Download The Human Body in Health and Illness

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.
3
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 bones
Introduced Human Dissection.
4
Back to the Baculum
• It’s a penis bone found
in most Placental
mammals.
• But not humans…
thanks to evolution
5
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.
Copyright © 2011, 2007 by Saunders,
an imprint of Elsevier Inc. All rights
reserved.
6
Skeletal System Overview
ENDOskeleton
• The skeletal system
is composed of
– Bones
– Joints
– Cartilage
– Ligaments
7
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
Copyright © 2011, 2007 by Saunders,
an imprint of Elsevier Inc. All rights
reserved.
8
Sizes and Shapes of Bones
•
•
•
•
Copyright © 2011, 2007 by Saunders,
an imprint of Elsevier Inc. All rights
reserved.
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
12
Ossification in the Fetus
• Intramembranous
ossification
– In flat bones of skull
• Endochondral
ossification
– In all other bones
Copyright © 2011, 2007 by Saunders,
an imprint of Elsevier Inc. All rights
reserved.
13
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
Copyright © 2011, 2007 by Saunders,
an imprint of Elsevier Inc. All rights
reserved.
15
Bones Remodeling
• Osteoclastic activity is
called resorption.
• Sculptor (osteoclasts)
hollows bone.
• Builder (osteoblasts)
deposits bone on outer
surface.
16
Bone Fractures
A 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
Copyright © 2011, 2007 by Saunders,
an imprint of Elsevier Inc. All rights
reserved.
18
Common Types of Fractures
What type is this?
Greenstick
Compound
20
What about this
Simple
21
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.
Copyright © 2011, 2007 by Saunders,
an imprint of Elsevier Inc. All rights
reserved.
26
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
Copyright © 2011, 2007 by Saunders,
an imprint of Elsevier Inc. All rights
reserved.
31
The Skull
Bones of the Skull
Human Skull, Inferior View
Paranasal Sinuses
• Frontal
• Ethmoidal
• Sphenoidal
• Maxillary
35
Paranasal Sinuses
 Hollow portions of bones surrounding
the nasal cavity
Figure 5.10
Paranasal Sinuses
 Functions of paranasal sinuses
 Lighten the skull
 Give resonance and amplification to voice
The 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
39
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
43
Cervical Vertebrae
Disorders of the Vertebral Column
• Scoliosis:
Lateral curve
• Kyphosis:
Hunchback
• Lordosis:
Swayback
47
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
49
The Thoracic Cage
Sternum
True Ribs (7)
False Ribs (3)
Floating Ribs (2)
Sacrum & 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)
56
Lower Limb: Ankle and Foot
• Foot bones
– Tarsals
– Metatarsals
– Phalanges
• Arches
– Form instep
Copyright © 2011, 2007 by Saunders,
an imprint of Elsevier Inc. All rights
reserved.
57
Lesson 8-3 Objectives
• List the main types and functions of joints.
• Describe the types of joint movement.
Copyright © 2011, 2007 by Saunders,
an imprint of Elsevier Inc. All rights
reserved.
58
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
•
•
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•
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Articular cartilage
Joint capsule
Synovial membrane
Synovial fluid
Cartilage
Some joints also have
– Bursae
– Ligaments
67
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