HESI A2 Anatomy & Physiology | 2026 Expert Verified | 150+ Key Concepts | Hormones, Heart, Muscles, Bones, Skin

This expertly verified guide summarizes over 150 core Anatomy & Physiology concepts in a fast-access Q&A format for the 2026 HESI A2 exam. It’s a comprehensive, glossary-style resource that explains high-yield definitions, organ functions, physiological processes, and system interactions in a way that supports rapid recall and deep understanding. Each entry is precisely defined and exam-aligned. Major topics include: Cardiovascular system (atrium, ventricle, tricuspid and bicuspid valves, sinoatrial node, systole/diastole, ECG) Muscle structure and contraction (actin, myosin, ATP, sarcomeres, calcium ions, sarcoplasmic reticulum) Skeletal system (long bones, axial/appendicular skeleton, osteoblasts, epiphysis, diaphysis, marrow, mineral storage) Endocrine system (hypothalamus, pituitary, cortisol, steroid vs. non-steroid hormones, tropic hormones, glands) Nervous system and reflexes (afferent/efferent neurons, cerebrum, cerebellum, medulla oblongata, spinal reflex arc) Integumentary system (epidermis, dermis, eccrine/apocrine/sebaceous glands, melanin, skin layers, homeostasis) Digestive & absorption functions (absorption into bloodstream, amino acids, antibodies) Respiratory & urinary foundations are also briefly referenced via muscular and circulatory roles. Perfect for: HESI A2 2026 candidates Pre-nursing, LPN, BSN, and ADN program applicants Health science students seeking accurate review of fundamental concepts Learners looking for flashcard-style prep with clear, structured definitions Keywords: HESI A2 2026, anatomy and physiology, muscle contraction, sarcomere, endocrine system, pituitary gland, adrenal hormones, ATP, cardiovascular system, SA node, ECG, skin glands, sebaceous, epidermis, osteoblast, axial skeleton, reflex arc, neuron types, hormone types, mitosis vs meiosis, expert verified answers