Skeletal System
Period: 5
Emory Celestino

Anatomy of the long bone

Types of bones

Names of all the bones

Bone remodeling

Bone fracture repair

Joints

Movements allowed by Synovial Joints

Differences between male and female skeleton

Disorders/diseases

Limbs(Appendicular)

Axial

The Skull and Sutures

Starting from the Anterior side:
Most Superior to most Inferior :
Frontal (aka forehead): Makes up the front side of the head
Nasal (aka nose bridge) : Makes up the "bridge" of the nose
Zygomatic (aka the cheek bone): Makes up the cheekbone
Maxillary ( aka the upper mouth): Makes up the upper mouth and is connected to the nasal and zygomatic
Mandible (aka jawline): Disconnected part of the skull
Suture: Coronal

Top view:
Partial: two bones fused together by sutures
Suture: Saggitial

Posterior:
Optical: Back of the head
Suture: Labium

Side view:
Temple: The area above cheek bone.
Suture: Squamous

Legs (Proximal to Distal)
Femur: Connected to the pelvic
Tibia: Tibia is more medial than its pair
Fabia: Fabia is more lateral than the tibia (it's pair)
Talus: Sits right above the tarsals
Tarsals: Seems like little rocks
Calcaneus: The heel
Metatarsals: not the toes, more like the entry way to the toes
Phalanges: the toes

Arms (Proximal to Distal)
Humorous: Connected toe scapula
Radius: More Medial to its pair
Ulna: More lateral to its pair (the radius)
Carpals: the wrist
Metacarpals: the palm
Phalanges: Fingers

Sternum:
Superior:
Manubrial , the flat bone closes to the clavicle
Body: longest bone of the sternum
Xiphoid process: the pointy part of the sternum
Costal Hyline Cartilage is what branches and supports the ribs

Shoulders
Clavicle: the collar bone
Scapula: The shoulder blade

Ribs:
1-7 are true ribs
8-12 are false ribs

Sacrum (medial to lateral) to the pelvic
Medial Sacrum Crest: Fused vertebrae
Coccyx: Tail bone
Illum: the widest part of the pelvic
Pelvic bone: the media at times can it the " virginal bone"
Pelvic arch + Pubic Symphysis

Spine:
Superior to Inferior
Cervical: closes to head
Atlas: has a long piece to it
Axis: has no long piece, but the opening is wider
Thoracic: Starts when vertebras increase in size
Lumbar: The widest type of vertebras and its fussed to the sacrum

Female pelvic:
Male Pelvic tend to have a wider hip frame
Ischial Spine and Pelvic inlet tend to be more of a circle shape
Pubic Arch is a wider at the entry way for the pubic arch

Male pelvic:
Male Pelvic tends to have a narrower hip frame.
Ischial spine and Pelvic inlet tend to a more oval shape rather than a circle
Pubic Arch is narrower and cramped

The basic structure

  • As explored before, the closer the bone is to the area of connection the more proximal it is, however the polar opposite of this is distal.
  • Applying this to the structure of the long bone, the ends of the bone is either called proximal epiphyseal or distal epiphyseal.
    -The structure that is squished in between is the diaphysis
  • Lining the bone is called periosteum
    -The solid and hard structure of the bone is called compact bone and this bone is found in every bone.

Structures found in the diaphysis
Yellow bone marrow, compact bone, militxry cavity, endosteum
Yellow Bone Marrow is found within the mallixary cavity, at the start of life red and yellow bone marrow is found in the cavity
Malliary cavitiy is a cavity (a hole)
Endosteum is the what lines the mallixary cavity

Structure found in both ends of the epiphyseal are spongy bone, epiphyseal plate
Spongy bone is found in both ends of the bones; it is described as honeycombs filled with red merrow
Spongy bone is found below and above the epiphyseal plate.
Epiphyseal plate is squish between spongy bone and is classified as compact bone.

Ossification is the process of bone tissue formation, cartilage becomes bone

Bone Deposit and bone resorption
Occurs at surface of both periosteum and endosteum
Remodeling units: packets of adjacent osteoblast and osteoclasts coordinate remodeling process

Irregular Bones
Different shaped bones that are ridged or abstract
Examples are the pelvic and vertrae

Short Bones
Cube-like bones, ex: wrist and ankels (carpals and tarsals and the calcaneus)

Long Bones
Longer bones bigger in length rather than width, ex: limbs

Treatement is called reduction (realignment of the broken parts)
Closed reduction means to have a physcian manipulate to the correct position
Open reduction: to surgically pin the bones in place
Immobilization, to align it with a cast or traction so it can heal
However there is a process

Classification of fractures:

Rickets
Results in bowed legs and other bone deformities because bones ends are enlarged and abnormally long

osteoporosis
Is group of diseases in which bone resorption exceeds deposit
mass declines causes brittle bones

Osteomalacia
Poorly mineralized
Osteoid is produced, but calcium salts not adequately deposited
Soft bones
Pain by any pressure applied

paget's disease
A deforming disease, due to bone rapiadly or slowly depost and resorption causes for growth to be rapid but poorly

Microscopic anatomy of bones

Cartilage

Formation of bones

  1. Hyaline cartilage
    Most wider spread and has the ability to support, resist and stretch + recoil
    Found everywhere, but most abundant in the joints, costal (ribs), respiratory support, and the tip of the nose

2.Elastic Cartilage
Same and hyaline but is makes up the structure of of the ear.

3.Fibrocartilage
Thick collegen fibers that is even more resistent and is found in the posterior of the body (spine)

Appositional growth
New matrix is form on top of the existing bone

Interstitial growth
New matrix is form with in the already existing bone

Flat Bones:
As the name implies the bones are thinned but also curved
ex: Sternum

Periosteum

Endosteum

Covers the external part of the bone
Fibrous Layer: most superficial layer consists of dense irregular connective tissue consisting of fibers that sucure the bone matrix: known as sharpey's fibers
Osteogenic layer: inner layer that constains the osteogenic stem that creates most of all bone cells

Characteristics:
Lines the internal cavities of the bone
Contains osteogenic cells that can develop into other bones

Organic findings with the bone

Osteogenic Cells (shape shifter)

Red Marrow
Found in the heads of humorous and femur but areas that contian the most red bone marrow is the diploe and the pelvic area

Osteoblast (most actively dividing/filled with energy)

osteocytes ( mature/helps maintain rather than create/ grandparents)

Bone-Lining Cells (parents)

osteoclast (the destroyer)

Flat cells on bone surfaces believed to also help maintain matrix (almost always across osteocytes)

Mature bone cells in lacunae that no longer divide (stationed)
helps to maintain bone matrix, which helps protect against stress or strain

Called Osteoprogenitor Cells
Constantly dividing stem cells in the linings of the bones
When they are stimulates, they can form into osteoblast or even bone-lining cells

Bone-forming cells that secrete unmineralized bone matrix called osteoid

Derived from the same hematopoietic stem cells that become macrophages
giant, multinucleate cells function in bone resorption (the breakdown of the bone)
most active osteoclast is in areas called resorption bays

Osteoid
Osteoid is made up of collagen and calcuim-binding proteins (more like support)
Collegen makes up 90% of bone protein

Compact bone
Called Lamellar Bone
Made of:
Osteo (Haversian system)
Canals and Canaliculi
Interstitial and Circumferential Lamellae

Canals and Canaliculi

Interstitial and Circumferential Lamellae

Osteo (Haversian system)
Refers to just a part of the compact bone (a unit)
Characteristics:
A elongated cylinder that runs along parallel
The rings surrounding the matrix is called the lamellae

Lamellae
Lamella contain collagen fibers that run in different direction in adjacent rings
Withstands stress
Bone salts are found between collagen fibers

Canaliculi: think canales that connec the lacunaw to each other and then the central canal

Central (Haversian) canal, runs through the core of osteon, houses blood vessels and nerve fibers
Perforating (Volkmann's) canals, canals lining the endosteum that occurs at a right angles to the central canal (connects the blood vessels and nerves of the periosteum, medullary cavity and the central canal

Lacunae: small cavities that contain osteocytes

Osteoblast that secretes the bone matrix maintain contact with each other and osteocytes via cell projections with gap junctions

Intramembranous Ossification
Bone Develops from fibrous membrane
bones are called membrane bones
creates frontal, parietal, occipital, temporal, and clavicle bones

Endochondral Ossification
bone forms by replacing hyaline cartilage
bones are called cartilage (endochondral) bones
form most of skeleton in adult hood

Bone deposited, the new bone matrix is deposited by osteblasts

bone resorption is made by the function of osteoclasts
Dig depressions or groves as they break down matrix
secrete lysosomal enzymes and protons that digest matrix
acidity converts calcium salts to soluble forms
Osteoclasts also phagocytize demineralized matrix and dead osteocytes

Can be classified by position

NonDisplaced, ends retain normal position

Displaced: out of alignment

Completeness of break

Incomplete: not broken all the way through

Complete: all the way through

Penetration of the skin

Open: skin is penetrated

Closed: not penetrated

Can be classified by location, external appearance or the degree of the break

Type of fracture:

Spiral ragged break (unorgainized)

Epiphyseal
Diaphysis and epiphysis are broken off

Compression, bone crush

Depressed: Broken bone inwards

Comminuted
Many fragments

Greenstick: Bent bone and a incomplete bone

can happen with force, but it more catastrophic with the elderly due to brittle bones

Crushing force

Twisting force, common with sport fracture

may happen more if cartilage cells are dying and calcification of the matrix is occuring

in falls but more common in children

skull fracture

  1. Bony callus formation
    Within a wekk, new trabeculae appear in the firbocartilaginous callus
    Callus is converted to bony (hard) callus of spongy bone
    Bony callus formation continues for about two months until firm union form
  1. Bone remodeling
    Compact bone is laid down again to reconstruct shaft walls
    the final product resembles original structure
  1. Fibrocartilaginous callus formation
    Cappollaries grow into hematoma
    Phagocytic cells clear debris
    Fibroblasts secrete collagen fibers to span break and connect ends
    Fibroblast, cartilage, and osteogenic cells egin reconstruction of bone
  • create cartilage matrix of repair tissue
  • osteoblasts from spongy bone within matrix
    This mass of repair tissue is called fribrocartilaginous callus

1, Hematoma formation:
A blood vessle breaks and forms a blood "pimple)
Site is swollen, painful, and inflamed

Caused by of a vitamin deficiency or insufficient dietary calcium

risk factors for osteoporosis
Often aged, postmenopausal women
estrogen plays a role in bone density, so when levels drop at menopause women have a higher risk
life style also plays a role in developing this diseases

Medicina and more natural elements can treat this diseases

Joints are also called articulations: sites where two or more bones meet
The functions of joints: give skeleton moility and hold skeleton togehter without causing pain

Two classifications

Functional classification: three types based on movement joint allows

  1. Synarthroses:
  2. amphiarthroses
  3. Diarthroses

Structural: three types based on what material binds the joints and whether a cavity is present

  1. Fibrous
  2. Cartilaginous
  3. Synovial

One of the classifications of the joints indicates how much it can move, they are defined as
1.Synarthoroses: Immovable joints

  1. Amphiarthroses: slightly movable joints
  2. Diarthroses: freely movable joints

Cartilaginous
Bones united by cartilage
no joint cavity
not very movable
Two types:
Synchondroses
Symphyses

Synovial Joint
Bones separated by fluid-filled joint cavity
All are diathrotic (freely movable)
Include almost all limb joints

Fibrous
Bones joined by dense fibrous connective tissue
no joint cavity
most are immovable

Three types of fibrous joints

Syndesmoses

gomphoses

Sutures

Found only in the skull
meant to allow growth during youth
these joints become immovable as we age
Completely immovable sutures refer to as synostoses

Bones connected by ligaments, bands of fibrous tissue
Fiber length varies, so movement varies

  • Short fiber offer little to no movement
  • longer fiber offer a larger range of movement

Peg-in-socket joints
Only examples are the teeth in alveolar sockets
fibrous connection is the periodontal ligament

Symphyses
Fibrocartilage unites bone in symphysis joint - hyaline cartilage also present as articular cartilage on bony surfaces
Symphyses are strong, amphiarthrotic (slightly movable joint)

Synchondroses
Bar or plates of hyaline cartilage unites bones
Almost all are synarthrotic (movable)

Characteristics of Synovial Joints:

Have six general features

allow several types of movements

Stablility is inflenced by three factors

classified into six different types

Have bursae and tendon sheaths associated with them

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Joint (cynovial) cavity: small, fluid filled potential space that is unique to the synovial joints

Articular Joint Capsul: two layers thick

Synovial fluid viscous, slippery filtrate of plasma and hyaluronic acids
Lubricates and nourishes cartilage
houses phagocytic cells to remove microbes and debris

Articular Cartilage: Consists of hyaline cartilage covering ends of bones- prevents crushing of bone ends

Different types of reinforcing ligaments

Nevers and blood vessels
Nevers detects pain and manages joint position and stretch
capillary beds supply filtrate for synovial fluid

Synovial membrane: loose connective tissue that makes synovial fluid

Fibrous layer: dense irregular connective tissue

Extracapsular outside the capsule

Intracapsular Deep to capsule, covered by synovial membrane

Capsular
Thickened part of fibrous layer

Articular discs (menisci)
Fibrocartilage separates articular surface to match the bone ends to stabilize joint and reduce trauma

Fatty Pads
For cushioing between fibrous layer of capsule and synovial membrane or bone

Bags of synovial fluid that act as oil or lubricating ball earing

Tendon Sheaths: elongated bursae wrapped completely aroud tendons victim to friction

Bursae: reduce friction where ligaments muscles skin, tendons or bones rub together

Pivot

Condylar

Hinge

Saddle

Plane

Ball-and-socket

Grinding

flexion and extension

rotation

Flexion, extension, adduction, and abduction

Adduction , abduction, flexion, and extension

moves in all direction but grinding

-Muscles attach to bone or connective tissue at no fewer than two points
-Muscle contracts causes insertion to move toward origin
-Movements can be transverse, frontal, or sagittal planes
-Range of motion allowed by synovial joint
Nonaxial: Slipping movemtn only
Uniaxial Movement in one plane
Biaxial: movement in two planes
Muiltiaaxial: movement in or around all three plane
-Three general types of movements
griding
angular movements
rotation

Surface of bones glides or slips over another similar surface , ex: joints

Movement along sagittal plane
Flexion: decreases the angle of the joint - moving down
extension: increases the angle of joint - neutral

Hyperextension: movement beyond the anatomical position - extending back

Abduction: movement along frontal plane, away from midline
Adduction: movement along frontal plane, towards midline

involves flexion, abdction,extension, adduction of limb
Medial- towards midline
Lateral- rotation away from midline

Special movement-

supination (radius and ulna parallel) and pronation (radius rotates over ulna)

Dorsiflexion (pushing back) and plantar flexion (extending)

Opposition- grasping

Inversion (moving foor inward) and eversion (moving foot away from medially)

Elevation (lift body) and depression (lower body) of mandible

protraction (moving jaw forward) and retraction (moving away)