Multilocular adipocyte Brown adipose tissue cell that contains multiple microdroplets of fat and abundant mitochondria specialized in the generation of body heat.

Also: multilocular fat cell · brown adipocyte

Unilocular adipocyte Cell specialized in storing energy in the form of a large single drop of lipids that moves the nucleus towards the cell periphery.

Also: unilocular fat cell · white adipocyte

Allantois Membranous diverticulum of the yolk sac involved in the formation of umbilical cord blood vessels and early urinary physiology.

Also: allantois

Endocardial pad Thickening of mesenchymal tissue in the atrioventricular canal and embryonic outflow tract, key for cardiac septation.

Also: endocardial bearing · endocardial cushion

Apophysis crista galli Vertical bony crest on the ethmoid bone that protrudes into the anterior cranial fossa where the falx cerebri is inserted.

Also: ethmoid cockscomb · crista galli

Xiphoid process Smaller cartilaginous or terminal bone element located at the lower end of the sternum bone.

Also: xiphoid appendix · xiphoid process

Arachnoids Intermediate and avascular meningeal layer with a network-shaped structure beneath which the cerebrospinal fluid circulates.

Also: arachnoid mater

Embryonic aortic arch Transitory arterial vessel that connects the aortic sac with the dorsal aortas through the pharyngeal arches during cardiovascular development.

Also: aortic arch

Pharyngeal arch Bilateral mesodermal structure visible externally in the cervical region of the embryo that participates in the formation of the face and neck.

Also: gill arch · pharyngeal arch

Aorta artery Main artery of the body from which all the branches that supply oxygenated blood to the systemic tissues arise.

Also: aorta

Common carotid artery Large arterial branch of the neck that bifurcates into the internal and external carotid to ensure craniofacial perfusion.

Also: common carotid artery · common carotid artery

External carotid artery Terminal branch of the common carotid that supplies the structures outside the skull, neck, and face.

Also: external carotid artery

Common iliac artery Terminal branch of the bifurcation of the abdominal aorta artery that divides into the internal and external iliac artery.

Also: primitive iliac artery · common iliac artery

Subclavian artery Pair arterial vessel that supplies oxygenated blood to the upper extremities, neck, and portions of the brain.

Also: subclavian artery

Fibrous astrocyte Astrocyte with long, thin processes located in the white matter of the central nervous system that provides structural support to myelinated axons.

Also: white matter astrocyte · fibrous astrocyte

Protoplasmic astrocyte Neuroglia cell with multiple branched processes that is located mainly in the gray matter of the central nervous system to provide metabolic support.

Also: gray matter astrocyte · protoplasmic astrocyte

Atlas First cervical vertebra that lacks a vertebral body and articulates directly with the occipital bone of the skull.

Also: C1 vertebra · atlas

Right atrium Cardiac cavity that receives deoxygenated blood from the superior and inferior vena cava and the coronary sinus.

Also: right atrium · right atrium

Left atrium Cavity of the heart that receives oxygenated blood from the lungs through the four pulmonary veins.

Also: left atrium · left atrium

Primitive atrium Region of the embryonic heart tube that partitions to give rise to the left and right atria.

Also: primitive cardiac atrium · primitive atrium

Axis Second cervical vertebra characterized by presenting the odontoid process that acts as a rotational pivot for the atlas.

Also: C2 vertebra · axis

Spleen Secondary lymphoid organ located in the left hypochondrium involved in blood filtration and the immune response.

Also: spleen

Metanephric blastema Mass of intermediate mesoderm that reciprocally interacts with the ureteral bud to form the functional nephrons of the definitive kidney.

Also: renal blastema · metanephric blastema

Blastocele Internal cavity filled with fluid that forms inside the morula during the blastulation process to give way to the blastocyst.

Also: segmentation cavity · blastocoel

Blastomer Each of the totipotent cells that originate from the mitotic divisions of the zygote during early segmentation.

Also: segmentation cell · blastomere

Pharyngeal pouch Internal invagination of the endoderm of the pharynx that gives rise to the Eustachian tube, tonsils, parathyroid and thymus.

Also: pharyngeal pouch

Main bronchus Fibrocartilaginous duct that arises from the bifurcation of the trachea and penetrates the pulmonary hilum to branch.

Also: primary bronchus · main bronchus

Ureteral outbreak Evagination of the mesonephric duct that gives rise to the ureter, renal pelvis, calyces and definitive collecting tubules.

Also: metanephric diverticulum · ureteric bud

Cardiac bulb Segment of the embryonic heart tube that gives rise to the right ventricle and the outlet trunks of the great arteries.

Also: bulbus cordis

Havers Canal Central osteon conduit through which blood vessels and nerve fibers pass that nourish compact bone tissue.

Also: osteonic canal · Haversian channel

Volkmann Channel Transverse or oblique canal in the compact bone that connects the Haversian canals to each other and to the periosteum.

Also: perforating conduit · Volkmann's channel

Cardias Anatomical transition zone of the stomach that surrounds the opening of the abdominal esophagus.

Also: cardia

Intraembryonic coelom Internal body cavity formed by the division of the lateral mesoderm that will give rise to the pleural, pericardial and peritoneal cavities.

Also: intraembryonic coelom

Kupffer cell Specialized and fixed macrophage located in the hepatic sinusoids that phagocytizes cellular debris and pathogens from the portal circulation.

Also: hepatic sinusoidal macrophage · Kupffer cell

Merkel cell Sensory receptor cell located in the basal stratum of the epidermis that is associated with afferent nerve endings to detect sustained touch.

Also: tectoepithelial cell · Merkel cell

Paneth cell Exocrine epithelial cell located at the bottom of the crypts of Lieberkühn that produces granules rich in lysozyme and defensins to regulate the intestinal microbiota.

Also: Paneth cell

Schwann cell Cell of the peripheral nervous system that surrounds the axons, forming the myelin sheath or supporting unmyelinated fibers.

Also: neurolemocyte · Schwann cell

Sertoli cell Support epithelial cell located in the seminiferous tubules of the testicle that nourishes and regulates the development of germ cells in spermatogenesis.

Also: testicular sustainacular cell · Sertoli cell

Hepatic stellate cell Cell in the perisinusoidal space of the liver that stores vitamin A under normal conditions and induces fibrosis in response to chronic liver damage.

Also: Ito cell · hepatic lipocyte

Interstitial Leydig cell Endocrine cell located in the intertubular connective tissue of the testicle responsible for the synthesis and secretion of androgens such as testosterone.

Also: Leydig cell · Leydig cell

Mesothelial cell Simple squamous epithelial cell that lines the serous cavities of the body and secretes visceral lubricating fluid.

Also: mesothelium · mesothelial cell

Striated (brush) border Apical specialization of the intestinal epithelial cell formed by parallel microvilli that increase nutrient absorption.

Also: ridged edge · striated border

Ciego First portion of the large intestine with the appearance of a blind sac located in the right iliac fossa below the ileocecal valve.

Also: cecum

Clavicle Long, curved bone with an Italian S shape that connects the upper extremity to the trunk through the sternum.

Also: clavicle

Type I collagen The most abundant fibrillar protein in the body that provides high resistance to tension in structures such as tendons, ligaments, dermis and bones.

Also: type I fibrillar collagen · type I collagen

Collagen type II Variety of fibrillar collagen located mainly in hyaline and elastic cartilage, where it resists inter-articular compression forces.

Also: cartilage collagen · type II collagen

Collagen type III Protein component that forms the reticular support fibers in lymphoid, hematopoietic organs and tissues with high compliance.

Also: reticular collagen · type III collagen

Collagen type IV Non-fibrillar collagen that forms a three-dimensional support network in the basal lamina of all epithelia in the body.

Also: basal lamina collagen · type IV collagen

Chondroblast Young cell derived from the perichondrium that actively produces cartilage matrix components before becoming trapped in its own lacuna.

Also: cartilage-forming cell · chondroblast

Chondrocyte Mature cell of the cartilaginous tissue that resides in lacunae and is responsible for maintaining the cartilaginous extracellular matrix.

Also: cartilage cell · chondrocyte

External auditory canal Bone and cartilaginous canal that directs sound waves from the pinna to the tympanic membrane.

Also: CAE · external auditory meatus

Cystic duct Drainage vessel that connects the gallbladder with the common hepatic duct to form the common bile duct.

Also: cystic duct

Gartner Pipeline Embryonic remnant of the mesonephric duct that can persist abnormally on the lateral wall of the vagina in women.

Also: Gartner's pipeline

Deferens vas Long muscular duct that transports sperm from the epididymis to the ejaculatory ducts of the prostate.

Also: vas deferens

Inferior dental canal Bone canal that runs through the jaw, transporting the nerve and the lower alveolar vessels for the teeth.

Also: mandibular canal · mandibular canal

Common hepatic duct Bile duct formed by the union of the right and left hepatic ducts that transports bile from the liver.

Also: common hepatic duct

Mesonephric duct Embryonic urinary duct that differentiates in the male to form the epididymis, vas deferens and seminal vesicles.

Also: Wolffian duct · mesonephric duct

Paramesonephric duct Bilateral embryonic tubular structure that fuses in women to give rise to the fallopian tubes, the uterus and the upper vaginal third.

Also: Müllerian duct · paramesonephric duct

Thoracic duct Main lymphatic duct of the body that transports most of the body's lymph back to the venous system.

Also: thoracic duct

Krause Corpuscle Sensory receptor with a spheroid structure that is located in the mucous membranes and superficial dermis, traditionally associated with thermal reception.

Also: Krause terminal bulb · Krause end bulb

Pacinin's Corpuscle Rapidly adapting encapsulated sensory receptor located in the deep dermis and connective tissue that detects vibrations and pressure.

Also: Pacinian receptor · Pacinian corpuscle

Ruffini Corpuscle Slowly adapting capsular sensory receptor sensitive to stretching of the skin and joint capsule.

Also: Ruffini receiver · Ruffini corpuscle

cerebral cortex External layer of gray matter of the cerebral hemispheres formed by neuronal somata, responsible for higher cognitive functions.

Also: cerebral cortex

False rib Ribs from the eighth to the tenth pair whose costal cartilages fuse to join indirectly to the sternum.

Also: vertebrochondral rib · false rib

Floating rib Ribs of the eleventh and twelfth pair that lack anterior union with the sternum, leaving them free in the abdominal wall.

Also: free rib · floating rib

True rib Each of the first seven thoracic ribs that articulate directly with the sternum through its costal cartilages.

Also: sternal rib · true rib

Gonadal crest Thickening of the intermediate mesoderm that represents the anatomical site of development of the future male or female gonad.

Also: urogenital ridge · gonadal ridge

neural crest Population of pluripotent cells of ectodermal origin that migrate to form ganglia, melanocytes, cranial bones and supporting tissue.

Also: neural crest

Cranial neural crest Neural crest cells that migrate towards the pharyngeal arches to originate the cartilaginous skeleton and craniofacial dental implications.

Also: cranial neural crest

Lieberkühn Crypt Simple tubular gland located in the lamina propria of the intestinal mucosa that contains stem and secretory cells.

Also: intestinal crypt · crypt of Lieberkuhn

Fourth ventricle Cavity of the ventricular system located between the brainstem and the cerebellum that drains into the ependymal duct.

Also: fourth ventricle

Ulna Long and medial bone of the forearm that forms the bony prominence of the elbow together with the humerus.

Also: ulna · ulna

Corpus callosum Interhemispheric commissure formed by a thick bundle of nerve fibers that connects and communicates the two cerebral hemispheres.

Also: corpus callosum

Ultimobranchial body Structure derived from the fourth pharyngeal pouch that provides calcitonin-producing C cells to the embryonic thyroid.

Also: ultimopharyngeal body

Optical dome Double-walled structure formed by the invagination of the optic vesicle that will give rise to the retina and the pigment epithelium.

Also: optic cup

Decidua basalis Portion of the uterine endometrium that directly underlies the implantation site of the blastocyst and forms the maternal side of the placenta.

Also: decidua basalis

Decidua capsularis Layer of the uterine endometrium that superficially covers the implanted blastocyst, isolating it from the free uterine cavity.

Also: decidua capsularis

Parietal decidua Part of the endometrium that lines the rest of the uterine cavity not occupied by the developing implanted embryo.

Also: decidua parietalis

Desmosoma Intercellular anchoring junction that firmly joins the intermediate filaments of neighboring cells, providing high mechanical resistance to tissues.

Also: macula adherens · desmosome

Duodenum First short and fixed portion of the small intestine where the discharge of pancreatic and bile juices occurs.

Also: duodenum

Dura Mater External, thick, fibrous meningeal layer that provides direct mechanical protection to the central nervous tissue and covers the skull and vertebral canal.

Also: dura mater

Ectoderm External germinal layer of the trilaminar embryo that will give rise to the epidermis of the skin and the central and peripheral nervous system.

Also: ectoderm

Embryoblast Group of internal cells of the blastocyst that will give rise to the embryo itself and various extraembryonic membranes.

Also: internal cell mass · embryoblast

Endocardium Thin epithelial and connective layer that internally lines the cardiac chambers and heart valves.

Also: endocardium

Endoderm Internal germ layer of the embryo that gives rise to the lining epithelium of the digestive and intestinal tracts and the respiratory system.

Also: endoderm

Endomysium Thin layer of loose connective tissue that individually surrounds each skeletal muscle fiber to provide vascular and innervation support.

Also: endomysium

Endosteum Thin layer of cellular connective tissue that lines the medullary cavities, Haversian canals and trabeculae of cancellous bone.

Also: bone internal membrane · endosteum

Ependymocyte Lining cell of the central nervous system that forms the epithelium of the cerebral ventricles and the ependymal duct.

Also: ependymal cell · ependymocyte

Epicardio Visceral layer of the serous pericardium that adheres directly to the surface of the myocardium of the cardiac chambers.

Also: epicardium

Epididymis Coiled tubular structure located above the testicle where sperm mature and are temporarily stored.

Also: epididymis

Epimysium Sheath of dense connective tissue that surrounds the entire skeletal muscle, protecting it and facilitating its external separation.

Also: epimysium

Pseudostratified epithelium Epithelium with a single layer of cells that simulates having several layers due to the variable position of its nuclei, common in the respiratory tract.

Also: cylindrical pseudostratified epithelium · pseudostratified epithelium

Simple cylindrical epithelium Tissue composed of a single layer of vertically elongated cells, common in the mucosa of the gastrointestinal tract where it performs active absorption functions.

Also: simple columnar epithelium · simple columnar epithelium

Simple cubic epithelium Lining tissue composed of a single layer of cells with similar height and width, specialized in absorption and secretion functions.

Also: simple cuboidal epithelium · simple cuboidal epithelium

Simple flat epithelium Epithelial tissue formed by a single layer of flattened cells that facilitates the passive transport and diffusion of gases in vessels and alveoli.

Also: simple squamous epithelium · simple squamous epithelium

Basophilic erythroblast Nucleated precursor cell of the erythroid line characterized by an intensely basophilic cytoplasm due to the large accumulation of ribosomes.

Also: basophilic erythroblast

Lung outline Ventral respiratory diverticulum originating from the endoderm of the anterior intestine that will give rise to the trachea and main bronchi.

Also: respiratory outbreak · lung bud

Scapula Flat, triangular-shaped bone of the posterior shoulder girdle that articulates with the clavicle and humerus of the arm.

Also: shoulder blade · scapula

Sclerotoma Ventromedial portion of the somite that gives rise to the vertebrae, the ribs and part of the cartilaginous support tissue.

Also: sclerotome

Vertebral sclerotoma Cell population of the embryonic somite that migrates medially around the notochord to give rise to the vertebral bodies.

Also: vertebral sclerotome

Esophagus Muscular duct of the digestive tract that directly connects the posterior pharynx with the cardia portion of the stomach.

Also: esophagus

Stereocilia Long, immobile apical extension of the cell membrane of an actinic nature, common in the epididymis and sensitive hearing cells.

Also: stereocilium

Stomodeo Previous ectodermal invagination that forms the primitive mouth and comes into contact with the embryonic pharynx.

Also: primitive mouth · stomodeum

Femur Long bone of the thigh that articulates with the coxal bone and the tibia, being the longest and most resistant bone in the body.

Also: femur

Elastic fiber Component of the extracellular matrix formed by elastin and fibrillin that gives tissues the ability to stretch and recover their original size.

Also: elastin fiber · elastic fiber

Reticular fiber Fine type III collagen fiber arranged in branched networks that serves as structural support for cells in soft organs such as the spleen and liver.

Also: reticular network · reticular fiber

Fibroblast The most common cell of connective tissue that synthesizes collagen and elastic fibers and the ground substance of the extracellular matrix.

Also: connective tissue cell · fibroblast

Foramen magnum Large bony opening at the base of the occipital bone through which the cranial cavity communicates with the vertebral canal.

Also: occipital foramen · foramen magnum

Cardiac foramen ovale Transitory opening in the interatrial septum of the fetal heart that allows the direct passage of blood from the right atrium to the left.

Also: foramen ovale · fetal fossa ovalis

Gastrulation Crucial embryonic process by which the bilaminar disc transforms into a trilaminar disc composed of ectoderm, mesoderm and endoderm.

Also: gastrulation

Parotid gland Larger major salivary gland located in front of the ear that pours its serous secretion through the Stenon's duct.

Also: parotid gland

Sublingual gland Minor and deeper salivary gland located in the floor of the mouth that secretes mainly mucous type saliva.

Also: sublingual gland

Submandibular gland Mixed predominantly serous salivary gland located in the submandibular triangle of the neck that empties under the tongue.

Also: submandibular gland · submandibular gland

Undifferentiated gonad Initial stage of gonad development in which neither male nor female morphological characteristics are appreciated.

Also: bipotential gonad · indifferent gonad

Isogenic group Group of chondrocytes that have originated from a single progenitor cell through mitotic division within the cartilage.

Also: chondrone · isogenous group

Hemidesmosoma Cell junction structure that anchors the intermediate filaments of the cytoskeleton to the underlying basal lamina of the extracellular matrix.

Also: dermoepidermal cell junction · hemidesmosome

Pharyngeal cleft External groove of ectoderm that separates the pharyngeal arches, contributing to the external auditory canal in its first arch.

Also: pharyngeal groove · pharyngeal cleft

Liver Large gland in the abdominal cavity that performs multiple metabolic, detoxifying, and exocrine biliary synthesis functions.

Also: liver

Hypothalamus Brain structure of the diencephalon that coordinates neuroendocrine functions, body autonomic control and thermoregulation.

Also: hypothalamus

Zygomatic bone Pair bone of the face that constitutes the skeleton of the cheekbone and part of the external lateral orbital rim.

Also: malar bone · zygomatic bone

Sphenoid bone Odd butterfly-shaped bone located at the base of the skull, articulated with all the other cranial bones to give them solidity.

Also: sphenoid bone

Ethmoid bone Odd and irregular bone at the base of the skull that contributes to forming the orbits and the upper portion of the nasal passages.

Also: ethmoid bone

Frontal bone Flat, odd bone of the skull that forms the forehead, the roof of the eye orbits and the anterior part of the cranial fossa.

Also: forehead bone · frontal bone

Hamate bone Bone of the distal row of the carpus characterized by having a hook-shaped bony protrusion on its palmar surface.

Also: hamate bone

Hyoid bone Horseshoe-shaped bone located in the anterior part of the neck that serves as an anchor for the lingual and laryngofascial muscles.

Also: hyoid bone

Occipital bone Unpaired bone located in the posterior and lower region of the skull that houses the foramen magnum for the spinal passage.

Also: occipital bone

Parietal bone Flat, paired bone that forms most of the superior and lateral portions of the bony cranial vault.

Also: parietal bone

Pisiform bone Small carpal bone of the proximal row that is located on the pyramidal bone of the wrist.

Also: pisiform bone

Semilunar bone Carpal bone of the proximal row with a crescent shape that actively articulates with the radius.

Also: lunate bone

Temporal bone Pair bone of the skull that forms the sides and base of the head, housing the structures of the middle and inner ear.

Also: temporal bone

Humerus Long bone of the upper extremity that constitutes the complete bony skeleton of the arm region.

Also: humerus

Ileon Third and last section of the small intestine that communicates with the cecum directly through the ileocecal valve.

Also: ileum

Ilion Superior and largest portion of the coxal bone that forms the iliac crest of the pelvic skeleton.

Also: ilium

Ischium Inferior and posterior part of the coxal bone on which the weight of the body rests when sitting.

Also: ischium

Base sheet Thin layer of extracellular matrix synthesized by epithelial cells that serves as a physical support and selective filter for macromolecules.

Also: basal lamina

Reticular sheet Layer of the basement membrane located below the basal lamina, composed of reticular fibers synthesized by connective tissue cells.

Also: reticular lamina

Bone lamella Thin layer of mineralized bone matrix that contains aligned collagen fibers, constituting the structural component of mature bone tissue.

Also: bone lamella

Primitive line Transitory linear structure on the surface of the epiblast that establishes the longitudinal axis of the embryo and through which cells migrate during gastrulation.

Also: primitive streak

Cerebrospinal fluid Colorless fluid that circulates through the subarachnoid space and the ventricular system, cushioning shocks and transporting metabolites from the brain.

Also: CSF · cerebrospinal fluid

Jaw Mobile and odd bone of the face that houses the lower teeth and temporarily articulates with the mandibular fossa of the skull.

Also: lower jaw · mandible

Manubrium of the sternum Widened upper portion of the sternum that articulates with the clavicles and the first pair of thoracic ribs.

Also: manubrium sterni

Upper jaw Pair bone of the face that forms the upper jaw, the roof of the mouth and the floor of the eye sockets.

Also: maxilla · maxilla

Megakaryocyte Giant, multinucleated bone marrow cell whose cytoplasmic fragmentation gives rise to active platelets.

Also: megakaryocyte

Melanocyte Cell in the basal layer of the epidermis that produces the pigment melanin and transfers it to adjacent keratinocytes to protect them from ultraviolet radiation.

Also: melanin-producing cell · melanocyte

oropharyngeal membrane Temporal bilaminar membrane formed by ectoderm and endoderm that separates the primitive oral cavity from the embryonic pharynx.

Also: oral membrane · buccopharyngeal membrane

Cloacal membrane Posterior bilaminar membrane of the embryo that separates the primitive anal canal from the outside before its cellular perforation.

Also: cloacal membrane

Meninges Three layers of connective tissue membranes that surround and protect the brain and spinal cord within their cavities.

Also: craniocerebral membranes · meninges

Mesoderm Middle germinal layer of the trilaminar embryo that gives rise to muscles, bones, blood vessels, the urogenital system and connective tissue.

Also: mesoderm

Intermediate mesoderm Cord of mesoderm that connects the paraxial mesoderm with the lateral one, originating most of the urogenital and renal structures.

Also: pedicle of the somites · intermediate mesoderm

Lateral mesoderm Thin layer of mesoderm that is divided into somatic and splanchnic sheets to cover the body wall and viscera.

Also: lateral plate mesoderm

Paraxial mesoderm Strip of mesoderm located on both sides of the neural tube that segments to form somites and somitomeres.

Also: paraxial mesoderm

Mesonephros Intermediate and transient kidney that functions temporarily during the first trimester of development before involuting.

Also: intermediate kidney · mesonephros

Metamyelocyte Granulopoiesis cell that has a split or kidney-shaped nucleus, incapable of dividing, intermediate before the band stage.

Also: metamyelocyte

Metanephros Renal primordium that begins its development in the fifth embryonic week and differentiates to constitute the definitive kidney of the mammal.

Also: final kidney · metanephros

Microglia Glial cell of the central nervous system that acts as the main resident macrophage for the active immune defense of the brain and spinal cord.

Also: microglial cell · microglia

Myeloblast Youngest hematopoietic precursor cell of the granulocytic series of the bone marrow that differentiates into a promyelocyte.

Also: myeloblast

Myelocyte Immature bone marrow cell that synthesizes specific secondary granules to differentiate towards the terminal granulocytic line.

Also: myelocyte

Neutrophilic myelocyte Intermediate stage of granulopoiesis in which the active production of specific secondary granules in the cytoplasm begins.

Also: neutrophilic myelocyte

Myoblast Mononucleated precursor cell of muscle tissue that fuses with other similar cells to form multinucleated skeletal myofibers.

Also: muscular progenitor · myoblast

Myofiber Highly specialized and multinucleated individual skeletal muscle cell that constitutes the functional unit of contraction in striated tissue.

Also: striated muscle cell · muscle fiber

Myofibril Intracellular cylindrical structure composed of aligned actin and myosin myofilaments that produces the contraction of the cardiomyocyte or myofiber.

Also: myofibril

Myotome Region of the somite that differentiates to give rise to the segmental skeletal musculature of the trunk and extremities.

Also: myotome

Morula Spherical mass of compact cells resulting from the first segmentation divisions of the zygote, comparable to a blackberry.

Also: morula

Biceps brachii muscle Muscle of the anterior region of the arm that performs elbow flexion and powerful supination of the forearm.

Also: biceps brachii

Deltoid muscle Thick, triangular muscle that covers the shoulder joint and performs arm abduction.

Also: deltoid muscle

Masseter muscle Powerful chewing muscle located in the cheek region that mechanically elevates and protrudes the jaw.

Also: masseter muscle

Temporal muscle Mastication muscle that occupies the temporal fossa and actively elevates the mandible against the upper jaw.

Also: temporal muscle

Trapezius muscle Large flat muscle of the upper back that elevates, retracts and laterally rotates the scapula.

Also: trapezius muscle

Triceps brachii muscle Muscle of the posterior region of the arm whose main function is the extension of the elbow joint.

Also: triceps brachii

Abducens nerve Sixth cranial motor nerve that selectively innervates the lateral rectus muscle of the eye allowing lateral ocular abduction.

Also: cranial nerve VI · external ocular motor · abducens nerve

Accessory nerve Eleventh cranial motor nerve that innervates the sternocleidomastoid and trapezius muscles of the neck and back.

Also: cranial nerve XI · spinal nerve · accessory nerve

Hypoglossal nerve Twelfth cranial motor nerve responsible for coordinating the intrinsic and extrinsic motility of the lingual muscles.

Also: cranial nerve XII · hypoglossal nerve

Pneumogastric nerve Widely distributed tenth cranial nerve that provides parasympathetic innervation to the thoracic and abdominal viscera.

Also: cranial nerve · vagus nerve · vagus nerve

Oculomotor nerve Third cranial motor nerve responsible for most eye movements and pupillary constriction.

Also: cranial nerve III · oculomotor nerve

Olfactory nerve First exclusively sensory cranial nerve responsible for transmitting olfactory impulses from the nasal mucosa to the brain.

Also: cranial nerve I · olfactory nerve

Trochlear nerve Fourth cranial nerve that exclusively innervates the superior oblique muscle of the eye, facilitating looking down and inward.

Also: cranial nerve IV · pathetic · trochlear nerve

Neuroblast Immature precursor cell of ectodermal origin that undergoes differentiation and migration to become a functional neuron of the nervous system.

Also: neural precursor · neuroblast

Neuroectoderm Specialized region of the ectoderm that receives inductive signals from the notochord to differentiate into the plate and neural tube.

Also: neuroectoderm

Hensen's nodule Raised structure at the anterior end of the primitive line that acts as the main embryonic organizer coordinating gastrulation.

Also: primitive node · Hensen's node

Nodule of Ranvier Natural and periodic interruption of the myelin sheath along the axon that facilitates the Saltatory conduction of the nerve impulse.

Also: Ranvier strangulation · node of Ranvier

Normoblast Late immature cell of the red series that expels its nucleus to become a mature erythrocyte after passing through the reticulocyte stage.

Also: orthochromatic erythroblast · normoblast

Notochord Elongated cellular structure of mesodermal origin that defines the symmetrical axis of the embryo and induces the formation of the neural plate.

Also: dorsal cord · notochord

Oligodendrocyte Glial cell of the central nervous system responsible for the formation of the myelin sheath around axons to accelerate nerve conduction.

Also: oligodendrogliocyte · oligodendrocyte

Osteoblast Young differentiated bone cell that synthesizes and secretes the active osteoid matrix, facilitating bone mineralization.

Also: bone-forming cell · osteoblast

Osteocyte Mature bone cell that resides within the lacunae of the mineralized bone matrix and communicates through calcophore ducts to maintain mineral homeostasis.

Also: mature bone cell · osteocyte

Osteoclast Mobile multinucleated giant cell that degrades and reabsorbs the mineralized bone matrix, allowing bone remodeling.

Also: bone degrading cell · osteoclast

Osteone Basic structural unit of compact bone formed by concentric bone lamellae arranged around a Haversian canal.

Also: Havers system · osteon

Ostium primum Transitory opening in the lower edge of the septum primum before its complete fusion with the atrial endocardial cushions.

Also: primary atrial orifice

Ostium secundum Orifice formed by apoptosis and perforation in the upper portion of the septum primum that guarantees the passage of interatrial blood.

Also: secondary ear hole

Perichondrium Layer of dense connective tissue that surrounds most of the cartilage, providing blood vessels and progenitor cells for its growth.

Also: cartilage cover · perichondrium

Perimisium Connective tissue sheath that groups skeletal muscle fibers into individual fascicles within the muscle.

Also: perimysium

Periosteum Dense connective tissue membrane that covers the external surface of bones, except on the articular surfaces, and has osteogenic potential.

Also: external bony covering · periosteum

Fibula Long bone of the leg located in a lateral position that does not support direct weight but serves for muscle insertion and the ankle.

Also: fibula · fibula

Piamadre Innermost, delicate and highly vascularized layer of the meninges that adheres directly to the surface of the central nervous tissue.

Also: pia mater

Pylorus Region of the stomach that connects the gastric cavity with the duodenum and functions as a muscular outlet valve.

Also: pylorus

Cardiogenic plate Area of anterior splanchnic mesoderm in the presomitic embryo where the progenitor cells of the heart develop.

Also: cardiogenic horseshoe · cardiogenic plate

Neural plate Elongated thickening of the ectoderm induced by the notochord that represents the first step of developmental neurulation.

Also: neural plate

Prechordal plate Mass of endodermal and mesodermal cells located in front of the notochord that acts as an organizer of the embryonic head.

Also: prechordal plate

Precordial plate Cell group that coordinates the induction of head development and influences the differentiation of the embryonic forebrain.

Also: prechordal plate

Crystalline placode Thickening of the superficial ectoderm of the head of the embryo induced by the optic cup that will form the ocular lens.

Also: lens placode

Olfactory placode Thickening of the superficial ectoderm of the head of the embryo that invaginates to form the nasal fossa and the olfactory sensory epithelium.

Also: nasal placode · olfactory placode

Otic placode Bilateral ectodermal thickening located on both sides of the hindbrain that invaginates to form the inner ear.

Also: auditory placode · otic placode

Parietal pleura Serous layer that covers the inner surface of the thoracic cavity, the mediastinum and the upper surface of the diaphragm.

Also: parietal pleura

Visceral pleura Thin serous membrane that closely lines the external surface of the lungs, penetrating its fissures.

Also: visceral pleura

Proctodeum Anal ectodermal depression that invaginates towards the cloacal membrane to form the terminal portion of the anal canal.

Also: anal fossa · proctodeum

Promyelocyte Immature granulopoiesis cell that derives from the myeloblast and is characterized by the appearance of primary azurophilic granules.

Also: promyelocyte

Pronephros Rudimentary, non-functional and transient renal structure that appears and disappears quickly at the cranial end of the embryo.

Also: pronephros

Pubis Previous and inferior portion of the coxal bone that articulates medially at the pubic symphysis to close the pelvis.

Also: pubes

Keratinocyte The most abundant cell in the epidermis that synthesizes keratin and undergoes progressive differentiation towards the most superficial layers of the skin.

Also: keratin epidermal cell · keratinocyte

Radio Long and lateral bone of the forearm articulated with the ulna and carpal bones of the wrist for the pronosupination movement.

Also: radius

Sarcoplasmic reticulum Specialized form of smooth endoplasmic reticulum in muscle cells that functions as a store and releaser of calcium ions essential for contraction.

Also: sarcoplasmic reticulum

Secondary yolk sac Extraembryonic structure formed after the migration of endodermal cells that contributes to hematopoiesis and initial nutrition of the embryo.

Also: final yolk sac · secondary yolk sac

Sarcolema Plasma membrane of the muscle cell that has an external basal lamina cover to couple contraction forces.

Also: sarcolemma

Sarcoplasm Muscle cell cytoplasm enriched with myoglobin, glycogen and abundant mitochondria necessary for contractile metabolism.

Also: sarcoplasm

Cervical sinus Transitory cavity of embryonic development of the neck formed by the growth of the second pharyngeal arch over the lower clefts.

Also: cervical sinus

Urogenital sinus Embryonic structure derived from the division of the cloaca that gives rise to the urinary bladder, the urethra and portions of the genital apparatus.

Also: urogenital sinus

Venous sinus Caudal receiving chamber of the embryonic cardiac tube that receives systemic venous and vitelline blood from the extraembryonic vessels.

Also: sinus venosus

Septum primum First growing membranous septum that descends from the roof of the primitive atrium towards the endocardial cushions.

Also: first atrial septum

Septum secundum Second thicker muscular septum that grows to the right of the septum primum and helps close the auricular foramen ovale.

Also: second atrial septum

Somita Bilateral segmented block of paraxial mesoderm that will give rise to the sclerotome, myotome and dermatome of the body trunk.

Also: somit · submit

Amorphous fundamental substance Hydrated gel of the extracellular matrix composed of glycosaminoglycans, proteoglycans and glycoproteins where the cells and support fibers are suspended.

Also: amorphous matrix · ground substance

Urorectal septum Wedge-shaped mesodermal mass that descends to divide the cloacal cavity into the anterior urogenital sinus and posterior anorectal duct.

Also: urorectal septum

Thalamus Region of the diencephalon that acts as the main sensory relay station for information that goes to the cortex.

Also: thalamus

Optical stem Tubular structure that connects the optic cup with the embryonic diencephalon and serves as a scaffold for visual nerve fibers.

Also: optical stalk

Dense connective tissue Fabric characterized by a high density of collagen fibers arranged in bundles, which offers great resistance to physical traction.

Also: dense connective tissue · dense connective tissue

Loose connective tissue Support tissue with abundant cells immersed in an extracellular matrix of gelatinous consistency and few fibers, highly irrigated.

Also: areolar connective tissue · loose connective tissue

Third ventricle Unpaired and intermediate cavity of the diencephalon located in the cerebral midline below the corpus callosum.

Also: third ventricle

Tibia Long bone of the leg located in a medial position that supports most of the body weight transmitted by the femur.

Also: shinbone · warm

Trophoblast Outer layer of blastocyst cells involved in uterine implantation and that will give rise to the fetal portion of the placenta.

Also: external cell mass · trophoblast

Primitive heart tube Tubular structure that originates from the fusion of the cardiac primordia and begins to beat actively in early phases.

Also: heart tube · primitive heart tube

Neural tube Embryonic precursor structure of the brain and spinal cord that originates from the invagination of the neural plate.

Also: neural tube

Seminiferous tubule Convoluted duct located within the testicular lobules where spermatogenesis takes place under the support of Sertoli cells.

Also: seminiferous tubule

T tubule Tubular invagination of the sarcolemma into the interior of the muscle cell that rapidly conducts the cellular action potential for coordinated contraction.

Also: transverse tubule · T-tubule

Ureter Bilateral muscular duct that actively transports urine through peristaltic waves from the renal pelvis to the urinary bladder.

Also: ureter

Female urethra Short tube that carries urine from the urinary bladder to the external urethral orifice in the vaginal vestibule.

Also: female urethra

Male urethra Long urinary and semen passage duct that passes through the prostate, the urogenital diaphragm and the corpus spongiosum of the penis.

Also: male urethra

Urothelium Specialized stratified epithelium of the urinary tract that has the ability to stretch and resist the toxicity of urine.

Also: urinary transitional epithelium · transitional epithelium

Myelin sheath Lipoprotein coating that surrounds the axons of many neurons, formed by concentric layers of cellular plasma membrane that electrically insulate the axon.

Also: myelin sheath

Urinary bladder Hollow and distensible muscular organ located in the pelvis that functions as a temporary reservoir for storing urine.

Also: urinary bladder

Inferior vena cava Large caliber vessel that transports deoxygenated blood from the abdomen, pelvis and lower limbs to the right atrium.

Also: inferior vena cava

Superior vena cava Large venous vessel that collects deoxygenated blood from the head, neck, upper extremities and thorax to take it to the heart.

Also: superior vena cava

Internal jugular vein Deep venous vessel in the neck that collects blood from the brain, face and neck to drain into the subclavian vein.

Also: internal jugular vein

Right ventricle Cavity that receives blood from the right atrium and pumps it towards the pulmonary trunk through the pulmonary valve.

Also: right ventricle

Left ventricle Thick-walled cardiac cavity that pumps oxygenated blood into the aorta artery through the aortic valve.

Also: left ventricle

Lateral ventricle Paired cavity inside each cerebral hemisphere filled with cerebrospinal fluid produced by choroid plexuses.

Also: lateral ventricle

Optic vesicle Lateral evagination of the embryonic diencephalon that interacts with the superficial ectoderm to initiate the differentiation of the eye.

Also: optic vesicle

Vomer Flat, odd bone of the face that forms the posterior and inferior portion of the nasal septum of the nose.

Also: vomer

Hepatic yolk Endodermal diverticulum of the foregut that actively proliferates to form the parenchyma and bile ducts of the liver.

Also: hepatic diverticulum · liver bud

Lung bud Endodermal evagination of the foregut that grows caudally and branches to form the main bronchi and lobes of the lung.

Also: respiratory diverticulum · lung bud

Zonula adherens Anchoring cell junction that connects the bundles of actin filaments of neighboring epithelial cells, reinforcing the stability of the tissue.

Also: intermediate union · belt desmosome

Zonula occludens Type of hermetic intercellular junction that seals the space between epithelial cells to prevent the free passage of molecules through the paracellular route.

Also: tight union · tight junction

Anatomy, embryology and histology

Other glossary specialties