BMS Anatomy Notes Exam 1 PDF

BMS Anatomy Lecture 1: Introduction **ANATOMY:** - Study of a structure and relationships among structures - **Subdivisions**: surface, gross, systemic, regional, radiographic, developmental - Regional: head, neck, trunk, upper limbs and lower limbs - Lower limb: glutea...

BMS Anatomy Lecture 1: Introduction **ANATOMY:** - Study of a structure and relationships among structures - **Subdivisions**: surface, gross, systemic, regional, radiographic, developmental - Regional: head, neck, trunk, upper limbs and lower limbs - Lower limb: gluteal, thigh, knee, leg, ankle, foot **ANATOMICAL TERMINOLOGY:** [Anatomical Position: ] - Allows precise and consistent anatomical references - Body upright, standing erect facing observer, head/eyes facing forward feet flat on the floor an forward, upper limbs to the sides, palms turned forward - **Recline position:** - [Prone]: lying face down - [Supine]: lying face up - [Recumbant] or decubitus: side lying [Planes and Sections: ] - **Sagittal plane**: vertical plane (divides right and left) - [Midsagittal] (median): equal divide - [Parasagittal]: unequal divide - **Frontal or coronal plane:** anterior (front) or position (back) - **Transverse or cross-sectional or horizontal plane:** superior (upper) or inferior (lower) - **Oblique plane:** passes through at an angle (between transverse/sagittal or transverse/frontal) [Directional Terms: ] - Precisely locate one part of the body relative to another - Dorsal (behind) vs Ventral (in front) - Distal (further from origin) vs Proximal (closer to origin) - Cephalad (head) vs caudal (tail end) - Superficial vs deep - External vs internal - Ipsilateral (using/on same side of body) vs contralateral (using/on opposite side of body) - Bilateral (Both sides) vs unilateral (one side) - Palmar vs dorsum (hand) - Plantar vs dorsum (foot) - Medial vs lateral [Terms of Movement: ] - **Flexion:** bending or decreasing the angle vs **Extension**: straightening or increasing the angle - **Abduction**: moving away from axis (+Horizontal for shoulder/hip) vs **Adduction**: moving towards the axis (+Horizontal for shoulder/hip) - **Rotation**: around the long axis (medial/internal or lateral/external) - **Circumduction**: combination of movements - **Protraction**: move anteriorly (roll shoulders forward) vs **Retraction**: move posteriorly (roll shoulder back) - **Elevation**: raising superiorly vs **Depression**: lowering interiorly - **Supination**: forearm rotated laterally (palm up) vs **Pronation**: forearm rotated medially (palm down) - **Ulnar** **deviation**: adduction of the wrist vs **Radial** **deviation**: abduction of the wrist - **Opposition**: thumb moves medially to meet other fingers vs **Reposition**: thumb back to neutral - **Eversion**: plantar surface of the foot moves laterally vs **Inversion**: plantar surface of the foot moves medially - **Dorsiflexion**: bend ankle towards shin vs **Plantar** **flexion**: bend ankle towards posterior - **SKELETAL SYSTEM** [Introduction: ] - **2 divisions:** - [Axial]: central core (80 bones -- longitudinal axis) - [Appendicular]: bones of upper and lower limbs and bones that attach limbs to axial skeleton (126 bones -- upper, lower, pelvic and pectoral girdles) - **Functions:** - Protection for vital structures - Movement - Support the body and vital cavities - Mineral deposition (storage for salts) - Blood element production - Energy storage - **Cartilage**: semi rigid and found where flexibility is required (eg. Costal cartilage and ribs) - [Types]: hyaline (joints), elastic (ear), fibrocartilage (discs of spinal column) [Bones: ] - Bone: living tissue subject to constant rebuilding - **Two types**: - [Compact:] superficial thin layer provides strength for weight bearing (found more at ends) - [Spongy/cancellous/trabecular:] deep to compact bone and superficial to marrow cavity and has small spaces - **Basic types:** - [Long:] greater length - Epiphysis: end - Metaphysis - Diaphysis: shaft or body - Epiphyseal plate: growth plate - [Short:] almost cube (equal length x width) - [Flat:] thin - [Irregular] - [Sesamoid:] develop in tendons (patella) - [Sutural:] In joint between skull - **Bone articulations:** articulation with another bone (surface covered in articular cartilage) - Head (rounded projection articulates with base of adjacent bone), neck (supports head), condyle (rounded protuberance at end), trochlea (groove at end -- forms joint or houses moveable tendon), facet (smooth flat surface) - [Bone Surface Markings: ] - **Depressions and opening:** participate in joints or allow the passage of soft tissue - [Fissure]: narrow slit for white blood vessels or nerves - [Foramen]: opening for blood vessels, nerves or ligaments - [Fossa]: shallow depression - [Sulcus]: furrow accommodates blood vessel nerve or tendon - [Meatus]: tubelike opening - **Processes:** projections or outgrowths that help form joints or serve as attachment points - [Condyle]**:** large, round protuberance at end of bone (joint) - [Facet]**:** smooth flat articular surface (Joint) -- means "small face" - [Head]**:** rounded articular projection supported on neck (joint) - [Crest]**:** prominent ridge or elongated projection - [Epicondyle]**:** projection above a condyle - [Line]**:** long narrow ridge (less than crest) - [Spinous] [process]**:** sharp and slender - [Trochanter]**:** very larger - [Tubercle]**:** small and round - [Tuberosity]**:** large, rounded and usually roughened Asynchronous Lecture 1: Introduction **Joint Classification:** - Arthrology = joint / syndesmology = ligaments - Joint is an **articulation between 2 bones** (often movement determined by the shape of the bones) - **Structure**: material holding joint together - **Function**: based on how much movement - *Synarthrosis*: little to no - *Amphiarthrosis*: some - *Diarthrosis*: freely [Structure of a Joint: ] 1. **Fibrous**: held by fibrous connective tissue a. *Suture*: bone of the skull, no movement (synarthrodial joint) b. *Syndesmosis*: fibrous connective tissue with some movement (Amphiarthrodial-- ulna/radius) c. *Gomphosis*: tooth and socket (alveolus), no movement (synarthrodial) 2. **Cartilaginous**: held together by cartilage (hyaline or fibrocartilage) d. *Synchondrosis***:** Primary -- connected by hyaline and often temporary (located in metaphyseal area -- e.g. epiphyseal growth plate) e. *Symphysis***:** Secondary -- connected by fibrocartilage, strong/slightly moveable (amphiarthrodial joints -- e.g. IVD between vertebrae) 3. **Synovial Joints:** - **Components**: synovial membrane, cavity, fluid, articular cartilage and accessory ligaments - *Intra-articular discs:* fibrocartilaginous discs found at joints under stress (TMJ and sternoclavicular joint) - *Menisci:* fibrocartilaginous disc found between femur and tibia I. **Planar Synovial:** - 2 flat surfaces articulating together (e.g. tarsal bones) - Allows gliding and sliding (1 plane -- uni-axial) - 1 degree of freedom (1 plane -- uniaxial rotation) II. **Hinge Synovial:** - Cylindrical surface fitting into cylindrical groove (e.g. elbow joint) - 1 degree of freedom (flexion and extension) III. **Pivot Synovial:** - Projection in a ring (ring usually formed by a ligament) (e.g., proximal radius and ulna) - 1 degree of freedom IV. **Condyloid (Ellipsoid) Synovial:** - Oval shaped projection fitting into an elliptical hole (e.g., wrist joint) - 2 degrees of freedom: flexion/extension and adduction/abduction V. **Saddle Synovial** - Opposing surfaces are concave-convex (e.g., 1^st^ carpometacarpal joint) - 2 degrees of freedom: flexion/extension and adduction/abduction VI. **Ball and socket Synovial:** - Spherical surface fitting into a bowl shape (e.g., glenohumeral joint) - 3 degrees of freedom(triaxial): flexion/extension and adduction/abduction and rotation **LIGAMENTS:** - **Ligament:** connective tissue structure that connects bone to bone - Stabilization of joints - Classified by anatomical relationship to joint capsule: - **Capsular:** bends with joint capsule; enhances strength of capsule - **Extracapsular:** close proximity to capsule - **Intracapsular:** within joint capsules; connection between articulating surfaces **VASCULATURE/INNERVATION OF JOINTS:** - Blood supply from articular arteries located in capsule - Rich nerves supply ending in the capsule - Sensory information to the brain about proprioception vs proprioceptive receptors - Pain receptors (not all structures) Overview of Muscular System: **MUSCLE TISSUE:** - **Skeletal muscle:** attached to bones -- voluntary (movement of body and joints) - Contraction and relaxation -- motor and sensory nerve - **Cardiac muscle:** walls of heart -- involuntary (beating of heart) - **Smooth (visceral) muscle:** wall of organs -- involuntary (movement of GI and secretion of fluids) **MUSCLAR SYSTEM:** - Voluntarily controlled muscles - Muscles are the motors of the skeletal system (bones to move/change position) - Muscle pulls with equal force on both attachments (fibre directions controls direction of pull) [Origin and Insertion: ] - **Origin**: attaches to bone or muscle (not moved by contraction of muscle) - **Insertion**: attaches to skin, bone or muscle (moved by contraction of muscle) - Belly = fleshy portion [Actions: ] - **Isometric** -- muscle contracts, produces forces but no gross movement occurs (stability) - **Concentric** -- muscle shortens while contractions, acceleration of body segments - **Eccentric** -- muscle lengthens while contracting, deceleration of body segments (shock absorption) [Roles: ] - **Agonist/prime mover**: principal muscle contracts actively - **Antagonist**: opposite anatomic action of the agonist (passively elongates or shortens) - **Synergist**: contracts at the same time as agonist - **Stabilizer/fixator/supporter**: active isometrically to keep limb from moving **SKELETAL MUSCLES:** - Important characteristics for their name: - **Direction**: rectus (parallel to midline), transverse (perpendicular to midline), oblique (diagonal) - **Size**: maximus, minimus, longus, brevis (short), latissimus, longissimus, magnus, major, minor, vastus - **Shape**: deltoid (triangular) trapezius, serratus (sawtoothed), rhomboid (diamond), orbicularis (circular), pectinate (comb), piriformis (pear), platys (flat), quadratus (square), gracilis (slender) - **Action:** flexor, extensor, abductor, adductor, levator, depressor, supinator, pronator, sphincter, tensor, rotator - **\# of origin:** biceps, triceps, quadriceps - **Location:** structure near (e.g., temporalis -- temporal bone) - **Origin/insertion:** sites (e.g., sternocleidomastoid -- sternum/clavicle to mastoid process) **TENDONS:** - Extensions of connective tissue that attach muscle to bone or other muscle - **Tendon**: cord of dense connective tissue - **Aponeurosis**: tendon that extends as a broad, flat layer - **Tendon sheaths**: tube-like connection tissue wrapped around tendons of wrist and ankle muscle where many tendons come together (inner -- visceral and outer -- parietal) - **Fascia**: - *Superficial*: loose connective tissue and fat underlying the skin (homologous to hypoderm and contains superficial veins and sensory) - *Deep*: dense irregular connective tissue that wraps the body (well defined in limbs) [Overview of Nerves ] - **Nerve**: enclosed, cable-like bundle of dendrites or axons - **Sensory**: receive sensory stimuli - **Motor**: stimulate muscle contraction (contains axons of the neurons that innervate skeleton muscles or glands) - **Spina**l: mixed sensory and motor from the spinal cord - **Cranial**: emerge directly from the brain containing sensory and motor fibres that innervate head and neck muscles Lecture two: Vertebral Column **VERTEBRAL COLUMN** - Function: posture, support body weight, locomotion, protection of spinal cord/roots - 33 vertebrae in 5 regions (26 separate bones) - **5 Regions:** - **Cervical**: 7, **Thoracic**: 12, **Lumbar**: 5, **Sacral**: 5 (fuse to make sacrum), **Coccygeal**: 2-4 (fuse to make coccyx) - **Curves:** - **Primary curvatures:** kyphotic (kyphosis) - Develop during fetal period -- concave anteriorly - Thoracic and sacral - **Secondary curvatures**: lordotic (lordosis) - Concave posteriorly - Cervical (infants hold their head -- 2-4 months), lumbar (begin standing/walking 12-18 months) **[Typical Vertebra: ]** - **Two major parts:** vertebral body (ant), vertebral arch (post) - **Dismantled**: - Body: anterior projection, largest segment, stacks on each other for column height and shock absorption - Vertebral arch: made up of the pedicles and laminae - 4 articular processes: extend superiorly and inferiorly from vertebrae, allows vertebrae to form joints with other - 2 transverse processes: right and left lateral projections extend in transverse plane from vertebrae, serves as attachment for ribs and muscle - Spinous process: extends posteriorly in sagittal plane from vertebrae, serves as attachment for ribs and muscle - 2 pedicles: connects body of vertebrae with transverse processes - 2 Lamina(e): connects transverse processes with spinous processes - **Vertebral foramen (all vertebrae together = canal)**: Formed by the body, pedicle, lamina and spinous processes and houses the spinal cord - **Intervertebral foramen**: formed by pedicles of adjacent vertebra on right and left and protects exiting spinal nerves (inter -- between) **ORGANIZATION OF SPINAL NERVES** - 31 pairs of spinal nerves exiting off the spinal cord into the intervertebral foramen (ventral and dorsal branches converging within vertebral canal) - 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal - After leaving the intervertebral foramen, the spinal cords divide into branches (rami) - Dorsal rami: deep back muscles + overlying skin  **CERVICAL VEREBRAE:** - 7 vertebrae - **Common features**: small body, transverse foramen in transverse process, bifurcated spinous process - Rectangular body with concave superior and convex inferior surfaces - **Uncinate process**: on superior and inferior surfaces of the body - **Spina bifida:** when the laminae do not articulate to a bifida [Unique Cervical Vertebrae ] - [**Atlas (C1):** ] - No body, no laminae, no pedicles - **Anterior and posterior arches (+ tubercle)** - **facet for dens:** articulate on Posterior surface of anterior arch - **Lateral mass** on either side of the vertebrae that contain articular surfaces - **Superior articular surface** for the occipital condyles of the skull - **Inferior articular surface** for axis - **Transverse ligament:** holds dens in place and creates a foramen - **[Axis (C2): ]** - Large **odontoid process (dens axis -- tooth-like process**) on superior surface of the body - Allows for rotation of the atlas on the axis - **[Vertebra prominens (C7):]** long and prominent spinous process which is palpable from the skin surface **THORACIC VERTEBRAE:** - Kyphotic 12 vertebrae's - **Main characteristics:** - **2 costal facet** are present on each side of the body for articulation with the heads of the ribs (semi -- facet) - **1 transverse costal facet** is present on each transverse processes for articulation with the tubercles of the ribs - **T11 and t12** have no transverse facets **THORACIC CAGE** 12 thoracic vertebrae (intervertebral dics), 12 pairs of ribs (costal cartilages), sternum - **Function:** - Attachment for upper limbs - Attachment for muscles of upper limb, neck, abdomen, back and respiratory - Protect thoracic and abdominal organs - Attachment for mammary glands of breast tissue - **Classification of rib (Costal) attachments:** - TRUE ribs (1-7) -- direct attachment to sternum - FALSE ribs (8-10) -- attach/fuse to costal cartilage of rib 7 to form indirect attachment - FREE ribs (11-12) -- no attachment to sternum - **Costal cartilage:** attaches ribs with the sternum - **Intercostal spaces:** space between each rib (filled by intercostal muscles and carry intercostal nerve and vessels) - **Costal arch:** continuous cartilage margin formed by costal cartilages of false ribs - **Superior thoracic aperture:** space between ribs 1, manubrium and thoracic vertebrae (covered by the diaphragm) - **Inferior thoracic aperture:** the costal cartilage of ribs 7-10 [Typical Ribs: ] - Long, twisted, flat bone - **Parts of a rib:** - **Head:** two semi-facets (superior/inferior) -- articulates with vertebral body and vertebra above - **Inter-articular crest:** separates semi-facets on head - **Neck:** constricted portion between head and tubercle - **Tubercle:** prominence on outer surface (between neck and shaft) - **Articular:** facet for articulation with transverse process - **Non-articular:** attachment to ligaments - **Shaft:** thin, flattened and twisted on its long axis - **Costal groove:** inferior border of the shaft (holds intercostal VAN -- vein, artery, nerve) - **Angle:** shaft bends sharply forward - **Anterior end:** attached to corresponding costal cartilage [Atypical Ribs: ] - **1^st^ rib:** Flattened and wider, no angle or costal groove, single articular facet on head - **Scalene tubercle:** medial border for insertion of anterior scalene muscle - **2^nd^ rib:** no costal groove - **10^th^ rib:** single articular facet on head - **11^th^ and 12^th^ rib:** single articular facet on head, no neck or tubercle, 11^th^ rib has slight angle and shallow costal groove, 12^th^ has neither [Sternum: ] 1. **Manubrium**: superior part (handle) - Articulates with clavicles and the first/upper part of the second costal cartilage on each side - **Suprasternal notch (jugular):** visible dip where the clavicle and first rib join 2. **The body:** - Articulates above with the manubrium and below with the xiphoid process - Notches articulation with lower part of second costal cartilage and ribs 3-6 via their costal cartilages - **Sternal angle (angle of louis):** junction between manubrium and body in the form of the **manubriosternal joint** - Marks the approximate level of the 2^nd^ pair of costal cartilages and the level of the intervertebral discs between T4 and T5 3. **Xiphoid process:** lowest and smallest part (tip) - **Xiphi-sternal joint:** separates the process from the transverse ridges and is an attachment for rib 7 **LUMBAR VERTEBRAE:** - Convex anteriorly with 5 vertebrae - Characteristics: - Body is big and kidney-shaped - Pedicles are strong - Laminae are thick - Transverse processes are long and slender - **Mammillary process:** posterior margin of the superior articular processes **SACRUM AND COCCYX** - 5 rudimentary vertebrae fused together to form a wedge-shaped bone and concave anteriorly - Upper border articulates with 5^th^ lumbar vertebrae - Lower border articulates with coccyx - **Posterior:** - **Sacral Crest:** spinous, articular and transverse processes fuse on the posterior surface - 4 pairs of sacral foramina - **Anterior:** - **Sacral Ala:** triangular flat surfaces on the sides of the first sacral vertebra - 4 foramina on each side - **Coccyx:** four vertebrae fused together to form a small triangular bone that articulates with apex of the sacrum **INTERVERTEBRAL DISCS:** - Fibrocartilaginous structure - **Functions:** - Strong attachment between vertebrae for support and protection - Weight bearing, shock absorption - 25% of column height (discs shrink over time) - **Composed of:** (like a jelly donut) - **Annulus fibrosus:** concentric rings of fibrocartilage (made of collagen fibres) - **Nucleus pulposus:** semi-gelatinous mass that acts as a shock absorber - Discs are named after the vertebral segment they connect: - No disc between atlas/skull, atlas/dens, sacral segments and coccygeal segments - **Herniated disc**: nucleus pulposus pushes out of annulus fibrosus - Can be a result of degeneration of annulus fibrosus - Postero-lateral herniation can impinge on roots of the spinal nerve in the intervertebral foramen **INTERVERTEBRAL JOINTS** 1. **Anterior intervertebral joint:** joint between two vertebral bodies and vertebral discs - **Function**: amphiarthrodial - **Structure**: cartilaginous symphysis joints - **Ligaments:** - **Anterior longitudinal ligament (ALL):** extend along the anterior surface of the vertebral bodies from the occipital bone to the sacrum - Limits backwards bending and supports anterior convexity in the lumbosacral area (high tensile strength) - **Posterior longitudinal ligament (PLL):** within the vertebral canal and extends along posterior vertebral bodies from the body of axis to the sacrum - Loosely attaches to the body - Does not restrict forward bending (low tensile strength) 2. **Posterior intervertebral (zygapophysial or facet) joint:** joint between inferior and superior articular processes (4 joints per vertebrae) - **Function**: diarthrodial - **Structure**: synovial planar joint (Enveloped by capsules - looser in the cervical) - **Ligaments:** - **Ligamenta Flava:** connect laminae of adjacent vertebrae from the axis to first segment of sacrum - Elasticity serves to preserve the upright posture and assist the column to resuming it after flexion - **Supraspinous ligament:** strong/fibrous, connects apices of spinous from the 7^th^ cervical vertebra to the sacrum - **Ligamentum nucha:** extension of supraspinous from C7 to occipital protuberance - **Interspinous ligaments:** thin/membranous, connects adjoining spinous processes - **Intertransverse ligaments:** interposed between the transverse processes **CRANIOVERTEBRAL JOINTS:** 1. **Atlantoaxial joints:** 1. **1 Medial atlantoaxial joint**: Anterior facet of dens articulates with posterior surface of anterior arch of atlas (facet for dens) -- for rotation of the neck - **Structure:** synovial pivot joint (50% of rotation) 2. **2 Lateral atlantoaxial joint:** superior articular facet of the axis and the inferior articular facet of the lateral mass of atlas - **Structure**: synovial planar joint - **Ligaments:** - **Anterior atlantoaxial ligament:** strong membrane, fixed, runs from the anterior arch of the atlas to the front axis body - **Posterior atlantoaxial ligament:** broad, thin membrane, runs from the posterior arch of the atlas to the axis (instead of ligamentum flavum) - **Cruciate ligament of the atlas:** - **Transverse ligament of the atlas:** thick, broad, attached to small tubercle on medial surface of the lateral mass of atlas (holds dens on anterior arch -- wraps posteriorly) - **Superior band:** attached to basilar part of occipital bone - **Inferior band:** attached to the posterior surface of axis body - **Tectorial membrane:** continuation of the PLL to the skull (covers cruciate) - **Alar ligaments:** on either side of the dens, attaches medial sides of dens to the sides of the occipital bones - Prevents side to side rocking of the dens - **Ligamentum nuchae** continues to connect the spinous processes 2. **Atlantooccipital joint:** articulation of atlas with the occipital bone - **Structure:** synovial condyloid joint - **Movement:** biaxial -- flexion/extension and slight lateral flexion - **Ligaments:** - **Anterior atlantooccipital membrane:** between the inferior border of the foramen magnum and the superior border of the anterior arch of the atlas - **Posterior atlantooccipital membrane:** between the inferior border of the foramen magnum and the superior border of the posterior arch of the atlas 3. **Uncovertebral joints:** articulate with the uncinate processes of the cervical vertebrae (C3-C7) - **Structure:** synovial planar joints (permit flexion and extension and limits lateral flexion) **THORACIC CAGE JOINTS** 1. **Costovertebral joint:** Articulations of the head of the ribs with the facets two vertebra bodies (Thoracic) and the associated intervertebral disc (e.g, rib 7 with vertebral body 7 and 6) - 1^st^, 10^th^, 11^th^ and 12^th^ articulate with single vertebra - **Structure**: synovial planar joint - **Function**: diarthrosis joint - **Ligaments**: - **Radiate ligament of head of rib**: connects the anterior part of the head of rib with the side of the bodies of two vertebrae - **Intra**-**articular ligament of head of rib:** attaches the intra-articular crest of the head and the intervertebral disc 2. **Costotransverse joints:** tubercle of the rib articulates with the costal facet on the transverse process - **Structure:** synovial joint - **Function:** diarthrodial joint - **Ligaments:** - **Superior costotransverse ligament:** neck of the rib to the transverse process above (holds the rib up) - **Costotransverse ligament:** connects space between the neck of the rib and the anterior surface of the transverse process - **Lateral costotransverse ligament:** tip of the transverse process to the rough non-articular tubercle of the rib (supports posterior aspect)  3. **Sternocostal joint**: cartilage of true ribs articulates with the sternum - **Structure (rib 1):** synchondrosis cartilaginous (does not ossify) - **Structure (rib 2-7)**: synovial planar joint - Permit mobility - **Ligaments**: - **Anterior and posterior radiate sternocostal ligament**: front/back of costal cartilages to the posterior/anterior sternum 4. **Costochondral joints:** the rib articulates with the costal cartilage - **Structure**: synchondrosis - **Function**: synarthrosis (permit flexibility) Sternocostal + costotransverse + costovertebral -- move the ribs superior and lateral direction (bucket handle) - Breath in: expansion of ribs superiorly and laterally Sternocostal: pulls sternum in anterior/superiorly direction (pump handle) **OVERVIEW CHART:** +-----------------+-----------------+-----------------+-----------------+ | **JOINTS** | **Articulations | **FUNCTION/STRU | **LIGAMENTS AND | | | ** | CTURE** | ATTACHMENTS** | +=================+=================+=================+=================+ | **INTERVERTEBRA | | | | | L | | | | | JOINTS** | | | | +-----------------+-----------------+-----------------+-----------------+ | **Anterior | Two vertebral | Function: | **Anterior | | Intervertebral | bodies and | amphiarthrodial | longitudinal | | Joint** | their vertebral | | ligament | | | discs | Structure: | (ALL):** | | | | cartilaginous | strong, | | | | symphysis | anterior | | | | | surface of | | | | | bodies of | | | | | occipital to | | | | | sacrum (limit | | | | | backbend) | | | | | | | | | | **Posterior | | | | | longitudinal | | | | | ligament | | | | | (PLL):** weak, | | | | | posterior | | | | | surface of | | | | | bodies (body of | | | | | axis to sacrum) | +-----------------+-----------------+-----------------+-----------------+ | **Posterior | Inferior and | Function: | **Ligamenta | | Intervertebral | superior | diarthrodial | Flava:** | | (Zygapophysial) | articular | | laminae of | | Joint** | processes of | Structure: | adjacent | | | joining | synovial planar | vertebrae from | | | vertebrae | | axis to sacrum | | | | | (upright | | | | | posture) | | | | | | | | | | **Supraspinous | | | | | ligament:** | | | | | strong, apices | | | | | of spinous | | | | | process from C7 | | | | | to sacrum | | | | | | | | | | **Interspinous | | | | | ligament:** | | | | | thin, adjoining | | | | | spinous | | | | | processes from | | | | | root of apex | | | | | | | | | | **Intertransver | | | | | se | | | | | ligament:** | | | | | transverse | | | | | processes | | | | | | | | | | **Ligamentum | | | | | nucha:** | | | | | continuous of | | | | | SSL from C7 to | | | | | occipital | +-----------------+-----------------+-----------------+-----------------+ | **CRANIOVERTEBR | | | | | AL | | | | | JOINTS** | | | | +-----------------+-----------------+-----------------+-----------------+ | **Lateral | Lateral masses | Structure: | **Anterior | | Atlantoaxial | of atlas and | synovial planar | atlantoaxial | | Joint** | superior | | ligament:** | | | articular | | strong | | | processes of | | membrane, | | | axis | | anterior arch | | | | | of atlas and | | | | | front axis body | | | | | | | | | | **Posterior | | | | | atlantoaxial | | | | | ligament:** | | | | | thin membrane, | | | | | posterior arch | | | | | of atlas and | | | | | upper edges of | | | | | laminae axis | | | | | | | | | | **Cruciate | | | | | ligament of | | | | | atlas:** | | | | | | | | | | a. **Transvers | | | | | e | | | | | ligament of | | | | | atlas:** | | | | | thick, | | | | | either side | | | | | of small | | | | | tubercle on | | | | | medial | | | | | surface of | | | | | lateral | | | | | mass of | | | | | atlas | | | | | | | | | | b. **Superior | | | | | band:** | | | | | basilar | | | | | part of | | | | | occipital | | | | | bone | | | | | | | | | | c. **Inferior | | | | | band:** | | | | | posterior | | | | | surface of | | | | | axis body | | | | | | | | | | **Tectorial | | | | | membrane:** | | | | | covers odontoid | | | | | process, upward | | | | | of PLL | | | | | | | | | | **Alar | | | | | ligaments:** | | | | | medial sides of | | | | | condyles of | | | | | occipital bone | | | | | and upper part | | | | | of dens | +-----------------+-----------------+-----------------+-----------------+ | **Medial | Odontoid | Structure: | | | Atlantoaxial | process (dens) | synovial pivot | | | Joint** | of axis and | (rotation of | | | | posterior | atlas -- 50% | | | | surface of | rotation in | | | | anterior arch | cervical spine) | | | | of atlas | | | +-----------------+-----------------+-----------------+-----------------+ | **Atlantooccipi | Atlas with | Structure: | **Anterior | | tal | occipital bone | synovial | atlantooccipita | | Joint** | | condyloid | l | | | | | membrane:** | | | | Function: | anterior | | | | flex/ext, | foramen magnum | | | | slight lateral | and anterior | | | | | arch of atlas | | | | | | | | | | **Posterior | | | | | atlantooccipita | | | | | l | | | | | membrane**: | | | | | posterior | | | | | foramen magnum | | | | | and posterior | | | | | arch of atlas | +-----------------+-----------------+-----------------+-----------------+ | **Uncovertebral | Superior and | Structure: | | | Joint** | inferior | synovial planar | | | | uncinate | | | | | processes of | Function: | | | | cervical | flex/ext, limit | | | | vertebrae | lateral flexion | | | | (C3-7) | | | +-----------------+-----------------+-----------------+-----------------+ | **THORACIC / | | | | | RIB CAGE** | | | | +-----------------+-----------------+-----------------+-----------------+ | **Costovertebra | Head of ribs to | Structure: | **Radiate | | l | facets on 2 | synovial planar | ligament of | | Joint\*** | bodies of | | head of rib:** | | | thoracic | Function: | anterior head | | | vertebrae (1, | diarthrodial | of rib and the | | | 10, 11, 12 rib | | side of both | | | = 1 body) | | bodies | | | | | | | | | | **Intra-articul | | | | | ar | | | | | ligament of | | | | | head of rib:** | | | | | intra-articular | | | | | crest of the | | | | | rib and the | | | | | intervertebral | | | | | disc (joint | | | | | interior) | +-----------------+-----------------+-----------------+-----------------+ | **Costotransver | Articular | Structure: | **Superior | | se | tubercle of rib | synovial joint | costotransverse | | Joint** | to transverse | | ligament:** | | | process | Function: | upper border of | | | | diarthrodial | rib neck to | | | | joint | transverse | | | | | process above | | | | | | | | | | **Costotransver | | | | | se | | | | | ligament:** | | | | | back of rib | | | | | neck to | | | | | anterior | | | | | surface of | | | | | transverse | | | | | process | | | | | | | | | | **Lateral | | | | | costotransverse | | | | | ligament:** | | | | | obliquely from | | | | | tip of | | | | | transverse | | | | | process to | | | | | non-articular | | | | | tubercle of rib | +-----------------+-----------------+-----------------+-----------------+ | **Sternocostal | Cartilage of | Structure (rib | **Anterior and | | Joint\* + | true ribs to | 1): | posterior | | \*\*** | the sternum | synchondrosis | radiate | | | | cartilaginous | sternocostal | | | | (does not | ligament:** | | | | ossify) | front/back of | | | | | costal | | | | Structure (rib | cartilages to | | | | 2-7): synovial | the | | | | planar joint | posterior/anter | | | | | ior | | | | Function: | sternum | | | | permits | | | | | mobility | | +-----------------+-----------------+-----------------+-----------------+ | **Costochondral | Rib to the | Structure: | | | ** | costal | synchondrosis | | | | cartilage | | | | **Joint\*** | | Function: | | | | | synarthrosis | | | | | (permit | | | | | flexibility) | | +-----------------+-----------------+-----------------+-----------------+ | \* Bucket | | | | | handle: move | | | | | ribs superiorly | | | | | and laterally | | | | | during | | | | | inhalation | | | | | together | | | | | | | | | | \*\* Pulls | | | | | sternum | | | | | superiorly and | | | | | anteriorly | | | | | during | | | | | inhalation | | | | +-----------------+-----------------+-----------------+-----------------+ [Back and Anterior Neck Muscles ] **BACK MUSCLES** - Two major groups: - **Extrinsic**: superficial and intermediate muscles that produce and control limp and respiratory movements (origin and insertion have different locations) - **Intrinsic**: deep specifically act on the vertebral column, producing its movements and maintaining posture (intrinsic = origin and insertion have same location) **EXTRINSIC BACK MUSCLES** - **Trapezius, latissimus dorsi, levator scapulae and rhomboids** - Connect axial skeleton (vertebral column) with the superior appendicular skeleton (upper limp) - For most part, receive their nerve supply from **anterior rami** of cervical nerves and act on upper limp - **Trapezius** receives motor fibres from **cranial nerve, the spinal accessory nerve** (CNXI) **INTERMEDIATE BACK MUSCLES [ ]** **Serratus posterior superior** (deep to rhomboid), **serratus posterior inferior** (deep to latissimus dorsi) - Thin, weak, commonly designated as superficial accessory respiratory muscles - More likely proprioceptive (perceive location) rather than motor in function - **Nerve supply:** ventral (anterior) rami of thoracic spinal nerves (intercostal nerves) **INTRINSIC BACK MUSCLES** - Runs from **pelvis to cranium** - Innervated by the posterior rami and act to maintain posture and control movement - **Thoracolumbar fascia**: deep facia that covers deep muscles (critically in lumbar) - Extends laterally from the spinous processes - **Superficial**: spinotransverse group (splenius capitis and splenius cervicis) - **Intermediate**: sacropinalis group (erector spinae -- spinalis, longissimus, iliocostalis - **Deep**: transversospinalis group (semispinalis, multifidus, rotatores) - Interspinal and intertransverse muscle **[Superficial Intrinsic: Spinotransverse group]** **Splenius muscles**: **capitis (head) and cervicis (neck)** - Thick and flat - Lie on lateral and posterior aspects of the neck, covering the vertical muscles - Cover and hold deep neck muscles in position - **Primary action:** - **Unilaterally**: flexes neck and ipsilateral rotation (head to side of active muscles) - **Bilaterally**: extend head/neck - **Nerve supply:** posterior rami of spinal nerves **[Intermediate Intrinsic: Sacrospinalis ]** - Sacrum spinalis **Erector spinae** - Lie in groove on each side of vertebral column between spinous process and angle of ribs - **Chief extensors** of vertebral column - **Three columns:** - **Iliocostalis**: lateral (lumborum, thoracis and cervicis) - **Longissimus**: intermediate (thoracis, cervicis, capitis) - **Spinalis**: medial (thoracis, cervicis, capitis) - **Common origin:** broad tendon that attaches inferiorly to the posterior part of the iliac crest, the posterior aspect of the sacrum, the sacro-iliac ligaments and the sacral/inferior lumbar spinous spinous - Dynamic (motion-producing) muscles, acting bilaterally to extend the flexed trunk - **Nerve supply:** posterior rami of spinal nerves - **Main action:** - **Unilaterally**: lateral flexion of vertebral column ipsilateral rotation - **Bilaterally**: extension of vertebral column and head; as back is flexed, control movement via eccentric contraction, **Iliocostalis**: fibres run superior/ lateral to angles of ribs and cervical TVP's **Longissimus**: fibres run superior to TVP's in thoracic and cervical regions and the mastoid process **Spinalis**: fibres run superior within the laminar groove to SP's in thoracic and cervical regions  **[Deep Intrinsic: Transversispinalis ]** - Transverse spinalis - Semispinalis, multifidus and rotatores - Transverse processes to spinous processes of more superior vertebrae - Occupy gutter between transverse and spinous processes - **Nerve supply:** posterior rami of spinal nerves **Semispinalis:** superficial and arises from approximately half of the vertebral column - Three parts: capitis, thoracis and cervicis - **Primary action:** extension of head, cervical spine and thoracic spine + contralateral rotation (unilateral action) **Multifidus:** short, triangular muscular bundles that are thickest in the lumbar region - **Primary action**: stabilization of vertebral column **Rotatores:** best developed in the thoracic region - **Primary actions:** stabilization of vertebral column, proprioception of column and may assist in small rotatory movements in thoracic spine  **SEGMENTAL MUSCLES** **Interspinales**: between spinous processes - **Primary action**: extension and rotation of vertebral column - **Nerve supply**: posterior rami of spinal nerves **Intertransversarii**: between transverse processes - **Primary action**: Stabilization and lateral flexion of vertebral column - **Nerve supply**: posterior and anterior rami of spinal nerves **Levatores** **Costarum**: - **Primary action**: assist with respiration in elevation of ribs; lateral flexion of column - **Nerve supply**: posterior rami of C8-11 spinal nerves  **SUBOCCIPITAL AND DEEP NECK MUSCLES** - Deep to superior posterior cervical region and deep to trapezius, sternocleidomastoid, splenius and semispinalis - Pyramidal space inferior to occipital + C1 and C2 **Major and minor rectus (straight) capitis posterior + superior and inferior obliquus capitis** - **Nerve supply**: posterior ramus of C1, the suboccipital nerve - **Primary action**: extension of atlanto-occipital joint and rotation of atlanto-axial joint **ANTERIOR NECK MUSCLES** **[Superior neck ]** - Platysma and sternocleidomastoid - Nerve supply: ventral rami of the cervical spinal nerves **Platysma:** - **Origin**: fascia over deltoid and pectoralis major muscles - **Insertion**: mandible and skin of lower face - **Primary action**: depresses/draws lower lip inferiorly and depresses mandible at TMJ (wrinkles the skin) - **Nerve supply:** Cranial nerve VII (facial nerve) **Sternocleidomastoid** - **Origin**: medial 1/3 of clavicle + manubrium of sternum - **Insertion**: mastoid process of temporal bone + lateral ½ of superior nuchal line of occipital bone - **Primary action**: - Unilateral: - Lateral flexion of head/neck - Contralateral rotation of head and neck - Bilateral: - Extension of head and upper neck - Flexion of lower neck - Elevation of sternum and clavicle (during forced inhalation - **Nerve supply**: CN XI (spinal accessory nerve) **[Deep Neck ]** - **Nerve supply: [ ]**anterior rami of spinal nerves - **Anterior vertebral muscles:** - **Longus capitis (head):** flexion of neck, contralateral rotation (unilateral) - **Longus coli (neck):** flexion of head - **Rectus capitis anterior**: Flexion of head - **Anterior scalene (Ladder):** lateral flexion , elevates 1^st^ rib in forced inspiration - **Lateral vertebral muscles:** - **Rectus capitis lateralis:** flexion of head - **Middle scalene:** lateral flexion of neck, elevates 1^st^ rib during forced inspiration - **Posterior scalene**: lateral flexion of neck, elevates 2^nd^ rib during forced inspiration    [Thoracic and Anterior Abdominal Walls ] **THORACIC CAGE** - 11 intercostal spaces filled with muscles and VAN's **External intercostal:** fibres move lateral -- superior to inferior - **Origin**: inferior border of rib - **Insertion**: superior border of rib below - **Primary action**: move rib superiorly during inspiration - **Nerve supply**: intercostal nerves **Internal intercostal:** - **Origin**: superior border of rib - **Insertion**: Inferior border of rib - **Primary action**: moves rib inferiorly during forced expiration - **Nerve supply:** intercostal nerves **[VANs of Thoracic Cage ]** - **Arterial supply of thoracic wall:** - Posterior intercostal arteries (mainly thoracic aorta) - Anterior intercostal arteries - **Venous drainage of thoracic wall:** - **Posterior intercostal veins** - R side: azygos vein - L side: hemiazygos or accessory hemiazygos - **Anterior intercostal veins:** - Directly/indirectly into internal thoracic veins right/left brachiocephalic veins - **Nerve supply:** - Mainly by anterior rami of the intercostal nerves (T1-11) - Anterior rami of spinal subcostal nerve is under rib 12 - Supply intercostal muscles, skin and parietal pleura - Lower intercostal nerves supply skin, muscles and peritoneum of abdominal wall **DIAPHRAGM** - **Attachments**: inferior thoracic aperture (join medially to the central tendon) - **Three main foramina**: Aortic hiatus (T12), esophageal hiatus (T10) and caval opening (T8) - **Nerve supply:** right and left phrenic nerves (C3,4,5) - **Primary action:** depresses to increase volume (decrease pressure) of thoracic cavity -- for inspiration **PECTORAL REGION** - External to thoracic wall, anchors upper limb **[Mammary Gland ]** - Modified sweat glands in superficial fascia - The gland is divided by suspensory ligaments - **Arterial supply of breast:** - Axillary artery, Internal thoracic artery, 2^nd^ -- 4^th^ intercostal arteries - **Venous drainage of breast:** - Axillary, internal thoracic and intercostal veins - **Innervation of breast:** - 2^nd^ -- 6^th^ intercostal nerves, 4^th^ intercostal nerve for nipple - **Lymphatic drainage of breast:** - 75% - axillary nodes, Rest -- parasternal lymph nodes **ANTERIOR ABDOMINAL WALL** - Supplied by **thoraco-abdominal nerves** = lower intercostal nerves (T7-11) - **Blood supply:** - Superior epigastric artery -- continuation of internal thoracic artery - Inferior epigastric artery -- branch of external iliac artery - Intercostal arteries - Peri-umbilical veins -- around umbilicus [Face, Scalp, Mastication, Neck and Cranial Nerves ] **SCALP** - **Skin**: physical barrier from trauma and potential pathogens - **Dense connective tissue:** hair follicles, vessels, nerves and lymph - **Aponeurosis (galea aponeurotica):** continuous with muscle - **Loose connective tissue**: mobility of scalp - **Pericranium**: dense irregular connective tissue, tightly adhered to cranium bone **FACE MUSCLES** **[Scalp, Forehead and Eyebrows ]** **Occipital belly of occipitofrontalis:** - **Origin**: superior nuchal line - **Insertion**: galea aponeurotica layer of skull - **Nerve supply**: CN VII (facial nerve) - **Primary action**: pulls scalp posteriorly **Frontalis belly of occipitofrontalis:** - **Origin**: galea aponeurotica layer of skull - **Insertion**: skin over eyebrows - **Nerve supply**: CN VII (facial nerve) - **Primary action**: pulls forehead superiorly (wrinkles forehead) and raises eyebrows **[Orbit (Eye Socket) ]** **Orbicularis oculi:** sphincter muscle arranged in concentric bands around the upper and lower eyelids - Palpebral part: in the eyelid (upper and lower) + orbital part: around the orbital - **Primary action**: contracting close the eye lids - **Nerve supply**: CN VII (facial nerve) **Levator palpebrae superioris:** triangular-shaped muscle located in each upper eyelid - **Primary action:** elevation and retraction of upper eyelid - **Nerve supply:** CN III (oculomotor nerve) **[Nose and Ears ]** - **Muscles of nose:** Provide evidence of breathing behaviours - **Muscles of the ears:** Helps to direct the ears towards sounds **[Mouth, Lips and Cheeks ]** - All muscles innervated by CN VII (facial nerve) **Elevators, retractors and evertors of the upper lip:** - Levator labii superioris, Zygomaticus major and minor, Risoris **Depressors, retractors and evertors of lower lip:** - Dilator muscles: radiate from lips and angles of mouth  **Orbicularis oris:** sphincter around the mouth - Closes and protrudes lips (kiss) - Keeps food in mouth **Buccinator**: in cheek - Press checks against molar teeth - Keep food under the teeth - Resists distension of mouth (when blowing) **[Mastication ]** **Temporalis**: - **Origin**: temporal fossa and fascia - **Insertion**: coronoid process + anterior border of ramus of mandible - **Nerve** **supply**: mandibular nerve (V3 -- 3^rd^ branch of CN V trigeminal nerve) - **Primary action**: elevation and retraction of mandible **Masseter**: - **Origin**: zygomatic arch - **Insertion**: lateral surface of ramus of mandible - **Nerve** **supply**: mandibular nerve (V3 -- 3^rd^ branch of CN V trigeminal nerve) - **Primary action**: elevation and protraction of mandible  **Medial** **pterygoid**: - **Origin**: pterygoid process of sphenoid bone - **Insertion**: medial surface of angle of mandible - **Nerve** **supply**: mandibular nerve (V3 -- 3^rd^ branch of CN V trigeminal nerve) - **Primary action**: elevation, protrusion and contralateral deviation of mandible **Lateral** **pterygoid**: - **Origin**: pterygoid process of sphenoid bone - **Insertion**: articular disc + neck of mandible - **Nerve** **supply**: mandibular nerve (V3 -- 3^rd^ branch of CN V trigeminal nerve) - **Primary action:** protrusion and contralateral deviation of mandible  **TEMPOROMANDIBULAR JOINT (TMJ)** - Modified **synovial hinge** joint - **Articular surfaces**: - Condylar process (head) of mandible - Articular tubercle of temporal bone - Mandibular fossa of temporal bone - **Articular disc:** oval fibrocartilage plate that divides cavity into two synovial compartments - Gliding of protrusion/retraction in superior compartment - Hinge of depression and elevation in inferior compartment - **TMJ capsule:** surround joint and attaches above to the articular tubercle and margins of mandibular fossa **[TMJ Ligaments ]** - **Lateral ligament: intrinsic ligament** - Two short bands on lateral surface of articular capsule - Extends inferiorly/posteriorly from inferior border and tubercle of zygomatic process to lateral/posterior aspect of neck of mandible - Strengths TMJ laterally -- prevent posterior dislocation of mandible - Covered by the parotid gland - **Sphenomandibular ligament: Extrinsic ligament** - Extends from spine of sphenoid to medial surface of ramus of mandible - Does not contribute strength - **Stylomandibular ligament: Extrinsic ligament** - Extends from styloid process of temporal bone to inferior/posterior borders of ramus of mandible - Separates the parotid gland from submandibular gland - Limits movement of mandible at TMJ - Dislocation: mandible dislocates anterior to articular tubercle (during yawning or large bites) - Sideways blow to chin when mouth is open can dislocate TMJ on side of blow **[Movements of Temporomandibular Joint ]** - **Elevation**: close mouth - Temporalis, masseter and medial pterygoid - **Depression**: open mouth - Lateral pterygoid, suprahyoid and infrahyoid (primarily due to gravity) - **Protrusion**: - Lateral pterygoid (primary), masseter and medial pterygoid - **Retrusion**: - Temporalis (posterior oblique and near horizontal fibres) - **Lateral movements:** - Temporalis of same side, pterygoids of opposite side and masseter **NERVES OF FACE AND SCALP** - Cutaneous (sensory) innervation: trigeminal nerve (CN V) - Motor innervations: branches of the facial nerve (CN VII) **AORTA** - Distributes **oxygenated blood** throughout the body - Arises from left ventricle in the middle mediastinum as **ascending aorta** - Enters superior mediastinum as **arch of aorta** which continues posterior as **descending aorta** - Descending aorta on the left side of vertebral column (**thoracic aorta**) and passes through diaphragm to enter abdominal cavity (**abdominal aorta**) - Branches: 1. **Brachiocephalic trunk** (artery) **right common carotid artery** and **right subclavian artery** 2. **Left common carotid artery** (ascends on left neck) **external and internal** **carotid arteries** (level of superior border of thyroid cartilage C3 or C4 -- supply head/neck) 3. **Left subclavian artery** (under clavicle towards left upper limb) **axillary artery** (after passing 1^st^ rib) **[Subclavian Artery Branches ]** - **Vertebral artery**: brain - **Internal thoracic artery:** anterior thoracic wall and breast - **Thyrocervical trunk**: larynx, trachea, esophagus, thyroid - **Suprascapular artery** - **Dorsal scapular artery** **[External Carotid Artery Branches ]** - **Superior thyroid artery:** thyroid gland and larynx - **Lingual artery:** tongue - **Facial artery:** face - **Occipital artery:** scalp covering occipital bone - **Posterior auricular:** scalp posterior to auricle - **Superficial temporal artery** (terminal branch): passes anterior to ear for scalp on sides of cranium and some of face - **Maxillary artery** (terminal branch): deep face including nasal/oral cavities and pharynx - **Middle meningeal branch**: dura mater **[Internal Carotid Artery Branches ]** - **Ophthalmic artery:** supratrochlear and supra-orbital branches - **Posterior communicating artery** - **Middle cerebral artery** - **Anterior cerebral artery** **VENOUS DRAINAGE: HEAD AND NECK** - Begins from three **main venous systems:** - Intracranial: cerebral veins (sinuses) - Superficial veins: - Deep veins: - **Internal and external jugular veins**: two main veins of neck - **Internal jugular:** level of jugular foramen as continuation of sigmoid sinus and travels with internal / carotid arteries to join subclavian vein brachiocephalic vein - Receives venous blood from face and deep parts of head/neck - **Anterior and external jugular:** superficial veins eventually drain into subclavian vein - Receives venous blood from posterior scalp and superficial neck **PERIPHERAL NERVES** - 31 pairs of spinal nerves: upper limb, trunk and lower limb - 12 pairs of cranial nerves: head and neck - Autonomic nerves - Sensory and motor signals -- conscious or unconscious **[Cranial Nerves ]** - **I: olfactory** - **II: optic** - **III: oculomotor** - **IV: trochlear** - **V: trigeminal** - **VI: abducent (abducens)** - **VII: facial** - **VIII: vestibulocochlear** - **IX: glossopharyngeal** - **X: vagus** - **XI: spinal accessory** - **XII: hypoglossal** **O**h **O**h **O**h**, T**o **T**ake **A F**un **V**acation**, G**o **V**agus **A**nd **H**awaii [Anatomy of the Skull ] - **Neurocranium**: brain box - Paired: parietal and temporal bones - Unpaired: frontal, occipital, sphenoid and ethmoid bone - **Viscerocranium**: facial skeleton - Paired: lacrimal, nasal, zygomatic, maxilla, inferior nasal concha and palatine bones - Unpaired: mandibular, vomer **ANTERIOR SKULL:** - Bones: zygomatic, frontal, mandible, middle, superior and inferior nasal concha, maxilla, vomer and nasal bones - **Bony landmarks:** - **Glabella**: between eyebrows - **Supraorbital notch (foramen):** above each orbit (for supraorbital VAN) - **Infraorbital foramen of maxilla** - **Anterior nasal aperture** - **Alveolar process of maxilla**: holds the root of the teeth - **Ramus of mandibular** - **Mental foramen of mandible** **LATERAL SKULL** - **Bones**: frontal, parietal, part of occipital, temporal, sphenoid, zygomatic, part of frontal, maxilla, mandible - **Bony landmarks:** - **Temporal fossa** - **Pterion**: junction of temporal, sphenoid, frontal and parietal bone (thinnest part) - **External acoustic meatus**: opening of the ear - **Mastoid process** - **Styloid process** - **Zygomatic arch:** zygomatic and temporal bones - **Condyle process of mandible** - **Head of condyle process** - **Mandibular notch** - **Ramus of mandible:** - Infratemporal fossa behind ramus - **Body of mandible** **POSTERIOR SKULL** - Bones: parietal, occipital, - Bone landmarks: - **Sagittal suture:** between parietal bones - **Lambdoid suture:** between parietal and occipital bones - **External occipital protuberance:** borderline of occipital neck vs head - **Superior nuchal line** - **Inferior nuchal line** - **Occipitomastoid suture:** between occipital and mastoid bones - **Occipital condyle** **SUPERIOR SKULL** - **Bones**: frontal, parietal, occipital bones - **Bony landmarks:** - **Coronal suture:** between frontal and parietal bones - **Sagittal suture:** between parietal bones - **Lambdoid suture:** between parietal and occipital bones - **Bregma:** meeting of coronal and sagittal sutures - **Lambda:** meeting of sagittal and lambdoid suture - On a newborn: soft tissue in sutures (Fontanelle allows brain to grow) - Anterior fontanelle = bregma, Posterior fontanelle = lambda **INFERIOR SKULL** - Bones: maxilla, palatine, vomer, sphenoid bones, temporal, occipital - Bony landmarks: - **Hard pallet:** maxilla and palatine bone - Incisive fossa - **Choanae (posterior nasal aperture):** opening of the nasal cavity - **Medial and lateral plate of pterygoid process of sphenoid bone** - **Carotid canal** - **Mandibular fossa** - **Articular tubercle** - **Stylomastoid foramen:** for facial nerve - **Jugular fossa (jugular foramen deep)** - **Mastoid foramen** - **Foramen magnum** - **Occipital condyle:** articulates with atlas **INTERNAL SURFACE OF CRANIAL BASE** **[Anterior Cranial Fossa]** - Frontal bone and ethmoid bone - Bony landmark: - Orbital plate (frontal) - Crista galli (ethmoid) - Cribriform plate: both sides of crista galli (ethmoid) **[Middle Cranial Fossa ]** - Sphenoid and temporal bone - Bony landmarks: - Sella turcica: - Hypophyseal fossa - Dorsum sellae - Groove for superior petrosal sinus **[Posterior Cranial Fossa ]** - Temporal, parietal and occipital bone - Bony landmarks: - Groove for sigmoid sinus - Groove for transverse sinus FORAMINA**/APERTURES OF CRANIAL FOSSAE** FORAMINA BONE ANATOMY CONTENTS ---------------------------------------------- ------------------------ --------------------------------------------- --------------------------------------------------------------------- **Cribriform foramina (olfactory foramen)** Ethmoid Cribriform plate Axons of olfactory cells in olfactory epithelium **Optic canal** Sphenoid Between lesser wing Optic nerves (CN II) **Superior orbital fissure** Sphenoid Between lesser and greater wing Ophthalmic nerve (CN V1); CN III, IV and VI **Foramen rotundum** Sphenoid Posterior to superior orbital fissure Maxillary nerve (CN V2) **Foramen Ovale** Sphenoid Greater wing of sphenoid Mandibular nerve (CN V3) **Foramen Spinosum** Sphenoid Just lateral to foramen ovale Middle meningeal artery **Foramen Lacerum** Sphenoid Spendoid meets temporal and occipital bones Covered by cartilage **Groove or Hiatus of great petrosal nerve** Greater petrosal nerve **Foramen magnum** Occipital Bordered by occipital condyles Brainstem (medulla), vertebral arteries and spinal portion of CN IX **Jugular foramen** Occipital and temporal Posterior cranial fossa CN IX, X and XI and internal jugular vein **Hypoglossal canal** Occipital Posterior cranial fossa Hypoglossal nerve (CN XII) **Mastoid foramen** **Stylomastoid foramen** Temporal Between mastoid and styloid process Facial nerve (CN VII) **Internal auditory meatus** Temporal Petrous portion of temporal bone CN VII and VIII **External auditory meatus** Temporal Anterior to mastoid process Open canal for sound waves **Carotid Canal** External temporal bone Middle cranial fossa Internal carotid artery [Anterior and Posterior Abdominal Wall Muscles ] **ANTERIOR ABDOMINAL WALL MUSCLES** **Obliquus externus abdominis** (external abdominal oblique muscle) - Largest, most superficial, moves lateral/superior to medial/inferior - **Origin**: external surfaces of lower 8 ribs - **Insertion**: Linea alba\*, pubic tubercle and anterior half of iliac crest - **Primary action**: - **Bilateral**: flexion of the trunk, compresses the abdominal contents to increase the abdominal pressure (coughing, sneezing, laughing) - **Unilateral**: contralateral rotation of the trunk - **Nerve** **supply:** lower intercostal nerves **Obliquus internus abdominis** (internal abdominal oblique muscles) - Thinner and smaller, irregularly quadrilateral form, lateral/inferior to medial/superior - **Origin**: lateral 1/3 of inguinal ligament\*\*, anterior 2/3 of iliac crest, thoracolumbar fascia - **Insertion**: linea alba, lower 3 ribs - **Primary action**: - **Bilateral**: flexion of trunk, compresses the abdominal contents - **Unilateral**: ipsilateral rotation of the trunk - **Nerve supply**: intercostal nerves (T6-12 and L1)  **Transversus abdominis muscle** - Most internal - **Origin**: inguinal ligament, iliac crest, thoracolumbar fascia and cartilages of lower 6 ribs - **Insertion**: linea alba - **Primary action**: almost at site of axis so no other movements - **Bilateral**: compresses the abdominal contents - **Nerve** **supply:** intercostal nerves (T6-12 and L1) **Rectus abdominis** - Long/flat, whole length of front abdomen, sides separates by linea alba - Crossed by fibrous bands (3) = tendinous intersections - **Origin**: pubic crest, symphysis pubis - **Insertion**: xiphoid process, cartilages of ribs 5,6,7 - **Primary action**: - **Bilateral:** flexion of the trunk, posterior tilt of the pelvis, compresses the abdominal contents - **Nerve supply**: intercostal nerves (T6-12) **\*Linea alba:** fusion of aponeurosis of anterior wall muscles from each side and extends from xiphoid process to symphysis pubis **\*\*Inguinal ligament:** inferior free border of the aponeurosis of the external abdominal oblique stretched between the anterior superior iliac spine and pubic tubercle **LAYERS OF ABDOMINAL WALL ANTERIOR** 1. **Skin** 2. **Camper's Fascia** - Thick superficial layer of adipose and areolar connective tissue - Just deep to skin - More prominent in lower abdomen (inferior to umbilicus) 3. **Scarpa's fascia = deep membranous layer** - Between camper's fascia and rectus sheath - Lateral anchor: aponeurosis of external oblique - Medial anchor: linea alba of rectus sheath 4. **[Rectus sheath = protective covering over rectus abdominus]** - **Composed of Aponeurosis** of 3 flat muscles as they form the median linea alba - Durable, resilient, fibrous compartment that contains and protects rectus abdominis - **Composition changes inferior to arcuate line** - **Arcuate line:** ½ of the distance between umbilicus and pubic symphysis - Aponeuroses pass **anterior to rectus abdominis** - Internal rectus abdominis is in direct contact with transversalis facia - Thin connective tissue between transversalis and parietal peritoneum posteriorly - **Superior to arcuate line:** - **Anterior lamina:** aponeurosis of external oblique + anterior ½ of aponeurosis of internal oblique - **Posterior lamina:** aponeurosis of transversus + posterior ½ of aponeurosis of internal oblique - **Inferior to arcuate line:** - **Anterior lamina:** aponeurosis of all 3 muscles - **Posterior lamina:** no aponeurosis just transversalis fascia 5. **Transversalis fascia** 6. **Extraperitoneal fat** 7. **Parietal peritoneum** **LAYERS OF ABDOMINAL WALL ANTEROLATERAL** 1. Skin 2. Camper's fascia 3. Scarpa's fascia 4. External oblique muscle 5. Internal oblique muscle 6. Transversus abdominis muscle 7. Transversalis fascia 8. Extraperitoneal fat 9. Parietal layer **MUSCLES OF POSTERIOR ABDOMINAL WALL** - Quadratus lumborum, psoas major/minor, iliacus and part of diagraph **Quadratus Lumborum** - **Origin:** iliac crest, iliolumbar ligament (TP of L5/iliac crest) - **Insertion:** ribs 12, transverse processes L1-4 - **Primary action:** - **Bilateral:** extension of the trunk, fixes rib 12 during inspiration (to help pull the diaphragm down) - **Unilateral:** lateral flexion of the trunk - **Nerve supply:** ventral rami of spinal nerves T12, L1-4 **Psoas Major** - **Origin:** bodies and transverse processes L1-5 - **Insertion:** lesser trochanter of femur - **Primary action:** - **Bilateral**: flexion of the trunk - **Unilateral**: Flexion of thigh, lateral rotation of thigh, lateral flexion of the trunk - **Nerve supply:** lumbar plexus (L1-3) **Iliacus** - **Origin:** iliac fossa, sacral ala - **Insertion:** lesser trochanter of femur - **Primary action:** - **Unilateral:** flexion of the thigh and lateral rotation of the thigh - **Nerve supply:** femoral nerve **INGUINAL CANAL** - Oblique canal, directing downward and medial, 4 cm - Made by the 3 abdominal muscles - Placed parallel with and a little above the medial half of inguinal ligament - **Contains:** - **Males**: spermatic cord (ductus (vas) deferens, testicular vessels, autonomic nerves and lymphatics) + ilioinguinal nerve (where testicles pass through) - **Females**: round ligament of uterus and ilioinguinal nerve - **Superficial inguinal ring:** triangular gap in external oblique aponeurosis - **Deep inguinal ring:** oval shape opening in fascia transversalis (situated half an inch above midinguinal point and lateral to stem of inferior epigastric vessels) - **Conjoint tendon:** fusion of lowest aponeurotic fibers of internal oblique and transversus muscle - Behind superficial inguinal ring - Strengthens abdominal wall - Inguinal hernia if the conjoint tendon bulges [Bones of the Upper Extremity ] **AXIAL VS APPENDICULAR SKELETON** - **Axial skeleton**: 80 bones - Along longitudinal axis - Skull, hyoid, vertebrae, ribs, sternum, ear ossicles - **Appendicular skeleton**: 126 bones - Upper limb: humerus, radius, ulna, carpal bones, metacarpal bones, phalanges - Lower limb: femur, tibia, fibula, patella, tarsal, metatarsal, phalanges - Pelvic girdle - Shoulder girdle **INTRODUCTION TO UPPER LIMB** - **Shoulder regions:** - Subdivisions: pectoral region, axilla/armpit, scapular region, deltoid region - Bones: clavicle, scapula - Joints: sternoclavicular joint, acromioclavicular joint - **Upper arm** (shoulder to elbow - brachium) - Bones: humerus - Joints: gleno-humeral joint (shoulder-joint) - **Forearm** (elbow to wrist - antebrachium) - Bones: radius, ulna - Joints: elbow joint, radio-ulnar joint - **Hand**: - Subdivision: wrist (carpus), hand proper (metacarpus), five digits (thumb/pollex, infex, middle, ring, little) - Bones: 8 carpal, 5 metacarpal, 15 phalanges (2 -- thumb, 3-fingers)  **CLAVICLE** - Part of **shoulder gridle** - Only bones that lies **horizontally** - **Medial 2/3** = anteriorly convex - **Lateral 1/3** = anteriorly concave - **Sternal end** = towards sternum - **Acromial end** = towards scapula - **Articular facet** for costoclavicular ligament is on the lower surface of the sternal end - **Subclavian groove** lies on inferior surface of the body (for the subclavian muscle) - **Conoid tuber:** near acromial end close to trapezoid line - **SCAPULA** - Shoulder blade - Triangular flat bone that lies on **posterolateral aspect of thorax, overlaying 2^nd^-7^th^ ribs** - Medial (vertebral), lateral and superior borders separated by superior/inferior angles and truncated lateral angle - **Subscapular fossa:** flat anterior (costal) surface, slightly concave - **Supraspinous fossa:** smaller dorsal surface - **Infraspinous fossa:** larger dorsal surface - **Acromion:** flatten process of the termination of spine of scapula - **Acromial articular facet:** oval articulation with clavicle near the lateral end - **Acromial angle:** readily palpable bony point - **Glenoid cavity:** on lateral angle (adjacent to neck of scapula) - **Supraglenoid tubercle:** small projection of upper border - **Infraglenoid tubercle:** below glenoid cavity - **Coracoid tubercle:** above glenoid cavity (bent at a right angle ventro-laterally) - **Suprascapular notch:** medial to base of coronoid process, on upper border of scapula - **Glenohumeral joint** = shoulder joint  **[Muscle Attachments on Scapula]** - Origins: - Supraspinatus: supraspinous fossa - Infraspinous: infraspinous fossa Deltoid: posterior of spine - Triceps branchii (long head): superior + slightly anterior lateral border of scapula - Teres minor: middle lateral border of scapula - Teres major: inferior lateral border of scapula - Biceps branchii (long head): supraglenoid tubercle - Biceps branchii (short head): coracoid process - Coracobrachialis: coracoid process - Subscapularis: subscapular fossa - Insertions: - Trapezius: superior spine and clavicle - Levator scapulae: medial border of supraspinous fossa - Rhomboid minor: medial border of spine - Rhomboid major: medial border of infraspinous fossa - Serratus anterior: anterior medial border of scapula - Pectoralis minor: medially surface of coracoid process **HUMERUS** **[Proximal End and Body ]** - **Proximal end:** head of humerus, anatomical neck, greater tubercle and lesser tubercle - **Intertubercular (bicipital) groove (sulcus):** between greater and lesser tubercle - Lateral and medial lip - **Surgical neck**: proximally on the body of humerus - **Deltoid tuberosity**: middle of body laterally - **Radial groove**: shallow sulcus on posterior body, behind deltoid tuberosity for radial nerve - **Body**: divided into antero-medial surface + antero-lateral surface - **Lateral and medial supracondylar ridges**: borders of medial/lateral surfaces **[Distal End]** - **Medial epicondyle:** medial side of humerus - **Lateral epicondyle:** lateral side of humerus - **Condyle of humerus**: trochlea, capitulum, olecranon, coronoid and radial fossae - **Lateral capitulum:** articulation with head of radius - **Radial fossa:** proximal to capitulum (anterior) - **Trochlea** (spool-shaped or pully): articulation with proximal end of ulna (trochlear notch) - **Coronoid fossa**: proximal to trochlea (anterior) - **Sulcus for ulnar nerve**: medial to trochlea - **Olecranon fossa**: posterior surface above trochlea - **Humeroradial and humeroulnar joints** **[Muscle Attachments of Humerus ]** - Origins: - Brachialis: inferior aspect of body - Brachioradialis: lateral supracondylar ridge - Extensor carpi radialis longus: lateral supra condylar ridge - Common extensor tendon: anterior surface of lateral epicondyle - Common flexor tendon: anterior surface of medial epicondyle - Triceps brachii (medial head): posterior body - Triceps brachii (lateral head): radial groove - Common flexor tendon: posterior medial epicondyle - Common extensor tendon: posterior lateral epicondyle - Anconeus: posterior lateral epicondyle - Insertions: - Supraspinatus: greater tubercle more anterior - Infraspinatus: greater tubercle more posterior - Subscapularis: lesser tubercle - Pectoralis major: lateral lip of intertubercular groove - Latissimus dorsi: medial lip of intertubercular groove - Teres major: most medial aspect of intertubercular groove - Teres minor: greater tuberosity posteriorly - Deltoid: deltoid tuberosity - Triceps brachii: olecranon of ulna - Coracobrachialis: medial to radial nerve - Brachialis: coronoid process of ulna - Biceps brachii: radial tuberosity **RADIUS** - **Shorter bone on lateral side** - **Head**: proximal end - Fovea articularis: continuous with articular circumference - **Radial tuberosity**: transition between neck and shaft - In transverse section of shaft, it is almost triangular with medially facing **interosseous border** - **Styloid process:** lower end - **Ulnar notch**: medial to styloid - **Carpal articular surfaces face distally** - Posteriorly: number of groove (varying depth) for **long extensor muscles** - **Dorsal tubercle (lister's tubercle)**: bony elevation lying on dorsal surface of distal end **ULNA** - **Longer bone on medial side** - **Articulate with humerus** - **Olecranon**: projects posteriorly - **Coronoid process**: projects anteriorly - **Trochlear notch**: between olecranon and coronoid process - **Tuberosity of ulna**: inferior to coronoid process - **Radial notch**: lateral side of coronoid process - Receives head of radius - **Supinator crest**: inferior to radial notch on lateral surface of shaft - **Supinator fossa**: between supinator crest and distal coronoid process - **Interosseous border**: medial of shaft - Attachment of interosseous membrane - **Head of ulna:** distal end - Styloid process: on head - **Radioulnar joints** **CARPAL BONES** - Arranged in **2 rows of 4** - **Proximal row** lateral -- medial: **scaphoid, lunate, triquetrum and pisiform** - Largest: scaphoid -- has tubercle on palmar side - **Distal row** lateral -- medial: **trapezium, trapezoid, capitate, hamate** - Hamulus (hook of hamate): curved laterally on palmar surface **[Carpal Arch and Tunnel ]** - Made up of 8 carpal bones - **Concaved anteriorly** - **Flexor retinaculum:** deep fascia on anterior wrist - Forms the **carpal tunnel** - 9 tendons and nerves pass through to from forearm to hand **METACARPAL BONES AND PHALANGES** - **Five metacarpals** with a head, shaft and base - **Base**: articular facet for carpals - **Head**: articular facet for proximal phalanges - **Metacarpophalangeal joints** - Each digit has **3 phalanges** with a head, shaft and base (proximal, middle, distal) -- minus thumb (no middle) - **Carpometacarpal joint** (proximal, intermediate and distal) **MOVEMENTS OF UPPER LIMB/PECTORAL GIRDLE** - **Shoulder joint: glenohumeral joint** - Abduction/adduction - Flexion and extension - Medial/lateral rotation - Circumduction - **Elbow joint: humeroradial and humeroulnar** - Flexion/extension - **Forearm: Radioulnar joints (superior and inferior)** - Pronation/supination - **Wrist joint: radiocarpal joint** - Abduction/adduction (radial and ulnar deviation) - Extension/flexion - Circumduction - **Fingers: metacarpophalangeal joints** - Abduction/adduction - Extension and flexion - circumduction - **Phalanges: carpometacarpal joint** - Flexion/extension - **Scapula (shoulder girdle)**: - Elevation/depression (up and down) - Retraction (adduction)/protraction (abduction) - Upward rotation (glenoid cavity up) /downward rotation (glenoid cavity down) [Brachial Plexus and Shoulder Girdle Muscles ] **BRACHIAL PLEXUS** - Lateral to cervical spine - The roots pass through scalene muscles - Heads infero-laterally underneath clavicle (axilla -- armpit) - Axilla: inferior to should joint at junction between upper limb and thorax - Bordered by serratus anterior, coracobrachialis, pec major and subscapularis muscles - Contains terminal branches of brachial plexus - Associated with arterial supply of upper limb (subclavian artery axillary artery) **[Formation]** - 5 roots, 3 trunks, 6 divisions, 3 cords and 5 terminal branches (Real Texans Drink Cold Beer) - Arrangements of terminal branches: musculocutaneous, axillary, radial, median, ulnar (MARMU) **[Roots ]** - **Anterior (ventral) branches** of **spinal nerves** exiting intervertebral foramen - Head lateral/inferior away from midline - **Spinal nerve C5,C6, C7, C8, T1** **[Trunks ]** - Roots pass through **scalene muscles** (anterior and middle) and combine into three trunks - **C5, C6 = superior trunk** - **C7 = middle trunk** - **C8, T1 = inferior trunk** **[Divisions ]** - Each trunk gives off two branches: **posterior and anterior** - Divisions pass **under clavicle** towards axilla **[Cords ]** - Three cords made in the axilla - Named by relative position to axillary artery - **Lateral cord: anterior divisions of superior and middle trunk** - **Posterior cord: posterior divisions of all trunks** - **Medial cord: anterior division of inferior trunk** **[Terminal Branches ]** - Three cords give rise to five branches that continue into upper limb for muscles/skin (also gives rise to multiple other nerves) - **Lateral cord:** - **Musculocutaneous nerve:** Innervates all muscles on anterior arm - **Posterior cord:** - **Axillary Nerve:** innervates deltoid and teres minor muscles) - **Radial nerves:** innervates all muscles of posterior arm and forearm - **Lateral/medial cord:** - **Median nerve:** innervates majority of muscles of anterior compartments of forearm and thenar muscles and two lumbricals of intrinsic muscles) - **Medial cord:** - **Ulnar nerve**: innervated 1 ½ muscle of anterior forearm and majority of intrinsic hand  **MUSCLES OF UPPER ARM** **[Trapezius ]** - **Origin**: - **Upper**: external occipital protuberance and medial superior nuchal line of occipital bone from ligamentum nuchae, the spinous process of C7 - **Middle**: SP of T1 to T5 - **Lower**: SP of T6-T12 - **Insertion**: lateral 1/3 clavicle; acromion and spine of scapula - **Primary action:** - **Upper**: - Extension/lateral flexion of head and neck - Contralateral rotation of head and neck - Elevation of scapula - Upward rotation of scapula - **Middle**: retraction (adduction) of scapula - **Lower**: - Depression of scapula - Upward rotation of scapula - **Nerve supply**: CN XI (spinal accessory nerve) **[Rhomboids Minor ]** - **Origin:** SP of C7 and T1 - **Insertion:** medial border of scapula at root of spine - **Primary action:** - Retraction (adduction) of scapula - Elevation of scapula - Downward rotation (hand behind back) of scapula - **Nerve supply:** dorsal scapular nerve **[Rhomboids Major ]** - **Origin:** SP of T2-T5 - **Insertion:** medial border of scapula inferior to spine - **Primary action:** - Retraction (adduction) of scapula - Elevation of scapula - Downward rotation of scapula - **Nerve supply:** dorsal scapular nerve **[Levator Scapulae ]** - **Origin:** TP of C1-C4 - **Insertion:** medial border of scapulae (above spine of scapula - **Primary action:** - Extension and lateral flexion of neck at spinal joints - Ipsilateral rotation of neck at spinal joints - Elevation of scapula at scapulocostal joint - Downward rotation of scapula at scapulocostal joint - **Nerve innervation:** dorsal scapular nerve \*Upward rotation (arm up behind head), Downward rotation (arm down behind back) of scapula **[Pectoralis Minor ]** - **Origin:** 3^rd^ to 5^th^ rib - **Insertion:** coracoid process - **Primary action:** - Protraction (adduction) of scapula - Downward rotation of scapula - Depression of scapula - Elevation of ribs 3-5 at sternocostal and costo-spinal joints - **Nerve supply:** medial pectoral nerve  **[Subclavius ]** - **Origin:** first rib - **Insertion:** subclavian groove of clavicle - **Primary action:** depression of clavicle at sternoclavicular and acromioclavicular joints - **Nerve innervation:** nerve to subclavius **[Serratus Anterior ]** - **Origin:** upper nine ribs - **Insertion:** anterior surface of vertebral border of scapula - **Primary action:** - Protraction (adduction) of scapula - Upward rotation of scapula - **Nerve supply:** long thoracic nerve (C5-7) **Pathology:** - **Winged scapula:** - Injury of long thoracic nerve **paralysis of serratus anterior** - Winged scapula: inferior angle of medial border is excessively prominent - Patient unable to do a pushing action or raise arm above head due to serratus anterior unable to rotate glenoid cavity superiorly  **[Pectoralis Major ]** - **Origin:** - Clavicular head: medial half of clavicle - Sternocostal head: sternum + costal cartilages of ribs 1-7 - **Insertion**: lateral lip of intertubercular groove - **Primary action**: - Flexion of arm (clavicular head) - Adduction of arm - Medial rotation of arm - Horizontal adduction of arm - **Nerve supply**: medial and lateral pectoral nerve **[Latissimus Dorsi ]** - **Origin:** SP T7-L5, crests of ilium/sacrum and lowest 4 ribs (via thoracolumbar fascia) - **Insertion:** floor of inter-tubercular groove - **Primary action:** - Extension of arm - Adduction of arm - Medial rotation of arm - Anterior tilt of the pelvis - **Nerve supply**: thoracodorsal neve (posterior cord) **SCAPULOHUMERAL (INTRINSTIC SHOULDER) MUSCLES** **[Deltoid ]** - **Origin:** - **Anterior fibres:** lateral clavicle - **Lateral fibres:** acromion - **Posterior fibres:** spine of scapula - **Insertion**: deltoid tuberosity of humerus - **Primary action**: - **Anterior fibres:** flexion and medial rotation of shoulder joint - **Posterior fibres:** extension and lateral rotation of shoulder joint - **All:** abduction of shoulder joint - **Nerve innervation:** axillary nerve (C5,6) **[Subscapularis ]** - **Origin:** subscapular fossa - **Insertion:** lesser tubercle of humerus - **Primary action:** medial rotation of shoulder joint - **Nerve innervation**: upper and lower subscapular never (C5,6)  **[Supraspinatus ]** - **Origin:** supraspinous fossa - **Insertion:** greater tubercle of humerus - **Primary action:** abduction of shoulder joint - **Nerve innervation:** suprascapular nerve (C5,6) **[Infraspinatus ]** - **Origin:** infraspinous fossa - **Insertion:** greater tubercle of humerus - **Primary action:** lateral rotation of shoulder joint - **Nerve innervation:** suprascapular nerve (C5,6) **[Teres minor]** - **Origin:** superior lateral border of scapula - **Insertion:** greater tubercle of humerus - **Primary action:** lateral rotation of shoulder joint - **Nerve innervation:** axillary nerve (C5,6) **[Teres Major ]** - **Origin:** inferior lateral border of the scapular - **Insertion:** medial lip of intertubercular (bicipital) sulcus (groove) of humerus - **Primary action:** extension, adduction and medial rotation of shoulder joint - **Nerve innervation:** Lower subscapular nerve (C5,6,7) **ROTATOR CUFF MUSCLES** - **4 muscles:** supraspinatus, infraspinatus, teres minor and subscapularis - Strength the shoulder joint capsule all around (except inferiorly)  **AXILLARY SPACES** - Three spaces carved by the muscles - Quadrangular space: axillary nerve and posterior humeral circumflex artery - Triangular interval: radial nerve and profunda brachii artery - Triangular space: circumflex scapular artery