Includes bones, cartilage, and joints The SKELETAL System Includes bones, cartilage, and joints

Functions of the Skeletal System Support Protection Movement Facilitation Mineral Storage and Homeostasis Storage of energy Hematopoiesis

Types of Bone Cells Osteogenic Cells = bone stem cells Osteoblasts = deposit Ca+ & P & collagen fibers--bone builders Osteocytes = mature bone cells-maintain tissue Osteoclasts = break down bone tissue

Osteoblasts and Osteoclasts

Bone Growth aka Ossification The process by which bones form in the body (Osteogenesis) Replacement of pre-existing connective tissue with bone

Intramembranous Ossification Membranes ----> Bone Periosteum - Width-wise Growth Examples: skull bones, mandible, clavicle

Endochondral Ossification Cartilage ----> Bone Epiphyseal (growth) Plate – Length-wise growth Examples: most of skeleton

Bone Structure Periosteum – outside membrane --Fibrous Layer-protection --Osteogenic Layer-stem cells Diaphysis = shaft of a long bone Epiphysis = ends of long bones

Bone Structure Medullary Cavity or Canal Yellow Marrow-in cavity--fat storage Red marrow--blood cell forming tissue Endosteum-lines medullary canal Articular (joint) Cartilage - Hyaline Cartilage

Compact Bone Structure (densely packed – strength) Dense & organized Lamellae: layers of bone Circular or interstitial Osteons (Haversian canals)--contains vertical canals - blood vessels and circular lamellae with lacunae

Compact bone structure Perforating or Volkman’s Canals - horizontal canals with blood vessels Lacunae: spaces that hold osteocytes Canaliculi: minute canals where osteocytes stretch out FYI: connect to other lacunae and eventually with central or perforating canals Gives bone strength

Spongy bone (loosely packed-reduces weight AKA -Trabecular Bone Irregular network Thin plates of bone with lots of intercellular space Spaces filled with Red Bone Marrow Responsible for Hematopoiesis

Types of Bones Long Bones: Longer than wide, have a shaft, slightly curved –spongy bone on ends. Examples: humerus, ulna, tibia, metacarpals, phalanges Short Bones: cube shaped, near equal in length and width, spongy bone on inside. Examples: carpals and tarsals Flat Bones: thin and flat, compact bone outside & spongy bone inside, provide protection. Examples: cranial bones, ribs, sternum, scapula

Types of Bones (cont.) Irregular – odd shaped Vertebrae Sesmoid – encased in tendon Patella Ball of foot

Bone Markings Foramen= a hole for blood vessels, nerves, or ligaments

Bone Markings Meatus= canal or passageway through bone

Sinuses Sinus= cavity or space in a bone, lightens the skull Frontal - forehead Sphenoid - back of nose Ethmoid – sides of nose Maxillary – upper jaw

Fossa A fairly deep pit or depression Examples include the olecranon fossa of the humerus and the mandibular fossa of the temporal bone

Bone Markings Process = any projection from the surface of a bone. Example: spinous processes Condyle = “Knuckle” - a large rounded prominence on a bone. Found on femur

Bone Markings cont Trochanter = a large blunt process found only on the femur Tubercle = a small rounded process

Bone Markings cont Tuberosity = an elevated, rounded, usually roughened area of a bone Facet = a smooth articular surface

Bone Markings Head= proximal end of bone, rounded projection

Medial and Lateral Malleolus Medial malleolus on the tibia Lateral malleolus on the fibula Make the ankle bones

Sutures Immovable joints Sagittal: separates parietal bones Coronal: separates frontal from parietal Lambdoid: separates occipital from parietal Squamous: separates temporal from parietal

Fontanels Provide room for rapid brain growth Make childbirth easier Move during childbirth Used for access to blood sampling and IV’s

Axial vs. Appendicular Axis of the body Three regions Appendages Skull Vertebral column Bony thorax Appendages Connected to trunk Shoulder girdle Pelvic girdle Upper limbs Lower limbs

Axial Skeleton Axis of the body--through the midline Three regions Skull Vertebral column Bony thorax

Skull Cranial Bones: six external bones and two internal bones Facial Bones: 14 Facial bones

Major Skull Bones Cranial Frontal Parietal Occipital Sphenoid Ethmoid Temporal (Mastoid Process) Facial Zygomatic Mandible Nasal Maxilla

Frontal Bone Forms the forehead Forms the roof of the eye sockets

Parietal bone Consists of two bones Forms the sides and roof of the cranial cavity

Occipital Bone The base of the cranial cavity Prominent posterior portion –occipital protuberance

Sphenoid Temple bone Makes up part of cranial floor Makes up part of orbit Looks like butterfly/bat

Ethmoid Separates the nasal cavity from the brain Roof of the nose, between the two orbits Helps to make up the orbit of the eye

Temporal Bones Consists of two bones Forms the lower sides of the Mastoid process Consists of two bones Forms the lower sides of the cranium and part of the cranial floor

Zygomatic Cheek bones

Nasal Bridge of the nose

Mandible The Lower Jaw

Maxilla The Upper Jaw

Vertebral Column Vertebrae can be identified by three criteria: 1. Shape and angle of the spinous process 2. Size of the vertebral body 3. Presence or absence of transverse foramen

Vertebral Column Divided into five regions Cervical - neck Thoracic - chest Lumbar – low back Sacrum - hips Coccyx - tailbone

Intervertebral Disks Made of fibrocartilage Provide cushioning and shock absorption for vertebrae

Hyoid Bone Does not articulate with any other bones Tongue muscles attach here Aids in swallowing

Bony Thorax Sternum--Manubrium, body, and xiphoid process 12 pair of ribs 7 pair of true ribs 3 pair of false ribs 2 pair of floating ribs

Appendicular Skeleton Attached to Axial Pectoral Girdle Pelvic Girdle Upper and Lower Extremities

The Pectoral Girdle Attaches the bones of the upper extremities to the axial skeleton Clavicle & scapula

Upper extremities Humerus – upper arm Radius – thumb side forearm bone Ulna – pinky side forearm bone Carpals – wrist Metacarpals – hand Phalanges - fingers

The Pelvic Girdle (Hip girdle) Attaches the bones of the lower extremities to the axial skeleton Pelvic or coxal bone

Female Vs. Male Pelvis Light and thin Wide ilium Pubic arch greater than 90o Wide sciatic notch Pelvic outlet wide Coccyx more moveable Heavy and thick Narrow ilium Pubic arch less than 90o Narrow sciatic notch Narrow pelvic outlet Coccyx less moveable and less curved

Lower Extremities Os coxa- pelvis Femur – thigh Patella – kneecap Ilium Ischium Pubis Femur – thigh Patella – kneecap Tibia – shin Fibula – outer lower leg Tarsals - ankle Metatarsals - foot Phalanges - toes

Names for thumb and big toe Thumb: Pollex Big toe: Hallux

JOINTS

Fibrous Joints Immovable Thin layer of fibrous connective tissue Sutures (skull) Gomphosis (teeth)

Cartilaginous Joints Bones connected by cartilage Slightly moveable Pubic Symphysis Intervertebral joints

Synovial Joints Contain synovial cavity Ligaments Freely moveable Several different kinds based on degree of motion

Types of Synovial Joints Saddle / Ball and Socket Gliding /Hinge Pivot / Condyloid

Supporting structures in synovial joints Bursa: small sack filled with synovial fluid Meniscus: Pad of cartilage in the knee joint Ligaments: connect bone to bone

Diseases and Disorders of the Skeletal System

Herniated Discs(Slipped Discs) rupture of fibrocartilage discs caused by compression forces occurs between L4 & L5 or L5 & 1st Sacral Vertebrae disc protrudes and exerts pressure on spinal nerves

Osteoarthritis Degenerative joint disease associated with aging Characteristics: degeneration of articular cartilage development of bone spurs usually effects large joints (knees, hips, etc)

Osteoporosis Decrease in bone mass Increase in susceptibility to fractures

Abnormal Curvatures of the Spine Scoliosis = lateral curvature of the spine

Abnormal Curvatures of the Spine Kyphosis = hunchback/humpback exaggeration of thoracic curvature 65

Abnormal Curvatures of the Spine Lordosis = swayback exaggeration of lumbar curvature 67

Spina Bifida congenital defect usually involves the lumbar vertebrae Symptoms mild to severe can be diagnosed during pregnancy by sonography, amniocentesis, blood tests

INFANTS WITH SPINA BIFIDA

Classification of Bone Fractures Closed (Simple) Fracture = bone does not break through skin Open (Compound) Fracture = bone ends break through skin Partial (Incomplete) Fracture = break does not completely transect bone (Greenstick Fracture) Complete Fracture = break transects bone & divides into two or more pieces

Bone Fractures Closed Reduction = re-alignment without surgical intervention Open Reduction = re-alignment by surgical procedures 71

COMMON BONE FRACTURES

FYI: Classification of Bone Fractures Pott’s Fracture = fracture distal end of Fibula Colles’ Fracture = fracture of distal end of radius Stress Fracture = fracture due repeated stress usually caused by: training habits(Volume-Intensity-Duration) change in training surface 25% involve distal third of fibula

Sprains Forcible wrenching or twisting of a joint 1st Degree Sprain = stretching of ligaments 2nd Degree Sprain = partial tearing of ligaments 3rd Degree Sprain = complete tear of ligaments

THE END