skeletal system. a little history first… this is a baculum. – what is it? 2
TRANSCRIPT
Skeletal System
A little history first…
• This is a Baculum.– What is it?
2
To explain, let us go back…
• Roman law: “No cutting up humans Yo!!!” – What animals have
skeletons?– Used nonhumans
instead.
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Then comes this guy
Andries Van Wesel (1514)•Aka: Andreas Vesalius•“De humani corporis fabrica”
– (On the fabric of the human body)
Proved the world wrong.Osteology: study of bonesIntroduced Human Dissection.
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Back to the Baculum
• It’s a penis bone found in most Placental mammals.
• But not humans… thanks to evolution
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Lesson 8-1 Objectives
• List the functions of the skeletal system.• Describe the structure of a long bone.• Compare compact and spongy bone.• Describe how bones grow.• Describe the roles of osteoblasts and
osteoclasts.
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Skeletal System Overview
ENDOskeleton•The skeletal system is composed of
– Bones– Joints– Cartilage– Ligaments
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Functions of the Skeletal System
• Supports body weight• Supports and protects soft organs• With muscles, enables body movement• Stores important minerals, including calcium
and phosphorus• Contains bone marrow, which produces blood
cells
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Sizes and Shapes of Bones
• Long• Short• Flat• Irregular
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Two Types of Bone
• Compact or hard– Osteons– Shafts: Long bones
• Spongy or soft– Trabecular plates– Swiss cheese– Bone marrow
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Parts of Long Bone • Diaphysis• Epiphysis• Epiphyseal disc• Medullary cavity• Endosteum• Periosteum• Articular cartilage• Marrow
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Two Types of Ossification
• Intramembranous ossification– Replacement of thin connective tissue membrane
with bone– In flat bones
• Endochondral ossification– Replacement of fetal cartilage skeleton with bone– In long, irregular, and short bones
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Ossification in the Fetus
• Intramembranous ossification– In flat bones of skull
• Endochondral ossification– In all other bones
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Bones Growing Taller
• Occurs at the epiphyseal disc– Osteoblasts invade cartilage in disc.– They mature into osteocytes (bone).
• Affected by hormones– Growth hormone– Estrogen– Testosterone
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Bones Remodeling
• Osteoclastic activity is called resorption.
• Sculptor (osteoclasts) hollows bone.
• Builder (osteoblasts) deposits bone on outer surface.
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Bone FracturesBone FracturesA break in a bone
Types of bone fractures
Closed (simple) fracture – break that does not penetrate the skin
Open (compound) fracture – broken bone penetrates through the skin
Greenstick- break in one side of bone
Bone fractures are treated by reduction and immobilization
Realignment of the bone
Types of Fractures
• Simple• Compound• Greenstick
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Common Types of FracturesCommon Types of Fractures
What type is this?Greenstick Compound
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What about this
Simple
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Bone Markings: Projections (Processes)• Condyle: Large knob (form joints)• Epicondyle: Enlargement near a condyle (muscle
attachment)• Head: Enlarged, rounded end (epiphysis)• Facet: Small flattened surface (flat bone)• Crest: Ridge (muscle attachment)• Spine: Sharp projection (vertebrae, muscle
attachment) • Tuberosity: Knoblike projection (muscle
attachment)• Trochanter: Large tuberosity only on femur
Bone Markings: Depressions and Openings
• Foramen: Opening, usually passage for nerves, blood vessels, ligaments
• Fossa: Groove (joints)• Meatus: Tunnel or tubelike passageway• Sinus: Cavity or hollow space within bone
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Lesson 8-2 Objectives
• List the bones of the axial skeleton.• List the bones of the appendicular skeleton.• Label important landmarks for selected bones
on the skeleton.
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Types of Bones
• Axial skeleton– 80 bones of the head and trunk
• Appendicular skeleton – 126 bones of the pelvis, shoulders,
arms, and legs
Bones of the Axial Skeleton
• Skull: Cranium, facial, middle ear bones
• Hyoid• Vertebral column• Thoracic cage: Ribs,
sternum, thoracic vertebrae
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Bones of the Skull• Cranial
– Held together by sutures
– Little movement
• Facial– Mandible contains
only movable joint
• Middle ear bones
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Special Markings • Temporal bone
– External auditory meatus
– Zygomatic process– Styloid process – Mastoid process
• Occipital bone– Foramen magnum– Occipital condyles
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The SkullThe Skull
Bones of the SkullBones of the Skull
Human Skull, Inferior ViewHuman Skull, Inferior View
Paranasal Sinuses
• Frontal• Ethmoidal• Sphenoidal• Maxillary
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Paranasal SinusesParanasal Sinuses
Hollow portions of bones surrounding the nasal cavity
Figure 5.10
Paranasal SinusesParanasal Sinuses Functions of paranasal sinuses
Lighten the skull
Give resonance and amplification to voice
The Hyoid BoneThe Hyoid Bone The only bone that
does not articulate with another bone
Serves as a moveable base for the tongue
Figure 5.12
Fetal Skull and Fontanels• Fontanels are
soft spots– Not yet
converted to bone
– Covered with fibrous tissue
– Allow for cranial growth
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Vertebral Column• Sections
– Cervical (C1-C7)– Thoracic (T1-T12)– Lumbar (L1-L5)– Sacrum and coccyx
• Curves– Cervical– Thoracic– Lumbar– Sacral
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Vertebrae • Atlas (C1): Nods “yes”• Axis (C2): Rotates
“no”• Other vertebral parts
– Vertebral foramen– Body– Lamina– Spinous process– Padded by
intervertebral discs
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Cervical Vertebrae
Disorders of the Vertebral Column
• Scoliosis: Lateral curve
• Kyphosis: Hunchback
• Lordosis: Swayback
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Thoracic Cage• Sternum
– Manubrium (Upper part)– Body– Xiphoid process (lower part)
• Ribs (12 pairs)– Seven pairs of true ribs– 3 pairs of false ribs– 2 pairs of floating ribs
• Thoracic vertebrae
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Sternum
True Ribs (7)
False Ribs (3)
Floating Ribs (2)
Sternum
True Ribs (7)
False Ribs (3)
Floating Ribs (2)
The Thoracic CageThe Thoracic Cage
Sacrum & CoccyxSacrum & Coccyx
Bones of the Appendicular Skeleton
• Pectoral girdle
• Upper limbs• Pelvic girdle
–Coxal bones• Lower limbs
Pectoral Girdle and Upper Limb• Pectoral girdle
– Clavicle (collarbone)– Scapula (shoulder
blade/wing bone)
• Upper limb– Humerus – Radius and ulna – Carpals – Metacarpals – Phalanges
Important Landmarks of Upper Limbs
• Acromion: tip of shoulder(scapula), articulates with clavicle
• Olecranon process: elbow• Glenoid Cavity: Arm socket/shoulder socket
– Where humerus fits into shoulder joint
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Pelvic Girdle: Coxal Bones• Functions
– Weight bearing– Attachment for lower
limbs– Protection of organs
• Coxal bone – Ilium– Ischium– Pubis
• Acetabulum (hip socket)
• Symphysis pubis
Lower Limb• Thigh
– Femur ( with trochanters)
• Leg bones– Patella– Tibia (with medial
malleolus)– Fibula (with lateral
malleolus)
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Lower Limb: Ankle and Foot
• Foot bones– Tarsals – Metatarsals – Phalanges
• Arches– Form instep
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Lesson 8-3 Objectives
• List the main types and functions of joints.• Describe the types of joint movement.
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Types of Joints
Articulation: point of contact between bones
–Synarthroses: Immovable–Amphiarthroses: Slightly movable–Diarthroses: Freely movable
Types of Synarthroses
• Sutures: found in skull
• Gomphoses: between root of tooth and process in mandible/maxilla (GUMphoses)
• Syndesmoses: ligaments connecting 2 bones
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Amphiarthroses
Cartilaginous joints: joined by hyaline cartilage or fibrocartilage
–Synchondroses: between articulating bones (sternum to ribs)
–Symphyses- pad or disk of cartilage between 2 bones (between vertebrae)
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Diarthroses• Synovial joints: Freely moving joints
–Lots of moving parts• Joint Capsule: casing around ends of
bones that binds them together• Synovial Membrane: lines joint capsule
and secretes synovial fluid• Articular cartilage: cartilage covering
articular surfaces of bone
Parts continued…• Joint cavity: space between two bones
• Menisci (Articular disks): pads of fibrocartilage between articulating bones
• Ligaments: strong cords that hold bones of synovial joint
• Bursae: synovial membrane filled with synovial fluid, cushions joints
Structure of Freely Movable Joints
• Articular cartilage• Joint capsule• Synovial membrane• Synovial fluid• Cartilage• Some joints also have
– Bursae– Ligaments
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Types of Freely Movable Joints• Hinge: Elbows, knees• Ball-and-socket:
Shoulders, hips• Pivot: Atlas-axis joint• Saddle: Carpometacarpal• Gliding: Wrist• Condyloid: Knuckles
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Joint Names: Articulating Bones• Tibiofemoral
– Tibia and femur• Humeroulnar
– Humerus and ulna• Metacarpophalangeal
– Metacarpal bone and phalange
• Glenohumeral– Glenoid cavity and
humerus
Types of Joint Movement• Flexion-extension• Inversion-eversion• Supination-pronation• Abduction-adduction• Dorsiflexion-plantar
flexion• Hyperextension• Circumduction