baroreceptors monitoring arterial blood pressure
C) They produce hormones
D) They store blood
E) They prevent blood clots

B) They act as baroreceptors monitoring arterial blood pressure
Explanation: Carotid sinuses are dilations in the internal carotid arteries that function as baroreceptors, monitoring and regulating arterial blood pressure.

p.1
Blood Vascular System Components

What structures make up the blood vascular system?
A) Heart, lungs, and kidneys
B) Heart, arteries, capillaries, and veins
C) Veins, lymph nodes, and arteries
D) Capillaries, lymphatic vessels, and heart
E) Heart, stomach, and intestines

B) Heart, arteries, capillaries, and veins
Explanation: The blood vascular system, also known as the cardiovascular system, consists of the heart, arteries, capillaries, and veins, which work together to circulate blood throughout the body.

p.2
Structure and Function of the Heart

What is the role of the epicardium in the heart?
A) To contract and pump blood
B) To provide a protective layer and support blood vessels
C) To facilitate gas exchange
D) To regulate heart rate
E) To store blood

B) To provide a protective layer and support blood vessels
Explanation: The epicardium serves as a protective layer for the heart and contains blood vessels and nerves, playing a crucial role in supporting the heart's structure.

p.4
Pathophysiology of Cardiovascular Diseases

Why do patients with artificial heart valves require anticoagulant agents?
A) To prevent heart murmurs
B) To prevent thrombus formation at the valve sites
C) To increase heart rate
D) To enhance blood flow
E) To repair damaged heart tissue

B) To prevent thrombus formation at the valve sites
Explanation: Artificial heart valves lack a complete endothelial covering, which increases the risk of blood clot formation (thrombus), necessitating the use of anticoagulant medications.

p.9
Overview of the Circulatory System

What are the carotid sinuses and aortic arch primarily associated with?
A) Digestive system
B) Autonomic nervous system
C) Muscular arteries
D) Respiratory system
E) Endocrine system

B) Autonomic nervous system
Explanation: The carotid sinuses and aortic arch are part of the autonomic nervous system, specifically referred to as paraganglia, which play a role in regulating cardiovascular functions.

p.2
Pulmonary and Systemic Circulation

What is the primary function of the pulmonary circulation?
A) To supply oxygenated blood to the body
B) To remove carbon dioxide from the blood
C) To pump blood to the lungs for oxygenation
D) To return deoxygenated blood to the heart
E) To distribute nutrients to tissues

C) To pump blood to the lungs for oxygenation
Explanation: The pulmonary circulation's main function is to transport deoxygenated blood from the right side of the heart to the lungs for oxygenation and then return oxygenated blood to the left side of the heart.

p.10
Vascular Wall Tissues

What type of muscle is primarily found in the media of arterioles?
A) Cardiac muscle
B) Skeletal muscle
C) Smooth muscle
D) Striated muscle
E) Epithelial muscle

C) Smooth muscle
Explanation: The media of arterioles consists of circularly arranged smooth muscle cells, which allow for the regulation of blood flow.

p.3
Structure and Function of the Heart

What is the primary function of the fibrous cardiac skeleton?
A) To generate electrical impulses
B) To separate the musculature of the atria from the ventricles
C) To produce lubricant fluid
D) To cushion underlying structures
E) To anchor the heart to the diaphragm

B) To separate the musculature of the atria from the ventricles
Explanation: The fibrous cardiac skeleton serves to separate the musculature of the atria from that of the ventricles, providing structural support and organization within the heart.

p.7
Structure and Function of the Heart

What happens to the elastin in arteries during ventricular contraction?
A) It contracts
B) It stretches
C) It hardens
D) It ruptures
E) It remains unchanged

B) It stretches
Explanation: During ventricular contraction (systole), the elastin in the arterial walls is stretched, allowing the arteries to accommodate the forceful movement of blood.

p.9
Blood Vascular System Components

What type of cells surround the capillaries in the carotid sinuses and aortic arch?
A) Epithelial cells
B) Glomus cells
C) Endothelial cells
D) Fibroblasts
E) Adipocytes

B) Glomus cells
Explanation: The capillaries in these structures are closely surrounded by glomus cells, which are neural crest-derived cells filled with neurotransmitter-containing vesicles.

p.7
Pathophysiology of Cardiovascular Diseases

What are foam cells in the context of atherosclerosis?
A) Healthy endothelial cells
B) Lipid-filled macrophages
C) Smooth muscle cells
D) Collagen fibers
E) Lymphocytes

B) Lipid-filled macrophages
Explanation: Foam cells are lipid-filled macrophages that accumulate during the progression of atherosclerosis, contributing to the formation of fatty streaks.

p.9
Blood Vascular System Components

What is the role of the vasa vasorum?
A) To transport hormones
B) To supply oxygen and nutrients to the outer layers of large arteries
C) To regulate blood flow
D) To filter waste products
E) To connect arteries to veins

B) To supply oxygen and nutrients to the outer layers of large arteries
Explanation: The vasa vasorum consists of small blood vessels that provide oxygen and nutrients to the cells in the adventitia of larger arteries, which are too far from the lumen to receive nourishment directly.

p.5
Endothelial Function and Importance

What role does the endothelium play in the vascular system?
A) It acts as a barrier between blood and interstitial fluid
B) It stores fat for energy
C) It generates electrical impulses
D) It produces red blood cells
E) It forms the outer layer of blood vessels

A) It acts as a barrier between blood and interstitial fluid
Explanation: The endothelium serves as a specialized epithelium that acts as a semipermeable barrier between the blood and interstitial tissue fluid, facilitating the exchange of molecules.

p.5
Endothelial Function and Importance

What is one function of endothelial cells in the vascular system?
A) They produce hormones
B) They regulate local vascular tone and blood flow
C) They store calcium
D) They generate heat
E) They form the outer layer of blood vessels

B) They regulate local vascular tone and blood flow
Explanation: Endothelial cells secrete various factors that stimulate smooth muscle contraction or relaxation, thereby regulating local vascular tone and blood flow.

p.6
Blood Vascular System Components

What is the function of the vasa vasorum in large blood vessels?
A) To carry oxygenated blood
B) To provide nutrients to the vessel wall
C) To facilitate blood clotting
D) To regulate blood pressure
E) To remove waste products from blood

B) To provide nutrients to the vessel wall
Explanation: The vasa vasorum are small blood vessels that supply nutrients and oxygen to the thick walls of larger blood vessels, as diffusion from the lumen alone is insufficient.

p.1
Lymphatic Vascular System

What is the function of the lymphatic vascular system?
A) To transport oxygen to tissues
B) To return fluid from tissue spaces to the blood
C) To pump blood through the heart
D) To filter blood
E) To produce red blood cells

B) To return fluid from tissue spaces to the blood
Explanation: The lymphatic vascular system collects lymph from tissue spaces and returns it to the blood vascular system, helping maintain fluid balance in the body.

p.10
Blood Vascular System Components

What is a key feature of capillaries in the circulatory system?
A) They have many smooth muscle layers
B) They are the site of leukocyte exit from vasculature
C) They are involved in the exchange of metabolites by diffusion
D) They have prominent valves
E) They conduct blood from the heart

C) They are involved in the exchange of metabolites by diffusion
Explanation: Capillaries are specialized for the exchange of metabolites between blood and tissues, primarily through diffusion.

p.5
Vascular Wall Tissues

What type of tissue is primarily found in the walls of blood vessels, excluding capillaries?
A) Epithelial tissue
B) Smooth muscle and connective tissue
C) Nervous tissue
D) Adipose tissue
E) Cartilage

B) Smooth muscle and connective tissue
Explanation: The walls of all blood vessels, except capillaries, contain smooth muscle and connective tissue in addition to the endothelial lining, which is essential for their structural integrity and function.

p.8
Pathophysiology of Cardiovascular Diseases

What are atheromas and their effect on elastic arteries?
A) They strengthen the arterial wall
B) They produce localized destruction within the wall
C) They have no effect on the arteries
D) They increase blood flow
E) They prevent aneurysms

B) They produce localized destruction within the wall
Explanation: Atheromas cause localized destruction in the walls of elastic arteries, weakening them and potentially leading to arterial bulges or aneurysms that can rupture.

p.7
Pathophysiology of Cardiovascular Diseases

What is atherosclerosis primarily associated with?
A) Increased blood flow
B) Damage to endothelial cells
C) Decreased blood pressure
D) Increased oxygen levels
E) Formation of new blood vessels

B) Damage to endothelial cells
Explanation: Atherosclerosis is initiated by damaged or dysfunctional endothelial cells that oxidize low-density lipoproteins (LDLs), leading to the disease's progression.

p.1
Overview of the Circulatory System

What is the primary function of the circulatory system?
A) To digest food
B) To pump and direct blood cells and substances to all tissues
C) To filter waste from the body
D) To produce hormones
E) To regulate body temperature

B) To pump and direct blood cells and substances to all tissues
Explanation: The circulatory system's main role is to pump and direct blood cells and various substances throughout the body, ensuring that all tissues receive necessary nutrients and oxygen.

p.8
Arterial Sensory Structures

Which cranial nerve is associated with the baroreceptors in the carotid sinuses?
A) Cranial nerve V
B) Cranial nerve VII
C) Cranial nerve IX
D) Cranial nerve X
E) Cranial nerve XII

C) Cranial nerve IX
Explanation: The carotid sinuses contain sensory nerve endings from cranial nerve IX, the glossopharyngeal nerve, which transmits signals related to blood pressure.

p.1
Microvasculature

What is the role of capillaries in the circulatory system?
A) To pump blood
B) To carry blood away from the heart
C) To exchange O2, CO2, nutrients, and waste products
D) To store blood
E) To connect arteries to veins

C) To exchange O2, CO2, nutrients, and waste products
Explanation: Capillaries are the smallest blood vessels and are primarily responsible for the exchange of oxygen, carbon dioxide, nutrients, and waste products between blood and tissues.

p.10
Structure and Function of the Heart

What is the typical diameter range of arterioles?
A) 10-100 μm
B) 1-10 mm
C) 100-10 μm
D) > 10 mm
E) 0.1-1 mm

C) 100-10 μm
Explanation: Arterioles are generally between 100 and 10 micrometers in diameter, which is significantly smaller than other types of arteries.

p.3
Cardiac Muscle and Heart Chambers

What role does the sinoatrial (SA) node play in the heart?
A) It prevents backflow of blood
B) It acts as the pacemaker of the heart
C) It separates the atria and ventricles
D) It generates blood pressure
E) It anchors the heart valves

B) It acts as the pacemaker of the heart
Explanation: The sinoatrial (SA) node is known as the pacemaker of the heart, initiating electrical impulses that stimulate rhythmic contractions in the heart muscle.

p.7
Blood Vascular System Components

What is a key characteristic of veins compared to arteries?
A) Thicker media
B) Larger lumen
C) More elastic laminae
D) Thinner adventitia
E) More valves

B) Larger lumen
Explanation: Veins have a larger lumen compared to arteries, which have a thicker media and a relatively narrow lumen.

p.8
Pathophysiology of Cardiovascular Diseases

What can atheromas in muscular arteries lead to?
A) Increased blood flow
B) Ischemic heart disease
C) Strengthened arterial walls
D) Decreased blood pressure
E) Improved oxygen delivery

B) Ischemic heart disease
Explanation: In muscular arteries, such as the coronary arteries, atheromas can occlude blood flow to downstream vessels, leading to ischemic heart disease.

p.9
Types of Blood Vessels

What is the primary function of muscular arteries?
A) To transport oxygen
B) To distribute blood to organs and regulate blood pressure
C) To absorb nutrients
D) To filter blood
E) To store blood

B) To distribute blood to organs and regulate blood pressure
Explanation: Muscular arteries, also known as distributing arteries, play a crucial role in distributing blood to various organs and regulating blood pressure through the contraction and relaxation of smooth muscle.

p.2
Cardiac Muscle and Heart Chambers

Why is the myocardium thicker in the ventricles than in the atria?
A) To accommodate more blood
B) To generate stronger contractions for pumping blood
C) To reduce the risk of heart disease
D) To facilitate faster blood flow
E) To support the heart valves

B) To generate stronger contractions for pumping blood
Explanation: The myocardium is thicker in the ventricles because they need to generate stronger contractions to pump blood through both the systemic and pulmonary circulations effectively.

p.10
Blood Vascular System Components

What is the primary role of muscular arteries in the circulatory system?
A) Conduct blood from the heart
B) Distribute blood to all organs and maintain steady blood pressure
C) Resist blood flow
D) Exchange metabolites
E) Return blood to the heart

B) Distribute blood to all organs and maintain steady blood pressure
Explanation: Muscular arteries are responsible for distributing blood to various organs and maintaining steady blood pressure through vasodilation and constriction.

p.4
Pathophysiology of Cardiovascular Diseases

What is a heart murmur?
A) A normal heart sound
B) An abnormal heart sound due to valve defects
C) A type of arrhythmia
D) A symptom of heart attack
E) A sign of high blood pressure

B) An abnormal heart sound due to valve defects
Explanation: A heart murmur occurs when heart valves do not close tightly, leading to slight regurgitation and backflow of blood, which produces an abnormal sound.

p.5
Vascular Wall Tissues

Which of the following factors can influence the arrangement of tissues in blood vessels?
A) Genetic factors
B) Mechanical and metabolic factors
C) Environmental factors
D) Hormonal factors
E) Nutritional factors

B) Mechanical and metabolic factors
Explanation: The amount and arrangement of tissues in blood vessels are influenced by mechanical factors, primarily blood pressure, and metabolic factors reflecting the local needs of tissues.

p.3
Cardiac Muscle and Heart Chambers

What is the primary role of the impulse conducting system in the heart?
A) To generate blood pressure
B) To stimulate rhythmic contractions in myocardial fibers
C) To separate the atria from the ventricles
D) To anchor the heart valves
E) To cushion the heart during movement

B) To stimulate rhythmic contractions in myocardial fibers
Explanation: The impulse conducting system of the heart is specialized to generate and conduct waves of depolarization, which stimulate rhythmic contractions in adjacent myocardial fibers.

p.5
Structure and Function of the Heart

What is the primary composition of the fibrous cardiac skeleton?
A) Smooth muscle
B) Dense irregular connective tissue
C) Epithelial tissue
D) Adipose tissue
E) Cartilage

B) Dense irregular connective tissue
Explanation: The fibrous cardiac skeleton consists of dense irregular connective tissue, which anchors the valves and maintains their proper shape within the heart.

p.8
Vascular Wall Tissues

What type of cells line the intima of arteries?
A) Cuboidal epithelial cells
B) Columnar epithelial cells
C) Simple squamous endothelial cells
D) Stratified squamous epithelial cells
E) Transitional epithelial cells

C) Simple squamous endothelial cells
Explanation: The intima of arteries is lined with simple squamous endothelial cells, which play a crucial role in vascular function.

p.1
Endothelial Function and Importance

What type of epithelium lines the internal surfaces of the blood and lymphatic systems?
A) Stratified squamous epithelium
B) Transitional epithelium
C) Simple cuboidal epithelium
D) Simple squamous epithelium
E) Columnar epithelium

D) Simple squamous epithelium
Explanation: The internal surfaces of all components of the blood and lymphatic systems are lined by a simple squamous epithelium known as endothelium, which plays a crucial role in vascular function.

p.10
Blood Vascular System Components

What role do the smooth muscle fibers at the ends of arterioles play?
A) They conduct blood from the heart
B) They act as sphincters to regulate blood flow into capillaries
C) They exchange metabolites with tissues
D) They drain capillary beds
E) They return blood to the heart

B) They act as sphincters to regulate blood flow into capillaries
Explanation: The smooth muscle fibers at the ends of arterioles function as sphincters, controlling the periodic blood flow into capillaries.

p.4
Structure and Function of the Heart

What effect does stimulation of the parasympathetic division have on the heart?
A) It accelerates the heartbeat
B) It has no effect on heart rate
C) It slows the heartbeat
D) It increases blood pressure
E) It causes arrhythmias

C) It slows the heartbeat
Explanation: Stimulation of the parasympathetic division, particularly through the vagus nerve, results in a decrease in heart rate, contrasting with the sympathetic division which accelerates heart activity.

p.4
Pathophysiology of Cardiovascular Diseases

What condition is referred to as angina pectoris?
A) A heart valve defect
B) Pain due to oxygen deprivation in the heart
C) A type of heart murmur
D) An increase in heart rate
E) A heart attack

B) Pain due to oxygen deprivation in the heart
Explanation: Angina pectoris is characterized by discomfort or pain resulting from reduced blood flow and oxygen to the heart, often due to partially occluded coronary arteries.

p.6
Endothelial Function and Importance

What is the primary function of the normal vascular endothelium?
A) To promote blood clot formation
B) To allow adhesion of blood cells and platelets
C) To prevent blood clot formation
D) To increase blood pressure
E) To facilitate oxygen exchange

C) To prevent blood clot formation
Explanation: The normal vascular endothelium is antithrombogenic, meaning it prevents the adhesion of blood cells and platelets, thereby inhibiting blood clot formation.

p.6
Pathophysiology of Cardiovascular Diseases

What initiates the aggregation of blood platelets when endothelial cells are damaged?
A) Exposure of collagen in subendothelial tissues
B) Increase in blood pressure
C) Release of oxygen
D) Decrease in blood flow
E) Activation of white blood cells

A) Exposure of collagen in subendothelial tissues
Explanation: When endothelial cells are damaged, collagen is exposed in the subendothelial tissues, which induces the aggregation of blood platelets, leading to clot formation.

p.3
Structure and Function of the Heart

What is the function of the chordae tendineae?
A) To generate electrical impulses
B) To prevent valves from turning inside-out during contraction
C) To cushion the heart during movement
D) To separate the atria from the ventricles
E) To produce lubricant fluid

B) To prevent valves from turning inside-out during contraction
Explanation: The chordae tendineae are cords that extend from the cusps of the atrioventricular valves and attach to papillary muscles, preventing the valves from turning inside-out during ventricular contraction.

p.3
Cardiac Muscle and Heart Chambers

Where is the atrioventricular (AV) node located?
A) In the left atrium
B) In the right atrial wall near the superior vena cava
C) In the floor of the right atrium near the AV valve
D) In the interventricular septum
E) In the left ventricle

C) In the floor of the right atrium near the AV valve
Explanation: The atrioventricular (AV) node is located in the floor of the right atrium near the AV valve, playing a crucial role in the conduction system of the heart.

p.6
Vascular Wall Tissues

Which layer of blood vessels is primarily composed of smooth muscle cells?
A) Tunica intima
B) Tunica media
C) Tunica externa
D) Endothelium
E) Subendothelial layer

B) Tunica media
Explanation: The tunica media is the middle layer of blood vessels and consists chiefly of concentric layers of helically arranged smooth muscle cells, which are crucial for regulating blood pressure.

p.2
Overview of the Circulatory System

What are the two main routes of blood circulation in the cardiovascular system?
A) Pulmonary and renal circulation
B) Systemic and pulmonary circulation
C) Coronary and systemic circulation
D) Pulmonary and coronary circulation
E) Systemic and lymphatic circulation

B) Systemic and pulmonary circulation
Explanation: The cardiovascular system operates through two primary routes: systemic circulation, which supplies blood to the body, and pulmonary circulation, which carries blood to the lungs for oxygenation.

p.9
Endothelial Function and Importance

What triggers the release of neurotransmitters from glomus cells?
A) High oxygen levels
B) Low blood pressure
C) Hypoxia, hypercapnia, or acidosis
D) High glucose levels
E) Increased heart rate

C) Hypoxia, hypercapnia, or acidosis
Explanation: Ion channels in the glomus cell membranes respond to stimuli such as low oxygen (hypoxia), excess carbon dioxide (hypercapnia), or acidosis, leading to neurotransmitter release.

p.6
Types of Blood Vessels

What distinguishes elastic arteries from other types of arteries?
A) They have a thin tunica media
B) They are primarily involved in nutrient exchange
C) They have thick tunica media with elastic lamellae
D) They are smaller in diameter
E) They do not contain smooth muscle fibers

C) They have thick tunica media with elastic lamellae
Explanation: Elastic arteries, such as the aorta, have a thick tunica media characterized by alternating layers of elastic lamellae and smooth muscle fibers, allowing them to conduct blood efficiently.

p.9
Types of Blood Vessels

What characterizes arterioles in the circulatory system?
A) They have no smooth muscle layers
B) They are the largest blood vessels
C) They have three or four layers of smooth muscle
D) They are the smallest arteries with one or two smooth muscle layers
E) They only transport oxygenated blood

D) They are the smallest arteries with one or two smooth muscle layers
Explanation: Arterioles are the smallest branches of muscular arteries, characterized by having one or two layers of smooth muscle, marking the beginning of an organ's microvasculature.

p.1
Cardiac Muscle and Heart Chambers

Which layer of the heart wall is responsible for the heart's rhythmic contractions?
A) Endocardium
B) Epicardium
C) Myocardium
D) Pericardium
E) Subendocardial layer

C) Myocardium
Explanation: The myocardium is the middle layer of the heart wall composed of cardiac muscle, which contracts rhythmically to pump blood through the circulatory system.

p.2
Overview of the Circulatory System

Approximately what percentage of blood is moving through the systemic circulation when the body is at rest?
A) 50%
B) 70%
C) 80%
D) 60%
E) 90%

B) 70%
Explanation: When the body is at rest, about 70% of the blood is circulating through the systemic circulation, highlighting its dominance in the overall circulatory system.

p.10
Blood Vascular System Components

What is the primary function of arterioles in the circulatory system?
A) Conduct blood from the heart
B) Distribute blood to all organs
C) Resist and control blood flow to capillaries
D) Exchange metabolites by diffusion
E) Return blood to the heart

C) Resist and control blood flow to capillaries
Explanation: Arterioles play a crucial role in regulating blood flow to capillaries and are major determinants of systemic blood pressure, making them essential in the circulatory system.

Study Smarter, Not Harder
Study Smarter, Not Harder