Skeletal System &Articulations. What Is Osteoporosis? Loss of bone density.Loss of bone density....
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Transcript of Skeletal System &Articulations. What Is Osteoporosis? Loss of bone density.Loss of bone density....
Skeletal System
&Articulations
What Is Osteoporosis?
• Loss of bone density.– Due to low hormone levels.
– Occurs prematurely due to extreme weight loss.
– Results in low estrogen levels.
TortoraPages: 113
What Is Osteology?
• Study of bone structure & treatment of bone disorders.
TortoraPages: 114
Dancing Skeleton
Functions of the Skeletal
System• Support• Protection• Assisting in movement
• Mineral homeostasis
• Production of blood
• Triglyceride storage
TortoraPages: 114
Types of Bones
• Long bones– Longer than wide
– Slightly curved
– Compact and spongy bone
– Ex - Radius, ulna, femur.
TortoraPages: 114
Types of Bones
• Flat bones– Thin– Composed of two plates compact bone.
– Spongy bone in between.
• Ex: cranium, ribs, scapula.
TortoraPages: 114
Types of Bones
• Short bones– Cubed shaped– Mostly spongy bone.
– Surface of compact bone
• Ex: wrist (carpals) & ankles (tarsals)
TortoraPages: 114
Types of Bones
• Irregular bones– No consistant shape.
– Varies in compact and spongy bone.
• Ex: Vertebrae
TortoraPages: 114
Types of Bones
• Others• Sutural bones
– Small bones found in joints between bones of skull.
• Sesamoid bones– Bones located in tendons.
– Vary in number.• Ex: Patellas
TortoraPages: 114
Macroscopic Structure of
Bone
• Diaphysis• Epiphysis• Metaphysis• Epiphyseal plate• Articular cartilage• Periosteum• Medullary cavity• Endosteum
TortoraPages: 115
Histology
• Consists of 4 types of connective tissue.– Cartilage– Bone– Bone marrow– periosteum
Histology
• Bone consists of:–loosely spaced cells.
–Matrix• 25% water• 50% mineral salts
• 25% collagenous fibers.
Histology• Bone contains 4 types of cells:– Osteoprogenitor
• Give rise to other cells.
– Osteoblasts• Bone forming cells.
– Osteocytes• Mature bone maintaining cells
– Osteoclasts• Bone breakdown
Pages: 98 - 100
Macroscopic Structure of
Bone
Monday 10/28Pages: 98 - 100
Articular cartilage
Microscopic Structure of
Bone
• Compact bone– Gives strength– Covers spongy bone.– Composed of osteons (Haversian systems)
Monday 10/28Pages: 98 - 100
Exhibit 6.1 Quiz
1. What two of the following minerals make the bone matrix hard?
A) Calcium B) Iron C) Zinc D) ATP E) Phosphorus
2. Which vitamin controls the activity, distribution, and coordination of osteoblasts and osteoclasts?
A) Vitamin E B) Vitamin A C) Vitamin C D) Vitamin D
3. General purpose growth hormone that causes growth in all tissues including bone.
A) HGH B) Estrogens C) Parathyroid hormone
D) Calcitonin E) Thyroxine
Exhibit 6.1 Quiz
4. Which vitamin helps maintain the bone matrix and whose deficiency leads to decrease in collagen?
A) Vitamin E B) Vitamin A C) Vitamin C D) Vitamin D
5. Which hormone promotes bone formation by inhibiting osteoclasts?
B) HGH B) Estrogens C) Parathyroid hormone
D) Calcitonin E) Thyroxine
Exhibit 6.1 Quiz
1) A,E2) B3) A4) C5) D
Macroscopic Structure of
Bone• Spongy bone
– Contains trabeculae
– Formed from collagenous fibers
– Reduces weight
– Maintains strength
TortoraPages: 98 - 100
Ossification
• Process by which bone forms.
• Starts during the 6th or 7th week of life.
TortoraPages: 102-104
Ossification
• Intramembraneous ossification:
• Starts as a membrane shaped like a bone.– Ex: skull, mandible, clavicle
TortoraPages: 102-104
Ossification
• Endochondral ossification:
• Starts with hyaline cartilage.
• Forms most bones.
• Ex: femur, tibia, humerus, etc.
TortoraPages: 102-104
Ossification• Step #1
– Cartilage model of bone develops.
– Surrounded by a perichondrium.
TortoraPages: 102-104
Ossification
• Step #2– Cartilage model
grows.– Cartilage begins
to calcify.– Cartilage cells
start to die.– Nutrient artery
grows into cartilage model.
– Osteoblasts in perichondrium start ossification
TortoraPages: 102-104
Ossification
• Step #3– Primary
ossification occurs.
– Forms collar around shaft of bone.
– Osteoblasts create new bone.
– Medullary canal created by action of osteoclasts.
TortoraPages: 102-104
Ossification
• Step #4– Secondary
ossification starts in the ends of the bone.
– Occurs about the time of birth
– Growth is outward from the center of the epiphysis towards the outside of the bone
TortoraPages: 102-104
Ossification
• Cartilage remains at ends of the bone (articular cartilage)
• Epiphyseal plate is last to ossify.
• Ends growth.• Remodeling is
only change possible afterwards.
TortoraPages: 102-104
Homeostasis
• Bone replaces itself throughout life.
• Referred to as remodeling.
TortoraPages: 104-106
Bone Surface Markings
• Depressions and openings– Foramen– Fossa
TortoraPages: 107-108
Bone Surface Markings
• Processes that form joints– Condyle
• Knuckle-like process
– Head• Rounded
projection, supported by constricted portion of bone.
– Facet• Smooth, flat
surface
TortoraPages: 104-106
Bone Surface Markings
• Processes that connect to ligaments and other connective tissue.– Tuberosity
• Large rouned area.
– Spinous process• Slender
projection– Trochanter
• Large blunt projection
– Crest• ridge
TortoraPages: 104-106
Male/female Differences
1. General Structure– Male:
Heavy/thick– Female:
Light/thin
2. Pubic Arch– Male: Less
than 90– Female:
Greater than 90
3. Obturator Foramen– Male: Round– Female: Oval
TortoraPages: 132-133
Articulations
• Gravity mandates a stiff and rigid skeleton.
• Movement requires flexibility.
• Flexibility created by articulations (joints)
TortoraPage: 156
Articulations
• Structure determines function.
• Movement is determined by– Structure of bones
forming the joint.– The flexibility of
connective tissue connecting the bones.
– Position of ligaments, tendons, and muscles.
– Hormones
TortoraPage: 157
Structural Classificati
on• Fibrous: bones
connected with fibrous connective tissue.
• EX: tibia - fibula
• Cartilaginous: Bones connected by cartilage.
• EX: Ribs - sternum• Synovial: Joint
surrounded by synovial membrane.
• EX: knee, elbow, hip.
TortoraPages: 157-160
Classification of Synovial
Joints• Gliding Joints
– Surfaces are flat
– Side to side motion
– Ex; Between carpals, tarsals.
• Hinge Joint– Convex surface -
concave surface.– Single plane
movement– EX: knee
TortoraPages: 160-163
Classification of Synovial
Joints• Pivot Joint
– Rounded or pointed with ring-like structure.
– Rotation movement– EX: atlas - axis,
radius ulna.• Condyle Joint
– Oval shaped - depression
– Side to side movement, back and forth movement.
– Radius - carpals
TortoraPages: 160-163
Classification of Synovial
Joints• Saddle Joint
– Metacarpaland carpal of thumb.
• Ball and Socket Joint– Rounded end - cup
like depression.– Movement in three
planes.– EX: Hip and
shoulder.
• Condyloid– Ex: radius and wrist
bones.
TortoraPages: 160-163
Structures of a Synovial
Joint
Saddle
• Synovial cavity• Articular
cartilage• Articular capsule
– Fibrous capsule (outer)
– Ligaments– Synovial membrane
(inner)– Synovial fluid
TortoraPages: 164-165
ATC Animati
on
ATC Surgery
Meniscus Repair Surgery
Structures of a Synovial
Joint
TortoraPages: 164-165
Saddle
• Accessory ligaments– Lie outside the
articular capsule.
• Articular discs (menisci)
• BursaeKnee Structure
MOVEMENT AT
SYNOVIAL JOINTS
Classification of Joints
• Structural classification– Fibrous– Cartilaginous– Synovial
• Functional Classification– Synarthrosis– Amphiarthrosis– Diarthrosis
TortoraPages: 157-160
Osteoarthritis
Basic Anatomical Position
• Standing erect– Toes forward– Head facing forward.
– Hands at side.– Palms facing forward.
TortoraPages 160-163
Basic Anatomical Position
TortoraPages 160-163
• Structural classification– Fibrous– Cartilaginous– Synovial
• Functional Classification– Synarthrosis– Amphiarthrosis– Diarthrosis
Categories of Movement
• Gliding– Flat bones form joint• Back and forth• Side to side
• Angular – Increase or decrease in angle of bones.
• Rotation– A bone rotates on long axis
• Special Movewment
TortoraPages 160-163
Angular Movements
• Flexion–Reducing angle of joint
–Extension • Increasing angle of joint
–Hyperextension• Beyond basic anatomical position
TortoraPages 160-163
Angular Movements
• Abduction–Movement away from midline of body.
• Adduction–Movement towards midline of body.
TortoraPages 160-163
Angular Movements
• Circumduction– Moving distal end of arm or leg in a circle.• Ex: shoulder
– hip
TortoraPages 160-163
Special Movements
• Inversion– Lifting of medial side of foot so that soles face each other.
• Eversion– Lifting of lateral side of foot so that sole faces outward.
TortoraPages 160-163
Special Movements
• Pronation– Movement of hand such that palm faces backward.
• Supination– Movement of palm such that it faces forward.
TortoraPages 160-163
Special Movements
• Dorsiflexion– Bending foot in the superior direction
Plantar FlexionBending of foot in the inferior direction
TortoraPages 160-163
Synovial Joint
Movements
TortoraPages: 160-163
• Flexion Vs Extension• Abduction Vs Adduction• Circumduction• Elevation Vs Depression• Supination Vs Pronation