Skeletal System

Functions of the Skeletal System Support/protection Movement: acts as a series of levers Hemopoiesis: production of blood cells Storage of minerals: Calcium and phosphorous

Minerals Lab

Tissues Connective tissues Bone Cartilage Ligaments Solid network of living cells and protein fibers (collagen and elastin) surrounded by deposits of Calcium salts

Compact Bone Osteon Lamelae Lacuna Osteocyte Central canal Perforating canal Canaliculi

Spongy Bone Composed of osteocytes and intercellular material Not aggregated around a central canal

Classify Your Bones Use sticky notes to classify the bones at your lab station into 4 groups. Explain to the class how your group classified the bones.

Classifications of Bone Long bones - have a distinct axis (longer than wide) Vary greatly in size Most common type of bone in the body Examples Short bones - length and width are about equal Exterior of compact bone and interior of spongy bone Flat bones - flat, thin surface Parallel surfaces of compact and spongy bone Surface for muscle attachment or protection Irregular bones - irregular shapes Junk drawer

Reclassify your bones!

Did you have any problems? Not suprising – texts vary on classifications of bones

Anatomy of Long Bones Diaphysis: shaft Epiphysis: ends Metaphysis Mature part between diaphysis and epiphysis Contains epiphyseal line Epiphyseal line Remnant of the epiphyseal plate (growth plate)

Anatomy of Long Bones (Con’t) Articular cartilage Hyaline cartilage at the ends of the bone Reduces friction and absorbs shock Medullary cavity Cylindrical space through the bone Contains yellow marrow

Anatomy of Long Bones (Con’t) Endosteum Internal surface of bone Active during bone growth and remodeling Periosteum Tough sheath covering outer surface of bone Dense connective tissue

Ossification: Bone Development Intramembranous ossification Formed from layers of connective tissue membranes Osteoblasts deposit calcium matrix around themselves Osteocyte: completely surrounded osteoblast Ex: flat bones of the skull

Ossification: bone development Endochondral ossification Forms from a hyaline cartilage model Cartilage begins to calcify Periosteum develops Growth continues in the primary and secondary ossification centers

Primary Ossification Center Cartilage inside starts to disintegrate Osteoblasts enter and develop spongy bone Osteoclasts break down the center creating the medullary cavity Secondary Ossification Center Similar to POC, in the metaphysis Center is not broken down and cartilage continues to grow, increasing length

Homeostasis

Levers Bones work as levers Rod or arm Fulcrum: pivot point Resistance: works against the lever Force: works to move the lever

Lever Lab

Hematopoiesis

ANATOMY

Skeletal Organization Axial skeleton Central axis of body- skull, vertebral column, ribs Appendicular skeleton Arms, legs, pelvic girdle, pectoral girdle

Bones of the Skull Cranium: forms the bowl that houses the brain Frontal Parietal (2) Occipital Temporal (2) Sphenoid Ethmoid

Bones of the Skull Facial Bones Maxillae Palatine Zygomatic Lacrimal Nasal Vomer Inferior nasal conchae Mandible

Vertebral Column Vertebrae separated by vertebral discs (fibrocartilage pads) Vertebral canal: formed by several vertebra; houses the spinal cord

Vertebrae Cervical Vertebrae Thoracic Vertebrae Lumbar Vertebrae C1: Atlas Rotates on the axis C2: Axis Dens: upward projection the atlas rests on C3-C7 Thoracic Vertebrae T1-T12 Lumbar Vertebrae L1-L5

Sacrum and Coccyx Sacrum 5 fused vertebrae Coccyx 4 fused vertebrae

Curvatures Cervical Thoracic Lumbar Pelvic

Vertebrae Body Pedicles Laminae Vertebral arch Spinous process Transverse process Vertebral foramen Articulating process or facet (superior/inferior)

Sort Your Vertebrae! Get in groups of 5-6 at lab stations 1-5 Identify the 3 vertebrae as cervical, thoracic, or lumbar Sketch the 3 vertebrae in your notes and label on each: Body Pedicles Laminae Vertebral Arch Spinous Process Transverse Process Vertebral Foramen

Thoracic Cage Ribs Thoracic vertebrae Sternum Costal cartilage Protects and expands when breathing

Ribs 12 pairs (1 pair attached to each of the 12 thoracic vertebrae) True ribs (7) attach directly to sternum at the costal cartilage False ribs (5) attach to costal cartilage attached to 7th true rib Floating ribs (2-3) not attached to costal cartilage at all

Sternum Midsagittal/anterior portion of the thoracic cage Manubrium (attaches to 1st rib) Body (attaches to remaining ribs) Xiphoid process

Pectoral Girdle and Upper Limb Clavicle Scapula Humerus Radius Ulna

Pectoral Girdle and Upper Limb Carpals Scaphoid Capitate Trapezoid Trapezium Lunate Hamate Triquetrum Pisiform Metacarpals Phalanges Proximal Middle Distal

Pelvic Girdle and Lower Limb Sacrum and Coccyx Pelvis Ilium Ischium Pubis

Femur Patella Tibia Fibula

Pelvic Girdle and Lower Limb Tarsals Talus Calcaneus Navicular Cuboid Lateral cuneiform Intermediate cuneiform Medial cuneiform Metatarsals Phalanges Proximal Middle Distal

Articulations Stability vs. mobility Inversely related FLEXIBILITY

Types of Articulations Fibrous Joints Connected by dense connective tissue Little to no movement Sutures: completely immovable fibrous joint Examples: sutures of the skull; distal ends of the tibia and fibula Fontanels: incompletely ossified joints; allows for birth and brain growth

Types of Articulations (con’t) Cartilaginous Joints Connected by hyaline cartilage Very little movement Examples: intervertebral discs; symphasis pubis; first rib and sternum

Types of Articulations (con’t) Synovial Joints Majority of joints Free movement Complex anatomy

Anatomy of a Synovial Joint Articular cartilage: hyaline cartilage Joint capsule: dense connective tissue Synovial membrane Joint cavity Synovial fluid

Types of Synovial Joints Ball and socket Ball shaped head and cup shaped cavity Movement on all planes; rotation Ex: shoulder; hip

(synovial joints) Condyloid Oval shaped condyle and elliptical cavity Movement on different planes; no rotation Between metacarpals and phalanges

(synovial joints) Gliding Nearly flat/slightly curved surfaces Sliding or twisting Ex: Between the bones of the wrist and ankle, sacroiliac joints, joints between ribs

(synovial joints) Hinge Convex surface and concave surface Flexion and extension Ex: elbow; phalanges

(synovial joints) Pivot Cylindrical and ring-shaped surface Rotation around a central axis Ex: Between proximal ends of ulna and radius

(synovial joints) Saddle Both surfaces has both convex and concave regions fitting complementary ends Variety of movement Ex: between the carpal and metacarpal of the thumb

Begin Planning Anatomy Dance Types of Movement P. 167,169 Flexion – Depression (17)