ATI TEAS 7 SCIENCE EXAM VERSION 1-3|| 3
DIFFERENT VERSION ALL QUESTIONS AND
100% CORRECT ANSWERS
Version 1: Human Anatomy & Physiology Focus
Questions 1-25: Cardiovascular & Respiratory Systems
1. Which of the following structures prevents blood from flowing backward from the left
ventricle into the left atrium?
A) Tricuspid valve
B) Pulmonary valve
C) Mitral valve
D) Aortic valve
Correct Answer: C) Mitral valve
Rationale: The mitral valve (also called the bicuspid valve) is located between the left atrium
and left ventricle. It prevents backflow of oxygenated blood into the left atrium when the left
ventricle contracts. The tricuspid valve separates the right atrium and right ventricle, while
the pulmonary and aortic valves are semilunar valves controlling flow into the pulmonary
artery and aorta respectively.
2. During inhalation, which of the following events occurs?
A) The diaphragm relaxes and moves upward
B) Intrathoracic pressure increases
C) The diaphragm contracts and flattens
D) The rib cage moves downward and inward
Correct Answer: C) The diaphragm contracts and flattens
Rationale: During inhalation (inspiration), the diaphragm contracts and flattens, increasing
the vertical dimension of the thoracic cavity. Simultaneously, the external intercostal muscles
contract, lifting the rib cage upward and outward. These actions decrease intrathoracic
pressure below atmospheric pressure, allowing air to flow into the lungs.
3. Which component of blood is primarily responsible for oxygen transport?
A) White blood cells
B) Platelets
C) Plasma
D) Red blood cells
Correct Answer: D) Red blood cells
,Rationale: Red blood cells (erythrocytes) contain hemoglobin, a protein with iron-containing
heme groups that bind reversibly to oxygen. Each hemoglobin molecule can carry up to four
oxygen molecules. White blood cells function in immunity, platelets in clotting, and plasma is
the liquid matrix that transports cells, nutrients, and waste products.
4. The sinoatrial (SA) node is located in which chamber of the heart?
A) Right ventricle
B) Left atrium
C) Right atrium
D) Left ventricle
Correct Answer: C) Right atrium
Rationale: The sinoatrial (SA) node, the heart's natural pacemaker, is located in the wall of
the right atrium near the opening of the superior vena cava. It generates electrical impulses
that initiate each heartbeat by causing atrial contraction before the impulse travels to the
atrioventricular (AV) node.
5. What is the primary function of the alveoli?
A) Produce mucus to trap pathogens
B) Warm and humidify incoming air
C) Facilitate gas exchange between air and blood
D) Filter particulate matter from inspired air
Correct Answer: C) Facilitate gas exchange between air and blood
Rationale: Alveoli are microscopic air sacs surrounded by pulmonary capillaries. Their thin
walls (one cell layer thick) allow for efficient diffusion of oxygen into the blood and carbon
dioxide out of the blood. This is the primary site of gas exchange in the respiratory system.
6. Which of the following correctly lists the pathway of blood flow through the heart?
A) Right atrium → right ventricle → lungs → left atrium → left ventricle → body
B) Left atrium → left ventricle → lungs → right atrium → right ventricle → body
C) Right atrium → left atrium → lungs → right ventricle → left ventricle → body
D) Left ventricle → left atrium → lungs → right ventricle → right atrium → body
Correct Answer: A) Right atrium → right ventricle → lungs → left atrium → left ventricle →
body
Rationale: Deoxygenated blood returns to the right atrium via the superior and inferior vena
cavae, flows into the right ventricle, and is pumped to the lungs via the pulmonary artery.
Oxygenated blood returns to the left atrium via pulmonary veins, flows into the left ventricle,
and is pumped to the body via the aorta.
7. What is the term for the volume of air that remains in the lungs after maximal
exhalation?
A) Tidal volume
,B) Vital capacity
C) Residual volume
D) Inspiratory reserve volume
Correct Answer: C) Residual volume
Rationale: Residual volume is the amount of air remaining in the lungs after a forceful
maximal exhalation. This volume (approximately 1,200 mL in adults) prevents lung collapse
and allows continuous gas exchange between breaths. Tidal volume is normal breath
volume, vital capacity is maximum exhaled volume after maximum inhalation, and
inspiratory reserve volume is additional air that can be inhaled after normal inspiration.
8. Which of the following blood vessels carries deoxygenated blood from the heart to the
lungs?
A) Aorta
B) Pulmonary vein
C) Pulmonary artery
D) Superior vena cava
Correct Answer: C) Pulmonary artery
Rationale: The pulmonary artery is unique as it carries deoxygenated blood from the right
ventricle to the lungs for oxygenation. The aorta carries oxygenated blood to the body,
pulmonary veins carry oxygenated blood from lungs to left atrium, and the superior vena
cava returns deoxygenated blood from the upper body to the right atrium.
9. The structure that connects the pharynx to the trachea and contains the vocal cords is
the:
A) Bronchus
B) Larynx
C) Esophagus
D) Epiglottis
Correct Answer: B) Larynx
Rationale: The larynx (voice box) connects the pharynx to the trachea and houses the vocal
cords (vocal folds). It also contains the epiglottis, which covers the trachea during
swallowing to prevent aspiration. The bronchi are airway branches, and the esophagus is the
food passageway behind the trachea.
10. Which component of the cardiac conduction system transmits impulses from the atria
to the ventricles?
A) Purkinje fibers
B) Bundle branches
C) Atrioventricular (AV) node
D) Bundle of His
, Correct Answer: C) Atrioventricular (AV) node
Rationale: The AV node is located in the lower portion of the right atrium and receives
impulses from the SA node. It delays the impulse slightly to allow complete atrial contraction
before transmitting it to the Bundle of His, then bundle branches, and finally Purkinje fibers,
which stimulate ventricular contraction.
11. Surfactant produced by type II alveolar cells serves which primary function?
A) Traps pathogens and debris
B) Reduces surface tension in the alveoli
C) Produces antibodies for immune defense
D) Transports oxygen across the alveolar membrane
Correct Answer: B) Reduces surface tension in the alveoli
Rationale: Surfactant is a phospholipoprotein that reduces surface tension within the alveoli,
preventing their collapse during exhalation. Without adequate surfactant (as seen in
premature infants with respiratory distress syndrome), alveoli collapse with each breath,
requiring significantly increased work of breathing.
12. Which of the following statements about blood pressure is correct?
A) Systolic pressure represents ventricular relaxation
B) Diastolic pressure represents ventricular contraction
C) Systolic pressure is the peak pressure during ventricular contraction
D) Blood pressure is highest in the vena cava
Correct Answer: C) Systolic pressure is the peak pressure during ventricular contraction
Rationale: Systolic pressure is the maximum arterial pressure achieved during ventricular
systole (contraction). Diastolic pressure is the minimum arterial pressure during ventricular
relaxation. Blood pressure is highest in the aorta and decreases through arteries, arterioles,
capillaries, venules, and veins, with the lowest pressure in the vena cavae.
13. The primary muscles involved in forced exhalation include:
A) Diaphragm and external intercostals
B) Internal intercostals and abdominal muscles
C) Sternocleidomastoid and scalenes
D) Pectoralis major and serratus anterior
Correct Answer: B) Internal intercostals and abdominal muscles
Rationale: Normal exhalation is passive due to elastic recoil. Forced exhalation requires
contraction of the internal intercostals (which pull ribs downward) and abdominal muscles
(which compress abdominal contents, pushing the diaphragm upward). The diaphragm and
external intercostals are primary inhalation muscles, while accessory muscles like
sternocleidomastoid are used during labored inhalation.
DIFFERENT VERSION ALL QUESTIONS AND
100% CORRECT ANSWERS
Version 1: Human Anatomy & Physiology Focus
Questions 1-25: Cardiovascular & Respiratory Systems
1. Which of the following structures prevents blood from flowing backward from the left
ventricle into the left atrium?
A) Tricuspid valve
B) Pulmonary valve
C) Mitral valve
D) Aortic valve
Correct Answer: C) Mitral valve
Rationale: The mitral valve (also called the bicuspid valve) is located between the left atrium
and left ventricle. It prevents backflow of oxygenated blood into the left atrium when the left
ventricle contracts. The tricuspid valve separates the right atrium and right ventricle, while
the pulmonary and aortic valves are semilunar valves controlling flow into the pulmonary
artery and aorta respectively.
2. During inhalation, which of the following events occurs?
A) The diaphragm relaxes and moves upward
B) Intrathoracic pressure increases
C) The diaphragm contracts and flattens
D) The rib cage moves downward and inward
Correct Answer: C) The diaphragm contracts and flattens
Rationale: During inhalation (inspiration), the diaphragm contracts and flattens, increasing
the vertical dimension of the thoracic cavity. Simultaneously, the external intercostal muscles
contract, lifting the rib cage upward and outward. These actions decrease intrathoracic
pressure below atmospheric pressure, allowing air to flow into the lungs.
3. Which component of blood is primarily responsible for oxygen transport?
A) White blood cells
B) Platelets
C) Plasma
D) Red blood cells
Correct Answer: D) Red blood cells
,Rationale: Red blood cells (erythrocytes) contain hemoglobin, a protein with iron-containing
heme groups that bind reversibly to oxygen. Each hemoglobin molecule can carry up to four
oxygen molecules. White blood cells function in immunity, platelets in clotting, and plasma is
the liquid matrix that transports cells, nutrients, and waste products.
4. The sinoatrial (SA) node is located in which chamber of the heart?
A) Right ventricle
B) Left atrium
C) Right atrium
D) Left ventricle
Correct Answer: C) Right atrium
Rationale: The sinoatrial (SA) node, the heart's natural pacemaker, is located in the wall of
the right atrium near the opening of the superior vena cava. It generates electrical impulses
that initiate each heartbeat by causing atrial contraction before the impulse travels to the
atrioventricular (AV) node.
5. What is the primary function of the alveoli?
A) Produce mucus to trap pathogens
B) Warm and humidify incoming air
C) Facilitate gas exchange between air and blood
D) Filter particulate matter from inspired air
Correct Answer: C) Facilitate gas exchange between air and blood
Rationale: Alveoli are microscopic air sacs surrounded by pulmonary capillaries. Their thin
walls (one cell layer thick) allow for efficient diffusion of oxygen into the blood and carbon
dioxide out of the blood. This is the primary site of gas exchange in the respiratory system.
6. Which of the following correctly lists the pathway of blood flow through the heart?
A) Right atrium → right ventricle → lungs → left atrium → left ventricle → body
B) Left atrium → left ventricle → lungs → right atrium → right ventricle → body
C) Right atrium → left atrium → lungs → right ventricle → left ventricle → body
D) Left ventricle → left atrium → lungs → right ventricle → right atrium → body
Correct Answer: A) Right atrium → right ventricle → lungs → left atrium → left ventricle →
body
Rationale: Deoxygenated blood returns to the right atrium via the superior and inferior vena
cavae, flows into the right ventricle, and is pumped to the lungs via the pulmonary artery.
Oxygenated blood returns to the left atrium via pulmonary veins, flows into the left ventricle,
and is pumped to the body via the aorta.
7. What is the term for the volume of air that remains in the lungs after maximal
exhalation?
A) Tidal volume
,B) Vital capacity
C) Residual volume
D) Inspiratory reserve volume
Correct Answer: C) Residual volume
Rationale: Residual volume is the amount of air remaining in the lungs after a forceful
maximal exhalation. This volume (approximately 1,200 mL in adults) prevents lung collapse
and allows continuous gas exchange between breaths. Tidal volume is normal breath
volume, vital capacity is maximum exhaled volume after maximum inhalation, and
inspiratory reserve volume is additional air that can be inhaled after normal inspiration.
8. Which of the following blood vessels carries deoxygenated blood from the heart to the
lungs?
A) Aorta
B) Pulmonary vein
C) Pulmonary artery
D) Superior vena cava
Correct Answer: C) Pulmonary artery
Rationale: The pulmonary artery is unique as it carries deoxygenated blood from the right
ventricle to the lungs for oxygenation. The aorta carries oxygenated blood to the body,
pulmonary veins carry oxygenated blood from lungs to left atrium, and the superior vena
cava returns deoxygenated blood from the upper body to the right atrium.
9. The structure that connects the pharynx to the trachea and contains the vocal cords is
the:
A) Bronchus
B) Larynx
C) Esophagus
D) Epiglottis
Correct Answer: B) Larynx
Rationale: The larynx (voice box) connects the pharynx to the trachea and houses the vocal
cords (vocal folds). It also contains the epiglottis, which covers the trachea during
swallowing to prevent aspiration. The bronchi are airway branches, and the esophagus is the
food passageway behind the trachea.
10. Which component of the cardiac conduction system transmits impulses from the atria
to the ventricles?
A) Purkinje fibers
B) Bundle branches
C) Atrioventricular (AV) node
D) Bundle of His
, Correct Answer: C) Atrioventricular (AV) node
Rationale: The AV node is located in the lower portion of the right atrium and receives
impulses from the SA node. It delays the impulse slightly to allow complete atrial contraction
before transmitting it to the Bundle of His, then bundle branches, and finally Purkinje fibers,
which stimulate ventricular contraction.
11. Surfactant produced by type II alveolar cells serves which primary function?
A) Traps pathogens and debris
B) Reduces surface tension in the alveoli
C) Produces antibodies for immune defense
D) Transports oxygen across the alveolar membrane
Correct Answer: B) Reduces surface tension in the alveoli
Rationale: Surfactant is a phospholipoprotein that reduces surface tension within the alveoli,
preventing their collapse during exhalation. Without adequate surfactant (as seen in
premature infants with respiratory distress syndrome), alveoli collapse with each breath,
requiring significantly increased work of breathing.
12. Which of the following statements about blood pressure is correct?
A) Systolic pressure represents ventricular relaxation
B) Diastolic pressure represents ventricular contraction
C) Systolic pressure is the peak pressure during ventricular contraction
D) Blood pressure is highest in the vena cava
Correct Answer: C) Systolic pressure is the peak pressure during ventricular contraction
Rationale: Systolic pressure is the maximum arterial pressure achieved during ventricular
systole (contraction). Diastolic pressure is the minimum arterial pressure during ventricular
relaxation. Blood pressure is highest in the aorta and decreases through arteries, arterioles,
capillaries, venules, and veins, with the lowest pressure in the vena cavae.
13. The primary muscles involved in forced exhalation include:
A) Diaphragm and external intercostals
B) Internal intercostals and abdominal muscles
C) Sternocleidomastoid and scalenes
D) Pectoralis major and serratus anterior
Correct Answer: B) Internal intercostals and abdominal muscles
Rationale: Normal exhalation is passive due to elastic recoil. Forced exhalation requires
contraction of the internal intercostals (which pull ribs downward) and abdominal muscles
(which compress abdominal contents, pushing the diaphragm upward). The diaphragm and
external intercostals are primary inhalation muscles, while accessory muscles like
sternocleidomastoid are used during labored inhalation.
