The human heart, about fist-sized and nestled in the mediastinum behind the sternum, has a pointed apex at the left fifth intercostal space and base at the second rib, with…
The hyoid bone parts include body (central, C3 level), greater horns (posterior/lateral projections for muscle/ligament attachments), lesser horns (small superior projections for stylohyoid ligament). It floats, anchored by supra/infrahyoid muscles.
The CT Scan of a Blowout Fracture of the Inferior Wall diagram typically shows orbital floor disruption with herniation of inferior rectus or orbital fat into the maxillary sinus, often…
Heart valves ensure one-way blood flow through precisely timed opening and closing. Atrioventricular valvesthe tricuspid on the right and mitral on the lefthang from chordae tendineae anchored to papillary muscles,…
Lacrimal nerve (V1 branch) enters orbit via superior orbital fissure, runs superolateral, supplies lacrimal gland (parasympathetic hitchhike from facial via pterygopalatine ganglion), conjunctiva, upper eyelid skin. It communicates with zygomatic…
The small intestine's histology maximizes surface area for digestion and absorption across its three segmentsduodenum, jejunum, ileumwith tall villi covered in microvilli on enterocytes forming the brush border loaded with…
The middle cranial fossa houses the temporal lobes, formed by greater sphenoid wings, squamous temporal, and anterior petrous temporal. Key features include superior orbital fissure, foramen rotundum/ovale/spinosum, carotid canal, and…
The circle of Willis is an anastomotic arterial ring at brain base: anterior cerebral (from internal carotid), anterior communicating, internal carotid, posterior communicating (from posterior cerebral), posterior cerebral (from basilar).…
Descent of the testis embryologically begins near kidneys at 7-8 weeks, guided by gubernaculum through inguinal canal (transabdominal phase via genitofemoral nerve), then inguinoscrotal phase (hormone-driven, testosterone/insulin-like factor 3) into…
The muscular triangle of the neck is bounded by midline, anterior digastric belly, and superior omohyoid belly, containing infrahyoid muscles (sternohyoid, sternothyroid, thyrohyoid), thyroid gland, trachea, esophagus, and common carotid…
The cardiac conduction pathway starts at the SA node (pacemaker), spreads through atria to AV node (delay), then bundle of His, left/right bundles, and Purkinje fibers for rapid ventricular activation.…
The pituitary gland sits in sella turcica, attached to hypothalamus by infundibulum, surrounded by cavernous sinuses laterally, optic chiasm superiorly, sphenoid sinus inferiorly. Relations affect surgical/transsphenoidal approaches and compression symptoms.
Regional blood supply to the cerebrum divides into anterior (anterior cerebral to medial surface), middle (middle cerebral to lateral surface, insula, basal ganglia), and posterior (posterior cerebral to occipital, inferior…
The submandibular ganglion hangs from lingual nerve, receives preganglionic parasympathetics from chorda tympani (facial), postganglionic fibers supply submandibular/sublingual glands for salivation. Sensory fibers pass through without synapse.
Posterior view of lower limb shows sciatic nerve emerging below piriformis, descending between greater trochanter and ischial tuberosity, dividing into tibial and common fibular near popliteal fossa. It supplies hamstrings…
ASIA scale assesses spinal cord injury impairment: A complete (no sensory/motor below level), B sensory incomplete, C motor incomplete with >50% key muscles
Neurulation forms the neural tube precursor to CNS as notochord induces overlying ectoderm to thicken into plate, then elevate neural folds that fuse dorsally starting mid-region progressing cranially and caudally,…
The mastoid fossa (antrum) is the largest mastoid air cell, opening into middle ear via aditus ad antrum, lined by mucosa continuous with tympanic cavity. It provides space for middle…