Anatomy of the Appendicular Skeleton PDF

Okay, here is the conversion of the image into a structured markdown format: ### 2.5 Appendicular Skeleton The appendicular skeleton consists of bones that **make up the limbs and the girdles** that support them. It can be divided into the following parts: * Pectoral Girdle * Upper limb * Pe...

Okay, here is the conversion of the image into a structured markdown format: ### 2.5 Appendicular Skeleton The appendicular skeleton consists of bones that **make up the limbs and the girdles** that support them. It can be divided into the following parts: * Pectoral Girdle * Upper limb * Pelvic Girdle * Lower limb You need to be able to identify various characteristics of these bones, including: * left or right * Anterior or Posterior * Superior or inferior * Distal or Proximal ends ### Pectoral Girdle This connects to the upper limbs to the axial skeleton and consists of 2 bones: * Scapula (Scapulae) * Clavicle ### Scapula (Shoulder Blade) The Scapula is a roughly triangular shaped bone with several important features: **Borders:** * Superior Border * Lateral Border * Medial Border **Angles:** * Superior angle (top corner) * Lateral angle (lateral corner) * Inferior angle (bottom corner) **Scapular Body:** The Broad, flat surface of the Scapula is called the **Scapular body.** ### Scapula Notes **Anterior Surface of the Scapula:** * **Subscapular Fossa:** A broad indentation in the anterior surface of the scapular body * **Glenoid cavity:** * Found on the lateral surface of the scapula * A shallow depression that forms a joint with the humeral head (ball of the upper arm bone) called the glenohumeral joint * **coracoid Process:** * Anterior and Inferior projection * shaped like a crow's beak * **Acromion:** * Posterior and Superior projection * The acromion forms a joint with the lateral portion of the Clavicle known as **the acromioclavicular joint** **Posterior surface of the scapula:** * **Scapular Spine:** A prominent ridge you can feel under the skin at your Shoulder blade * **Supraspinous fossa:** depression located superior to the scapular Spine * **Infraspinous fossa:** depression located inferior to the scapular spine **Important key concepts from Chat: Identification:** * Be able to identify the **left or right scapula based on the location** of features such as the glenoid cavity, Coracoid process, and acromoin * The anterior surface has the **Subscapular fossa,** while the posterior surface has the **Scapular Spine** **Articulations:** * The glenoid cavity articulates with the **humerus** (upper arm bone) to form the **glenohumeral joint** * The acromoin articulates with the **clavicle** to form the **acromioclavicular joint** ### Clavicle bone & scapula/clavicle photos **Clavicle bone:** * Is a pair of small **S-Shaped bones** that spans between the acromoin of the scapula bone to It's lateral & Posterior roundish & thinner acromial end & the manubrium of the sternum bone to it's **medial & anterior flat & thicker sternal end.** * **S-shaped from superior view, nearly straight from anterior view** * **Bone acts as a brace, holding the upper limb in place away from the body** * **If fractured, your shoulder will be pulled anteriorly and medially** The image also contains the following diagrams which can be described as: 1. A diagram of a right clavicle bone, superior view, showing the Acromial end as the lateral end and the Sternal end as the medial end. 2. A diagram of a pectoral girdle, showing the Sternoclavicular joint, Acromioclavicular joint, Clavicle bone, Acromion, Coracoid process, Scapula bone, Manubrium, Humerus bone. 3. Three separate diagrams of a right scapula bone showing anterior, lateral and posterior view, labeled with different features of the scapula with each view. ### Upper limb The upper limb consists of the arm, forearm, wrist, and hand. The main bones include the humerus, radius, vina, Carpal bones, metacarpals, and phalanges. **Humerus Bone:** * **Proximal end** * Humeral head: Fits into the glenoid cavity * Greater tubercle and lesser tubercle Seperated by the intertubercular sulcus * Deltoid tuberosity: Where the deltoid muscle attaches * Radial Groove: where the radial nerve travels * **Distal end:** * medial and lateral epicondyles * medial trochlea and lateral capitulum * Radial fossa (lateral) and coronoid fossa (medial) * olecranon fossa (Posterior side) **Radius & vina** **Ulna:** * Proximal end: olecranon process (elbow bone), coronoid process, and trochlear notch (fits around humerus) * Distal end: Ulnar head and medial stylord process * Articulates with radius at the radial notch (proximal) and vinar notch (distal) **Radius:** * Proximal end: Radial head (articulates with capitulum) * Distal end: Radial tuberosity and lateral styloid process * Radius and ulna are connected by the interosseous membrane **Carpal bones (wrist)** * Proximal row (medial to lateral): Triquetrum, Pisiform, lunate, Scaphoid * Distal row (medial to lateral): Hamate, Capitate, trapezoid, trapezium * metacarpals: Five bones of the hand, each articulating with phalanges * Phalanges: 14 bones; the thumb has 2 (proximal & distal), Others have 3 (proximal, intermediate, & distal) ### Pelvic Girdle The pelvic girdle connects the lower limbs to the trunk and supports pelvic organs. It consists of the sacrum and two coxal (hip) bones **Pelvis Structure** * Pelvic Inlet: The opening into the pelvis * Pelvic Brim: Ridge around the pelvic inlet, Seperating the greater pelvis (above) and lesser pelvis (below) * Pelvic outlet: Inferior edge of the lesser pelvis **Coxal bones (made up of llium, Ischium, and pubis):** * Ilium: largest Part, includes the iliac crest, iliac fossa, anterior and Posterior Superior iliac Spines * Ischium: Forms the posterior-inferior part of the pelvis, with ischial tuberosities * Pubis: Forms the anterior portion of the pelvis. The pubic symphysis connects (sit bones) the two pubic bones **Sex differences in the pelvis** * Female Pelvis: wider, oval-shaped pelvic inlet, larger publc arch, and more movable Coccyx to allow for childbirth * male pelvis: Narrower, heart-shaped pelvic inlet, Smaller pubic arch, and less movable Coccyx ### Lower limb The lower limb includes the thigh, Patella, leg, ankle, and foot **Femur (thigh)** * Proximal end: Femoral head (articulates with acetabulum) and fovea capitis (ligamentum teres attaches) * Femoral Neck: Weakest part of the femur, common site of fractures (broken hip) * Trochanters: Greater Trochanter (anterolateral) and lesser trochanter (posteromedial) * Diaphysis: Includes the gluteal tuberosity (for gluteus maximus attachment) and linea aspera (attachment Point for many muscles) * Distal end: medial and lateral epicondyles, medial and lateral condyles (form the knee joint) and intercondylar fossa (posterior) ### Tibia and Fibula * **Tibia:** The larger, medial leg bone. Features include tibial plateau (articulates with femur), tibial tuberosity (Patellar ligament attachment), and medial malleolus (medial ankle bone) * **Fibula:** The Smaller, lateral bone. Features include the fibular head and lateral malleolus (lateral ankle bone) **Tibia & Fibula joints:** * Proximal and distal tibiofibular joints, Connected by the interosseous membrane **Tarsal bones (Ankle)** * Calcaneus: Heel bone * Talus: Articulates with tibia and fibula to form the ankle joint * Navicular: Articulates distally with talus * Cuneiforms: medial, intermediate, lateral * Cuboid: lateral tarsal bone * metatarsals: Five long bones of the foot * Phalanges: 14 bones in the toes: The big toe (**Hallux**) has two (Proximal & distal), others have three (proximal, intermediate, distal) **Bone markings (Quick reference)** * Epicondyle: Knuckle-like projections above a condyle(ex. medial & lateral epicondyles of the humerus) * Tuberosity: Roughened projection(ex. deltoid tuberosity) * Fossa: Shallow depression (ex. radial fossa, olecranon fossa) * Process: Any Projection or bump (ex. olecranon process of the ulna) * Foramen opening or hole (ex. Obturator foramen) ### 2.3 Skull The Skull has 22 bones, divided into 8 cranial and 14 facial bones **Cranial bones:** These bones encase & protect the brain * **Frontal bone (1):** forms the forehead, Superior orbit, and anterior Cranial fossa. Contains the frontal sinuses * **Parietal bones (2):** form the lateral walls of the Cranium. meets at the Sagittal Suture, coronal suture (front), lambdoid Suture (back), and Squamous Suture (sides) * **Temporal bones (2):** form lateral walks of the cranium **Key regions:** * Squamous: Zygomatic process and mandibular fossa (TMJ) * Tympanic: External auditory meatus, Styloid Process * mastoid: mastoid process (air cells), Stylo - mastoid foramen * Petrous foramen lacerum, carotid canal, jugular foramen, internal acoustic meatur * **Occipital bone (1):** Contains the foramen magnum (spinal cord) and occipital condyles (atlanto-occipital joint) * **Sphenoid Bone (1):** Butterfly Shaped. Keystone bone, articulates with 12 bones. **Features:** * Optic canals: for vision perves * Sella turcica: houses the pituitary gland * Greater wings have foramina: rotundum, ovale, and spinosum (mnemonic: "Rigatoni over spaghetti") * **Ethmoid bone (1):** located between the sphenoid and nasal bones (forms part of the nasal cavity) **Features:** * Cribiform plate (olfactory nerves) * Crista galli (attachment for brain meninges) * nasal Conchae: for airflow in the nasal cavity **Facial bones (14):** these bones form the facial Structure * **mandible(1):** lower jaw, contains mental foramen, mandibular rami, Coronoid and condylar processes (Tms joint) * **maxillae (2):** upper jaw, forms part of the orbit and nasal cavity **Features:** * Infraorbital foramen (nerve passage) ### 2.3 continued * maxillary sinuses and Palatine processes form the hard palate * **Lacrimal Bones (2):** Small bones in the medial orbit, Part of tear drainage system * **nasal bones (2):** Form the bridge of the nose * **Vomer (1):** forms the lower part of the bony nasal septum * **Inferior Nasal Conchae (2):** form part of the nasal cavity walls * **Palatine Bones (2):** L-Shaped, form the posterior hard palate and nasal cavity walls * **Zygomatic Bones (2):** Form the Cheekbones, Part of the zygomatic arch * **Paranasal Sinuses:** Air-filled Cavities in the frontal, maxillae, ethmoid, Sphenoid, and temporal bones bones (mastoid sinuses). Help filter, warm, and humidify air * orbit formation: formed by parts of 7 bones: frontal, sphenoid, ethmoid, lacrimal, zygomatic, maxillae,and palatine * nasal cavity formation: formed by parts of 6 bones: ethmoid, sphenoid, vomer, maxillae, Palatine,and inferior nasal conchae **(OVERVIEW OF LAST PAGES)** * The Cranial bones form the Calvaria (skull Cap) and the cranial base, which contains indentations known as the Cranial fossae (anterior, middle, Posterior) that support the brain. The facial bones form the anterior side of the skull and face * Additionally, some cranial and facial bones Contain Paranasal sinuses, which are air-filled cavities lined with mucous membranes. These sinuses help filter, warm, and humidify air entering the nasal cavity. The paranasal Sinuses are found in the frontal maxillae, ethmoid, sphenoid, and temporal (mastoid) bones * Near frontal bone: Glabella (smooth area between eyes) Supraorbital foramina (small holes over the brow ridge, Part of the Supraorbital margin) * The frontal bone internally contains frontal Sinuses * Parietal bones terms: Pterion: Junction with frontal, Sphenoid and temporal bones * Asterion: Junction with occipital and temporal bones Hope this helps!