The glenoid labrum is a fibrocartilaginous structure that attaches as a rim to the articular cartilage of the glenoid fossa and serves to deepen and increase the surface area. In this capacity, it acts as a static stabiliser of the glenohumeral joint, preventing dislocation and subluxation at th...
There are a number of glenoid labral variants, whose importance is mainly due to the fact that the unwary may misinterpret them as pathology (e.g. Bankart lesion or labral tear). These include:
superior sublabral sulcus
The globes or simply, the eyes are paired spherical sensory organs, located anteriorly on the face within the orbits, which house the visual apparatus.
The globe is suspended by the bulbar sheath in the anterior third of the bony orbit.
Each globe is an approxim...
The globus pallidus (plural: globus pallidi) is a paired structure and one of the nuclei that make up the basal ganglia. It is a subcortical structure at the base of the forebrain and in anatomical relation to the caudate nucleus and putamen. It forms the lentiform nucleus with the putamen.
The glomus body is a component of the dermis that is involved in thermoregulation.
It consists of a specialised arteriovenous anastomosis surrounded by a connective tissue capsule. They are most numerous in the fingers and toes and exist to shunt blood from the skin surface when...
The glossopharyngeal nerve is the ninth (IX) of the twelve pairs of cranial nerves. It exits the brainstem out from the sides of the upper medulla, just rostral to the vagus nerve and has sensory, motor, and autonomic components.
The sensory ganglion cells lie in the supe...
The superficial gluteal muscles lie within the gluteal region posterolateral to the bony pelvis and proximal femur. From superficial to deep lie the gluteus maximus, medius and minimus. The gluteus maximus is an important in hip extension and lateral rotation. Gluteus medius and minimus are hip ...
The gluteus maximus is the largest muscle in the gluteal region and overlies most of the other gluteal muscles.
gluteal surface of the ilium behind the posterior gluteal line
the lumbar fascia
lateral mass of sacrum
insertion: gluteal tuberosity of th...
The gluteus medius and gluteus minimus muscles are two muscles of the more superficial group in the gluteal region.
origin: gluteal surface of the ilium between the posterior and anterior gluteal line
insertion: posterolateral surface of the greater trochanter of femur
The gluteus minimus and gluteus medius muscles are two muscles of the more superficial group in the gluteal region.
origin: gluteal surface of the ilium between the anterior and inferior gluteal lines
insertion: anterior surface of the greater trochanter of femur
arterial supply: sup...
The glymphatic pathway has only recently been described and functionally represents the brain’s lymphatic system, although no anatomical structure equivalent to the peripheral lymphatic system is present within the brain parenchyma. It is believed to be a crucial normal homeostatic feature allow...
The gonadal arteries are the paired primary vascular supply to the ovaries in the female and the testes in the male. As the anatomy of the gonadal arteries differs substantially between the sexes, they are covered separately:
The gonadal veins are paired structures that drain the gonads in males and females. In males it is called the testicular vein and in females it is called the ovarian vein. The gonadal veins ascend with the gonadal arteries in the abdomen along the psoas muscle anterior to the ureters. Like the s...
The gracilis is the most superficial muscle in the medial compartment of the thigh and descends almost vertically down the medial side of the thigh.
origin: a line on the external surfaces of the body of the pubis, inferior pubic ramus, and the ramus of the ischium
insertion: medial s...
The great cardiac vein (GCV) runs in the anterior interventricular groove and drains the anterior aspect of the heart where it is the venous complement of the left anterior descending artery. It is the main tributary of the coronary sinus.
It begins on the anterior surface of th...
The great saphenous vein (GSV) forms part of the superficial venous system of the lower limb.
Origin and course
The GSV lies within the subcutaneous tissues of the leg in the thigh in the saphenous compartment, which is bounded posteriorly by the deep fascia and superficially b...
The great vessel space is the fourth retroperitoneal space along with the anterior and posterior pararenal spaces, and the perirenal space 1, 2. Unlike other retroperitoneal spaces, it is not well-defined by fascial planes and thus disease process affecting other retroperitoneal spaces can also ...
The greater auricular nerve is a cutaneous branch of the cervical plexus that innervates the skin of the auricle as well as skin over the parotid gland and mastoid process. The greater auricular nerve also supplies branches that innervate the deep layer of the parotid fascia.
The greater occipital nerve is a spinal nerve that innervates the skin of the occiput and upper neck.
The greater occipital nerve arises from the medial branch of the dorsal ramus of C2.
The greater occipital nerve emerges between axis (C2) and the obliquus capit...
The greater palatine foramen is the opening in the posterior hard palate of the greater palatine canal, which is formed between the articulation of maxillary bone and the greater palatine sulcus of palatine bone. The canal is also known as the pterygopalatine canal. A small accessory canal branc...
The greater palatine nerve (or anterior palatine nerve) is a branch of the maxillary division of the trigeminal nerve and contributes to the pterygopalatine ganglion.
The greater palatine nerve divides off the maxillary division just after emerging from the foramen rotundum to en...
The greater sciatic foramen is a foramen within the pelvis and is a major conduit of neurovascular structures from the pelvis to the lower limb.
In a clockwise fashion, its boundaries include:
superior: anterior sacroiliac ligament
posteromedial: sacrotuberous liga...
The greater sciatic notch is a large notch in the pelvis above the ischial spine. The addition of the sacrospinous ligament converts the notch into the greater sciatic foramen.
The greater (superficial) petrosal nerve originates at the geniculate ganglion, where the nervus intermedius and facial nerve join. It contains mainly preganglionic parasympathetic fibers and some sensory taste afferent from the soft palate.
It arises at the geniculate ganglion, passes through ...
The greater trochanteric bursa is located posterior to the greater trochanter of the femur, subjacent to the iliotibial band.
The clinical importance of the bursa lies in the fact that it commonly becomes inflamed (see: trochanteric bursitis).
The greater wing or ali-sphenoid of the sphenoid bone is a process which projects from either side of the lower part of the sphenoid body, at a common junction with the pterygoid process. 1 It is a paired structure, which curves upward, backward and laterally from each side of the sphenoid body,...
The Griffiths point (or Griffiths critical point) refers to the site of watershed anastomosis between the ascending left colic artery and the marginal artery of Drummond occurring in the region of the splenic flexure. Most anatomy texts describe the location as two-thirds along the transverse co...
Guyon’s canal is a fibro-osseous tunnel extending from the transverse carpal ligament at the proximal aspect of the pisiform to the origin of the hypothenar muscles at the hook of hamate. It is approximately 4 cm in length.
roof: palmar carpal ligament, palmaris brevi...
The gyrus rectus, or straight gyrus, is located at the medial most margin of the inferior surface of frontal lobe 1,2. Its function is unclear but it may be involved in higher cognitive function (e.g. personality) 3.
The gyrus rectus is bounded medially by the interhemispheric fi...
The habenula is part of the epithalamus and receives input from the brain via the stria medullaris. It outputs to many midbrain areas involved in releasing neuromodulators, such as dopamine, norepinephrine, and serotonin.
The habenula was traditionally divided into lateral (limbic) and medial (...
The hallux sesamoid bones are paired, dual ossicles of the foot. They function as a fulcrum to increase the leverage of both flexor hallucis brevis and longus.
The hallux sesamoids are ovoid-shaped ossicles. There is a medial (tibial) and lateral (fibular) hallux sesamoid and ar...
The hamate is one of the carpal bones, forms part of the distal carpal row and has a characteristic hook on its volar surface.
The hamate has a wedge-shaped body. It bears an uncinate (unciform) hamulus (hook of hamate) which projects in a volar fashion from the dista...
The hamstrings are the muscles of the posterior compartment of the thigh and include the:
lateral: biceps femoris
medial: semimembranosus and semitendinosus
Apart from the short head of biceps femoris, the muscles share two common features:
span both the hip and knee joints and therefore pro...
All the intrinsic muscles of the hand are innervated by the ulnar nerve, except four muscles which are supplied by the median nerve and are easily recalled with the mnemonic:
FOAL or LOAF
F: flexor pollicis brevis
O: opponens pollicis
A: abductor pollicis brevis
L: lateral two lum...
The hand is part of the upper limb below the forearm and wrist. In the supinated anatomical position, the palm is facing anteriorly. The bones of the hand are:
The hard palate is the anterior horizontal bony part of the palate that forms the roof of the oral cavity and floor of the nasal cavity. It is formed by the palatine processes of the maxillae and the horizontal plates of the palatine bones. On its inferior oral surface it is lined by oral mucosa...
The haustral folds represent folds of mucosa within the colon. They are formed by circumferential contraction of the inner muscular layer of the colon.
The outer longitudinal muscular layer is organised into three bands (taeniae coli) which run from the caecum to the rectum. These muscular band...
Head and neck anatomy is important when considering pathology affecting the same area. In radiology, the 'head and neck' refers to all the anatomical structures in this region excluding the central nervous system, that is, the brain and spinal cord and their associated vascular structures and en...
The heart is a hollow, muscular organ of the middle mediastinum, designed to pump oxygenated blood around the systemic circulation and de-oxygenated blood around the pulmonary circulation
The heart has a somewhat conical form and is enclosed by pericardium. It is positioned poste...
There are four heart chambers, the right atrium, left atrium, right ventricle and left ventricle. These receive blood from the body and lungs, and contract to transmit blood to the lungs for oxygenation and to the body for use in metabolism.
It is best to list the four chambers in order of the ...
The hemiazygos vein is the asymmetric counterpart to the azygos vein and forms part of the azygos venous system.
The hemiazygos vein is formed by the confluence of the left ascending lumbar and left subcostal veins.
The hemiazygos vein enters the thorax either ...
Hemivertebra is a type of vertebral anomaly and results from a lack of formation of one half of a vertebral body. It can be a common cause of a congenital scoliosis.
The estimated incidence is at ~0.3 per 1000 live births 2.
It falls under the spectrum of segmentation...
The hepatic artery proper or the proper hepatic artery arises from the common hepatic artery as it divides into its two terminal branches, the hepatic artery proper and the gastroduodenal artery.
The hepatic artery proper runs anterior to the portal vein and to the left ...
The hepatic veins are three large veins which drain the hepatic parenchyma into the inferior vena cava (IVC), named the right hepatic vein, middle hepatic vein and left hepatic vein. The veins are important landmarks, running in between and hence defining the segments of the liver. There are sep...
The hepatobiliary system consists of the:
biliary tree (both intra- and extra-hepatic)
The pancreas is included by some.
Hepatoduodenal ligament is the peritoneal ligament of lesser omentum, which attaches the duodenum to the liver.
Hepatoduodenal ligament contains:
common hepatic duct
part of cystic duct
Hepatoduodenal ligament is a rout of spread of diseases of pancratic head t...
The hepatogastric (gastrohepatic) ligament is a peritoneal ligament that together with the hepatoduodenal ligament forms the lesser omentum. It derives from the embryonic ventral mesentery.
The hepatogastric ligament extends from the fissure of the ligamentum venosum and porta he...
Heschl's gyrus, also known as transverse temporal gyrus, is part of the temporal lobe and contains the primary auditory cortex (Brodmann area 41). It is entirely hidden within the Sylvian fissure, with the planum temporale and superior temporal gyrus located lateral to it.
Hesselbach's triangle or the inguinal triangle is a triangular area on the inferior interior aspect of the anterior abdominal wall within the groin.
base: inguinal ligament
lateral border: inferior epigastric vessels
medial border: lateral border of the rectus sheat...
Heterotaxy syndrome or situs ambiguus (also commonly, but etymologically less correctly, spelled situs ambiguous) is a disturbance in the usual left and right distribution of the thoracic and abdominal organs which does not entirely correspond to the complete or partial mirror image.
It occurs ...
The hilar point on chest radiographs is formed by the outer margins of the superior pulmonary vein and the descending pulmonary artery as they cross past each other.
Hilton's law states that a joint tends to be innervated by a branch of a motor nerve which also supplies a muscle extending and acting across the joint. Another branch of the nerve often supplies the overlying skin.
The hindfoot is the most posterior portion of the foot and is composed of the talus and calcaneus. The mid-tarsal joint (Chopart joint) joins the hindfoot to the midfoot.
Hinge joints are a type of synovial joint that permit movement in one direction like the hinge on a door. Usually this is achieved by a concave surface articulating with a corresponding convex surface.
Hinge joints allow for movement in a single translational plane only. This one d...
The hip joint is a synovial joint between the femoral head and the acetabulum of the pelvis. This article considers the hip joint specifically, however it is worth noting that the word hip is often used to refer more generally to the anatomical region around this joint.
The hip joint capsule is strong and dense, and is attached above to the acetabular margin 5-6 mm beyond its labrum, in front to the outer labral aspect and, near the acetabular notch, to the transverse acetabular ligament and the adjacent rim of the obturator foramen. It surrounds the femoral ne...
Hippocampal sulcus remnant cysts are remnants of incomplete involution of the embryonic hippocampal fissure, and are an incidental finding.
They are seen in more than ~25% (range 10-40%) of the adult population 1,3.
They consist of small (1-2 mm) cys...
The hippocampus is an important component of the human brain, situated in the temporal lobe. It plays a role in information processing and the reproductive cycle and is involved in Alzheimer disease.
The hippocampus lies in the hippocampal sulcus immediately below the f...
The walls of arteries and veins are composed of endothelial cells, smooth muscle cells and extracellular matrix (including collagen and elastin). These are arranged into three concentric layers: intima, media and adventitia.
The intima is the inner layer abutting the vessel lumen. The adventit...
Hoffa's fat pad is the largest of the anterior knee fat pads.
antero-inferior: infra patella tendon
postero-central: knee joint
patellar tendon lateral fem...
The horizontal fissure (also called the minor fissure) is a unilateral structure in the right lung that separates the right middle lobe from the right upper lobe.
The horizontal fissure arises from the right oblique fissure and follows the 4th intercostal space from the sternum u...
Horseshoe kidneys are the most common type of renal fusion anomaly. They render the kidneys susceptible to trauma and are an independent risk factor for the development of renal calculi and transitional cell carcinoma of the renal pelvis.
Horseshoe kidneys are found in approximate...
Horseshoe lung is one of the rare congenital anomalies of the lung. A band of pulmonary parenchyma is formed extending between the right and left lungs. The pulmonary tissue can be seen either anterior to the aorta or posterior to the pericardium at the caudal end.
The humerus (plural: humeri) is a tubular bone of the arm that articulates proximally at the shoulder with the glenoid of the scapula, and distally at the elbow, with the radius and ulna.
The humerus begins proximally as a rounded head and joins the greater and lesser ...
The hyoglossus muscle is a thin, quadrilaterally shaped muscle in the upper neck and the floor of the mouth. It is one of the extrinsic muscles of the tongue. The submandibular ganglion suspended from the lingual nerve sits on it.
origin: hyoid bone: from the entire length of the great...
The hyoid is a "horseshoe-shaped" bone that serves as a structural anchor in the mid-neck. It is the only bone in the human body that does not directly articulate with another bone, sesamoids aside. It is a place of convergence of multiple small neck muscles that permit the pharyngeal phase of s...
A column of Bertin is the extension of renal cortical tissue which separates the pyramids, and as such are normal structures. They become of radiographic importance when they are unusually enlarged and may be mistaken for a renal mass (renal pseudotumour).
Nomenclature of such enlarged columns ...
Hypodontia refers to the congenital absence of one or more teeth.
Hypodontia is common, affecting ~15% of the population with a recognised variations in ethnicities, e.g. prevalence of 1% in indigenous Australians through to 30% in Japanese populations. There is a female preponder...
The hypoglossal canal is located between the occipital condyle and jugular tubercle and runs obliquely forwards (posteromedial to anterolateral) allowing the hypoglossal nerve (12th cranial nerve) to exit the posterior cranial fossa.
Its proximal portion is often divided by a fibrous (sometime...
The hypoglossal nerve is the twelfth and last cranial nerve and supplies the tongue with motor control. It only has one catch: it receives hitch-hiking C1 nerve root fibres, which it distributes before reaching the tongue.
The nerve emerges from the medulla laterally, between the...
The hypopharynx or laryngopharynx forms the most inferior portion of the pharynx, being the continuation of the oropharynx superiorly and both the larynx and oesophagus inferiorly.
The hypopharynx begins as the continuation of the oropharynx at the pharyngoepiglottic fold (which...
The hypothalamus is located, as the name would suggest, below the thalamus, and is intimately associated with both the limbic system and the pituitary gland.
Its boundaries are in some places poorly defined (outlined in blue in Figure 2):
anterior: lamina terminalis...
The ileocaecal valve separates the terminal ileum from the caecum and functions to regulate flow between these two structures and prevent reflux from the caecum into the small intestine.
The ileocaecal valve consists of two muscular layers of ileum, an upper and lower lip, that ...
The ileocolic artery is a branch of the superior mesenteric artery (SMA) that runs obliquely to the ileocaecal junction.
It divides into an ileal branch that supplies the terminal ileum and anastomoses with the terminal SMA and a colic branch that supplies the proximal ascending colon and anast...
The ileum is the final part of the small intestine, following the duodenum and jejunum.
The ileum is not to be confused with the ilium.
The ileum is 2-4 m in length and is separated from the caecum by the ileocaecal valve (ICV). While there is no discrete line demar...
The iliacus muscle is one of the muscles of the posterior abdominal wall and contributes to the iliopsoas muscle and tendon.
origin: superior 2/3s of the iliac fossa, anterior sacroiliac ligaments and anterior sacral ala
insertion: into the psoas major tendon to form iliopsoas tendon ...
Iliofemoral deep vein thrombosis occurs when a thrombus in the iliac vein (common, external or internal) or common femoral vein obstructs the venous outflow from the lower limb leading to marked oedema.
To be added
To be added
To be a...
The iliofemoral ligament is very strong and shaped like an inverted Y, lying anteriorly and intimately blended with the capsule. Its apex is attached between the anterior inferior iliac spine and acetabulum rim, its base to the intertrochanteric line. The oblique lateral ligament attaches to a t...
The iliohypogastric nerve arises from the anterior ramus of the L1 nerve root of the lumbar plexus along with the ilioinguinal nerve. It a sensory nerve that provides lateral and anterior cutaneous branches supplying the posterolateral gluteal skin and skin in the pubic region.
The ilioinguinal nerve arises from the anterior ramus of the L1 nerve root from the lumbar plexus along with the iliohypogastric nerve. The predominantly sensory nerve eventually passes through the superficial inguinal ring to provide cutaneous sensation to the upper medial thigh, mons pubis and...
The iliolumbar artery is one of three branches of the posterior division of the internal iliac artery.
origin: posterior division of the internal iliac artery
supply: ilium, iliacus muscle, psoas major muscle, quadratus lumborum muscle, erector spinae muscle, anterio...
The iliolumbar ligament is a strong band of connective tissue which courses from the transverse process of L5 (in over 96% of cases) to the posterior iliac wing and iliac crest. It functions to maintain the alignment of L5 on the sacrum during various movements 1, 2.
It is an important landmark...
The iliopsoas compartment is an extra-retroperitoneal space that runs along the posterior aspect of the abdomen and pelvis and extends into the thigh.
The iliopsoas compartment is bound by the iliopsoas fascia, which is continuous with:
anteriorly: transversalis fasc...
The iliopsoas muscle is found within the iliopsoas compartment and is an important muscle in locomotion and upright posture.
origin: fusion of psoas major and iliacus muscles
insertion: lesser trochanter of the femur
nerve supply: femoral nerve; lumbar plexus
blood supply: iliolumb...
The iliotibial band (ITB) is a thick band of fascia formed proximally at the hip by the fascia of the gluteus maximus, gluteus medius and tensor fasciae latae muscles.
The band consists of deep and superficial layers:
the superficial layer is the main tendinous component and inserts onto Gerd...
The ilium (pl. ilia) is among the three bones of the innominate bone: ilium, ischium, and pubis. These are individual bones in the youth and unite to form one bone in adults, the principal union being in the acetabulum.
Ilium is called so as it supports the 'flank'.
The ilium is not to be conf...
The medical terms ileum and ilium have been causing great confusion to medical students and junior doctors alike for decades now. Only separated by one letter, the second vowel, the pronunciation may be identical, or differ slightly with the i sound resembling that in "bit" for ilium (ɪlɪəm) or ...
The maxillary incisive canal runs through the maxilla in the midline. It connects the inferior nasal cavity with the superior oral cavity, opening at the incisive foramen posterior to the central maxillary incisor teeth. It contains the descending palatine artery and the nasopalatine nerve.
The incisive foramen (also known as nasopalatine foramen or anterior palatine foramen) is the oral opening of the nasopalatine canal. It is located in the maxilla in the incisive fossa, midline in the palate posterior to the central incisors, at the junction of the medial palatine and incisive s...
The incisive nerve is one of the two terminal branches of the inferior alveolar nerve, a branch of the posterior division of the mandibular division of the trigeminal nerve. It continues running anteriorly in the medullary cavity of the mandible after the mental nerve branches off and exits via ...
Incomplete double aortic arch is a rare vascular ring anomaly wherein a segment of the minor aortic arch, usually the left, is atretic.
As in the case of other vascular rings, this anomaly can cause 1:
Some patients may reach adulthood with...
Incomplete hippocampal inversion unsurprisingly describes the situation where the normal inversion of the hippocampus fails to happen during development.
Incomplete hippocampal inversion is the most correct description of this finding. Hippocampal malrotation is a term used by some...
The incus is the middle of the ossicles articulating with the head of the malleus anteromedially and the stapes inferomedially.
a body which articulates with the head of the malleus, and to which the superior ligament of the incus is attached (to the roof of the middle ear cavit...