The HESI A2 Anatomy & Physiology section is the single most common deciding factor in HESI preparation outcomes. It carries 25–30 scored questions per exam form, rewards depth over breadth, and does not lend itself to cramming. This review covers the 12 body systems tested on the HESI, ranked by how often each one appears on recent exam forms, with specific focus points for each system.
The HESI A&P content was developed by doctoral-level health sciences faculty and mirrors the structure and depth of the actual exam. Questions test your ability to connect structure to function — not raw memorization. Students who understand why a body system does what it does consistently outperform students who only memorize what structures exist.
How to use this review
Work top-down. The four Highest/High-yield systems should take roughly 60% of your A&P study time. The Medium-yield systems take 30%. The Lower and Foundational topics together fit into the remaining 10% — they matter, but studying them first is one of the most common HESI preparation mistakes.
Heart chamber anatomy, cardiac cycle (systole/diastole), blood flow pathway through the heart and great vessels, electrical conduction (SA/AV nodes, bundle of His), blood pressure regulation, and the composition of blood (plasma, erythrocytes, leukocytes, platelets).
Exam tip: If you learn only one body system cold, make it this one. Nearly every HESI A2 administration includes multiple cardiovascular questions.
Upper and lower respiratory tract anatomy, ventilation mechanics (Boyle’s law applied to inspiration and expiration), gas exchange at the alveolar-capillary membrane, oxygen and CO2 transport in blood, and central respiratory control (medullary chemoreceptors).
Exam tip: Questions often pair anatomy with function — do not memorize structures without learning what they do.
Kidney gross anatomy and the nephron in detail (glomerulus, Bowman’s capsule, PCT, loop of Henle, DCT, collecting duct), the three processes of urine formation (filtration, reabsorption, secretion), fluid and electrolyte balance, and acid-base regulation.
Exam tip: Know the nephron diagram cold. Questions frequently reference specific nephron segments by name.
Neuron structure, action potential phases, synaptic transmission and major neurotransmitters, CNS divisions (brain regions and spinal cord), autonomic nervous system (sympathetic vs. parasympathetic), reflexes, and cranial nerves.
Exam tip: Autonomic nervous system contrasts (fight-or-flight vs. rest-and-digest) appear on nearly every HESI.
Bone types and classifications, the axial and appendicular skeleton, joint types (ball-and-socket, hinge, pivot), skeletal muscle structure (sarcomere, actin, myosin), the sliding filament theory of contraction, and major muscle groups.
Exam tip: The sliding filament mechanism is tested often — learn the sequence of contraction step by step.
GI tract anatomy from mouth to anus, accessory digestive organs (liver, pancreas, gallbladder), major digestive enzymes and where they act, absorption sites for macronutrients and key vitamins, and basic nutrition terminology.
Exam tip: Know which enzyme acts on which macronutrient in which segment of the GI tract.
Major endocrine glands and their hormones, negative feedback loops (especially the HPA and thyroid axes), the action of insulin and glucagon in blood glucose regulation, and the distinction between endocrine and exocrine function of the pancreas.
Exam tip: Feedback loops are a classic HESI question type — practice tracing them.
Innate vs. adaptive immunity, the five antibody classes (IgG, IgM, IgA, IgD, IgE) and their functions, T-cell and B-cell roles, primary vs. secondary immune response, and the lymphatic system’s role in fluid balance.
Exam tip: Antibody class names and their functions are commonly tested in vocabulary-style HESI items.
The three skin layers (epidermis, dermis, hypodermis), skin appendages (hair, nails, glands), the role of skin in thermoregulation and vitamin D synthesis, and wound healing stages.
Exam tip: Fewer questions, but easy points when they appear. Do not skip.
Male and female reproductive anatomy, the menstrual cycle (follicular, ovulatory, luteal phases), major reproductive hormones (FSH, LH, estrogen, progesterone, testosterone), fertilization, and basic stages of fetal development.
Exam tip: Hormone timing in the menstrual cycle is the most commonly tested element.
This overlaps with the Biology section but carries over into A&P questions. Know organelles and their functions, cell membrane structure and transport (passive, active, osmosis, endocytosis), and the differences between prokaryotic and eukaryotic cells.
Exam tip: Cellular content gets asked in both sections — learning it once pays off twice.
Directional terms (superior/inferior, medial/lateral, proximal/distal, anterior/posterior), body planes (sagittal, transverse, frontal), body cavities, and the 11 body systems as an organizing framework.
Exam tip: A clean grasp of directional terms prevents losing easy points on otherwise simple anatomy items.
Most college A&P courses cover 11 body systems over one or two semesters. The HESI does not test that full breadth equally. Instead, the test weights systems based on their clinical relevance to nursing practice — cardiovascular, respiratory, renal, and nervous dominate, while integumentary and reproductive appear less frequently.
HESI A&P also differs in question style. Classroom exams tend toward recall (“name the structure”). HESI questions are applied: they describe a physiological scenario, an abnormality, or a functional relationship, and ask which mechanism or structure is responsible. Students who prepared by memorizing labeled diagrams often score lower than students who prepared by learning how each system works.
If your A&P class is more than two years behind you, assume you need to rebuild understanding, not just refresh it. The StudyBuddy HESI course is built around 34 video lectures and 4,255 HESI-specific questions that target this exact difference between classroom learning and exam performance.
4,255 HESI-specific questions, 34 video lectures, AI tutor that targets your weakest body systems. From $29/month.
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Section-by-section strategy, score targets, and a study schedule. Faculty-developed.