COMSAE 114 EXAM | 2026/2027 Edition | Real Exam
Questions with 100% Verified Correct Answers
National Board of Osteopathic Medical Examiners (NBOME) COMSAE | Expert-Verified Q&A | Certification-
Ready Format
Introduction
This document presents the COMSAE 114 actual exam focusing on the critical integration of basic and clinical
biomedical sciences, osteopathic principles and practice (OPP), normal and abnormal structure and function, and
clinical decision-making required to demonstrate readiness for the COMLEX-USA and safe, competent medical
practice. All 200 questions are expert-verified with 100% correct answers, designed for accurate evaluation and
pass-level readiness in accordance with the 2026/2027 NBOME COMSAE blueprint.
Content Area Overview
Content Area Questions Key Topics Weight
Normal Structure and 50 Anatomy, physiology, 25%
Function biochemistry, histology,
embryology
Abnormal Structure and 50 Pathology, 25%
Function pathophysiology,
microbiology,
immunology
Diagnostic Studies and 50 History & physical, 25%
Clinical Medicine lab/imaging
interpretation,
differential diagnosis
Osteopathic Principles 50 OPP, OMT, ethics, patient 25%
and Practice (OPP) & management, evidence-
Medical Decision Making based medicine
Total 200 100%
Examination Questions
Domain: Normal Structure and Function
1. Which structure is responsible for the production of cerebrospinal fluid?
A. Choroid plexus
B. Arachnoid granulations
C. Dura mater
D. Pia mater
Correct Answer: A
Rationale: The choroid plexus produces cerebrospinal fluid in the ventricles.
Why Wrong: B absorbs CSF. C and D are meningeal layers.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
2. What is the primary function of the sodium-potassium pump?
A. To create a resting membrane potential by pumping sodium out and potassium in
B. To generate action potentials
C. To transport glucose into cells
D. To produce ATP
,Correct Answer: A
Rationale: The Na+/K+ ATPase maintains the resting membrane potential by pumping 3 Na+ out and 2
K+ in.
Why Wrong: B is the result of the gradient. C is GLUT transporters. D is oxidative phosphorylation.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
3. Which cranial nerve is responsible for taste sensation from the anterior two-thirds of the
tongue?
A. Facial nerve (CN VII)
B. Glossopharyngeal nerve (CN IX)
C. Vagus nerve (CN X)
D. Trigeminal nerve (CN V)
Correct Answer: A
Rationale: The facial nerve (via chorda tympani) carries taste from the anterior 2/3 of the tongue.
Why Wrong: B carries posterior 1/3. C carries from epiglottis. D is general sensation.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
4. What is the primary site of erythropoietin production in adults?
A. Liver
B. Kidneys
C. Bone marrow
D. Spleen
Correct Answer: B
Rationale: The kidneys produce erythropoietin in response to hypoxia.
Why Wrong: A produces EPO in fetuses. C is where RBCs are made. D is not primary.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
5. Which layer of the heart wall is responsible for contraction?
A. Epicardium
B. Myocardium
C. Endocardium
D. Pericardium
Correct Answer: B
Rationale: The myocardium is the thick muscular layer responsible for contraction.
Why Wrong: A is the outer layer. C is the inner lining. D is the sac.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
6. What is the normal range for arterial blood pH?
A. 7.0 – 7.2
B. 7.35 – 7.45
C. 7.5 – 7.7
D. 6.8 – 7.0
Correct Answer: B
Rationale: Normal arterial pH is tightly regulated between 7.35 and 7.45.
Why Wrong: A and D are acidotic. C is alkalotic.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
,7. Which hormone is primarily responsible for milk ejection during lactation?
A. Prolactin
B. Oxytocin
C. Estrogen
D. Progesterone
Correct Answer: B
Rationale: Oxytocin causes myoepithelial cell contraction leading to milk ejection.
Why Wrong: A stimulates milk production. C and D are pregnancy hormones.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
8. What is the functional unit of the kidney?
A. Glomerulus
B. Nephron
C. Loop of Henle
D. Collecting duct
Correct Answer: B
Rationale: The nephron is the functional unit of the kidney.
Why Wrong: A is part of the nephron. C and D are segments within the nephron.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
9. Which vitamin is essential for the synthesis of clotting factors II, VII, IX, and X?
A. Vitamin A
B. Vitamin K
C. Vitamin D
D. Vitamin C
Correct Answer: B
Rationale: Vitamin K is required for gamma-carboxylation of clotting factors.
Why Wrong: A is for vision. C is for calcium. D is for collagen.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
10. What is the primary neurotransmitter at the neuromuscular junction?
A. Norepinephrine
B. Acetylcholine
C. Dopamine
D. GABA
Correct Answer: B
Rationale: Acetylcholine is released at the neuromuscular junction to trigger muscle contraction.
Why Wrong: A is sympathetic. C is CNS. D is inhibitory.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
11. Which structure connects the two cerebral hemispheres?
A. Corpus callosum
B. Fornix
C. Thalamus
D. Internal capsule
Correct Answer: A
Rationale: The corpus callosum is the major commissure connecting the hemispheres.
, Why Wrong: B is limbic. C is relay. D is white matter tract.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
12. What is the normal glomerular filtration rate (GFR) in a healthy adult?
A. 60–80 mL/min
B. 90–120 mL/min
C. 30–50 mL/min
D. 150–180 mL/min
Correct Answer: B
Rationale: Normal GFR is approximately 90–120 mL/min/1.73m².
Why Wrong: A is mild decrease. C is moderate decrease. D is elevated.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
13. Which hormone stimulates the release of thyroid-stimulating hormone (TSH)?
A. Thyrotropin-releasing hormone (TRH)
B. Corticotropin-releasing hormone (CRH)
C. Gonadotropin-releasing hormone (GnRH)
D. Growth hormone-releasing hormone (GHRH)
Correct Answer: A
Rationale: TRH from the hypothalamus stimulates TSH release from the anterior pituitary.
Why Wrong: B stimulates ACTH. C stimulates FSH/LH. D stimulates GH.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
14. What is the primary function of surfactant in the lungs?
A. To increase surface tension
B. To decrease surface tension and prevent alveolar collapse
C. To increase oxygen diffusion
D. To produce mucus
Correct Answer: B
Rationale: Surfactant (dipalmitoylphosphatidylcholine) reduces surface tension.
Why Wrong: A is the opposite. C and D are incorrect.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
15. Which cell type is responsible for producing myelin in the central nervous system?
A. Schwann cells
B. Oligodendrocytes
C. Astrocytes
D. Microglia
Correct Answer: B
Rationale: Oligodendrocytes myelinate axons in the CNS.
Why Wrong: A myelinate in the PNS. C support neurons. D are immune cells.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
16. What is the normal fasting blood glucose level?
A. 40–60 mg/dL
B. 70–99 mg/dL
C. 100–125 mg/dL
Questions with 100% Verified Correct Answers
National Board of Osteopathic Medical Examiners (NBOME) COMSAE | Expert-Verified Q&A | Certification-
Ready Format
Introduction
This document presents the COMSAE 114 actual exam focusing on the critical integration of basic and clinical
biomedical sciences, osteopathic principles and practice (OPP), normal and abnormal structure and function, and
clinical decision-making required to demonstrate readiness for the COMLEX-USA and safe, competent medical
practice. All 200 questions are expert-verified with 100% correct answers, designed for accurate evaluation and
pass-level readiness in accordance with the 2026/2027 NBOME COMSAE blueprint.
Content Area Overview
Content Area Questions Key Topics Weight
Normal Structure and 50 Anatomy, physiology, 25%
Function biochemistry, histology,
embryology
Abnormal Structure and 50 Pathology, 25%
Function pathophysiology,
microbiology,
immunology
Diagnostic Studies and 50 History & physical, 25%
Clinical Medicine lab/imaging
interpretation,
differential diagnosis
Osteopathic Principles 50 OPP, OMT, ethics, patient 25%
and Practice (OPP) & management, evidence-
Medical Decision Making based medicine
Total 200 100%
Examination Questions
Domain: Normal Structure and Function
1. Which structure is responsible for the production of cerebrospinal fluid?
A. Choroid plexus
B. Arachnoid granulations
C. Dura mater
D. Pia mater
Correct Answer: A
Rationale: The choroid plexus produces cerebrospinal fluid in the ventricles.
Why Wrong: B absorbs CSF. C and D are meningeal layers.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
2. What is the primary function of the sodium-potassium pump?
A. To create a resting membrane potential by pumping sodium out and potassium in
B. To generate action potentials
C. To transport glucose into cells
D. To produce ATP
,Correct Answer: A
Rationale: The Na+/K+ ATPase maintains the resting membrane potential by pumping 3 Na+ out and 2
K+ in.
Why Wrong: B is the result of the gradient. C is GLUT transporters. D is oxidative phosphorylation.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
3. Which cranial nerve is responsible for taste sensation from the anterior two-thirds of the
tongue?
A. Facial nerve (CN VII)
B. Glossopharyngeal nerve (CN IX)
C. Vagus nerve (CN X)
D. Trigeminal nerve (CN V)
Correct Answer: A
Rationale: The facial nerve (via chorda tympani) carries taste from the anterior 2/3 of the tongue.
Why Wrong: B carries posterior 1/3. C carries from epiglottis. D is general sensation.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
4. What is the primary site of erythropoietin production in adults?
A. Liver
B. Kidneys
C. Bone marrow
D. Spleen
Correct Answer: B
Rationale: The kidneys produce erythropoietin in response to hypoxia.
Why Wrong: A produces EPO in fetuses. C is where RBCs are made. D is not primary.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
5. Which layer of the heart wall is responsible for contraction?
A. Epicardium
B. Myocardium
C. Endocardium
D. Pericardium
Correct Answer: B
Rationale: The myocardium is the thick muscular layer responsible for contraction.
Why Wrong: A is the outer layer. C is the inner lining. D is the sac.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
6. What is the normal range for arterial blood pH?
A. 7.0 – 7.2
B. 7.35 – 7.45
C. 7.5 – 7.7
D. 6.8 – 7.0
Correct Answer: B
Rationale: Normal arterial pH is tightly regulated between 7.35 and 7.45.
Why Wrong: A and D are acidotic. C is alkalotic.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
,7. Which hormone is primarily responsible for milk ejection during lactation?
A. Prolactin
B. Oxytocin
C. Estrogen
D. Progesterone
Correct Answer: B
Rationale: Oxytocin causes myoepithelial cell contraction leading to milk ejection.
Why Wrong: A stimulates milk production. C and D are pregnancy hormones.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
8. What is the functional unit of the kidney?
A. Glomerulus
B. Nephron
C. Loop of Henle
D. Collecting duct
Correct Answer: B
Rationale: The nephron is the functional unit of the kidney.
Why Wrong: A is part of the nephron. C and D are segments within the nephron.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
9. Which vitamin is essential for the synthesis of clotting factors II, VII, IX, and X?
A. Vitamin A
B. Vitamin K
C. Vitamin D
D. Vitamin C
Correct Answer: B
Rationale: Vitamin K is required for gamma-carboxylation of clotting factors.
Why Wrong: A is for vision. C is for calcium. D is for collagen.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
10. What is the primary neurotransmitter at the neuromuscular junction?
A. Norepinephrine
B. Acetylcholine
C. Dopamine
D. GABA
Correct Answer: B
Rationale: Acetylcholine is released at the neuromuscular junction to trigger muscle contraction.
Why Wrong: A is sympathetic. C is CNS. D is inhibitory.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
11. Which structure connects the two cerebral hemispheres?
A. Corpus callosum
B. Fornix
C. Thalamus
D. Internal capsule
Correct Answer: A
Rationale: The corpus callosum is the major commissure connecting the hemispheres.
, Why Wrong: B is limbic. C is relay. D is white matter tract.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
12. What is the normal glomerular filtration rate (GFR) in a healthy adult?
A. 60–80 mL/min
B. 90–120 mL/min
C. 30–50 mL/min
D. 150–180 mL/min
Correct Answer: B
Rationale: Normal GFR is approximately 90–120 mL/min/1.73m².
Why Wrong: A is mild decrease. C is moderate decrease. D is elevated.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
13. Which hormone stimulates the release of thyroid-stimulating hormone (TSH)?
A. Thyrotropin-releasing hormone (TRH)
B. Corticotropin-releasing hormone (CRH)
C. Gonadotropin-releasing hormone (GnRH)
D. Growth hormone-releasing hormone (GHRH)
Correct Answer: A
Rationale: TRH from the hypothalamus stimulates TSH release from the anterior pituitary.
Why Wrong: B stimulates ACTH. C stimulates FSH/LH. D stimulates GH.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
14. What is the primary function of surfactant in the lungs?
A. To increase surface tension
B. To decrease surface tension and prevent alveolar collapse
C. To increase oxygen diffusion
D. To produce mucus
Correct Answer: B
Rationale: Surfactant (dipalmitoylphosphatidylcholine) reduces surface tension.
Why Wrong: A is the opposite. C and D are incorrect.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
15. Which cell type is responsible for producing myelin in the central nervous system?
A. Schwann cells
B. Oligodendrocytes
C. Astrocytes
D. Microglia
Correct Answer: B
Rationale: Oligodendrocytes myelinate axons in the CNS.
Why Wrong: A myelinate in the PNS. C support neurons. D are immune cells.
Reference: 2026 COMSAE Blueprint, Domain 1 - Normal Structure and Function, First Aid for COMLEX &
Foundations of Osteopathic Medicine.
16. What is the normal fasting blood glucose level?
A. 40–60 mg/dL
B. 70–99 mg/dL
C. 100–125 mg/dL
