A severe L4L5 disc herniation occurs when the nucleus pulposus protrudes through the annulus fibrosus, compressing nearby nerve roots. At this level, the L5 nerve root is commonly affected. Patients may experience lower back pain radiating down the leg, often View Diagram Severe herniation of L4 L5 disc
Muscles of the pelvic floor, including the levator ani and coccygeus, support pelvic organs, maintain continence, and contribute to core stability. They form the urogenital and anal diaphragms, integrating with connective tissue and neurovascular structures. Understanding their anatomy is essential View Diagram Muscles of the Pelvic Floor
Episiotomy is a surgical incision of the perineum during childbirth to enlarge the vaginal opening and prevent tearing. Knowledge of perineal anatomy is essential for obstetricians, midwives, and medical students in performing episiotomy, managing trauma, and postpartum repair. Understanding the View Diagram Episiotomy
The anterior ethmoidal nerve is a branch of the nasociliary nerve that supplies the nasal cavity. This anatomy diagram of the anterior ethmoidal nerve shows its origin within the orbit, passage through the anterior ethmoidal foramen, and distribution to the View Diagram Anterior Ethmoidal Nerve
The nerve point of the neck is a clinically important region where multiple cutaneous branches of the cervical plexus emerge, including the lesser occipital, great auricular, transverse cervical, and supraclavicular nerves. This area, located along the posterior border of the View Diagram The Nerve Point of the Neck
Pharyngeal nerves arise from the cranial nerves, primarily the glossopharyngeal and vagus nerves, and supply the pharyngeal muscles and mucosa. They are essential for swallowing, phonation, and sensory input from the pharynx. The course of these nerves passes through the View Diagram Pharyngeal Nerve Course Supply
At the optic chiasm, fibers from the medial halves of each retina cross to the opposite side. These medial fibers carry information from the temporal visual fields. This partial crossing allows visual information from the same visual field to be View Diagram Medial Fibres Crossing over at the Optic Chiasm
The membranous labyrinth is a fluid-filled structure within the bony labyrinth of the inner ear. It contains endolymph and includes the cochlear duct, utricle, saccule, and semicircular ducts. These structures are responsible for hearing and balance. Damage may result in View Diagram The Membranous Labyrinth
The testes produce sperm and testosterone and are enclosed within the scrotum. Internally, they contain seminiferous tubules where spermatogenesis occurs. The epididymis lies posteriorly and stores and matures sperm before transport via the vas deferens. Blood supply comes from the View Diagram The Testes and Epididymis
Blowout fractures of the orbital floor involve disruption of the inferior orbital wall, often due to blunt trauma to the eye. CT imaging identifies the fracture, orbital content herniation, and potential muscle entrapment, which can cause diplopia or restricted eye View Diagram CT Scan of a Blowout Fracture of the Inferior Wall
The lingual tonsil is part of Waldeyers ring at the base of the tongue, comprising lymphoid tissue that contributes to immune defense. It traps pathogens and participates in mucosal immunity. Knowledge of lingual tonsil anatomy is essential for ENT specialists, View Diagram The Lingual Tonsil Waldeyers Ring
The nerves of the dorsum of the foot provide sensory innervation to the skin of the dorsal surface. This anatomy diagram of the anatomy of the nerves of the dorsum of the foot highlights the superficial and deep fibular nerves. View Diagram Anatomy of the Nerves of the Dorsum of the Foot Superficial and Deep Fibular Nerves
Head rotation mainly occurs at the atlantoaxial joint between the first and second cervical vertebrae. The dens of the axis acts as a pivot, allowing the atlas and skull to rotate around it. Muscles such as sternocleidomastoid and splenius capitis View Diagram Head Rotation
The infrahyoid muscles of the neck, including sternohyoid, omohyoid, sternothyroid, and thyrohyoid, depress the hyoid and larynx during swallowing and speech. Lateral views reveal their attachments to the hyoid, sternum, and thyroid cartilage. Knowledge of infrahyoid anatomy is essential for View Diagram Lateral View of the Infrahyoid Muscles of the Neck
The lacrimal nerve, a branch of the ophthalmic division of the trigeminal nerve, provides sensory innervation to the lateral upper eyelid and conjunctiva. Knowledge of its course is essential for ophthalmologists, plastic surgeons, and medical students in eyelid surgery, trauma View Diagram Course of the Lacrimal Nerve
Mastoiditis is an infection of the mastoid air cells located in the mastoid process of the temporal bone. These air-filled spaces communicate with the middle ear, so infections often arise secondary to otitis media. The condition can cause swelling, pain View Diagram Mastoiditis Infection of the Mastoid Air Cells of the Ear
The cardiac conduction pathway ensures coordinated contraction of the heart. It begins at the sinoatrial node in the right atrium, which acts as the natural pacemaker. The impulse travels to the atrioventricular node, where it is briefly delayed. From there, View Diagram Overview of Conduction Pathway Components
Measuring the female pelvis involves assessing obstetric and diagonal conjugates to determine pelvic capacity for childbirth. The obstetric conjugate measures the narrowest anteroposterior diameter of the pelvic inlet, while the diagonal conjugate extends from the sacral promontory to the pubic View Diagram Measuring the Female Pelvis Obstetric and Diagonal Conjugates
The palmar cutaneous branch of the median nerve arises proximal to the carpal tunnel and supplies sensation to the central palm. Because it travels superficial to the flexor retinaculum, sensation over the palm is preserved in carpal tunnel syndrome.
