Supradiaphragmatic liver has been reported as a very rare variant in liver morphology.
In this variant, liver tissue extends into the right hemithorax through an opening in the right hemidiaphragm. The tissue is connected to the right hepatic lobe by a pedicle. In one report, the caudate lobe ...
The suprahyoid muscles are a group of muscles in the neck, named because of their position to the hyoid bone:
anterior suprahyoid muscles
anterior bellies of digastric muscle
posterior suprahyoid muscles
posterior bellies of digastric muscle
The supramarginal gyrus is a portion of the parietal lobe of the brain. It is one of the two parts of the inferior parietal lobule, the other being the angular gyrus. It plays a role in phonological processing and emotional responses.
The supramarginal gyrus is horsesh...
The supramesocolic space is the peritoneal space above the root of the transverse mesocolon. The inframesocolic space lies below the root of the transverse mesocolon.
It can be arbitrarily divided into right and left spaces and subspaces. These are normally in communication with each other, but...
The supraoptic nucleus (SON) contains neurosecretory cells that produce hormones (oxytocin and vasopressin/antidiuretic hormone).
The supraoptic nucleus is found in the medial area of the anterior hypothalamus, sitting superior to the optic tract 1.
The hormones travel down the...
The supraoptic recess is a small angular recess or diverticulum that sits at the junction of the floor and anterior wall of the third ventricle, immediately above the optic chiasm.
When the third ventricle is expanded due to hydrocephalus (e.g. aqueduct stenosis) this recess,...
The supraorbital artery is a branch of the ophthalmic artery supplying part of the orbit and face.
The supraorbital artery originates from the ophthalmic artery, upon branching it lies medial to the optic nerve.
The supraorbital artery courses superiorly and med...
Supraorbital air cells are an anatomical variant of the paranasal sinuses. They consist of cells originating from the anterior ethmoid air cells extending posteriorly and superiorly over the orbit from the frontal recess. They may mimic septated frontal sinuses as their posterior wall is the sku...
The supraorbital foramen or notch is the small opening at the central edge of the superior orbital margin in the frontal bone just below the superciliary arches that transmits the supra-orbital nerve, artery and vein.
It is lateral to the supratrochlear foramen, where the supratrochlear nerve, ...
The supraorbital nerve is the lateral and larger of the two branches of the frontal nerve, a branch of ophthalmic division of the trigeminal nerve. As it courses through the superior aspect of the extraconal space of the orbit it exits the orbit through the supraorbital notch to supply the conju...
The supraorbital ridge, also known as the supraorbital margin or superciliary arch is the superior margin of the bony orbit. Part of the frontal bone, the supraorbital ridge contains the supraorbital foramen (or notch). The corrugator supercilii muscles arise from the medial end of the supraorbi...
The suprapatellar bursa, also known as the suprapatellar recess, is one of several bursae of the knee. It is located proximal to the knee joint, between prefemoral and suprapatellar fat pads. As with all bursae, its purpose is to reduce friction between moving structures.
In most (~85%) people,...
The suprapleural membrane, also known as Sibson fascia, is a dense fascial layer that is attached to the inner border of the first rib and costal cartilage anteriorly, C7 transverse process posteriorly and to the mediastinal pleura medially.
It is flat and lies in the oblique plane of the thora...
The suprascapular artery is 1 of the 4 branches of the thyrocervical trunk (off the first part of the subclavian artery).
It traverses inferiorly and laterally in the lower anterior neck superficial to the anterior scalene muscle and phrenic nerve before crossing the third part of the subclavia...
The suprascapular nerve is the only branch of the upper trunk (C5 and C6) of the brachial plexus, supplying the supraspinatus and infraspinatus muscles and sensation to the acromioclavicular and glenohumeral joints.
The suprascapular nerve arises from the upper trunk of t...
The suprascapular notch is located on the superior aspect of the scapula, at the scapula's anterolateral aspect.
The suprascapular notch separates the superior border of the scapula from the anterior coracoid process.
Relations and/or boundaries
The suprascapular nerve passes ...
The suprasellar cistern (also known as the chiasmatic cistern or pentagon of basal cisterns) is a cerebrospinal fluid-filled cistern located above the sella turcica, under the hypothalamus and between the uncus of the temporal lobes. It contains the proximal part of Sylvian fissure, the optic c...
Supraspinatus is one of the four muscles that make up the rotator cuff, the others being: infraspinatus, teres minor and subscapularis.
origin: supraspinous fossa of the scapula
insertion: greater tuberosity of the humerus
innervation: suprascapular nerve (C5-6)
arterial supply: sup...
The supraspinous ligament runs along the tips of adjacent spinous processes and is particularly thick in the cervicothoracic region. Above the level C7 spinous process the ligament no longer directly attaches to the spinous process but rather continues as the nuchal ligament up to its attachment...
The suprasternal space (of Burns) is a space of the inferior neck.
Inferior to the hyoid bone, the superficial or investing layer of the deep cervical fascia divides into anterior and posterior leafs to attach to the respective borders of the suprasternal (jugular) notch, forming...
Suprasternal tubercle is a sternal normal variant which forms when a suprasternal ossicle fuses with manubrium 1. It can be unilateral or bilateral. It usually appears as triangular or pyramidal bony projection in continuity with the superior margin of manubrium. It is better depicted in coronal...
The supratrochlear artery, also known as the frontal artery, originates from the ophthalmic artery as one of its terminal branches.
After arising from the ophthalmic artery, it pierces the orbital septum and courses in the superior and medial aspect of the orbit, medial to the su...
The supratrochlear foramen is the small opening at the medial edge of the superior orbital margin in the frontal bone that transmitts the supratrochlear nerve, artery and vein. When incomplete, it forms a notch. It is variably present, and when absent the neurovascular bundle will simple exit th...
The supratrochlear nerve is the medial and smaller of the two branches of the frontal nerve, a branch of ophthalmic division of the trigeminal nerve. As it courses through the superomedial aspect of the extraconal space of the orbit, it passes over the trochlear and exits the orbit under the sup...
The supravesical fossae are concave depressions of peritoneum in the paravesical space bounded by the median umbilical fold and the medial umbilical folds. It partially overlies the inguinal (Hesselbach’s) triangle. The supravesical fossae are usually occupied by small bowel loops and the urinar...
The supreme intercostal arteries, or superior intercostal arteries, are formed as a direct result of the embryological development of the intersegmental arteries. These arteries are paired structures of the upper thorax which normally form to provide blood flow to the first and second intercosta...
The supreme meatus is an air passage of the lateral nasal cavity located between the supreme nasal concha and lateral nasal wall. The ostium of a posterior ethmoidal air cell may be seen in the supreme meatus.
The plural of meatus is meatus (Latin noun of the fourth declension) or ...
The supreme nasal concha or turbinate is one of the conchae in the nose and is a bony projection, arising from the medial surface of the labyrinth of the ethmoid above the superior nasal concha. Its presence is variable and has been reported in up to 52% of subjects 1.
The air passage between t...
The suspensory ligament of the axilla is the inferior extension of the clavipectoral fascia on each side of the thorax.
The suspensory ligament of the axilla originates from the inferior border of pectoralis minor, where the 'leaflets' of the clavipectoral fascia have fused again...
The sustentaculum tali is a horizontal shelf that arises from the anteromedial portion of the calcaneus. The superior surface is concave and articulates with the middle calcaneal surface of the talus. The inferior surface has a groove for the tendon of flexor hallucis longus.
There are many sutures of the skull, which are where skull bones meet. In general, sutures don't fuse until brain growth is complete, therefore allowing the skull to increase in size with the developing brain.
Sutures are fibrous joints with the periosteum externally and outer la...
The Sylvian cistern, also known as the insular cistern, is one of the CSF-filled subarachnoid cisterns.
There are two paired cisterns on either side. It is the subarachnoid space extending into the fissure of the frontal and temporal lobes (i.e. the lateral sulcus). It therefore ...
The Sylvian fissure, also known as the lateral sulcus, separates the frontal and parietal lobes superiorly from the temporal lobe inferiorly. The insular cortex is located immediately deep to the Sylvian fissure.
Anteriorly the fissure courses medially to the 'stem' of the lateral fissure, int...
The sympathetic chain is a component of the autonomic nervous system and is composed of general visceral afferent and efferent axons that allow for involuntary control of bodily functions via the hypothalamus.
The overarching function of the sympathetic system is to control the 'fight, fright o...
Symphalangism refers to ankylosis of the interphalangeal joints (i.e. fusion of the phalanges) in either the toes or the fingers. Less commonly, the metacarpophalangeal joints may be affected.
One study reports symphalangism of the fifth toe in ~55% (range 40-75%) of the populatio...
Symphyses are secondary cartilaginous joints composed of fibrocartilage. They are considered amphiarthroses, meaning that they allow only slight movement and are all found at the skeletal midline.
symphysis pubis between the pubic bones medially
manubriosternal joint between the ste...
Synarthroses are a functional class of joint that permit very little or no movement under normal conditions.
fibrous joints such as cranial sutures
synchondroses (primary cartilaginous joints) such as growth plates
Synchondroses are primary cartilaginous joints mainly found in the developing skeleton, but a few also persist in the mature skeleton as normal structures or as variants.
Synchondroses are cartilaginous unions between bone composed entirely of hyaline cartilage. Most exist between os...
Syndesmoses are a type of fibrous joint where strong collagen rich connective tissue holds two portions of bone together allowing very little movement. They consist of an interosseous membrane and ligamentous thickenings.
distal tibiofibular syndesmosis
Synovial cysts are para-articular fluid-filled sacs or pouch-like structures containing synovial fluid and lined by synovial membrane. They can occur around virtually every synovial joint in the body and also around tendon sheaths and bursae. Communication with the adjacent joint may or may not ...
Synovial joints are a type of joint with an articular capsule, consisting of an outer fibrous layer and an inner synovial membrane, which surrounds a fluid-filled synovial cavity. The articulating surfaces are covered by hyaline cartilage, designed to slide with little friction and to absorb com...
Synovial plicae are folds of synovium, thought to represent embryologic remnants. They are common, present in ~90% of arthroscopies 3.
They have been implicated in anterior knee pain and possibly in chondromalacia patellae although their role remains controversial 1,3.
T11 is an atypical thoracic vertebra. In contrast to typical thoracic vertebrae, it contains a single costal facet that articulates with the atypical eleventh rib. There are no facets on the transverse processes.
T12 is an atypical thoracic vertebra. In contrast to typical thoracic vertebrae, it contains a single costal facet with no facets on transverse processes.
T1 is an atypical thoracic vertebra. In contrast to typical thoracic vertebrae, it contains a complete facet for the 1st rib and a demifacet for the 2nd rib. It contains lips on the upper surface of the body. T1 also has a spinous process more horizontal than other thoracic vertebrae.
The taeniae coli are the three outer muscular bands of the colon. They sit on top of the inner circumferential layer and result in the classical appearance of the colon: the haustral markings are interrupted unlike the valvulae conniventes within the small bowel.
The talar declination angle is drawn on the weightbearing lateral foot radiograph between the mid-talar axis and the supporting surface. It should usually measure approximately 21°.
If the first metatarsal axis is steep, the mid-talar axis approaches the horizontal and is projected above the fi...
Talocalcaneal coalition is one of the two most common sub-types of tarsal coalition, the other being calcaneonavicular coalition. It accounts for 45% of all tarsal coalitions, and although all three facets of the talocalcaneal joint can be involved, the middle facet is most commonly involved.
The talocalcaneal joint, also called the anatomical subtalar joint, is an important and complex joint in the hindfoot that allows articulation of the talus and calcaneus.
It comprises three articulations between talus and calcaneus 1:
anterior: head of talus with anterior facet ...
The talus is a tarsal bone in the hindfoot that articulates with the tibia, fibula, calcaneus, and navicular bones. It has no muscular attachments and around 60% of its surface is covered by articular cartilage.
The talus has been described as having three main components: head,...
Tanycytes are one of the three types of ependymal cells, themselves a type of glial cell. They are found lining the floor of the third ventricle and the median eminence of the hypothalamus 1.
It is believed that these specialised cells are involved in the feedback mechanisms on the anterior p...
The tarsal bones are the seven bones of the foot excluding the metatarsals and phalanges. They are collectively known as the tarsus. The seven bones are:
There are several mnemonics for the tarsals.
Mnemonics of the tarsal bone are numerous and useful for memorising the order and location of tarsal bones. They usually describe the position of the tarsal bones from superior to inferior, medial to lateral in a right foot:
The Cab in New Mexico Is Land Cruiser
The Cure of Nemaline Myopathy I...
Tarsal coalition describes the complete or partial union between two or more bones in the midfoot and hindfoot. Tarsal coalition refers to developmental fusion rather than fusion that is acquired secondary to conditions such as rheumatoid arthritis, trauma or post-surgical.
The tarsal plate of the eye is formed by dense fibrous tissue, moulded to the curvature of the eyeball. It anchors roots of eyelashes and contains tarsal (Meibomian) glands. These glands secrete oil which makes the lid margins waterproof, covers tears and delays tear evaporation.
The tarsal sinus (or sinus tarsi) is a cylindrical cavity located between the talus and calcaneus on the lateral aspect of the foot. MRI is the investigation of choice for evaluating the tarsal sinus structures.
The tarsal sinus is situated on the lateral side of the foot; distal...
The tarsal tunnel is a fibro-osseous canal found in the medial aspect of the ankle.
roof: flexor retinaculum
floor: medial surfaces of the tibia, talus and calcaneus 1, 2
From anterior to posterior:
tibialis posterior tendon
flexor digitorum longus tend...
The tectorial membrane is the thin superior continuation of the posterior longitudinal ligament from the body of the axis. It joins the axis body to the clivus on the anterior half of the foramen magnum, and ascends as high as the spheno-occipital synchondrosis and laterally extends to the hypog...
Teeth can be both primary and secondary, with the eruption of permanent teeth occurring over a long period between the ages of 6 and 24.
There are twenty deciduous (primary) teeth in young children, with ten per jaw and five in each quadrant, which consist of (distal to mesial):...
The tegmentovermian angle is an important measurable parameter in the assessment of posterior fossa abnormalities in the fetus. The angle is constructed on midsagittal images of the fetal brain, ideally on MRI.
The angle is formed by the intersection of the following two lines 1:
line 1: along...
The tegmentum is one of the areas of the brainstem. It is a phylogenetically old part of the brainstem and, in adults, is the location of the brainstem nuclei.
In the midbrain, it sits between the quadrigeminal plate and cerebral peduncles. In the pons, it is posterior to the basilar part of t...
The tela choroidea is the thin, highly vascularised, loose connective tissue portion of pia mater that gives rise to the choroid plexus. Thus, it is basically the lamina propria of the ependyma and lies directly adherent to it, without any tissue in between the two 6.
Being part ...
The temporal bone is situated on the sides and the base of the cranium and lateral to the temporal lobe of the cerebrum. The temporal bone is one of the most important calvarial and skull base bones. The temporal bone is very complex and consists of five parts:
The temporal fossa is located in the temporal region and communicates inferiorly with infratemporal fossa deep to the zygomatic arch.
The temporal fossa is bounded by a few anatomical landmarks, anteriorly the frontal process of the zygomatic bone, superiorly and posteriorly the...
The temporalis muscle is one of the muscles of mastication. It is responsible for both closing the mouth and retraction (posterior fibres).
origin: temporal fossa between the infratemporal crest and inferior temporal line
insertion: coronoid process and ramus of mandible
The temporal lobe is one of the four lobes of the brain (along with the frontal lobe, parietal lobe, and occipital lobe), and largely occupies the middle cranial fossa.
The temporal lobe is the second largest lobe, after the larger frontal lobe, accounting 22% of the total neocor...
The temporal pole is an anatomical landmark that corresponds to the anterior end of the temporal lobe, lying in the middle cranial fossa.
It corresponds to Brodmann area 38 and has strong connections with the amygdala and orbital prefrontal cortex, and is sometimes recognised as a component of...
The temporomandibular joint (TMJ) is an atypical synovial joint located between the condylar process of the mandible and the mandibular fossa and articular eminence of the temporal bone. It is divided into a superior discotemporal space and inferior discomandibular space by the TMJ disc (or meni...
The temporopolar artery is usually a dorsolateral branch from the M1 segment of the middle cerebral artery (MCA) and supplies the polar and anterolateral portions of the temporal lobe.
This artery may arise as a branch from the anterior temporal artery 1.
The temporozygomatic suture (or zygomaticotemporal suture) is between the zygomatic process of the temporal bone and the temporal process of the zygomatic bone.
It can mimic a zygoma fracture.
The tendinous ring, also known as the annulus of Zinn, is the common origin of the four rectus muscles (extraocular muscles).
The tendinous ring straddles the superior orbital fissure and through it (from superior to inferior) pass:
superior division of the oculomotor nerve (CN III)
The Tenon capsule, also known as fascia bulbi or bulbar sheath, functions as an extraocular muscle pulley. It also provides a socket which separates the globe from the surrounding fat and allows free movement. It merges posteriorly with the dural sheath of the optic nerve and extends anteriorly ...
The tensor fasciae latae muscle is the most anterior of the superficial group of muscles in the gluteal region and overlies the gluteus minimus and the anterior part of the gluteus medius.
origin: lateral aspect of crest of ilium between anterior superior iliac spine and tubercle of cr...
The tensor fasciae suralis muscle is an uncommon accessory muscle in the popliteal fossa. It can be an unusual cause of a popliteal fossa soft-tissue swelling or mass.
origin: may arise from the distal aspect of any of the hamstring muscles, in the majority of reported cases it origin...
The tensor tympani is a short muscle in the middle ear that arises from the superior surface of the cartilaginous part of the Eustachian tube, the greater wing of the sphenoid, and the petrous part of the temporal bone. It passes across the tympanic cavity and inserts into the upper end of the h...
The tensor veli palatini is one of the 5 paired muscles of the soft palate. It is triangular in shape and it's tendon wraps around the pulley of pterygoid hamulus to alter the shape of the soft palate.
origin: it has 3 sites of origin:
scaphoid fossa of the medial pterygoid plate
The tentorial nerve is the first branch of the ophthalmic division of the trigeminal nerve (CN Va) which is the dominate dural nerve supplying most of the supratentorial dura. It specifically supplies the falx, calvarial dura and superior surface of the tentorium.
The tentorium cerebelli is the second largest dural fold after the falx cerebri. It lies in the axial plane attached perpendicularly to the falx cerebri and divides the cranial cavity into supratentorial and infratentorial compartments 1. It contains free and attached margins 2.
Teres major is one of the seven scapulohumeral muscles that act around the glenohumeral joint to facilitate shoulder movement.
origin: caudal two thirds of lateral border and inferior angle of scapula
insertion: medial border of the intertubercular groove, which is the crest of lesser...
Teres minor is one of the four muscles that make up the rotator cuff, the others being: supraspinatus, infraspinatus, and subscapularis.
origin: lateral border of the scapula
insertion: greater tuberosity of the humerus
innervation: axillary nerve (C5-6)
arterial supply: circumflex ...
The terminal bronchioles are a continuation of the bronchi and are the last divisions of the conducting airways.
Terminal bronchioles, are confusingly named, as they not the final branches but rather the distal bronchioles that do not bear alveoli. The first 19 divisions from ...
Each breast lobe is drained by a collecting duct terminating in the nipple. The collecting duct has several branches, which ends in a terminal ductal-lobular unit (TDLU), the basic functional and histopathological unit of the breast. The TDLU is composed of a small segment of the terminal duct a...
The terminal ileum is the most distal segment of small bowel. It immediately precedes the small bowel's connection with the colon through the ileocaecal valve. It is of particular interest since a number of infectious and inflammatory processes preferentially involve the segment.
location: the ...
The terminal tuft is the most distal part of a distal phalanx, and comprises of the flared bone distal to the shaft.
spade phalanx sign
terminal tuft masses
as it is close to the nail, pathology or injuries of one can affect the other
The Terminologia Anatomica (TA) is the global standard for correct gross anatomical nomenclature in humans 1. The second edition was published in 2011 4.
The standard anatomical terms are from Latin and Ancient Greek roots. The English edition of the Terminologia Anatomica provides the accepte...
Testicular and epididymal appendages are remnants of embryonic ducts and are quite common, with one or more being present in ~70% of patients 1.
Four such appendages have been described:
testicular appendix (hydatid of Morgagni)
it is a Müllerian duct remnant (paramesonephric d...
A testicular appendix (alternatively called appendix of testis or appendix testis) represents a developmental remnant of the paramesonephric duct (Müllerian duct) which is situated in the upper pole of the testis inside a groove between the testicle and the head of epididymis 1.
The testicular arteries (also known as the spermatic arteries) are the long, small-diameter gonadal arteries in the male that supply the testis alongside the cremasteric artery and the artery to the ductus deferens.
As paired structures they arise symmetrically, slightly...
Testicular descent occurs after the fourth month of fetal life. The testes are derived from the gonadal ridge medial to the mesonephric ridge of the intermediate cell mass. An elongated diverticulum of the peritoneal cavity, the processus vaginalis precedes the testis through the inguinal canal ...
The testes, also known as the testicles, are the male gonads and are contained within the scrotum. The testes are responsible for the production of sperm and testosterone.
At birth, testes measure approximately 1.5 cm (length) x 1 cm (width), reaching ~4 mL volume at puberty 1.
The thalamencephalon is an anatomic region that includes the thalamus, metathalamus and epithalamus. It is one of the components that form the diencephalon.
Thalamostriate veins are formed by the joining of anterior caudate vein and the vein of stria terminalis. They join the septal veins and form internal cerebral veins.
The thalamostriate veins can be compressed in preterm neonates who have had germinal matrix haemorrhage. This...
The thalamus is the largest of the structures comprising the diencephalon.
The thalamus acts as a relay centre, receiving and distributing information between the peripheries and higher centres such as the cerebral cortices. It contributes to functions such as: