System: Musculoskeletal

Interspinales

Interspinales The structure indicated is the interspinales muscle. The interspinales muscles belong to the deep group of back muscles. The muscles of the back can be considered in terms of a superficial group, an intermediate group and a deep group of muscles. The deep group of back muscles consists of: Spinotransversales muscles Erector spinae muscles and transversospinales muscles Segmental muscles Suboccipital muscles The interspinales muscles belong to the segmental muscle group of the deep muscles. As the name suggests, the interspinales run between adjacent spinous processes. There is one interspinales muscle on either side, lateral to the interspinous ligament. The …

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interspinales

Splenius Capitis

Splenius Capitis The structure indicated is the splenius capitis muscle. The splenius capitis muscle is one of 8 muscles in the posterior triangle of the neck. The posterior triangle of the neck is bounded as follows: Anteriorly: posterior border of sternocleidomastoid Posteriorly: anterior border of trapezius Apex: Occipital bone between attachment sites of trapezius and sternocleidmastoid Base: middle third of clavicle Origin: Lower half of ligamentum nuchae and spinous processes of C7-T4 Insertion: Mastoid process, and part of skull inferior to lateral superior nuchal line. Action: Contraction together – extension of the neck. Contraction individually – Lateral flexion of neck …

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Splenius Capitis

Hyoglossus Muscle

Hyoglossus Muscle The structure indicated is the hyoglossus muscle of the tongue. The hyoglossus muscle is one of the extrinsic muscles of the tongue. The muscles involved with the tongue consist of intrinsic muscles which lie within the tongue itself, and the extrinsic muscles which attach to the tongue and are responsible for depression, elevation, protraction and retraction of the tongue. There are four sets of extrinsic tongue muscles: Genioglossus Hyoglossus Palatoglossus Styloglossus Origin: Greater horn and body of hyoid bone Insertion: Lateral aspect of tongue Action: Depression and retraction of tongue Innervation:  Hypoglossal nerve (cranial nerve XII) Learn all …

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Hyoglossus

Soleal Line

Soleal Line The structure indicated is the soleal line of the tibia. The soleal line is an oblique line visible on the posterior surface of the tibia. The popliteus muscle inserts above the soleal line. Three other muscles in the posterior compartment of the leg take their origin, or part of their origin from the soleal line: Soleus Flexor digitorum longus Tibialis posterior Learn all about the anatomy of the tibia and the fibula.
Soleal Line of Tibia

Middle Nasal Concha

Middle Nasal Concha The structure indicated is the middle nasal concha. There are three nasal conchae which make up the lateral wall of the nasal cavity. The nasal conchae are curved bones which create channels for the flow of air through the nose. There are four air channels: Inferior nasal meatus (underneath inferior nasal concha) Middle nasal meatus (underneath medial nasal concha) Superior nasal meatus (underneath superior nasal concha) Spheno-ethmoidal recess (between superior nasal concha and nasal roof) The superior and middle nasal concha are formed from the ethmoidal labyrinths of the ethmoid bone. The ethmoidal labyrinths lie on either …

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Middle Nasal Concha

Sacrospinous Ligament

Sacrospinous Ligament The structure indicated is the sacrospinous ligament. The sacrospinous ligament attaches at one end to the ischial spine, and at the other end to the lateral aspect of the sacrum and coccyx, lying deep to the sacrotuberous ligament. The sacrotuberous ligament runs from the sacrum to the ischial tuberosity. The sacrotuberous ligament converts the greater sciatic notch into the greater sciatic foramen. Likewise, it converts the lesser sciatic notch into the lesser sciatic foramen. Learn more about the bones of the pelvis in this tutorial.
Sacrospinous Ligament

Lateral Cuneiform Bone

Lateral Cuneiform Bone The structure indicated is the lateral cuneiform bone of the foot. The foot contains three groups of bones: Tarsals Metatarsals Phalanges The lateral cuneiform bone is one of seven tarsal bones. There are three groups of tarsal bones: Proximal group Intermediate group Distal group The lateral cuneiform bone belongs to the distal group of tarsal bones. There are three cuneiform bones: Lateral cuneiform Intermediate cuneiform Medial cuneiform Anteriorly they articulate with the medial three metatarsals. Posteriorly they articulate with the navicular bone, and laterally they articulate with the cuboid bone. Learn more about the bones of the …

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Lateral Cuneiform

Adductor Magnus

Adductor Magnus The structure indicated is the adductor magnus muscle of the thigh. The adductor magnus muscle is one of six muscles in the medial compartment of the thigh. The medial compartments consists of the following muscles: Gracilis Pectineus Adductor longus Adductor brevis Adductor magnus Obturator externus The adductor magnus muscle is the largest muscle in the medial compartment. It lies deep to the adductor brevis and the adductor longus. It has two parts to it: Adductor part Hamstring part The adductor part originates on the ischiopubic ramus, and as the name suggests, contraction causes adduction, as well as medial …

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Adductor Magnus

Perpendicular Plate of Ethmoid Bone

Perpendicular Plate of Ethmoid Bone The structure indicated is the perpendicular plate of the ethmoid bone. The ethmoid bone is one of the bones in the skull that separates the nasal cavity from the brain. There are three parts of which the ethmoid bone is comprised: Cribriform plate Ethmoidal labyrinth (one on either side) Perpendicular plate The perpendicular plate of the ethmoid bone extends inferiorly from the base of the cribriform plate and contributes to the median nasal septum. It has the following articulations: Anteriorly: spine of frontal bone Posteriorly: sphenoidal crest Inferiorly: septal cartilage anteriorly, vomer posteriorly Learn more …

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Perpendicular Plate of Ethmoid Bone

Abductor Digiti Minimi

Abductor Digiti Minimi The structure indicated is the abductor digiti minimi muscle of the hand. The abductor digiti minimi muscle is one of the intrinsic muscles of the hand that belongs to the hypothenar group. The hypothenar group of intrinsic hand muscles consist of three muscles: Abductor digiti minimi Opponens digiti minimi Flexor digit minimi brevis All the intrinsic muscles of the hand, except the thenar muscles and the lateral two lumbrical muscles are innervated by the deep branch of the ulnar nerve. The thenar muscles and the lateral two lumbrical muscles are innervated by the median nerve.  A useful …

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Abductor Digiti Minimi