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 goove, 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 publication of the second edition is imminent.
The standard anatomical terms are from Latin and Ancient Greek roots. The English edition of the terminologia anatomica provides the ...
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 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:
Thigh refers to the portion of the lower limb between the hip and knee joints. Note that in an anatomical context "leg" refers to the portion between the knee and ankle joints and not to the entire lower limb.
The third condyle (also known as condylus tertius or median occipital condyle) is a rare anatomic variant of the occipital condyles. It is a small separate ossicle at the anteromedial margin of the occipital condyle formed by the failure of the embryonic proatlas (4th occipital sclerotome) to un...
The third ventricle is one of the four CSF-filled cavities that together comprise the ventricular system.
The third ventricle is a median cleft between the two thalami and is bounded laterally by them and the hypothalamus. Its anterior wall is formed by the lamina terminalis, and...
Thoracic anatomy encompasses the anatomy of all structures of the thoracic cavity.
This anatomy section promotes the use of the Terminologia Anatomica, the global standard for correct gross anatomical nomenclature.
The thoracic aorta is the most superior division of the aorta and is divided into three sections:
The thoracic aorta begins at the aortic valve, located obliquely just to the left of the midline at the level of the the third intercostal space. It ...
The thoracic cage refers to the skeleton of the thorax:
thoracic vertebral column
12 pairs of ribs
The thoracic duct is the main lymphatic channel for the return of chyle to the venous system. It drains lymph from both lower limbs, abdomen (except the convex area of the liver), left hemithorax, left upper limb and left face and neck.
The thoracic duct is the superior continua...
Thoracic lymph nodes are divided into 14 stations as proposed by the International Association for the Study of Lung Cancer (IASLC) 1, principally in the context of oncologic staging.
highest mediastinal nodes: low cervical, supraclavicular, and sternal notch nodes
The thoracic plane, also known as the transthoracic plane or the plane of Ludwig is an artificial horizontal plane used to divide the mediastinum into the superior mediastinum and the inferior mediastinum.
It is defined as a horizontal line that runs from the manubriosternal joint (sternal angl...
A handy mnemonic to remember the structures found at the level of the thoracic plane (also known as the plane of Ludwig) is:
C: cardiac plexus
L: ligamentum arteriosum
A: aortic arch (inner concavity)
P: pulmonary trunk
T: tracheal bifurcation (carin...
The thoracic spine forms the middle part of the vertebral column. It extends from below C7 on the cervical spine to above L1 on the lumbar spine. There are 12 thoracic vertebra, termed T1-T12 (some older doctors and texts refer to the dorsal spine and D1-D12).
The thoracic spine is unique due ...
The thoracoacromial artery is a vessel arising from the axillary artery at the axilla.
origin: first branch of the second part of the axillary artery 1
supply: pectoralis major and minor, anterior part of the deltoid, and dermal sensation overlying the clavipectoral ...
A useful mnemonic to remember the branches of the thoracoacromial artery is:
The thoracodorsal nerve also known as the middle subscapular or long subscapular nerve arises from the posterior cord of the brachial plexus and supplies the latissimus dorsi muscle.
The thoracodorsal nerve arises from the posterior cord of the brachial plexus with fibres...
The thoracoepigastric vein provides a communication between the superficial epigastric vein and the lateral thoracic vein as it ascends superficially on anterolateral chest and abdominal wall. It, therefore, drains into both the superior vena cava via the axillary vein and the inferior vena cava...
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.
It is relatively large...
The thyrocervical trunk is one of the 3 branches of the first part of the subclavian artery and gives of 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 wall...
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.
The thyroglossal duct arises from foramen caecum located at the junction of...
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.
origin: oblique line ...
The thyroid cartilage is the largest of the cartilages of the larynx, with its superior pole sitting at the level of the C4 vertebrae.
The thyroid cartilage consists of two laminae that are fused anteriorly in the median plane to form the laryngeal prominence. Each laminae posses...
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:
right common carotid artery
internal thoracic artery
The thyroidea ...
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.
The thyroid extends from C5 to T1 and lies anterior to the thyroid and cricoid cartilages of the lar...
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.
The tibia has a prismoid shaft, expande...
The tibialis anterior muscle is one of the muscles of the anterior compartment of the leg involved in dorsiflexion and inversion of the foot.
origin: body of the tibia
insertion: medial cuneiform and first metatarsal
action: dorsiflexion and inversion of the foot
arterial supply: an...
The tibialis posterior muscle is one of the small muscles of the deep posterior compartment of the leg.
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...
The tibial nerve is one of two terminal branches of the sciatic nerve and supplies the leg and foot with motor and sensory supply.
origin: the terminal branch of sciatic, at or above the popliteal fossa
course: courses straight down the popliteal fossa, passing deep to gastrocnemius t...
The tibial plateau is the proximal articular surface of the tibia.
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...
The tibiofemoral joint is a modified hinge synovial joint between the distal femur and the proximal tibia.
articulation: modified hinge joint between the medial and lateral condyles of the femur and the tibial condyles
ligaments: transverse ligament of the knee, medial an...
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.
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.
The tongue has a tip, ventral surface, dorsal surface and root. The tongue is made of a midline lingual septum an...
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.
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...
The trachea, known colloquially as the windpipe, connects the upper respiratory tract to the lungs via the tracheobronchial tree, enabling gas exchange.
The trachea is a tube-shaped structure consisting of 15-to-20 D-shaped cartilage rings anterolaterally bridged by annular ligam...
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...
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...
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...
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 assimilation: complete or partial fusion of C1 and the o...
The transition zone of a nerve describes a roughly 2 mm length region 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...
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 l...
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...
Transversalis fascia is the lining fascia of the anterolateral abdominal wall which lies between the transversus abdominis muscle and peritoneum.
The transversalis fascia, inferior diaphragmatic fascia, pelvic fascia and iliacus fascia form a continuous lining of the abdominal a...
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.
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...
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...
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.
The transverse colon is the longest and most mobile part of the large intestine. It measures up to 45 cm in length.
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...
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...
The transverse ligament of the knee is a ligament within the anterior aspect of the knee joint.
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.
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...
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).
The muscles fibres attach prox...
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.
It is superior to the left atrium and posterior to the intrapericardial parts of the pulmonary trunk a...
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...
Transverse vaginal (transvaginal) septum (TVS) is a type of rare congenital uterovaginal anomaly (class II under the Rock and Adam classification).
It is rare with a frequency of 1 in 70,000 females.
In the case of a complete septum, patients commonly prese...
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.
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.
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...
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.
According to Pfitzner, the trapezium secondarium is one of four potential secondary ossifica...
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.
origin: superior nuch...
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.
The trapezoid is an irregular, boot-shaped bone. The dorsal surface is larger than the palmar surface and i...
The trapezoid ligament is one of two components forming the coracoclavicular (CC) ligament. The conoid ligament is the other component.
The trapezoid ligament is a broad quadrilateral ligament that is quite thin. Its positioned almost horizontally. It is the anterolateral part of...
The triangle of Guillain and Mollaret, also known as the dentatorubro-olivary pathway, has three corners 1:
inferior olivary nucleus
contralateral dentate nucleus
Rubro-olivary fibres descend from the parvocellular division of each red nucleus along the central tegmental tracts t...
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...
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...
The triangular fibrocartilage complex (TFCC) is a complex structure that is a major contributor to the stability of the wrist.
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...
Triangular space of cruciate ligaments (TSC) is defined as the potential extrasynovial space between anterior and posterior cruciate ligaments of the knee joint.
anteriorly: anterior cruciate ligament
posteriorly: posterior cruciate ligament
inferiorly: tibial plate...
A useful mnemonic to remember the tributaries of the inferior vena cava is:
I Like To Rise So High
I: common iliac veins
L: lumbar veins
T: right testicular (gonadal) vein
R: renal veins
S: suprarenal veins
H: hepatic veins
The triceps brachii, which often referred to simply as the triceps is a three-headed muscle in the posterior compartment of the arm.
long head: infraglenoid tubercle of the scapula
medial head: posterior humerus, inferior to the radial groove, medial intermuscular septum
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...