S

SACRAL ALA: The superior surface of the lateral portion of the sacrum. image

SACROILIAC JOINT: The joint made between the articular surfaces of the sacrum and ilium. Partly fibrous and partly synovial. image

SACRUM: The triangular bone made up of five fused vertebrae that is situated below the lumbar vertebrae and between the hip bones. image

SAGITTAL VIEW: An anteroposterior (AP) vertical plane, parallel to the median plane of the body. The perspective is similar to a Lateral view. image image

SARTORIUS MUSCLE: Muscle which originates at the naterior superior iliac spine and inserts into the medial side of proximal end of tibia. It contributes to flexion of the thigh and leg. The "tailor's" muscle. image

SAPHENOUS VEIN: (Magna)The vein that extends from the dorsum of the foot to just below the inguinal ligament, making it the longest vein in the body. Used to supply vascular grafting material for cardiac (coronary artery) bypass surgery. image

SCAPHOID: A "boat shaped" bone of the hand and foot. Also called the navicular. NOTE: In the hand, this bone is prone to develop aseptic necrosis after a fracture. image image image image
FX Scaphoid (Carpal Navicular)
FX Scaphoid (Carpal Navicular)
FX Tarsal Navicular

SCAPULA: A complex flat bone that forms the shoulder girdle (joint). Also called the 'shoulder blade'. image image image image

SCLERA: The white fibrous outer coating of the eyeball. image

SCUTUM: Latin for spur. The Tympanic scutum forms the bony division between the upper portion of the tympanic cavity and the mastoid cells. image image

SELLA TURCICA: Literally "turkish saddle", the rounded transverse depression on the superior side of the sphenoid bone that contans the hypophysis (pituitary gland). image

SEMICIRCULAR CANALS: Three looped bone canals within the petrous pyramid, forming part of the bony labryrinth of the ear, that produce five openings into the vestibule. image

SEMINAL VESICLES: Paired pouches attached to the posterior portion of the bladder. The seminal ducts join with the ipsilateral ductus deferens to form the ejaculatory duct. image

SESAMOID BONE: A bone within a tendon. image

SHOULDER: This is a ball and socket joint, without "weight bearing", formed by the distal clavicle, the scapula, and the proximal humerus. image image image image

Shoulder Anatomy
Shoulder Position
Shoulder Dislocation

SIGMOID COLON: S-shaped portion of the colon, extending from the pelvic brim to the third segment of the sacrum. image

SOFT PALATE: The posterior fleshy portion of the horizontal partition separating the nasal from the oral cavity. image

SPERMATIC CORD: The tissues extending from the abdominal inguinal ring to the testis, containing the ductus deferens, testicular artery, pampiniform (venous) plexus, and nerves. image

SPHENOID SINUS: Made up of two cavities, separated by a bony septum, in the anterior portion of the body of the sphenoid bone. The sphenoid sinus communicates with the nasal cavity. image image

SPINAL CORD: Portion of the central nervous system within the vertebral canal, running from the foramen magnum to the upper part of the lumbar region, ending as theconus medullaris. image

SPINE OF SCAPULA: Plate of bone attached to the back of the scapula, with the tip at the vertebral border and ending laterally as the acromion process. image

SPINOUS PROCESS: The portion of the vertebrae that projects backward from the arch and is a point of muscular attachment. image

SPLEEN: Gland-like but ductless organ located on the left side of the upper abdominal cavity, lateral to the cardiac region of the stomach.
NOTE: No natural "vent" is present. image image image

SPLENIC ARTERY: Originating from the celiac trunk and branching into the pancreatic and splenic branches, left gastro-omental, and short gastric arteries. image

SPLENIC FLEXURE: Bend within the large intestine where the transverse colon becomes the descending colon. image

SPLENIC-PORTAL VEIN CONFLUENCE: The point where these two veins merge into one. image

SPLENIC VEIN: The vein originating at the junction of several branches at the hilum of the spleen, and joining the superior mesenteric vein, to form the portal vein, at the neck of the pancreas. image

STERNOCLAVICULAR ARTICULATION: The joint formed by the junction of the sternal end of the clavicle, the clavicular notch of the manubrium, and the first costal cartilage. image

STERNOHYOID MUSCLE: Muscle that originates at the manubrium sterni, and inserts into the body of the hyoid bone. It is responsible for the depression of the hyroid bone and larynx. image

STERNOTHYROID MUSCLE: Muscle which originates at the manubrium sterni, and inserts into the thyroid cartilage. It is responsible for the depression of the thyroid cartilage. image

STERNUM: The longitudinal midline plate of bone that articulates with the clavicles and cartilages of the first seven ribs, forming the middle portion of the anterior chest wall of the thorax. image

STRAIGHT SINUS: A large venous dural sinus, at the junction of the falx and the tentorium cerebelli. image

STYLOID PROCESS: A spike/penlike projection from the inferior portion of the temporal bone, anterior to the stylomastoid foramen, that allows for muscular attachment of the stylo-hyoid/thyroid muscles. image

SUBARACHNOID SPACE: Cerebrospinal fluid filled space between the arachnoidea and the pia mater of the central nervous system. image

SUBCLAVIAN ARTERY: Artery which originates from the brachiocephalic artery on the right side and directly from the arch of aorta on the left side. They branch into the vertebral, internal thoracic arteries, thyrocervical and costocervical trunks. image image image
Aberrant Right Subclavian Artery

SUBGLOTTIC AIRWAY: The airway below the "glottis", that is below the true vocal cords. image

SUBMANDIBULAR GLAND: Paired salivary gland, located in the middle of the posterior half of the base of the mandible. image

SUBSCAPULARUS MUSCLE: Muscle originating at the subscapular (ventral/anterior) fossa of the scapula and inserting at the lesser tubercle of the humerus. image

SUPERFICIAL: Of, relating to, or located near the surface.

SUPERFICIAL TEMPORAL ARTERY: Originating from the external carotid artery and branching into the parotid, auricular, and occipital rami, tranverse facial, zygomatico-orbital, and middle temporal arteries. image

SUPERIOR GLUTEAL ARTERY: Artery originating from the internal iliac artery and branching into the superficial and deep branches of the buttocks. image

SUPERIOR MESENTERIC ARTERY: Artery which originates from the abdominal aorta and branches into the inferior pancreaticoduodenal, jejunal, ileal, ileocolic, right colic, and middle colic arteries. image

SUPERIOR MESENTERIC VEIN: The vein that parallels the superior mesenteric artery and joins the splenic vein to form the portal vein. image

SUPERIOR PUBIC RAMUS: Portion of the pubic bone that projects posterosuperolaterally to join the iliopubic eminence, to form part of the acetabulum. image

SUPERIOR RECTUS MUSCLE: The muscle which originates at the lateral margin of the optic foramen, and inserts into the upper aspect of the sclera. It is responsible for the adduction and upward medial rotation of the eyeball. image

SUPERIOR SAGITTAL SINUS (SSS): Venous sinus within the dura mater of the falx (at it's attachment to the sagittal suture), that extends from the crista galli to the junction with the tentorium and the torcular herophili. image image
SSS Thrombosis

SUPERIOR THYROID ARTERY: Artery which originates from the external carotid artery and branches into the pharyngeal, esophageal, and tracheal rami, inferior laryngeal and ascending cervical arteries. image

SUPERIOR VENA CAVA: The vein created by the joining of the two brachiocephalic veins and empties into the right atrium of the heart. It drains the head, neck, upper extremities and chest. image image image image image image

SUPERIOR VESICLE ARTERY: Artery which stems from the umbilical artery, supplying the bladder urachus, and ureter. image

SUPINE: Lying on the back or with the face upward.

SUPRAPATELLAR BURSA: A saclike cavity filled with a viscid fluid located between the distal end of the femur and the quadriceps tendon. image

SUPRASELLAR CISTERN: The enlarged subarachnoid space just above the pituitary fossa, containing the arteries of the Circle of Willis and the infundibulum/pituitary stalk. image
Subarachnoid Hemorrhage

SUSTENTACULUM TALI: image

SYLVIAN FISSURE: The deep cleft that begins at the anterior perforated substance, continuing between the frontal and temporal lobes, and then posteriorly between the temporal and parietal lobes. It is bound by the overhaning margins ("opercula") of the frontal, temporal, and parietal lobes, as well as deeply by the insular cortex. image

SYNDESMOSIS: (Tibiofibular) A fibrous union between the fibular notch of the tibia and a triangular surface on the fibula. image


Bug Report
Portions © 1997, 2002-2011 J.G. Smirniotopoulos, M.D. and others.