Post on 16-Dec-2015
Objectives
• Identify and describe the five functions of the skeletal system
• Distinguish between long bones, short bones, flat bones, and irregular bones; provide examples of each
• Identify parts of a typical long bone
Skeletal System
• Bones are made of several tissues
• About 206 bones in the human body
Functions of Skeletal System
• SUPPORT: Hard framework that supports and anchors the soft organs of the body.
• PROTECTION: Surrounds organs such as the brain and spinal cord.
• MOVEMENT: Allows for muscle attachment therefore the bones are used as levers.
• STORAGE: Minerals and lipids are stored within bone material.
• BLOOD CELL FORMATION: The bone marrow is responsible for blood cell production.
Parts of the Skeletal System
• Axial skeleton– Skull and bones that support it– Includes vertebra and ribs– 80 bones
• Appendicular skeleton– Limbs– 126 bones
Parts of the Skeletal System
• 206 bones• 4 TYPES BONE
– Long bones– Short bones– Flat bones– Irregular bones
• 2 TYPES BONE TISSUE– Compact– Cancellous (spongy)
Classification of Bones: By Shape
• Long bones – longer than they are wide (e.g., humerus)
• Designed to absorb stress
Classification of Bones: By Shape
• Short bones– Cube-shaped bones
of the wrist and ankle
– Equal in length and width
Classification of Bones: By Shape
• Flat bones – thin, flattened, and a bit curved (e.g., sternum, ribs, and most skull bones)
Classification of Bones: By Shape
• Irregular bones – bones with complicated shapes (e.g., vertebrae, face bones, hip bones)
Features of a Long Bone:
Epiphysis: Ends of the bone.
Diaphysis: The shaft of the bone which surrounds the medullary cavity.
Articular Cartilage: Cushions the ends of the bones and allows for smooth movement.
Epiphyseal Plate:Areas made of cartilage allowing for the growth of the bone.
Objectives
• Describe the inorganic and organic components of bone tissue
• Distinguish between the 3 types of bone cells on the basis of their functions
• Understand the role of calcium and phosphorus for bone growth
• List the axial skeleton components• Identify the 8 cranium bones and the
13 facial bones
Bone Composition
• Bone tissue( 10), cartilage, dense connective tissue, blood-forming tissue, BVs, nerves
• Bone tissue– Inorganic materials (salts form crystals –hydroxyapatite)• Crystals 2/3 total bone weight• Provide hardness
– Organic materials (collagen)• Reinforce/strengthen matrix
Types of Bone Cells - 3
• Osteoblasts– Arise from embryonic cells– Produce matrix ( mineral salts and collagen)– Contributes to new bone
• Osteocytes– Mature bone cells– Move nutrients/waste through bone matrix
Types of Bone Cells cont.
• Osteoclasts– ‘Wandering’ bone cells– Secrete substance that dissolves bone matrix
back into original components: calcium, phosphorus work their way into circulatory system
– Activity controlled by hormones hence osteoporosis is linked to hormonal changes
Types of Bone Cells cont.
• Osteoblasts giveth.Osteoclasts taketh away.Osteocytes maintaineth.
• Work together to not only build new bone but to strengthen existing bone– Cracks, fractures
Types of Bone Cells cont.
– Osteoporosis: rate of bone loss exceeds bone regrowth• Osteoclasts reasborbing more bone tissue
than osteoblasts are replacing
Bone Growth and Minerals
Calcium• Most common mineral
found in body• Contributes to bone
strength• A component in
hydroxyapatite• Phosphorus
codependency• 206 bones contain 3
lbs of calcium
Phosphorus• Second most common
mineral found in body• Other major
component in hydroxyapatite
• Bones/teeth store 85% of body’s total
• Calcium codependency
The Axial Skeleton
• Made up of bones that roughly form the body’s “head to toe” vertical axis– Skull– Vertebral column (backbone)– Ribs– Sternum (breastbone)
The Skull: Protection for the Brain
• Set of bones of the head region– Bones of cranium
• 8 bones– Frontal bone, Parietal bones(2), occipital bone,
temporal bones(2), sphenoid bone, ethomoid bone
– Facial bones• 13 immovable bones
– Maxillary bones (2), palatine bones (2), zygomatic bones (2), nasal bones (2), lacrimal bones (2), vomer bone, inferior nasal conchae
• 1 movable lower jaw– Mandible
Bones of the Skull
Human Skull, Superior ViewHuman Skull, Superior View
Slide 5.23Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 5.8
The Skull
Skull – Inferior View
Objectives
• Name and identify the regions of the vertebral column and give the number of vertebrae in each segment
• Distinguish between three types of ribs• Name and identify the components of the
pectoral girdle and pelvic girdle• List the primary subdivisions of the
appendicular skeleton
Objectives
• Compare and contrast pectoral girdle and pelvic girdle– Structure– Purpose– Male vs. female
• Identify the components of the lower limbs and upper limbs
• Compare and contrast bones of the arm and forearm with the bones of the thigh and leg
Vertebral Column
• Vertebrae separated by intervertebral discs
• Spine has normal curvature• Each vertebrae is given a name
according to location
Vertebral Column
• 7 Cervical vertebrae• 12 thoracic• 5 lumbar• 1 sacrum (5 fused)• 1 coccyx (4 fused)
Structure of a Typical Vertebrae
Ribs, Sternum and Thoracic Vertebrae
• Ribs– True ribs (1st seven pairs)– False ribs – Floating ribs
• Sternum• Thoracic Vertebrae• Coastal cartilage
Ribs, Sternum and Thoracic Vertebrae
Appendicular Skeleton
• Pectoral girdle• Limbs (appendages)• Pelvic girdle
Appendicular Skeleton
The Pectoral (Shoulder) Girdle
• Composed of two bones– Clavicle (collarbone)– Scapula (shoulder blade)
• These bones allow the upper limbs to have exceptionally free movement
Bones of the Shoulder Girdle
Bones of the Upper Limb
• The arm is formed by a single bone– Humerus
Bones of the Upper Limb
• The forearm has two bones– Ulna– Radius
Bones of the Upper Limb
• The hand– Carpals
• Wrist
– Metacarpals• Palms
– Phalanges• Fingers
Bones of the Pelvic Girdle
• Hip bones• Composed of three pair of fused bones
– Ilium– Ischium– Pubic bone
• Total weight of upper body rests on pelvis
• Protects reprod. organs, urinary bladder, part of large intestine
The Pelvis
Gender Differences of the Pelvis
Bones of the Lower Limbs
• The thigh has one bone– Femur
• Thigh
Bones of the Lower Limbs
• The leg has two bones– Tibia– Fibula
Bones of the Lower Limbs
• Foot– Talsus
• Ankle
– Metatarsals• Sole
– Phalanges• Toes
• Intro to Skeleton
Objectives
• Define joint and the two classifications of joints • Distinguish between functional classification and
structural classification of joints• Identify where in the body the 3 types of
functional joints are located• Define the 6 types of synovial joints,
distinguishing between each in terms of plane movement and example locations
Joints
• Region where two or more bones (or parts of bone) unify articulation
• Functions– Holds bone together– Allow for mobility
• Classified by– Function – how much movement permitted– Structure – diff type of material/mechanism
by which bone surfaces interact
Functional Classification of Joints
• 3 Types1. Synarthrosis
– Immovable joints– Ex: Joints between skull bones, tooth in
socket
2. Amphiarthrosis– Slightly movable joints– Ex: Joints between tibia and fibula,
discs between vertebrae
Functional Classification of Joints
3. Diarthrosis– Freely movable joints– Ex: Hip joint, elbow
Structural Classification of Joints
• 3 Types1. Fibrous joints
– United by fibrous tissue– Generally immovable (synarthrosis)
2. Cartilaginous joints– United by cartilage– Immovable or slightly movable
(amphiarthrosis)
Structural Classification of Joints
3. Synovial joints– Contains joint cavity which contains
fluid allowing bones to slide over one another without grinding
– Freely movable (diarthrosis)
Synovial Joints
• Classified further according to shape of articular surfaces or movement – Plane joints– Hinge joints– Saddle joints– Condyloid joints– Ball and socket joints– Pivot joints
Synovial Joints: Range of Motion
• Nonaxial – slipping/gliding movement only
• Uniaxial – movement in one plane• Biaxial – movement in two planes• Multiaxial – movement in or around
all three planes
Synovial Joints
• Plane Joints – gliding and sliding movement due to the flat articular surface; allow movement in a single plane (nonaxial)– Ex: shoulder blade and collar bone
• Hinge Joints – Allow movement in a single plane (uniaxial)– Ex: Elbow
Synovial Joints
• Saddle Joints– Shaped like a saddle. Permit movement in two separate
planes (biaxial)– Back and forth movement, side – to –side, and some
pivotal– Ex: Thumb joint
• Condyloid(Ellipsoid) Joints– Back and forth movement,
circular movement– Joints are biaxial.– Ex: Knuckle
Synovial Joints
• Ball and socket Joints– Consist of spherical head articulating with a
dome shaped cup. Allows for movement on multiple planes. (Multiaxial)
– Ex: Hip joint
• Pivot Joints– Allow rotation on one plane. (Uniaxial)– Movement limited to rotation about a
central axis– Ex: Joint between 1st and 2nd vertebrae
Objectives
• Distinguish between gliding, angular, rotation and misc. categories of movement
• Define each of the above• Provide body examples of each misc.
category movement
Movements• Gliding• Angular
– Flexion/Extension– Abduction/Adduction– Circumduction
• Rotation– Medial/Lateral
• Misc– Elevation/depression– Protraction/retraction– Inversion/Eversion– Pronation/Supination– Dorsiflexion/Plantar flexion
Gliding
• Linear motion• One plane of motion• 2 opposing surfaces pass one
another• Ex:
– Clavicle and sternum
Angular
• Changes in longitudinal position of bone
• Flexion/Extension/Hyperextension– Flexion: decrease in angle btw bones– Extension: increase in angle btw bones– Hyperextension: extension beyond the
standard anatomical position
Angular continued
• Abduction/Adduction/Circumduction– Abduction: movement away from
midline– Adduction: movement toward the
midline– Circumduction: combination
Rotation
• Spin along a longitudinal axis • Medial
– Rotation towards the midline
• Lateral– Rotation away from the midline
Misc.
• Elevation/Depression– Superior & inferior bone movement– Ex: Scapula, mandible
• Protraction/Retraction– Anterior & Posterior bone movement– Ex: Mandible
Misc. cont.
• Inversion– Inward movement of functional surface;
toward midline of the body– Ex: Sole of foot
• Eversion– Outward movement of functional
surface; away from midline of the body– Ex: Sole of foot
• Inversion/Eversion
Misc. cont.
• Pronation– Eversion of the foot, medial rotation of
forearm( toward midline)
• Supination– Inversion of the foot, lateral rotation of
forearm
• Video
Misc. cont.
• Dorsiflexion– Movement of the foot upward
• Plantar flexion– Movement of the foot downward