Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

2,602 results found
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Thymus

The thymus is a T-cell producing lymphoid organ in the anterior mediastinum that plays a role in the development of the immune system, particular the maturation of T-cells. It typically has a retrosternal location and hence can mimic retrosternal pathology. Gross anatomy It is relatively large...
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Thyrocervical trunk

The thyrocervical trunk is one of the 3 branches of the first part of the subclavian artery and gives off numerous branches to supply viscera of the neck, the brachial plexus, neck muscles and the scapular anastomosis. The trunk arises lateral to the vertebral artery from the anterosuperior wal...
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Thyroglossal duct

The thyroglossal duct is an epithelium-lined connection between the foramen caecum and the thyroid that develops during the descent of the thyroid. It usually involutes in the 8th-10th week of gestation.  Gross anatomy The thyroglossal duct arises from foramen caecum located at the junction of...
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Thyrohyoid muscle

The thyrohyoid muscle is an infrahyoid muscle of the neck that is innervated by the ventral ramus of C1. The primary function of the thyrohyoid muscle is to depress and fix the hyoid bone and larynx though it may also raise the larynx when the hyoid bone is fixed. Summary origin: oblique line ...
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Thyroid cartilage

The thyroid cartilage is the largest of the cartilages of the larynx, with its superior pole sitting at the level of the C4 vertebrae. Gross Anatomy The thyroid cartilage consists of two laminae that are fused anteriorly in the median plane to form the laryngeal prominence. Each laminae posses...
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Thyroidea ima artery

The thyroidea ima artery is an uncommon variant of the blood supply to the inferior aspect of the thyroid gland. It is reported in ~7.5% (range 1.5-12.2%) of individuals and can arise from: brachiocephalic trunk right common carotid artery aortic arch internal thoracic artery The thyroidea ...
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Thyroid gland

The thyroid gland is an endocrine organ in the neck which is completely enveloped by pretracheal fascia (middle-layer of the deep cervical fascia) and lies in the visceral space.  Gross anatomy The thyroid extends from C5 to T1 and lies anterior to the thyroid and cricoid cartilages of the lar...
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Tibia

The tibia (plural: tibiae) is the largest bone of the leg and contributes to the knee and ankle joints. (shin- or shank-bone are lay terms). It is medial to and much stronger than the fibula, exceeded in length only by the femur. Gross anatomy Osteology The tibia has a prismoid shaft, expande...
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Tibialis anterior muscle

The tibialis anterior muscle is one of the muscles of the anterior compartment of the leg involved in dorsiflexion and inversion of the foot. Summary origin: body of the tibia insertion: medial cuneiform and first metatarsal action: dorsiflexion and inversion of the foot arterial supply: an...
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Tibialis posterior muscle

The tibialis posterior muscle is one of the small muscles of the deep posterior compartment of the leg. Summary origin: inner posterior borders of the tibia and fibula insertion: navicular and medial cuneiform the tendon splits into two slips after passing inferior to plantar calcaneonavicu...
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Tibial nerve

The tibial nerve is one of two terminal branches of the sciatic nerve and supplies the leg and foot with motor and sensory supply. Summary origin: the terminal branch of sciatic, at or above the popliteal fossa course: courses straight down the popliteal fossa, passing deep to gastrocnemius t...
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Tibial plateau

The tibial plateau is the proximal articular surface of the tibia. Gross anatomy The tibial plateau is composed of two parts: concave articular surfaces of the oval-shaped medial and circular-shaped lateral tibial condyles (medial and lateral tibial plateaus) the medial tibial plateau is lar...
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Tibiofemoral joint

The tibiofemoral joint is a modified hinge synovial joint between the distal femur and the proximal tibia. Summary articulation: modified hinge joint between the medial and lateral condyles of the femur and the tibial condyles joint: knee ligaments: transverse ligament of the knee, medial an...
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Tibioperoneal trunk

The tibioperoneal or TP trunk, which occasionally referred to as the tibiofibular​ trunk is the direct continuation of the popliteal artery in the posterior upper leg after the anterior tibial artery origin. It is a short trunk that bifurcates into two terminal branches. Summary origin: contin...
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Tongue

The tongue is a complex, principally muscular, structure that extends from the oral cavity to the oropharynx. It has important roles in speech, swallowing and taste.  Gross anatomy The tongue has a tip, ventral surface, dorsal surface and root. The tongue is made of a midline lingual septum an...
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Torus ethmoidalis

Torus ethmoidalis, also known as torus lateralis, is the term given when there is no air cell in the ethmoid bulla (failure of pneumatisation). It is encountered in 8% of subjects.
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Torus tubarius

Torus tubarius or cushion of the auditory canal is a mucosal elevation in the lateral aspect of the nasopharynx, formed by the underlying pharyngeal end of the cartilaginous portion of the Eustachian tube. The opening of the Eustachian tube is anterior to the torus tobarius. Immediately posterio...
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Trachea

The trachea, known colloquially as the windpipe, connects the upper respiratory tract to the lungs via the tracheobronchial tree, enabling gas exchange. Gross anatomy The trachea is a tube-shaped structure consisting of 15-to-20 D-shaped cartilage rings anterolaterally bridged by annular ligam...
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Tracheal bronchus

A tracheal bronchus (with some variations also known as a pig bronchus) is an anatomical variant where an accessory bronchus originates directly from the supracarinal trachea. The latter term (pig bronchus or bronchus suis) is often given when the entire upper lobe (usually right side) is suppli...
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Tracheobronchial branching anomalies

Tracheobronchial branching anomalies can be seen as an isolated finding or accompanying heterotaxy syndromes, pulmonary sling, and conditions associated with pulmonary underdevelopment (agenesis and aplasia), including the scimitar syndrome. Abnormal branching patterns include: right sided iso...
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Tracheobronchial tree

The tracheobronchial tree is the branching tree of airways beginning at the larynx and extending inferiorly and peripherally into the lungs as bronchioles. The luminal diameter decreases as the branching increases more peripherally into the lungs. The walls of the airway down to the level of the...
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Transitional vertebra

Transitional vertebra is one that has indeterminate characteristic and features of vertebrae from adjacent vertebral segments. They occur at the junction between spinal morphological segments: atlanto-occipital junction atlanto-occipital assimilation: complete or partial fusion of C1 and the o...
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Transition zone

The transition zone of a nerve describes a region of a few millimetres where the myelin sheath changes from central to peripheral type. This zone is susceptible to mechanical irritation and is implicated in neurovascular compression syndromes such as trigeminal neuralgia (CN V), hemifacial spasm...
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Transposition of inferior vena cava

Transposition of inferior vena-cava (also known as left-sided IVC) refers to a variant course of the inferior vena cava. It is the most common anomaly of IVC and occurs due to persistence of left supracardinal vein. Diagnosis of left sided IVC is important for: planning of vascular procedures ...
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Transpyloric plane

The transpyloric plane, also known as Addison's plane, is an imaginary axial plane located midway between the jugular notch and superior border of pubic symphysis, at approximately the level of L1 vertebral body. It an important landmark as many key structures are visualised at this level, altho...
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Transversalis fascia

Transversalis fascia is the lining fascia of the anterolateral abdominal wall which lies between the transversus abdominis muscle and peritoneum. Gross anatomy The transversalis fascia, inferior diaphragmatic fascia, pelvic fascia and iliacus fascia  form a continuous lining of the abdominal a...
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Transverse acetabular ligament

The transverse acetabular ligament is part of the labrum but has no cartilage cells. Its strong, flat fibres cross the acetabular notch forming a foramen through which vessels and nerves enter the joint.
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Transverse arch

The transverse arch of the foot is an arch in the coronal plane formed by the three cuneiforms, the cuboid, and the bases of the five metatarsals. They are held together by the deep transverse metatarsal ligaments. The peroneus longus and tibialis posterior tendons assist in maintaining the curv...
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Transverse cervical artery

The transverse cervical artery, also known as the cervicodorsal trunk, is 1 of the 4 branches of the thyrocervical trunk (off the first part of the subclavian artery). It is a short artery that bifurcates into the superficial and deep branches, both which course superficially and laterally acro...
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Transverse cervical nerve

The transverse cervical nerve, also known as the superficial cervical nerve, cutaneous cervical nerve or anterior cutaneous cervical nerve of the neck, is a cutaneous branch of the cervical plexus that innervates the skin covering the anterior cervical region. Gross anatomy Origin The transve...
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Transverse colon

The transverse colon is the longest and most mobile part of the large intestine. It measures up to 45 cm in length.  Gross anatomy The transverse colon is the continuation of the ascending colon from the right colic flexure. It passes from the right to left hypochondrium in a downward convex p...
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Transverse ligament of the hip

The transverse ligament of the hip bridges the acetabular notch (located anteroinferiorly along the margin of the acetabulum) and joins the two ends of the acetabular labrum, thus forming a complete ring. Beneath it (through the acetabular foramen) pass nutrient vessels which enter the ligamentu...
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Transverse ligament of the knee

The transverse ligament of the knee is a ligament within the anterior aspect of the knee joint. Gross anatomy The transverse ligament is a variable band-like intracapsular knee ligament. It attaches transversely across the anterior aspects of the convex margins of the medial and lateral menisci.
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Transverse mesocolon

The transverse mesocolon is a broad, meso-fold of peritoneum, which connects the transverse colon to the posterior wall of the abdomen. It is continuous with the two posterior layers of the greater omentum, which, after separating to surround the transverse colon, join behind it, and are contin...
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Transverse muscle of the tongue

The transverse muscle of the tongue is one of the 4 intrinsic muscles of the tongue which alters the shape of the tongue mass, being entirely confined to the tongue without an attachment outside the tongue (like the extrinsic muscles of the tongue). Gross anatomy The muscles fibres attach prox...
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Transverse pancreatic artery

The transverse pancreatic artery, also known as the inferior pancreatic artery, is a branch of the splenic artery that supplies the pancreatic tail and body. It arises from the proximal splenic artery and descends a short distance to run to the left along the posterior margin of the pancreas ne...
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Transverse pericardial sinus

The transverse pericardial sinus is the transverse communication between the left and right parts of the pericardial space proper behind the two outflow arteries of the heart.   Gross anatomy It is superior to the left atrium and posterior to the intrapericardial parts of the pulmonary trunk a...
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Transverse sinus

The transverse sinus is one of the dural venous sinuses and drains the superior sagittal sinus, the occipital sinus and the straight sinus, and empties into the sigmoid sinus which in turn reaches the jugular bulb. The two transverse sinuses arise at the confluence of the three aforementioned s...
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Transverse vaginal septum

Transverse vaginal (transvaginal) septum (TVS) is a type of rare congenital uterovaginal anomaly (class II under the Rock and Adam classification). Epidemiology It is rare with a frequency of 1 in 70,000 females. Clinical presentation In the case of a complete septum, patients commonly prese...
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Transversospinalis group

The transversospinalis group is the deep layer of the intrinsic back muscles. These muscles lie between the transverse and spinous processes and are grouped by length of the fascicles, as well as region covered. The groups are rotatores, multifidus, and semispinalis. Gross anatomy Rotatores T...
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Transversus abdominis muscle

The transversus abdominis muscle, named according to the direction of its muscle fibres, is one of the flat muscles that form the anterior abdominal wall. It is deep to the internal oblique muscle and ends in the anterior aponeurosis, which ultimately blends with the linea alba.  Summary origi...
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Transversus thoracis muscle

The transversus thoracis muscle is the most anterior muscle of the inner layer (external intercostal, internal intercostal and transversus thoracis) of the thoracic wall.   Gross anatomy The transversus thoracis is a thin band of muscle and tendon arising from the lower posterior surface of th...
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Trapezium

The trapezium (greater multangular) is one of the eight carpal bones of the hand. It is the most lateral (radial) bone of the distal row, located between the scaphoid and the first metacarpal bone . It articulates with the scaphoid proximally, the trapezoid medially, and the thumb and index meta...
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Trapezium secondarium

The trapezium secondarium (or trapezium secundarium or secondary trapezium) is an accessory ossicle of the wrist. It can be seen adjacent to the tubercle of the trapezium superomedially 1,2. Embryology According to Pfitzner, the trapezium secondarium is one of four potential secondary ossifica...
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Trapezius muscle

The trapezius muscle is a large, broad superficial muscle of the posterior neck and back. It gains its name from its diamond shape. Along with sternocleidomastoid muscle, it is invested by the superficial layer of the deep cervical fascia, which splits around it.  Summary origin: superior nuch...
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Trapezoid

The trapezoid bone (also known as the os trapezoideum or the lesser multangular) is the smallest carpal bone in the distal row, sitting lateral to the capitate.  Gross anatomy Osteology The trapezoid is an irregular, boot-shaped bone. The dorsal surface is larger than the palmar surface and i...
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Trapezoid ligament

The trapezoid ligament is one of two components forming the coracoclavicular (CC) ligament. The conoid ligament is the other component. Gross anatomy The trapezoid ligament is a broad quadrilateral ligament that is quite thin. Its positioned almost horizontally. It is the anterolateral part of...
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Triangle of Guillain and Mollaret

The triangle of Guillain and Mollaret, also known as the dentatorubro-olivary pathway, has three corners 1: red nucleus inferior olivary nucleus contralateral dentate nucleus Rubro-olivary fibres descend from the parvocellular division of each red nucleus along the central tegmental tracts t...
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Triangle of safety

The triangle of safety is an anatomical region in the axilla that forms a guide as to the safe position for intercostal catheter (ICC) placement. With the arm abducted, the apex is the axilla, and the triangle is formed by the: lateral border of the pectoralis major anteriorly lateral border o...
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Triangles of the neck

The triangles of the neck are surgically focussed divisions of the neck, first described from early dissection-based anatomical studies which predated cross-sectional anatomical description based on cross-sectional imaging (see deep spaces of the neck). The neck can be divided into anterior and...
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Triangular fibrocartilage complex

The triangular fibrocartilage complex (TFCC) is a complex structure that is a major contributor to the stability of the wrist.  Gross anatomy The TFCC is located on the ulnar aspect of the wrist joint between the ulna and the lunate and triquetrum of the proximal carpal row. It has an elongate...
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Triangular ligament

The triangular ligament may refer to a component of the triangular fibrocartilage complex (TFCC). It is commonly grouped with the ulnar collateral ligament and meniscal homologue, together comprising the ulnar-sided components of the TFCC. The triangular ligament attaches from the distalmost uln...
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Triangular space of cruciate ligaments

Triangular space of cruciate ligaments (TSC) is defined as the potential extrasynovial space between anterior and posterior cruciate ligaments of the knee joint. Gross anatomy Boundaries anteriorly: anterior cruciate ligament posteriorly: posterior cruciate ligament inferiorly: tibial plate...
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Tributaries of the inferior vena cava (mnemonic)

A useful mnemonic to remember the tributaries of the inferior vena cava is: I Like To Rise So High Mnemonic I: common iliac veins L: lumbar veins T: right testicular (gonadal) vein R: renal veins S: suprarenal veins H: hepatic veins
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Triceps brachii

The triceps brachii, which often referred to simply as the triceps is a three-headed muscle in the posterior compartment of the arm. Summary origin long head: infraglenoid tubercle of the scapula medial head: posterior humerus, inferior to the radial groove, medial intermuscular septum late...
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Triceps coxae

The triceps coxae is the tricipital (three headed) collection of 3 of the muscles in the posterior hip which act together on the hip, primarily to laterally rotate the extended thigh. It comprises (in order from superior to inferior) the superior gemellus, obturator internus and inferior gemellu...
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Triceps surae

Triceps surae is another term used for the calf muscles, more specifically two of the three muscles of the superficial posterior compartment of the leg: medial and lateral heads of the gastrocnemius muscle soleus muscle The group of muscles are innervated by the tibial nerve and form the Achi...
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Tricuspid valve

The tricuspid valve is one of the four cardiac valves. It is the atrioventricular valve that allows blood to flow from the right atrium to the right ventricle. It opens during diastole and closes during systole. The valve has anterior, posterior and septal leaflets (cusps), the bases of which at...
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Trigeminal nerve

The trigeminal nerve is the fifth cranial nerve and its primary role is relaying sensory information from the face and head, although it does provide motor control to the muscles of mastication. It is both large and complicated and has multiple brainstem nuclei (sensory and motor) as well as man...
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Trigeminal nerve branches (mnemonic)

A mnemonic for remembering the names of the skull foramina that the division of the trigeminal nerve (CN V) pass through is: Standing Room Only Mnemonic standing: superior orbital fissure (ophthalmic division of trigeminal nerve) room: foramen rotundum (maxillary division of trigeminal nerve...
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Trigone of the lateral ventricle

The trigone of of lateral ventricle, also known as the atrium, is a triangular area at the floor of the lateral ventricle that forms the transition point between the occipital and temporal horns. It is the classic location for intraventricular meningioma.
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Triquetrum

The triquetrum (os triquetrum) is one of the carpal bones and forms part of the proximal carpal row. Gross anatomy Osteology The triquetrum is wedge-shaped carpal bone located between the lunate and the pisiform. It has an oval facet for articulation with the pisiform. Articulations along w...
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Triradiate cartilage

The triradiate cartilage is the Y- shaped epiphyseal plate that occurs at the junction where the ischium, ilium and pubis meet in the skeletally immature skeleton.   The vertical component of the "Y" is the meeting of the ischium and pubic bone, the anterior arm is the junction of the ilium and...
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Triscaphe joint

The triscaphe joint is the shared joint between the scaphoid, trapezium and trapezoid bones in the wrist. This joint is also referred to by its much longer name, the scaphotrapeziotrapezoid (STT) joint. Related pathology This joint may be fused as an alternative to scapholunate fusion in treat...
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Trochlea (diambiguation)

Trochlea (sing., pl. trochleae) is a general term that refers to an anatomic structure that resembles the grooved part of a pulley system: Trochlea have been described in: orbit: trochlea of the superior oblique muscle trochlear nerve (CN IV) humeral trochlea femoral trochlea trochlea of ...
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Trochlear nerve

The trochlear nerve is the fourth cranial nerve and is the motor nerve of the superior oblique muscle of the eye.  It can be divided into four parts: nucleus and an intraparenchymal portion cisternal portion cavernous sinus portion orbital portion Gross anatomy Nucleus and intraparenchy...
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True vocal cords

The true vocal cords are the thickened, free edge of the cricovocal membrane, the cricovocal ligament, lined by mucous membrane 1. Together they form part of the glottis, the V-shaped aperture through which air passes. Their primary role is in phonation where vibration of the adducted vocal cord...
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Tuber cinereum

Tuber cinereum is a hollow eminence of gray matter. It is a part of the hypothalamus. Gross anatomy It is located between mammillary bodies and optic chiasm. Devoid of the blood brain barrier, it normally enhances after contrast administration. Relations It is continuous: laterally: with an...
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Tuberculum sellae

The tuberculum sellae is the ridged process of the sphenoid bone which forms the anterior wall of the sella turcica. Gross anatomy Relations The tuberculum sellae forms the anterior wall of the sella turcica, which houses the pituitary gland. It is an elongated ridge located immediately poste...
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Tunica albuginea (testis)

The tunica albuginea (TA) forms the fibrous covering of the testis and is itself covered by the serous layer, the tunica vaginalis. The covering is total, except for at the point of attachment of the epididymis, and a small defect posteriorly where the spermatic cord vessels enter and leave the ...
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Tunica (disambiguation)

Tunica is a word used in anatomy to refer to a type of covering.  tunica adventitia (also known as tunica externa) tunica albuginea tunica albuginea (ovary) tunica albuginea (penis) tunica albuginea (testis) tunica intima tunica media tunica vaginalis tunica vaginalis (ovary) tunica va...
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Tunica vaginalis (testis)

The tunica vaginalis (TV) represents the investing serosal covering of the testis. It forms as the embryological testis descends and passes out through the superficial inguinal ring carrying its abdominal peritoneal covering with it. The tunica vaginalis is said to consist of two layers, the pa...
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Twelfth rib

The twelfth rib is an atypical rib. It is the shortest rib, and one of two floating ribs. Gross anatomy Osteology The 12th rib has a single facet on its head for articulation with the T12 vertebra. It has a short neck and no tubercle. It also lacks a costal groove and angle. internal surface ...
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Tympanic annulus

The tympanic annulus is the thickened edge of the pars tensa of the tympanic membrane, anchoring it in the tympanic sulcus 3. Gross anatomy The tympanic annulus is formed by a fibrocartilaginous thickening of the edge of the pars tensa and has a horseshoe-shaped configuration. It is deficient ...
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Tympanic membrane

The tympanic membrane is a thin membrane that separates the external ear from the middle ear. It acts to transmit sound waves from air in the external auditory canal (EAC) to the ossicles of the middle ear. Gross anatomy The tympanic membrane is shaped like a flat cone pointing into the middle...
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Tympanic part of temporal bone

The tympanic part of the temporal bone is situated inferiorly to the squamous part and anteriorly to the mastoid part. The tympanic part surrounds the external auditory meatus, forming the anterior wall, floor and some of the posterior wall of the bony external acoustic meatus. The lateral bord...
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Tympanosquamosal suture

The tympanosquamosal suture or fissure separates the tympanic part of the temporal bone from the squamous part. It is parallel and anterior to the bony external auditory meatus and medially continuous with the petrotympanic fissure and petrosquamous fissure.
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Typical cervical vertebrae

Of the seven cervical vertebrae, C3 through C6 have typical anatomy, while C7 looks very similar. C1 (atlas) and C2 (axis) have very distinct anatomical features. For a basic anatomic description of the structure a generic vertebra, see vertebrae. Gross anatomy small, oval-sized vertebral bodi...
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Typical ribs

Typical ribs are those numbered 2 to 10 with ribs 1, 11 and 12 considered atypical. Gross anatomy A typical rib is long and flat. They contain a: head neck tubercle shaft angle Ribs have a rounded, smooth superior border. The inferior border is thin and sharp.  Osteology Head The head...
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Typical thoracic vertebrae

Given the twelve thoracic vertebrae are largely similar, most are considered typical thoracic vertebrae with the exceptions T1 and T9 to T12. For a basic anatomic description of the structure of typical vertebrae, see vertebrae. Gross anatomy Relative to cervical and lumbar vertebrae, thoracic...
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Ulna

The ulna (plural: ulnae) is one of the two long bones of the forearm. It is located medially in the supinated anatomic position. It has a larger proximal end and tapers to a smaller distal end (opposite to the radius).  Gross anatomy Prominent features of the ulna include: proximal: olecranon...
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Ulnar artery

The ulnar artery is a terminal branch of the brachial artery, arising at the proximal aspect of the forearm. Along with the radial artery, it is one of the main arteries of the forearm.  Summary origin: terminal branch of the brachial artery location: inferior aspect of the cubital fossa sup...
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Ulnar nerve

The ulnar nerve is one of the terminal branches of the brachial plexus and has motor and sensory supply to the forearm and hand. Gross anatomy Origin The ulnar nerve originates as a terminal branch of the medial cord of the brachial plexus with nerve root fibres from C8-T1. Course Arm In t...
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Ulnar vein

The ulnar vein is one of the two major deep veins of the forearm, along with the radial vein. As is usual in the upper and lower limbs, there are often two veins (venae comitantes) that run on either side of the ulnar artery and anastomose freely with each other. It forms in the hand from the d...
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Ulnomeniscal homologue

The ulnomeniscal homologue (UMH) is an obliquely oriented, fibrocartilaginous structure, that forms part of the ulnar collateral ligament complex (ULC) of the wrist. Gross anatomy The UMH is located between the ulnar styloid process and the triquetrum. It adheres to the ulnar joint capsule and...
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Umbilical artery

The umbilical artery gives rise to both a nonfunctional remnant of the fetal circulation and an active vessel giving supply to the bladder. In the adult, the obliterated area of the vessel is identifiable as the medial umbilical ligament and the patent segment is the superior vesical artery. Su...
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Umbilical cord

The umbilical cord is a fetal organ that connects the placenta to the developing fetus and is a vital passage for nutrients, oxygen and waste products to and from the fetus.  The umbilical cord inserts into the centre of the placental bulk and into the fetus at the umbilicus. Variations in inse...
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Umbilical vein

The umbilical vein is the conduit for blood returning from the placenta to the fetus until it involutes soon after birth. The umbilical vein arises from multiple tributaries within the placenta and enters the umbilical cord, along with the (usually) paired umbilical arteries. Once it enters the...
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Uncinate process

The uncinate process of the ethmoid bone is a thin hook-like osseous structure of the wall of the lateral nasal cavity. Gross anatomy Together with the ethmoid bulla, it forms the boundaries of the hiatus semilunaris and ethmoid infundibulum. The course of the free edge of the uncinate proces...
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Uncinate process of the cervical spine

The uncinate process of the cervical spine is a hook-shaped process found bilaterally on the superolateral margin of the cervical vertebral bodies of C3-C7. The uncinate processes are more anteriorly positioned in the upper cervical spine and more posteriorly location in the lower cervical spin...
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Uncovertebral joint

Uncovertebral joints, also called Luschka’s joints, are seen bilaterally between adjacent cervical vertebrae, identified by the cat ear shaped uncinate processes of the C3-7 vertebrae (C1 and C2 have no uncinate processes). Gross anatomy Articulations The articulation forms between the uncina...
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Uncus

The uncus is the innermost part of the anterior parahippocampal gyrus, part of mesial temporal lobe.  Gross anatomy The uncus is the most anterior portion of the medial parahippocampal gyrus. It belongs to the limbic system. Housing the primary olfactory cortex, it is part of the olfactory sys...
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Unfused spinous process

Unfused spinous process, which is really failure of fusion of the neural arch, is a relatively common anatomical variant and is part of the spectrum of spina bifida occulta.  This should be differentiated from accessory ossicles of the spinous process, which appear after non-fusion of the secon...

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