ATI TEAS 7 SCIENCE EXAM VERSION 1-3|| 3
DIFFERENT VERSION 150 QUESTIONS AND 100%
CORRECT VERIFIED ANSWERS
Test Bank: 150 Questions with Detailed Rationales
Section 1: Human Anatomy & Physiology – Cardiovascular and
Respiratory Systems (Questions 1-20)
1. Which of the following correctly describes the pathway of blood flow through the
pulmonary circulation?
A) Left ventricle → aorta → body → vena cava → right atrium
B) Right ventricle → pulmonary artery → lungs → pulmonary vein → left atrium
C) Right atrium → pulmonary vein → lungs → pulmonary artery → left ventricle
D) Left atrium → pulmonary artery → lungs → pulmonary vein → right ventricle
Correct Answer: B) Right ventricle → pulmonary artery → lungs → pulmonary vein → left
atrium
Rationale: Pulmonary circulation carries deoxygenated blood from the right ventricle to the
lungs via the pulmonary artery. After gas exchange, oxygenated blood returns to the left
atrium via pulmonary veins. This is the only circuit where arteries carry deoxygenated blood
and veins carry oxygenated blood.
2. Which of the following structures prevents food from entering the trachea during
swallowing?
A) Epiglottis
B) Uvula
C) Pharynx
D) Larynx
Correct Answer: A) Epiglottis
Rationale: The epiglottis is a flap of elastic cartilage that folds downward during swallowing
to cover the glottis (opening to the larynx and trachea). This mechanism prevents aspiration
of food and liquids into the lower respiratory tract. The uvula prevents food from entering
the nasopharynx.
3. Which component of the cardiac conduction system is known as the "pacemaker" of the
heart?
A) Atrioventricular (AV) node
B) Purkinje fibers
C) Bundle of His
D) Sinoatrial (SA) node
,Correct Answer: D) Sinoatrial (SA) node
Rationale: The SA node, located in the right atrium, generates electrical impulses
spontaneously at a rate of 60-100 times per minute, establishing the heart's rhythm. While
other structures can generate impulses, the SA node normally dominates as the primary
pacemaker due to its fastest intrinsic firing rate.
4. Which of the following correctly describes the relationship between intrapulmonary
pressure and atmospheric pressure during inhalation?
A) Intrapulmonary pressure is greater than atmospheric pressure
B) Intrapulmonary pressure is less than atmospheric pressure
C) Intrapulmonary pressure equals atmospheric pressure
D) Intrapulmonary pressure fluctuates independently
Correct Answer: B) Intrapulmonary pressure is less than atmospheric pressure
Rationale: During inhalation, the diaphragm contracts and flattens, increasing thoracic
volume. According to Boyle's law, increased volume decreases intrapulmonary pressure
below atmospheric pressure (negative pressure), creating a pressure gradient that draws air
into the lungs.
5. Which of the following blood vessels has the thickest tunica media relative to its lumen
diameter?
A) Vein
B) Capillary
C) Arteriole
D) Artery
Correct Answer: D) Artery
Rationale: Arteries have the thickest tunica media, composed of smooth muscle and elastic
tissue, allowing them to withstand and maintain high blood pressure. Arterioles also have
significant smooth muscle for resistance regulation. Veins have thinner walls, and capillaries
consist of a single endothelial layer.
6. Which of the following is the primary site of gas exchange in the respiratory system?
A) Bronchioles
B) Terminal bronchioles
C) Alveoli
D) Respiratory bronchioles
Correct Answer: C) Alveoli
Rationale: Alveoli are thin-walled air sacs surrounded by pulmonary capillaries, forming the
respiratory membrane where gas exchange occurs. Their large surface area (approximately
,70-100 m²), thin walls, and extensive capillary network optimize diffusion of oxygen and
carbon dioxide.
7. Which of the following correctly describes the function of the chordae tendineae?
A) Generate action potentials in the ventricles
B) Prevent prolapse of the atrioventricular valves
C) Anchor the semilunar valves
D) Connect the atria to the ventricles
Correct Answer: B) Prevent prolapse of the atrioventricular valves
Rationale: Chordae tendineae are fibrous cords that attach the AV valves (mitral and
tricuspid) to the papillary muscles in the ventricles. During ventricular contraction, the
papillary muscles contract, tightening the chordae tendineae to prevent valve leaflets from
everting into the atria.
8. Which of the following correctly lists the order of structures that air passes through
during inhalation?
A) Pharynx → larynx → trachea → bronchi → bronchioles → alveoli
B) Larynx → pharynx → trachea → bronchi → bronchioles → alveoli
C) Trachea → pharynx → larynx → bronchi → bronchioles → alveoli
D) Pharynx → trachea → larynx → bronchi → alveoli → bronchioles
Correct Answer: A) Pharynx → larynx → trachea → bronchi → bronchioles → alveoli
Rationale: Air enters through the nasal cavity, passes through the pharynx (throat), larynx
(voice box), trachea (windpipe), primary bronchi, secondary bronchi, tertiary bronchi,
bronchioles, terminal bronchioles, respiratory bronchioles, and finally reaches the alveoli
where gas exchange occurs.
9. Which of the following is a characteristic of the pulmonary veins?
A) Carry deoxygenated blood to the lungs
B) Carry oxygenated blood to the left atrium
C) Have thick muscular walls
D) Contain valves to prevent backflow
Correct Answer: B) Carry oxygenated blood to the left atrium
Rationale: Pulmonary veins are unique among veins as they carry oxygenated blood from
the lungs to the left atrium. There are four pulmonary veins (two from each lung). They have
thinner walls than arteries and, like other veins, contain valves to prevent backflow.
10. Which of the following factors would most likely decrease oxygen-hemoglobin binding
affinity?
A) Increased pH (alkalosis)
B) Decreased temperature
, C) Increased partial pressure of carbon dioxide
D) Decreased 2,3-DPG
Correct Answer: C) Increased partial pressure of carbon dioxide
Rationale: Increased PCO₂ decreases hemoglobin's oxygen affinity (Bohr effect), shifting the
dissociation curve to the right and facilitating oxygen unloading in metabolically active
tissues. Increased pH, decreased temperature, and decreased 2,3-DPG all increase oxygen
affinity.
11. Which of the following correctly describes the function of the pleural membranes?
A) Produce surfactant to reduce surface tension
B) Create a negative pressure space for lung expansion
C) Exchange gases between blood and air
D) Warm and humidify inspired air
Correct Answer: B) Create a negative pressure space for lung expansion
Rationale: The pleural membranes (visceral and parietal pleurae) enclose the pleural cavity
containing a thin layer of fluid. This creates surface tension that adheres the lungs to the
thoracic wall, allowing the lungs to expand and contract with thoracic movements. The
negative intrapleural pressure is essential for ventilation.
12. Which of the following correctly describes the QRS complex on an electrocardiogram
(ECG)?
A) Atrial depolarization
B) Ventricular depolarization
C) Ventricular repolarization
D) Atrial repolarization
Correct Answer: B) Ventricular depolarization
Rationale: The QRS complex represents ventricular depolarization, which triggers ventricular
contraction. The P wave represents atrial depolarization, and the T wave represents
ventricular repolarization. Atrial repolarization occurs during the QRS complex and is
obscured by the larger ventricular signal.
13. Which of the following is the functional unit of the respiratory system?
A) Alveolus
B) Bronchiole
C) Respiratory membrane
D) Lobule
Correct Answer: A) Alveolus
Rationale: The alveolus is the functional unit of the respiratory system because gas exchange
occurs across its walls. While the respiratory membrane (alveolar wall + capillary wall) is the
DIFFERENT VERSION 150 QUESTIONS AND 100%
CORRECT VERIFIED ANSWERS
Test Bank: 150 Questions with Detailed Rationales
Section 1: Human Anatomy & Physiology – Cardiovascular and
Respiratory Systems (Questions 1-20)
1. Which of the following correctly describes the pathway of blood flow through the
pulmonary circulation?
A) Left ventricle → aorta → body → vena cava → right atrium
B) Right ventricle → pulmonary artery → lungs → pulmonary vein → left atrium
C) Right atrium → pulmonary vein → lungs → pulmonary artery → left ventricle
D) Left atrium → pulmonary artery → lungs → pulmonary vein → right ventricle
Correct Answer: B) Right ventricle → pulmonary artery → lungs → pulmonary vein → left
atrium
Rationale: Pulmonary circulation carries deoxygenated blood from the right ventricle to the
lungs via the pulmonary artery. After gas exchange, oxygenated blood returns to the left
atrium via pulmonary veins. This is the only circuit where arteries carry deoxygenated blood
and veins carry oxygenated blood.
2. Which of the following structures prevents food from entering the trachea during
swallowing?
A) Epiglottis
B) Uvula
C) Pharynx
D) Larynx
Correct Answer: A) Epiglottis
Rationale: The epiglottis is a flap of elastic cartilage that folds downward during swallowing
to cover the glottis (opening to the larynx and trachea). This mechanism prevents aspiration
of food and liquids into the lower respiratory tract. The uvula prevents food from entering
the nasopharynx.
3. Which component of the cardiac conduction system is known as the "pacemaker" of the
heart?
A) Atrioventricular (AV) node
B) Purkinje fibers
C) Bundle of His
D) Sinoatrial (SA) node
,Correct Answer: D) Sinoatrial (SA) node
Rationale: The SA node, located in the right atrium, generates electrical impulses
spontaneously at a rate of 60-100 times per minute, establishing the heart's rhythm. While
other structures can generate impulses, the SA node normally dominates as the primary
pacemaker due to its fastest intrinsic firing rate.
4. Which of the following correctly describes the relationship between intrapulmonary
pressure and atmospheric pressure during inhalation?
A) Intrapulmonary pressure is greater than atmospheric pressure
B) Intrapulmonary pressure is less than atmospheric pressure
C) Intrapulmonary pressure equals atmospheric pressure
D) Intrapulmonary pressure fluctuates independently
Correct Answer: B) Intrapulmonary pressure is less than atmospheric pressure
Rationale: During inhalation, the diaphragm contracts and flattens, increasing thoracic
volume. According to Boyle's law, increased volume decreases intrapulmonary pressure
below atmospheric pressure (negative pressure), creating a pressure gradient that draws air
into the lungs.
5. Which of the following blood vessels has the thickest tunica media relative to its lumen
diameter?
A) Vein
B) Capillary
C) Arteriole
D) Artery
Correct Answer: D) Artery
Rationale: Arteries have the thickest tunica media, composed of smooth muscle and elastic
tissue, allowing them to withstand and maintain high blood pressure. Arterioles also have
significant smooth muscle for resistance regulation. Veins have thinner walls, and capillaries
consist of a single endothelial layer.
6. Which of the following is the primary site of gas exchange in the respiratory system?
A) Bronchioles
B) Terminal bronchioles
C) Alveoli
D) Respiratory bronchioles
Correct Answer: C) Alveoli
Rationale: Alveoli are thin-walled air sacs surrounded by pulmonary capillaries, forming the
respiratory membrane where gas exchange occurs. Their large surface area (approximately
,70-100 m²), thin walls, and extensive capillary network optimize diffusion of oxygen and
carbon dioxide.
7. Which of the following correctly describes the function of the chordae tendineae?
A) Generate action potentials in the ventricles
B) Prevent prolapse of the atrioventricular valves
C) Anchor the semilunar valves
D) Connect the atria to the ventricles
Correct Answer: B) Prevent prolapse of the atrioventricular valves
Rationale: Chordae tendineae are fibrous cords that attach the AV valves (mitral and
tricuspid) to the papillary muscles in the ventricles. During ventricular contraction, the
papillary muscles contract, tightening the chordae tendineae to prevent valve leaflets from
everting into the atria.
8. Which of the following correctly lists the order of structures that air passes through
during inhalation?
A) Pharynx → larynx → trachea → bronchi → bronchioles → alveoli
B) Larynx → pharynx → trachea → bronchi → bronchioles → alveoli
C) Trachea → pharynx → larynx → bronchi → bronchioles → alveoli
D) Pharynx → trachea → larynx → bronchi → alveoli → bronchioles
Correct Answer: A) Pharynx → larynx → trachea → bronchi → bronchioles → alveoli
Rationale: Air enters through the nasal cavity, passes through the pharynx (throat), larynx
(voice box), trachea (windpipe), primary bronchi, secondary bronchi, tertiary bronchi,
bronchioles, terminal bronchioles, respiratory bronchioles, and finally reaches the alveoli
where gas exchange occurs.
9. Which of the following is a characteristic of the pulmonary veins?
A) Carry deoxygenated blood to the lungs
B) Carry oxygenated blood to the left atrium
C) Have thick muscular walls
D) Contain valves to prevent backflow
Correct Answer: B) Carry oxygenated blood to the left atrium
Rationale: Pulmonary veins are unique among veins as they carry oxygenated blood from
the lungs to the left atrium. There are four pulmonary veins (two from each lung). They have
thinner walls than arteries and, like other veins, contain valves to prevent backflow.
10. Which of the following factors would most likely decrease oxygen-hemoglobin binding
affinity?
A) Increased pH (alkalosis)
B) Decreased temperature
, C) Increased partial pressure of carbon dioxide
D) Decreased 2,3-DPG
Correct Answer: C) Increased partial pressure of carbon dioxide
Rationale: Increased PCO₂ decreases hemoglobin's oxygen affinity (Bohr effect), shifting the
dissociation curve to the right and facilitating oxygen unloading in metabolically active
tissues. Increased pH, decreased temperature, and decreased 2,3-DPG all increase oxygen
affinity.
11. Which of the following correctly describes the function of the pleural membranes?
A) Produce surfactant to reduce surface tension
B) Create a negative pressure space for lung expansion
C) Exchange gases between blood and air
D) Warm and humidify inspired air
Correct Answer: B) Create a negative pressure space for lung expansion
Rationale: The pleural membranes (visceral and parietal pleurae) enclose the pleural cavity
containing a thin layer of fluid. This creates surface tension that adheres the lungs to the
thoracic wall, allowing the lungs to expand and contract with thoracic movements. The
negative intrapleural pressure is essential for ventilation.
12. Which of the following correctly describes the QRS complex on an electrocardiogram
(ECG)?
A) Atrial depolarization
B) Ventricular depolarization
C) Ventricular repolarization
D) Atrial repolarization
Correct Answer: B) Ventricular depolarization
Rationale: The QRS complex represents ventricular depolarization, which triggers ventricular
contraction. The P wave represents atrial depolarization, and the T wave represents
ventricular repolarization. Atrial repolarization occurs during the QRS complex and is
obscured by the larger ventricular signal.
13. Which of the following is the functional unit of the respiratory system?
A) Alveolus
B) Bronchiole
C) Respiratory membrane
D) Lobule
Correct Answer: A) Alveolus
Rationale: The alveolus is the functional unit of the respiratory system because gas exchange
occurs across its walls. While the respiratory membrane (alveolar wall + capillary wall) is the
