The Skeletal System: Part II, F2024 PDF

CHAPTER 5 THE SKELETAL SYSTEM PART II The Axial and Appendicular Skeleton © 2012 Pearson Education, Inc.  Bone Markings They are surface features of bones and sites of att...

CHAPTER 5 THE SKELETAL SYSTEM PART II The Axial and Appendicular Skeleton © 2012 Pearson Education, Inc.  Bone Markings They are surface features of bones and sites of attachments for muscles, tendons, and ligaments. Passages for nerves and blood vessels Categories of bone markings Projections or processes — grow out from the bone surface Terms often begin with “T” like Tuberosity, tubercle, Trochanter. Depressions or cavities — indentations Terms often begin with “F” (except facet) like fissure, foramen, fossa. © 2012 Pearson Education, Inc.  Bone Markings © 2012 Pearson Education, Inc.  The Axial Skeleton (80 Bones) © 2012 Pearson Education, Inc.  The Axial Skeleton Forms the longitudinal axis of the body. Divided into three parts: 1. Skull 2. Vertebral column 3. Bony thorax © 2012 Pearson Education, Inc.  Skull The skull contains 22 bones overall. Rests on superior end of vertebral column. Two sets of bones Cranium bones enclose brain ( 8 bones) Facial bones ( 14 bones) Hold eyes in anterior position Allow facial muscles to express feelings Bones are joined by sutures. Only the mandible is attached by a freely movable joint called as Temporomandibular joint. © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc.  Cranium 1 Frontal bone 2 Occipital bone 3 Ethmoid bone 4 Sphenoid bone 5,6 Parietal bones (paired) 7,8 Temporal bones (paired) https://www.youtube.com/watch?v=FrpVzSK23Q0 © 2012 Pearson Education, Inc.  Cranial bones Frontal bone – forehead and superior part of the eye socket (orbit). Parietal bones – form superior and lateral walls of the cranium. Temporal bones – inferior to parietal bones. Occipital bone – most posterior bone – base and back wall of skull. Sphenoid bone – spans the width of the skull and part of the floor of the cranial cavity. Ethmoid bone – irregular shape, lies anterior to sphenoid, separates the nasal cavity from the brain, forms roof of nasal cavity and medial walls of the orbits © 2012 Pearson Education, Inc.  Sutures of the Skull Sutures are interlocking, immovable, fibrous tissue joints. Only mandible is attached to the rest of the skull by a movable joint. Temporomandibular joint, form the only non- sutured joints in the skull. © 2012 Pearson Education, Inc.  Sutures of the Skull The coronal suture joins the frontal bone to the parietal bones. The sagittal suture joins the two parietal bones to each other. The lambdoid suture joins the parietal bones to the occipital bone. The squamous suture joins the parietal bones to the temporal bones. © 2012 Pearson Education, Inc.  Human Skull, Anterior and Posterior Views © 2012 Pearson Education, Inc.  Temporal bone markings Inferior to parietal bone and joined by the squamous suture Bone markings: External acoustic meatus – canal leading to eardrum and middle ear. It is route through which sound enters the ear. Styloid process – sharp projection inferior to external acoustic meatus. - Attachment point for muscles of the neck Zygomatic process – bone bridge joining the zygomatic bone. Mastoid process – full of mastoid sinuses. Inferior and posterior to the external acoustic meatus. Attachment point for neck muscles. Can become infected, called Mastoiditis. Jugular foramen – allows passage for the jugular vein which is the largest vein of head (to drain brain). © 2012 Pearson Education, Inc.  Skull: Lateral view Coronal suture Frontal bone Parietal bone Sphenoid bone Temporal bone Ethmoid bone Lambdoid Lacrimal bone suture Squamous suture Nasal bone Occipital bone Zygomatic process Zygomatic bone Maxilla External acoustic meatus Mastoid process Alveolar processes Styloid process Mandible (body) Mental foramen Mandibular ramus for the jugular vein © 2012 Pearson Education, Inc. Figure 5.9  Superior view (top of cranium removed) Frontal bone Cribriform plate Ethmoid Crista galli bone Sphenoid bone Optic canal for the optic nerve Sella turcica Foramen ovale for the trigeminal nerve to Temporal bone attach to mandible Jugular foramen for the jugular vein, drains brain Internal acoustic meatus for cranial nerves VII and VIII Parietal bone Occipital bone Foramen magnum © 2012 Pearson Education, Inc. Figure 5.10  Occipital Bone Markings Most posterior bone – forms base and back wall of skull. Foramen Magnum present at base of occipital bone, is a large opening which allows spinal cord to connect with the brain. Occipital Condyles- which rests on the first vertebra of the spinal column. © 2012 Pearson Education, Inc.  Inferior view (mandible removed) Maxilla Hard (palatine process) palate Palatine bone Maxilla Zygomatic bone Sphenoid bone Temporal bone (greater wing) (zygomatic process) Foramen ovale Vomer Mandibular fossa Carotid canal Styloid process Mastoid process Jugular foramen for the jugular vein Temporal bone Occipital condyle Parietal bone Foramen magnum Occipital bone © 2012 Pearson Education, Inc. Figure 5.11  Sphenoid bone Bone markings: Butterfly-shaped bone. Sella Turcica or Turk’s saddle – A small depression forming enclosure for the pituitary gland. Optic Canal- allows optic nerve to pass to the eye. Sphenoid Sinuses: Central part with air cavities. (located behind the eyes) © 2012 Pearson Education, Inc.  Coronal suture Frontal bone Parietal bone Nasal bone Superior orbital fissure Sphenoid bone Optic canal Ethmoid bone Temporal bone Lacrimal bone Zygomatic bone Middle nasal concha of ethmoid bone Maxilla Inferior nasal concha Vomer Mandible Alveolar processes © 2012 Pearson Education, Inc. Figure 5.12  Ethmoid Bone Irregular shaped bone. It forms the roof of the nasal cavity. Crista galli (Cock’s comb): outermost covering of brain attaches to this projection. Superior and Middle Nasal Concha: Increases surface area, helps in increasing turbulence of air flowing through the nasal passage. © 2012 Pearson Education, Inc.  Facial Bones Facial Bones form the anterior portion of the skull. 14 bones composes face: 12 paired bones and 2 single bones (mandible and vomer) © 2012 Pearson Education, Inc.  Facial bones Paired Bones: Zygomatic bones (Cheek bones) – Also form portion of lateral walls of orbits. Lacrimal bones – form medial walls of the orbit (eye socket). Smallest and most fragile bone of skull. Contains lacrimal fossa which houses lacrimal sac. Nasal bones – form bridge of the nose. Inferior nasal conchae – thin, curved bones projecting medially from the lateral walls of the nasal cavity. © 2012 Pearson Education, Inc.  Facial bones Paired Bones Maxillae – fused bones forming upper jaw. All bones join it except mandible. This bone contain Paranasal sinuses. Carry upper teeth in alveolar process. Extension of maxillae is, Palatine process, which form anterior part of hard palate of mouth. Palatine bones – posterior to palatine process (maxilla) Attachment point for muscles of the neck. © 2012 Pearson Education, Inc.  Facial bones Single Bones of the face are as follows: Vomer bone : Single bone in the median line of the nasal cavity and forms most of the bony nasal septum. It separates nasal cavity into right and left sides. Mandible (Lower Jaw): Joins temporal bones to form the only freely movable joints in the skull. Largest and strongest facial bone of the face is mandible. Horizontal part (called body) forms the chin. Rami are two bars. ` The lower teeth lie in alveoli (sockets) in the alveolar process. © 2012 Pearson Education, Inc.  Coronal suture Frontal bone Parietal bone Nasal bone Superior orbital fissure Sphenoid bone Optic canal Ethmoid bone Temporal bone Lacrimal bone Zygomatic bone Middle nasal concha of ethmoid bone Maxilla Inferior nasal concha Vomer Mandible Alveolar processes © 2012 Pearson Education, Inc. Figure 5.12  Name all the Bones of the Skull Cranial bones Facial bones Mandible (1) Frontal bone (1) Maxillae (2) Parietal bones (2) Lacrimal bones (2) Occipital bone (1) Nasal bones (2) Temporal bones (2) Palatine bones (2) Zygomatic bones (2) Sphenoid bone (1) Inferior nasal conchae (2) Ethmoid bone (1) Vomer (1) © 2012 Pearson Education, Inc.  Paranasal Sinuses Sinus: Sinus is a cavity in the substance of a bone of the skull that usually communicates with the nostrils and contains air. They are lined with respiratory epithelium (ciliated pseudostratified columnar epithelium). Location: Bones surrounding the nasal cavity. © 2012 Pearson Education, Inc.  Paranasal Sinuses Functions Produce Mucus, moisturizing nose. Mucosa lining is continuous with the nose and throat. Lighten the skull, decreasing weight of especially facial bones. Amplify sounds as we speak. Immunological defense. Can become infected (sinusitis) © 2012 Pearson Education, Inc.  Identify the following bone (Label A) and mention the type of the bone (Cranial or Facial). A © 2012 Pearson Education, Inc.  Key Words Vertebral column or Spine or Back bone Spinal cord Vertebra Vertebrae Intervertebral discs © 2012 Pearson Education, Inc.  The Vertebral Column (Spine) Extends from skull to pelvis (where it distributes the weight of the body. Spine is formed from 26 irregular bones connected and reinforced by ligaments. There are 24 single vertebral bones separated by intervertebral discs ( pads of fibrocartilage – for shock absorption and flexibility) 7 vertebrae are in the neck – Cervical vertebrae 12 are in the chest region- Thoracic Vertebrae. 5 supporting the lower back- Lumbar Vertebrae. Sacrum (formed by fusion of 5 vertebrae) Coccyx (formed by fusion of 3–5 vertebrae) Before birth, spine consists of 33 vertebrae, 9 vertebrae fuse to form two composite bones, Sacrum and Coccyx © 2012 Pearson Education, Inc.  Anterior Posterior 1st cervical vertebra (atlas) Cervical curvature 2nd cervical (concave) Spine is vertebra (axis) 7 vertebrae, C1 – C7 formed 1st thoracic from 26 vertebra Transverse irregular bones process Spinous Thoracic curvature process (convex) All the curves 12 vertebrae, Intervertebral T1 – T12 help the vertebral disc column support Intervertebral the weight of the foramen body. 1st lumbar vertebra Lumbar curvature (concave) 5 vertebrae, L1 – L5 Sacral curvature (convex) 5 fused vertebrae Coccyx 4 fused vertebrae © 2012 Pearson Education, Inc. Figure 5.16  The Vertebral Column (Spine) Running through the central cavity of spine is a delicate Spinal cord ,which the vertebral column surrounds and protects. © 2012 Pearson Education, Inc.  What are Intervertebral Discs? Fibrocartilage pads between vertebrae. What is the function of Intervertebral Disks? Anchor vertebrae to each other Cushion and allow movement © 2012 Pearson Education, Inc.  Homeostatic Imbalance Herniated (slipped) discs © 2012 Pearson Education, Inc.  Clinical Note - Damage to Intervertebral Discs. Herniated (slipped) discs: Tear in the outer, T12 fibrous ring of an intervertebral disc Normal intervertebral which allows the soft, disc central portion to bulge L1 out beyond the damaged outer rings. Bulging Usually due to age disc related degeneration of L2 intervertebral discs, twisting forces on spine (lifting injuries or straining) a A lateral view of the lumbar region of the spinal column, showing a bulging intervertebral disc © 2012 Pearson Education, Inc.  Primary and Secondary Curvatures © 2012 Pearson Education, Inc.  The C-Shaped Spine Typical of a Newborn Primary curvatures – Thoracic and sacral regions are formed first during fetal development so they are called Primary Curvatures. Present from birth. Convex shape posteriorly. Form a C-shaped curvature as in newborns. Secondary curvatures - The spinal curvatures of the cervical and lumbar regions Develop after birth. In adults, allows to center our body weight on our limbs. Concave shape posteriorly Form an S-shaped curvature as in adults © 2012 Pearson Education, Inc.  Spinal curvatures Cervical curvature (concave) Development of secondary 7 vertebrae, C1 – C7 curvatures is critical to our species’ ability to walk upright Thoracic curvature Cervical curvature allows us to hold (convex) 12 vertebrae, T1 – T12 our heads up, and lumbar curvature shifts weight of body onto sacrum Lends balance and support needed to Lumbar curvature (concave) 5 vertebrae, walk on two legs. L1 – L5 Sacral curvature (convex) 5 fused vertebrae © 2012 Pearson Education, Inc.  Abnormal spinal curvatures: © 2012 Pearson Education, Inc.  Kyphosis Abnormally excessive convex of thoracic curve of the spine. Vertebral collapse, Bone loss which results in hunched over posture. Common in elderly. Result from advanced osteoporosis. Poor posture © 2012 Pearson Education, Inc.  Vertebral Column (Spine) Parts of a typical vertebra Body (centrum) Vertebral arch Pedicle Lamina Vertebral foramen Transverse processes Spinous process Superior and inferior articular processes © 2012 Pearson Education, Inc.  Common features Body (centrum) – disc like, weight- of Vertebrae bearing, faces anteriorly in the spinal column. Vertebral arch – formed from the joining of posterior extensions (laminae and pedicles). Vertebral foramen – canal for the spinal cord. © 2012 Pearson Education, Inc.  Common features of Vertebrae © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc.  A B C F D E © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc.  Cervical vertebrae © 2012 Pearson Education, Inc.  Structure of the Cervical Vertebrae C1 and C2 are notably different from other cervical vertebrae © 2012 Pearson Education, Inc.  Special Cervical vertebrae (Atlas & Axis) Seven cervical vertebrae (C1 – C7) form neck region. The first two are: Atlas (C1) Axis (C2) Atlas (C1) – Most superior vertebrae which bears skull. No body, No spinous process. Large superior depressions of transverse process are attached to skull at the occipital condyles. Allows head to nod “ Yes”. (Atlantooccipital joint) © 2012 Pearson Education, Inc.  Special Cervical Vertebrae (Axis) Axis (C2) inferior to altas Characterised by large process- Dens (acts as pivot point). C2 acts as a pivot for the rotation of the atlas and skull above. Joint between atlas and axis allows to rotate head side to side to indicate “No” © 2012 Pearson Education, Inc.  Atlas and Axis (C1 and C2 together) © 2012 Pearson Education, Inc.  (b) TYPICAL CERVICAL VERTEBRAE Typical Cervical Facet on superior Spinous Vertebrae articular process process Vertebral Smallest and lightest (C3 tovertebrae. C7) foramen Transverse Process Shorter spinous processes split into Superior view (Small) two (bifid) (C2 to C6). Superior Body articular process Spinous Oval shaped body. process Transverse process Facet on inferior Each transverse process has holes articular process Right lateral view (foramina) for the vertebral arteries to pass through it (C1 to C7). Each vertebra has a pair of facet joints (synovial). They are lined with smooth cartilage to enable limited movement between two vertebrae. Figure 5.20b © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc.  Thoracic vertebrae (T1 to T12) (c) THORACIC VERTEBRAE Spinous process (long & thick) ) Transverse Vertebral Process foramen (large) Facet Facet on for rib superior articular process Body Superior view Facet on Body superior articular process Facet on transverse process Costal facet Spinous Process for rib hooks downwards Right lateral view © 2012 Pearson Education, Inc. Figure 5.20c © 2012 Pearson Education, Inc.  Lumbar vertebrae (L1 to L5) (d) LUMBAR VERTEBRAE Spinous process 5 large, sturdy vertebrae. (short & blunt) Vertebral foramen Short, blunt spinous process, Transverse Process looks like a moose. (Thin &Tapering) Facet on Body superior articular Massive body which is kidney Superior view process shaped. Superior Body articular process Spinous Facet on inferior process articular process Right lateral view © 2012 Pearson Education, Inc. Figure 5.20d  CHARACTERISTIC Cervical (C3- C7) Thoracic (T1-T12) Lumbar (L1- L5) Body Oval Heart Kidney Spinous Process Short and Split (C2 to C6) Long, Sharp & Thick Short, Blunt (Bifid) ( like Giraffe) (like Moose) Size Small, Lightest Larger than Cervical Largest Transverse Process Has holes for arteries No holes, No holes, thin tapered (Transverse foramina) , Fairly larger Large Small Bears facets for ribs Articulate facets for Absent Present Absent Ribs Vertebral foramen Triangular, large Circular Triangular One Vertebral and two One Vertebral One Vertebral Transverse © 2012 Pearson Education, Inc.  The Bony Thorax Thoracic cage – It consists of 1.Sternum 2.Ribs 3.Thoracic vertebrae. Forms a cage to protect major organs like heart, lungs, blood vessels. © 2012 Pearson Education, Inc.  Thoracic Cage 1. Sternum or Breastbone: A flat bone with 3 fused bones Manubrium: superiormost segment, articulates with clavicles of pectoral girdle; First rib cartilages attach just below clavicular notches. Body : large middle segment. Xiphoid process : inferior segment; protrusion that provides an attachment site for certain abdominal muscles. Sternum is attached directly to first seven pairs of ribs via Costal cartilages.Sternum is ideal for sternal puncture. © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc.  Thoracic Cage © 2012 Pearson Education, Inc.  T1 vertebra Jugular notch Clavicular notch Manubrium Sternal angle Body Xiphisternal Sternum joint Xiphoid process Intercostal spaces L1 Vertebra Costal cartilage Floating ribs (11, 12) (a) © 2012 Pearson Education, Inc. Figure 5.22a  Think First-responders are taught carefully how to perform chest compressions. If chest compressions are performed inaccurately, what are some potential consequences? The major consequence of improper chest compressions is fracture of the xiphoid process. This scenario could lead to further complications if the xiphoid process punctures the pericardium of the heart or the pleura of the lungs. © 2012 Pearson Education, Inc.  The Appendicular Skeleton (126 Bones) © 2012 Pearson Education, Inc.  The Appendicular Skeleton It is composed of 126 bones. It consists of : 1. Limbs (appendages) 2. Pectoral girdle (shoulder girdle) Composed of 2 bones: Clavicle and scapula 3. Pelvic girdle Composed of 3 bones 2 coxal bones (ossa coxae) “hip bones” Sacrum © 2012 Pearson Education, Inc.  The Human Skeleton © 2012 Pearson Education, Inc.  Bones of Pectoral Girdle The shoulder girdle or pectoral girdle is the set of bones which connects the arm to the axial skeleton on each side. Light, poorly reinforced girdle. Composed of two bones. 1. Clavicle 2. Scapula © 2012 Pearson Education, Inc.  Bones of the Shoulder Girdle Slender, doubly curved. Clavicle articulates with the manubrium of sternum medially forming sternoclavicular joint. Clavicle articulates with the acromion process of the scapula laterally forming Acromioclavicular joint. Clavicle prevent shoulder dislocation. © 2012 Pearson Education, Inc.  Clavicle Fxns: Posterior 1.Helps form the Sternal (medial) shoulder joint. end 2. Helps to prevent shoulder Acromial (lateral) Anterior dislocation. end The acromial end Superior view of the clavicle is Acromial end Sternal end concave anteriorly, Anterior while the sternal end is convex anteriorly. Posterior Inferior view (b) Right clavicle, superior and inferior views © 2012 Pearson Education, Inc. Figure 5.23b  Acromio- clavicular Clavicle joint Scapula (a) Articulated right shoulder (pectoral) girdle showing the relationship to bones of the © 2012 Pearson Education, Inc. thorax and sternum Figure 5.23a © 2012 Pearson Education, Inc.  Coracoid process Suprascapular notch Acromion – connect with clavicle Superior angle Supraspinous fossa Spine Infraspinous fossa Glenoid cavity at lateral angle Medial border Lateral border (c) Right scapula, posterior aspect © 2012 Pearson Education, Inc. Figure 5.23c  Acromion Suprascapular notch Superior border Coracoid process Superior angle Glenoid cavity Subscapular fossa Lateral (axillary) Medial border (vertebral) border Fossa's contain muscles that stabilize the shoulder. Inferior angle (d) Right scapula, anterior aspect © 2012 Pearson Education, Inc. Figure 5.23d © 2012 Pearson Education, Inc.  Shoulder girdle movement Very light and freely moving (exceptional flexibility) because: 1. Each shoulder girdle is attached to the axial skeleton at only one point called the Sternoclavicular joint. 2. Loose attachment of scapula allows easy movement. 3. The glenoid cavity is shallow, and the shoulder joint is poorly reinforced by ligaments. © 2012 Pearson Education, Inc.  Quick Review © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc.  Bones of the Upper Limbs 1. Humerus 2. Ulna Forearm 3. Radius © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc.  Head of Greater humerus tubercle Lesser tubercle Anatomical neck Intertubercular sulcus Right humerus Anterior view Deltoid tuberosity Radial fossa Medial epicondyle Receives coronoid process of ulna. Coronoid fossa Articulates with head of Radius Capitulum Trochlea articulates with the Ulna (a) © 2012 Pearson Education, Inc. Figure 5.24a  Head of humerus Anatomical Surgical neck neck Right humerus Radial groove Posterior view Deltoid tuberosity Medial Olecranon epicondyle fossa Lateral Trochlea epicondyle (b) © 2012 Pearson Education, Inc. Figure 5.24b  The Right Humerus and Elbow Joint. Humerus Radial fossa Capitulum Trochlea Medial epicondyle Head of radius Coronoid process of ulna Radial notch of ulna Elbow joint, anterior view 87 © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc.  Bones of the Upper Limbs The forearm has two bones 1. Ulna — medial bone in anatomical position Proximal end of articulation: Coronoid process and olecranon articulate with the humerus. 2. Radius—lateral bone in anatomical position Proximal end of articulation: Head articulates with the capitulum of the humerus. © 2012 Pearson Education, Inc.  Remember this The Radius is on the thumb side and Ulna is on the pinky side © 2012 Pearson Education, Inc.  Bones of the Upper Limbs At proximal and distal end of the radius and ulna articulate at Radioulnar joint. Two bones connected by interosseous membrane. Both the bones have styloid process at distal end which serves as point of attachment of muscles. Disc shaped head of the radius forms a joint with capitulum of the humerus. Radial tuberosity-tendon of the biceps muscle attaches. © 2012 Pearson Education, Inc.  Trochlear notch Olecranon Head Coronoid Radius and Ulna Neck process Anterior view Radial Proximal radioulnar tuberosity joint Radius Ulna Inter- osseous membrane Ulnar styloid Radial process styloid Distal process radioulnar joint (c) © 2012 Pearson Education, Inc. Figure 5.24c  Olecranon Trochlear notch Coronoid process Radial notch Ulnar tuberosity Ulna c Lateral view of ulna, showing trochlear notch 93 © 2018 Pearson Education, Ltd. Bones of the Forearm Figure The elbow joint.  Bones of the Upper Limbs Hand Carpals—wrist Eight bones arranged in two rows of four bones in each hand Metacarpals—palm Five per hand Phalanges—fingers and thumb Fourteen phalanges in each hand In each finger, there are three bones In the thumb, there are only two bones © 2012 Pearson Education, Inc.  Review © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc.  Right hand Anterior view Distal Middle Phalanges (fingers) Proximal Sally Left The Party To Take Carmen Home 4 3 2 Metacarpals 5 (palm) 1 Hamate Trapezium Carpals Pisiform Trapezoid (wrist) Triquetrum Scaphoid Lunate Capitate Ulna © 2012 Pearson Education, Inc. Radius  Bones of the Pelvic Girdle The pectoral girdles are to the upper limbs as the pelvic Girdle is to the lower limbs. The girdles are the parts of the appendicular skeleton that anchor the appendages to the axial skeleton. Pelvic girdle is strong and rigid compared to pectoral girdle. © 2012 Pearson Education, Inc.  Functions of the Pelvic Girdle The total weight of the upper body rests on the pelvis. It protects several organs like Reproductive organs Urinary bladder Part of the large intestine © 2012 Pearson Education, Inc.  lliac crest Sacroiliac joint llium Coxal bone (or hip bone) Sacrum Pelvic brim Pubis Coccyx Ischial spine Acetabulum Ischium Pubic symphysis Pubic arch (a) © 2012 Pearson Education, Inc. Figure 5.26a  Bones of the Pelvic Girdle Pelvic girdle is formed by : Two Coxal bones (ossa coxae) or Hip bones A Sacrum Pelvic girdle = 2 Coxal bones + Sacrum Bony pelvis = 2 Coxal bones + Sacrum + Coccyx © 2012 Pearson Education, Inc.  Bones of the Pelvic Girdle Each hip bone(Coxal bone) is composed of three pairs of fused bones. 1. Ilium – largest and most superior 2. Ischium – “sit bones” most inferior 3. Pubis – most anterior Pubic symphysis. each hip bone articulate anteriorly to form a cartilaginous joint © 2012 Pearson Education, Inc.  Bones of the Pelvic Girdle 1. Ilium - largest and most superior Connects posteriorly with the sacrum at the Sacroiliac joint. It is a large, flaring bone that forms most of the hip bone. Important markings are: Alae – the wing like portion of the ilia Iliac crest – the upper edge of the alae © 2012 Pearson Education, Inc.  lliac crest Sacroiliac joint llium Coxal bone (or hip bone) Sacrum Pelvic brim Pubis Coccyx Ischial spine Acetabulum Ischium Pubic symphysis Pubic arch (a) © 2012 Pearson Education, Inc. Figure 5.26a Right coxal bone IIium Lateral view Ala Posterior IIiac crest superior iliac Anterior superior spine iliac spine Posterior inferior Anterior inferior iliac spine iliac spine Greater sciatic notch Acetabulum Ischial body Body of pubis Ischial spine Pubis Ischial tuberosity Inferior pubic ramus Ischium Obturator Ischial ramus foramen (b) © 2012 Pearson Education, Inc. Figure 5.26b  Bones of the Pelvic Girdle 2. Ischium: “sit bones” It is the ―sit-down bone, since it forms the most inferior part of the coxal bone. Important Bone markings are: Ischial tuberosity – is a roughened area that receives body weight when your are sitting. Ischial spine – important anatomical landmark, particularly in the pregnant women, because it narrows the outlet of the pelvis through which the baby must pass during the birth process. Greater sciatic notch – allows blood vessels and the large sciatic nerve to pass from the pelvis posteriorly into the thigh. Injections in buttock should be given away from this area © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc.  Sciatic Nerve Injury in the Buttock Symptoms like pain, numbness and Sciatic weakness in a leg from a Nerve pinched nerve can be caused by injury or compression of the sciatic nerve © 2012 Pearson Education, Inc.  Bones of the Pelvic Girdle 3. Pubis (Pubic Bone): Is the most anterior part of the coxal bone. Important markings are: Obturator foramen – It is an opening that allows blood vessels and nerves to pass into the anterior part of the thigh. It is the fusion of rami of pubis anteriorly and ischium posteriorly forms bar of bone enclosing obturator foramen. Pubis symphysis – a cartilaginous joint (fibrocartilage) resulted from the fusion of two pubic bones of the hip. Acetabulum – where the ilium, ischium, and pubis are fused together; it receives the head of the thigh bone. © 2012 Pearson Education, Inc. Right coxal bone IIium Lateral view Ala Posterior IIiac crest superior iliac Anterior superior spine iliac spine Posterior inferior Anterior inferior iliac spine iliac spine Greater sciatic notch Acetabulum Ischial body Body of pubis Ischial spine Pubis Ischial tuberosity Inferior pubic ramus Ischium Obturator Ischial ramus foramen (b) © 2012 Pearson Education, Inc. Figure 5.26b  Differences between the female and male pelvis. © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc.  False Pelvis and True Pelvis False pelvis False pelvis : It is superior to the true pelvis. Inlet of An area medial to the flaring true pelvis portion of ilia. Pelvic brim Pubic arch (more than 90°) (c) True Pelvis: Figure 5.26c It is surrounded by bone. Lies inferior to pelvic brim. © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc.  Bones of the Lower Limbs - Thigh Bone Thigh Bone - composed of single bone Femur. Femur is the heaviest, strongest and longest bone in the body. In the proximal end: Head articulates with the acetabulum of the coxal (hip) bone. In the distal end: Lateral and medial condyles articulate with the tibia in the lower leg © 2012 Pearson Education, Inc.  Neck Greater Head trochanter Head Inter- Inter- trochanteric Lesser trochanter trochanteric Lesser trochanter crest line Gluteal tuberosity Lateral condyle Patellar Intercondylar surface fossa (a) Medial Lateral Lateral condyle condyle condyle Patellar surface Femur anterior (b) Femur posterior © 2012 Pearson Education, Inc. Figure 5.27a © 2012 Pearson Education, Inc.  Neck C Head D Inter- trochanteric A Lesser trochanter line B Lateral condyle Patellar E surface (a) F G Lateral condyle Patellar surface Femur anterior (b) Femur posterior © 2012 Pearson Education, Inc. Figure 5.27a © 2012 Pearson Education, Inc.  Bones of the Lower Limbs – Lower Leg © 2012 Pearson Education, Inc.  Remember this The FibuLA is always LAteral. © 2012 Pearson Education, Inc.  Intercondylar eminence Lateral Medial condyle condyle Head Tibial tuberosity Tibia and fibula Proximal tibiofibular anterior joint Interosseous membrane Anterior border Fibula Tibia Distal tibiofibular joint Medial Lateral malleolus malleolus (c) © 2012 Pearson Education, Inc. Figure 5.27c © 2012 Pearson Education, Inc.  Bones of the Lower Limbs The foot Tarsals— seven bones Two largest tarsals carry most of the body wt: 1. Calcaneus (heel bone) 2. Talus – between calcaneus and tibia Metatarsals—five bones form the sole of the foot (named 1-5) Phalanges—fourteen bones form the toes © 2012 Pearson Education, Inc.  Phalanges: Distal Middle Proximal Tarsals: Medial Metatarsals cuneiform Tarsals: Intermediate cuneiform Lateral cuneiform Navicular Cuboid Talus Calcaneus © 2012 Pearson Education, Inc. Figure 5.28 © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc.  THE END http://www.meddean.luc.edu/lumen/MedEd/GrossAnatomy/ learnem/bones/main_bone.htm © 2012 Pearson Education, Inc.