liminfoAnatomy Reference
Free reference guide: Anatomy Reference
About Anatomy Reference
The Human Anatomy Reference is a structured, searchable guide covering the major systems of the human body. It includes detailed entries on the skeletal system (skull bones, vertebral column, upper and lower limb bones), the nervous system (12 cranial nerves, brachial plexus C5-T1, lumbosacral plexus), and the cardiovascular system (coronary arteries, aortic branches, and the Circle of Willis).
The muscular system section covers clinically important muscle groups such as the four rotator cuff muscles (SITS mnemonic), thigh compartments (quadriceps, hamstrings, adductors), and abdominal wall layers with inguinal canal anatomy. Each entry includes muscle origins, insertions, innervation with spinal cord levels, and key clinical correlations such as common injury patterns.
Organ anatomy entries provide systematic coverage of pulmonary lobes and segments, the Couinaud liver classification with portal triad and hepatic veins, renal structure and nephron vasculature, and the gastrointestinal tract from esophagus to rectum with arterial supply territories. All content includes both Korean and English anatomical nomenclature for bilingual study.
Key Features
- Skeletal system: skull (8 neurocranium + 14 viscerocranium bones), vertebral column (33 vertebrae with curves), upper/lower limb bones
- 12 cranial nerves with number, name, function type (sensory/motor/mixed), and clinical significance
- Brachial plexus (C5-T1) with roots, trunks, divisions, cords, branches, and Erb-Duchenne/Klumpke palsy patterns
- Coronary arteries (LAD, LCx, RCA) with dominance patterns and myocardial infarction territory mapping
- Circle of Willis anatomy with anterior/posterior circulation and stroke territory correlations
- Rotator cuff (SITS), thigh muscles, abdominal wall layers, and inguinal canal anatomy with innervation details
- Organ anatomy: pulmonary segments, Couinaud liver segments, renal nephron, GI tract, thyroid, and inner ear
- Anatomical directional terms, body planes, and joint movement terminology in both Korean and English
Frequently Asked Questions
What are the 12 cranial nerves and their functions?
The 12 cranial nerves are: I Olfactory (smell), II Optic (vision), III Oculomotor (eye movement), IV Trochlear (superior oblique), V Trigeminal (face sensation/mastication), VI Abducens (lateral rectus), VII Facial (facial expression/taste), VIII Vestibulocochlear (hearing/balance), IX Glossopharyngeal (taste/swallowing), X Vagus (parasympathetic), XI Accessory (trapezius/SCM), XII Hypoglossal (tongue movement).
What muscles make up the rotator cuff?
The four rotator cuff muscles are remembered by the SITS mnemonic: Supraspinatus (initiates abduction, most commonly torn, suprascapular nerve C5-C6), Infraspinatus (external rotation, suprascapular nerve), Teres Minor (external rotation, axillary nerve C5-C6), and Subscapularis (internal rotation, subscapular nerve C5-C7).
How is the Circle of Willis structured?
The Circle of Willis connects anterior and posterior cerebral circulation. The internal carotid arteries supply the anterior cerebral arteries (ACA, medial frontal/parietal) and middle cerebral arteries (MCA, lateral hemisphere). The vertebral arteries form the basilar artery, which gives rise to the posterior cerebral arteries (PCA, occipital lobe). The anterior communicating artery (AComm) connects both ACAs, and the posterior communicating arteries (PComm) connect the ICA to the PCA.
What are the Couinaud liver segments?
The Couinaud classification divides the liver into 8 functional segments: left lobe (S2, S3, S4a, S4b), right lobe (S5, S6, S7, S8), and caudate lobe (S1). The portal triad consists of the proper hepatic artery, portal vein, and common hepatic duct. The liver receives 25% of blood from the hepatic artery and 75% from the portal vein.
How many vertebrae are in the spinal column?
The vertebral column has 33 vertebrae: 7 cervical (C1-C7, with C1 Atlas and C2 Axis being specialized), 12 thoracic (T1-T12, with rib articulations), 5 lumbar (L1-L5, largest for weight bearing), 5 sacral (fused), and 3-5 coccygeal (fused). There are 23 intervertebral discs from C2-S1. The column has four curves: cervical and lumbar lordosis, thoracic and sacral kyphosis.
What are the coronary artery territories?
The left coronary artery (LCA) divides into the LAD (supplies anterior wall and septum with diagonal branches) and LCx (supplies lateral wall with obtuse marginal branches). The right coronary artery (RCA) supplies the inferior wall via the posterior descending artery (PDA). Right dominance (85%): RCA gives PDA; left dominance (8%): LCx gives PDA; co-dominance (7%).
What is the brachial plexus and why is it clinically important?
The brachial plexus (C5-T1) supplies the upper limb through the sequence Roots, Trunks (upper/middle/lower), Divisions (anterior/posterior), Cords (lateral/medial/posterior), and terminal Branches (musculocutaneous, median, ulnar, radial, axillary nerves). Upper trunk injury (C5-C6) causes Erb-Duchenne palsy (waiter's tip), while lower trunk injury (C8-T1) causes Klumpke palsy (claw hand).
How are the lungs segmented?
The right lung has 3 lobes and 10 segments: upper (S1 apical, S2 posterior, S3 anterior), middle (S4 lateral, S5 medial), lower (S6 superior, S7-S10 basal). The left lung has 2 lobes and 8-10 segments: upper (S1+2 apicoposterior, S3 anterior, S4-S5 lingular), lower (S6 superior, S8-S10 basal). The carina is at T4-T5, and the right main bronchus is shorter, wider, and more vertical, making it the more common site for aspirated foreign bodies.