Exam 2 Flashcards by Laura Pitt

i. Contains no blood vessels or nerves

ii. Surrounded by the perichondrium (dense irregular CT) that resists outward expansion

Skeletal Cartilage

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a. Provides support, flexibility, and resilience
b. Most abundant skeletal cartilage
c. Present in these cartilages
i. Articular – covers the ends of long bones
1. Form a joint
ii. Costal – connects the ribs to the sternum
iii. Respiratory – makes up larynx; reinforces air passages
iv. Nasal - supports the nose

Skeletal Cartilage

Hyaline

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a. Similar to hyaline cartilage
i. BUT contains more elastic fibers
ii. Found in
1. External ear
2. Epiglottis

Skeletal Cartilage

Elastic

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a. Highly compressed
b. Great tensile strength
c. Contains collagen fibers – Really thick, can see them
d. Found in
i. Menisci of the knee
ii. Pubic symphysis
iii. Glenoid (shoulder)
iv. Acetabular labrum (hip)
v. Intervertebral discs
e. Located in places that take a LOT of compression

Skeletal Cartilage

Fibrocartilage

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Appositional Growth
Insterstitial Growth
Calcification/Ossification

Types of growth in cartilage

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i. Cells in the perichondrium secrete matrix against the external face of existing cartilage
ii. Grows to the side and outward

Appositional Growth

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i. Lacunae bound chondrocytes inside the cartilage divide and secrete new matrix,
ii. expanding the cartilage from within.

Interstitial Growth

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i. During normal bone growth
1. Increases length and width of the bone
ii. During old age
1. Decreases flexibility at the joints

Calcification/Ossification

growth of cartilage

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Axial Skeleton

Appendicular Skeleton

Major regions of skeleton

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i. Bones of skull
ii. Vertebral column
iii. Rib cage

Axial region of skeleton

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i. Bones of upper limbs
ii. Lower limbs
iii. Shoulder
iv. Hip

Appendicular region of skeleton

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a. Support – form the framework that supports the body and cradles soft organs
b. Protection – provide a protective case for the brain, spinal cord, and vital organs
c. Movement – provide levers for muscles
d. Mineral storage – reservoir for minerals, especially calcium and phosphorus
e. Blood cell formation – hematopoiesis occurs within the red marrow cavities of bones

5 important functions of bones

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Long
Short
Flat
Irregular

Classifications of bones based on shape

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Bone shape - longer than they are wide

Ex: Humerus

Long bones

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Bone shape - Cube shaped bones of the wrist and ankle

Short bone shape

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Bone shape - thin, flattened, and a bit curved

i. Eg. Sternum
ii. Most skull bones

Flat bone

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Bone shape - bones with complicated shapes

i. Ex: vertebrae
ii. Pelvis bone

Irregular bone shape

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bone-forming cells

osteoblasts

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mature bone cells

osteocytes

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large cells that resorb or break down bone matrix
As bone resorbed, minerals released into blood
Similar to macrophage

osteoclasts

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mitotic cartilage cells

chondroblasts

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more mature cartilage cells

chondrocytes

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i. Sites of Muscle and Ligament Attachment

bone marking

Projections

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i. Lets things go through?
ii. Or hold up against?
iii. Conduit/canal for blood vessels and nerves
(bone marking type)

Depressions/Openings

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One bone type is the dense outer layer; a.k.a. cortical bone The other is honeycomb of trabeculae filled with bone marrow aka: woven bone, trabecular bone, cancellous bone

Compact Bone | Spongy Bone

Contains: Diaphysis Epiphyses

Long Bone

1. Tubular shaft that forms the axis of long bones 2. Composed of compact bone (cortical bone) that surrounds the medullary cavity a. Yellow bone marrow (fatty) contained in medullary cavity

Long Bone | Diaphysis

1. Expanded ends of the long bones 2. Exterior is compact bone 3. Interior is spongy bone 4. Joint surfaces are covered with articular (hyaline) cartilage& perichondrium 5. Epiphyseal Plate 6. Epiphyseal Line

Long Bone | Epiphyses

Part of the Long Bone a. Active hylaine Cartilage b. Separates diaphysis from epiphyses until end of puberty c. Ossifies --> growth ceases --> epiphyseal line

Epiphyseal Plate

Part of Long Boone a. Detected on x-ray b. Separates the diaphysis from the epiphyses after growth in length stops c. The epiphyseal plate has been ossified. (after long bone growth stops)

Epiphyseal Line

* Bone Membrane * Double layered protective membrane 1. Outer fibrous layer – Dense Irregular Connective Tissue 2. Inner Osteogenic (new) layer composed of osteoblasts and osteoclasts 3. Richly supplied with nerve fibers a. This is the source of pain during bone fractures and bone bruises 4. Supplied with blood and lymphatic vessels, which enter the bone via nutrient foramina a. A hole 5. Secured to the underlying bone by Sharpey’s fibers

Periosteum

1. VERY delicate membrane covering internal medullary surfaces of bones 2. Also osteogenic

Endosteum

Bones that form within tendons | Example includes the patella

Sesamoid bones

Bone Marking | rounded projection

Tuberosity

Bone Marking | narrow, prominent ridge of bone

Crest

Bone Marking | large, blunt irregular surface

Trochanter

Bone Marking | narrow ridge of bone

LineS

Bone Marking | small rounded projection

Tubercle

Bone Marking | Raised area above a condyle

Epicondyle

Bone Marking | Sharp, slender projection

Spine

Bone Marking | Any bony prominence

Process

Bone Marking | bony expansion carried on a narrow neck

Head

Bone Marking | Smooth, nearly flat articular surface

Facet

Bone Marking | Rounded articular projection

Condyle

Bone Marking | Arm like bar of bone

Ramus

Bone Marking | Canal like passageway

Meatus

Bone Marking | Cavity within a bone

Sinus

Bone Marking | Shallow, basin like depression

Fossa

Bone Marking | Furrow

Groove

Bone Marking | Indentation at the edge of a structure

Notch

Bone Marking | Narrow, slit like opening

Fissure

Bone Marking | Round or oval opening through bone

Foramen

i. Thin plates of periosteum-covered compact bone on the outside with endosteum-covered spongy bone (known as diploe) on the inside ii. Have no diaphysis or epiphyses iii. Contain red (hematopoietic) bone marrow between the trabeculae

Short/Flat/Irregular Bone Structure

i. Infants 1. Found in medullary cavity and every bone’s spongy bone Childhood - red marrow slowly replaced by yellow marrow ii. Adults 1. Only found in the diploe of flat bones 2. Head of the femur 3. Head of the humerus

Location of Hematopoietic Tissue (Red Marrow)

The structural unit of COMPACT bone

Osteon

Made of LAmellae Haversian canal Volkmann's canals

Osteon - structural unit of compact bone | Microscopic Structure of Compact Bone

a. Weight bearing, column-like matrix tubes i. Composed mainly of collagen ii. Osteon lamellae + interstitial lamellae + circumferentiale lamellae

Microscopic Structure of Compact Bone | Lamellae - Osteon

a. Central canal | b. Central channel containing blood vessels and nerves

Microscopic Structure of Compact Bone Haversian canal Osteon

Microscopic Structure of Compact Bone a. Channels lying at right angles to the central canal b. Connecting blood and nerve supply of the periosteium to that of the Haversian canal Perpendicular to the Haversian canal

Microscopic Structure of Compact Bone | Volkmann's canals

Microscopic Structure of Compact Bone 1. Small cavities in bone that contain osteocytes 2. Osteocytes – mature bone cells

Lacunae

Microscopic Structure of Compact Bone 1. Hair-like canals that connect lacunae to each other and the central canal allow osteocytes to share nutrients and communicate

Cannaliculi

composed of proteoglycans, glycoproteins, and collagen

Un-minzeralized bone matrix composition | Osteoid

``` Osteoblasts Osteocytes Osteoclasts Osteoid The *LIVING* part of the bone ```

Organic Composition of Bone

i. Hydroxyapatites 1. Mineral salts 2. 65% of bone by mass 3. Primarily calcium phosphates 4. Responsible for a. Bone hardness b. Resistance to compression

Inorganic Composition of BOne

1. The process of bone tissue formation, which leads to: a. Formation of bony skeletons in embryos b. Bone growth until early adulthood c. Bone thickness d. Bone remodeling e. Bone repairing

Osteogenesis and Ossification

Bone Growth a. “Within the membrane” b. Formation of most of the flat bones of skull, the mandible, and part of clavicles c. Recall the fibrous connective tissue membranes are formed by the mesenchyme cells

Intramembranous Ossification

a. Ossification center appears in the fibrous connective tissue membrane i. This fibrous membrane is actually Dense Irregular CT b. Bone matrix (osteoid) is secreted within the fibrous membrane c. Bone (diploe) and periosteum form d. Bone collar of compact bone forms and red marrow appears e. In babies, this continues for awhile. The babies have soft spots of dense irregular connective tissue. Will continue to make bone

Stages of Intramembranous Ossification

1. Bones form by replacing hyaline cartilage 2. Formation of all long bones and most other bones of the body EXCEPT FLAT 3. Uses hyaline cartilage templates or “models” for bone construction 4. Requires the breakdown of hyaline cartilage prior to ossification

Endochondral Ossification

a. Primary ossification center develops in center of hyaline template the epiphyseal cartilage on side closest to epiphysis is relatively INACTIVE. b. Formation of periosteal (osteoid) bone collar c. Calcification and Cavitation of the diaphysis hyaline cartilage d. Invasoin of internal cavities by the periosteal bud, and spongy bone formation e. Diaphysis elongates and medullary cavity forms i. Plus the appearance of secondary ossification centers in the epiphyses f. Ossification of the epiphyses, with hyaline cartilage remaining only in the epiphyseal plates

Endochondral Ossification | Steps

i. Cartilage continually grows and is replaced by bone ii. Cartilage on the side of the epiphyseal plate closest to the epiphysis is relatively inactive iii. Cartilage abutting the diaphysis (shaft) of the bone organizes into a pattern that allows fast, efficient growth iv. Cells of the epiphyseal plate closest to the diaphysis form 3 functionally different zones 1. Growth 2. Transformation 3. Osteogenic

Growth in LENGTH of Long Bones

i. Appositional Growth – Bone is added by osteoblasts at the periosteal surface and resorbed by osteoclasts at the endosteal surface ii. Allows for thicker, stronger bones without becoming too heavy. 1. How we remodel from fetal bone shape to adult bone shape.

Growth in WIDTH of Long Bones

i. Epiphyseal plate activity is stimulated by Growth Hormone

Hormones/Nutrients in Reg of Bone Growth/Maintenance

i. Testosterones and Estrogens 1. Initially promote adolescent growth spurts 2. Cause masculinization and feminization of specific parts of the skeleton 3. Later induce epiphyseal plate closure, ending longitudinal bone growth

Puberty Bone Growth and Maintenance

Gigantism

Bone Growth and Maintenance | Too much Growth Hormone

Pituitary Dwarfism

Bone Growth and Maintenance | Too Little Growth Hormone

a. When adjacent osteoblasts and osteoclasts deposit and resborb bone at periosteal and endosteal surfaces, respectively 1. Osteoblasts a. Deposit bone at periosteal and endosteal surfaces 2. Osteoclasts a. Resorb bone at periosteal and endosteal surfaces

Bone remodeling

i. Occurs where bone is injured or added or where added strength is needed ii. Sites of new matrix deposition (By osteoblasts) are revealed by the

Bone Deposition

un-mineralized band of bone matrix abrupt transition zone between the osteoid seam and the older mineralized bone

Osteoid seam Calcification front

One week to calcify

osteoid

1. Diet rich in a. Protein b. Vitamins i. A ii. C iii. D iv. K2 c. Calcium d. Phosphorus e. Magnesium f. Manganese 2. Poor nutrition = weak bones and poor fracture healing 3. Alkaline phosphatase is essential for the mineralization of bone 4. Also mechanical stimulation (gravity loading)

Dietary Requirements for Calcification

i. Accomplished by osteoclasts 1. Essentially mobile phagocytes ii. Resorption bays - grooves formed by osteoclasts as they break down bone matrix iii. Resorption involves osteoclasts secretion of 1. Lysosomal enzymes that hydrolyze the organic matrix 2. Acids that convert calcium salts into soluble forms iv. Dissolved matrix is transcytosed (“across the cell”) acorss the osteoclasts’s cell where it is secreted into the interstitial fluid and then into the blood v. Osteoclasts then undergo apoptosis 1. Cell death

How does bone resorption work?

a. Body will add/remove as needed i. Transmission of nerve impulses ii. Muscle contraction iii. Blood coagulation (clotting) iv. Secretion by glands and nerve cells (neurotransmitters) v. Cell division (mitosis/meiosis) b. Homeostatic Mechanisms i. Rising Blood calcium levels trigger the thyroid to release calcitonin 1. Stimulates calcium salt deposit in bone ii. Falling Blood Ca levels triggers the parathyroid gland to release PTH 1. Signals osteoclasts to degrade bone matrix and relase Ca into the blood

Hormonal Mechanism/Control Loop to maintain Calcium homeostasis in the body

a. “a bone grows or remodels in response to the forces or demands placed upon it” b. Few observations supporting this include i. Long bone compact bone is thickest midway along the shaft 1. Where bending stress is greatest ii. Curved bones are thickest where they are most likely to buckle iii. Handedness (R or L) results in bones being larger in the dominant upper extremity iv. Bony projections are largest where heavy, active muscles attach c. Clinically used to maximize the healing of fractures.

Wolff's law

1. Bones retain their normal position 2. Bone ends are out of normal alignment 3. Bone is broken all the way through 4. Bone is not broken all of the way through

i. Non-displaced Fracture ii. Displaced Fracture iii. Complete Fracture iv. Incomplete Fracture

1. The tracture I parallel to the long axis of the bone | 2. Found often in prison escapees

Linear fracture

1. Think perpendicular | 2. The fracture is perpendicular to the long axis of the bone

Transverse

i. Comminuted ii. Compression iii. Spiral Epiphysea iv. Depressed v. Greenstick

Common Types of Fractures

i. Comminuted 1. Bone fragments into three or more pieces 2. Common in the elderly

ii. Compression 1. Bone is crushed 2. Common in porous bones (of spine)

iii. Spiral 1. Ragged break when bone is excessively twisted 2. Common sports injury a. Soccer players who already have a knee brace

iv. Epiphyseal 1. Epiphysis separates from diaphysis along epiphyseal line 2. Occurs where cartilage cells are dying

v. Depressed 1. Broken bone portion pressured inward 2. Typical skull fracture

vi. Greenstick 1. Incomplete fracture where one side of the bone breaks and the other side bends 2. Common in children a. Bones are more flexible

1. Hematoma (blood pool formation) 2. Fibrocartilaginous callus forms 3. Bony Callus forms 4. Bone remodeling

Healing a Bone Fracture | The steps

a. Torn blood vessels hemorrhage b. Mass of clotted blood (the hematoma) forms at the fracture site c. Site becomes swollen, painful, and inflamed i. Due to highly innervated and highly vascularized periosteum

Healing a Bone Fracture The steps Hematoma

a. Granulation tissue (soft callus) forms a few days after the fracture b. Capillaries grow into the tissue and phagocytic cells begin cleaning debris c. Osteoblasts and fibroblasts migrate to the fracture and begin reconstructing the bone d. Fibroblasts secrete collagen fibers that connect broken one ends e. Osteoblasts begin forming spongy bone f. Osteoblasts furthest from capillaries secrete an externally bulging cartilaginous matrix that later calcifies. g. Entire mass of repair tissues = fibrocartilaginous callus, which splints the fractured bone i. It holds the bone but is not healed

Healing a Bone Fracture The steps Fibrocartilaginous callus forms

a. New bone traveculae appear in the fibrocartilaginous callus b. Fibrocartilaginous callus converts into a bony (hard) callus to spongy bone c. Bone callus appears on x-ray 10-14 days after injury, and continues until firm union is formed 2-3 months later i. Up to 4 months if elderly

Healing a Bone Fracture The steps Bony Callus Forms

a. Excess material on the bone shaft exterior and in the medullary canal is remoed b. Compact bone is laid down to reconstruct shaft walls c. Responds to mechanical stress i. May take up to 18 months to restore pre-fracture shape

Healing a Bone Fracture The steps Bone remodeling

Disorders of Bone Remodeling i. Adult bones are inadequately mineralized causing softened, weakened bones (osteoid) ii. Main symptom is pain when weight is put on the affected bone (periosteal pain) iii. Caused by insufficient absorption of calcium and/or vitamin D deficiency

Osteomalacia

Disorders of Bone Remodeling i. Children’s bones are inadequately mineralized, causing softened, weakened bones ii. Signs 1. Bowed legs and deformities of the pelvis, skull, and rib cage iii. Caused by 1. Insufficient absorption of calcum and/or by vitamin D deficiency iv. Isolated cases in the U.S. 1. Essentially eliminated due to fortified juice, cereal and milk products 2. Breastfeeding mothers who are deficient in Vit. D. and Calcium (don’t absorb w/o Vit D) will have unsufficient Calcium and Vitamin D in the milk, so infants will develop this.

Rickets

Disorders of Bone Remodeling i. Bone matrix contains inadequate collagen (low tensile strength) and bones fracture easily ii. Genetic and often present at birth iii. Results in multiple (often fatal) fractures as infant comes through the birth canal.

Osteogenesis Imperfecta

Disorders of Bone Remodeling i. Group of diseases where bone reabsorption outpaces bone deposition ii. Bones become so fragile that sneezing, stepping off a curb, or pulling on a heavy door can cause fractures iii. Spongy bone of the spine is the most vulnerable iv. Occurs most often in menopausal women (estrogen restrains osteoclasts)

Osteoporosis

Disorders of Bone Remodeling v. Prevention and Treatment 1. Calcium, Vitamin D and Vitamin K supplements 2. Increased Weight Bearing Exercise 3. Hormone (estrogen) replacement therapy (HRT) slows bone loss but does not reverse it a. Serious side effects i. Increase of heart attack, ii. Stroke, iii. And breast cancer 4. Natural bio-identical progesterone cream prompts new bone growth 5. Statins (drugs for lowering cholesterol) also found to increase bone mineral density but have serious side effects including liver and muscle damage. e. Paget’s Disease

Osteoporosis Treatment

Disorders of Bone Remodeling i. Characterized by excessive and inconsistent bone formation and breakdown ii. Pagetic bone has an excessively high ratio of spongy to compact bone iii. Pagetic bone has patches of reduced mineralization, which causes spotty weakening of bone iv. Late in the disease, osteoclast activity decreases, but osteoblast activity continues tow work, 1. Leaves regions of excessive bone thickening and filling of the medullary cavity 2. Usually localized in the spine, pelvis femur, and skull a. Unknown cause  suspect a viral trigger v. Some successful control via a Calcitonin inhaler (increases Calcium mineralization)

Paget's Disease

1. Mesoderm gives rise to embryonic mesenchymal cells, which produce dense irregular connective tissue membranes and the hyaline cartilage that form the embryonic skeleton 2. The embryonic skeleton ossifies in a predictable timetable that allows fetal age to be easily determined from sonograms 3. By birth, most long bones are well ossified a. Except for the epiphyses

Fetal Developmental Aspects of Bone Formation

1. By age 25, nearly all bones are completely ossified 2. In old age, bone resorption outpaces deposition 3. A single gene that codes for vitamin D docking determines both the tendency to accumulate bone mass early in life, and the risk for osteoporosis later in life a. The more you hold on to, the more you have to lose.

By age 25

a. Transmit weight of trunk to the lower limbs b. Surrounds and protects the spinal cord c. Flexible, curved structure containing 26 irregular bones (vertebrae)

Vertebral Column

``` 7 Cervical bones 12 Thoracic bones 5 Lumbar Sacrum Coccyx ```

Vertebral Column

Increases resilience, flexibility, and force load capability of the _

Vertebral Column

a. Outward curvature of the spine (arch points posteriorly | i. Thoracic Kyphosis

Kyphosis (it's the middle one and points posteriorly)

a. Inward curvature of the spine i. Cervical lordosis ii. Lumbar lordosis

Lordosis

i. Anterior and posterior longitudinal ligaments 1. From neck to sacrum, anterior and posterior to the body of the vertebra ii. Ligamentum flavum 1. Connects adjacent vertebrae (lamina to lamina) iii. Short ligaments 1. Connect each vertebra to those above and below a. Ex: i. Supraspinous ligament ii. Interspinous ligament

Ligaments of Vertebral Column

i. Fibrocartilage pad composed of two parts

Intervertebral Discs

1. Nucleus pulposus a. Inner gelatinous nucleus that gives the disc its elasticity and compressibility 2. Annulus fibrosus a. “Annular rings” b. Outer collar composed of alternating diagonal layers of collagen and fibrocartilage

Intervertebral Discs | Componenets

a. Inner gelatinous nucleus that gives the disc its elasticity and compressibility

Intervertebral Disc | Nucleus Pulposus

a. “Annular rings” | b. Outer collar composed of alternating diagonal layers of collagen and fibrocartilage

Intervertebral Disc | Annulus fibrosus

a. In conjunction with the spinal curvatures, serves to increase the force load capability of the spine

Purposse of Intervertebral Disc

a. Important to mtaintain these neutral curvatures | b. Increase the resilience, flexibility, and force load capability of the spine

5. Indicate a common function of the spinal curvatures and the intervertebral discs.

1. Abnormal lateral curve | a. Usually in the T spine

Scoliosis

1. Hunchback | a. Only pathological IF excessive

Hyperkyphosis

1. Swayback | a. Only pathological IF excessive

Hyperlordosis

i. Ilia have a decreased forward tilt ii. Adapted for support of male’s heavier build and stronger muscles iii. Cavity of true pelvis is narrow and deep

Male Pelvis

i. Adapted for childbearing ii. True pelvis (inferior to pelvic brim) begins at the pelvic inlet and defines the upper portion of the birth canal iii. Cavity of the true pelvis is broad, shallow, and has greater capcity

Female Pelvis

Lighter, thinner, smoother Heavier, thicker, more prominent markings

F/M Bone Thickness

80-90 degrees 50-60 degrees

Pubic arch/angle

Small; farther apart Large; closer together

Acetabula

Wider, shorter; sacral curvature is accentuated Narrow, longer; sacral promontory more ventral

Sacrum

More movable; straighter | Less movable; curves ventrally

Coccyx

Wide and shallow Narrow and deep

Greater Sciatic Notch

Wider; oval from side to side Narrow, basically heart shaped

Pelvic inlet (brim)

Wider; ischial tuberosities shorter, farther apart and everted Narrower; ischial tuberosities longer, sharper, and point more medially

Pelvic Outlet

a. Arches are maintained by interlocking foot bones, ligaments, and tendons b. Arches allow the foot to bear weight

Importance of foot arches

* Locate i. Lateral longitudinal ii. Medial longitudinal iii. Transverse

foot arches yay!

Joint classification based on amount of movement allowed by the joint

Functional

Immovable

Synarthroses

Slightly movable joints

Amphiarthroses

Freely movable

Diarthroses

Weakest parts of the skeleton

Joints

Any site where two or more bones meet

Articulation

Give the skeleton mobility | Hold the skeleton together

Function of joints

``` classification is based on the material binding the bones together and whether or not a joint cavity is present. Include Fibrous Cartilaginous Synovial ```

Structural Classification of Joints

1. The bones are JOINED by fibrous tissue (denser Connective Tissues Propers, periosteum) 2. There is NO joint cavity. Suture Syndesmosis Gomphosis

Fibrous Joint

1. Occurs between the bones of the skull 2. Comprised of interlocking junctions filled with thick and short dense irregular CT 3. Binds bones tightly together, but allows for growth during youth 4. Immovable due to tightness of CT fibers (synarthrosis) 5. ~ Age 40 a. Many skull bones are fused and joints now called synostoses (“without movement of bone)

Fibrous Joint | Suture

1. Bones are connected together by a fibrous tissue ligament (dense regular CT) 2. Movement is slight to moderate (amphiarthrosis), dependent upon the fiber length a. Ex: i. Connection between the tibia and fibula ii. Connection between the radius and ulna

Fibrous Joint | Syndesmosis

1. The peg-in socket fibrous joint between a tooth and its alveolar socket (synarthrosis) 2. The dense regular CT fibrous connection is referred to as the periodontal ligament Function: Synarthroses

Fibrous Joint | Gomphosis

1. Articulating bones are united by cartilage 2. There is no joint cavity Synchondroses Symphysis

Cartilaginous Joints

a. A bar/plate of hyaline cartilage unites the bone b. All are synarthrotic joints i. Ex: 1. Epiphyseal plates of children and adolescents 2. Joint between the costal cartilage of the first rib and the manubrium of the sternum

Cartilaginous Joints | Synchondroses

a. Hyaline cartilage covers the articulating surface of the bone and is fused to an intervening pad of fibrocartilage b. Slightly moveable (amphiarthrotic) joints designed for strength and flexibility i. Ex: 1. Intervertebral joints 2. Pubic symphysis of the pelvis

Cartilaginous Joints | Symphysis

1. Joints in which the articulating bones are separated by a fluid-containing joint cavity 2. All are freely moveable (diarthroses) 3. Ex: a. All limb joints b. Most other joints of the body

Synovial Joints

``` Articular cartilage: = hyaline Joint (synovial) cavity = small potential space 1. Articular capsule = 2. Synovial Fluid 3. Reinforcing ligaments 4. Nerve and Blood Vessels ```

Components of ANY synovial Joint

a. Outer fibrous capsule of dense irregular CT b. Inner synovial membrane of loose connective CT i. Mostly Areolar ii. Plus Serous Membrane 1. Whose epithelial cells = simple squamous!

Articular (joint) Capsule | Synovial Fluid

a. Viscous and slippery filtrate of plasma (from blood capillaries) + hyaluronic acid i. Lubricates and nourishes the articular cartilage b. Contains phagocytes which clean up microbes and cellular damage debris

Synovial Fluid | General Synovial Joint Components

Capsular ligaments Extracapsular LIgaments Intracapsular ligaments All are dense regular CT

Reinforcing ligaments | Synovial Joints

i. “intrinsic” ligaments 1. Areas of dense regular CT within the dense irregular CT portion of the capsule 2. Buried within capsule; not in the fluid

Capsular Ligaments

i. Distinct dense regular CT band | ii. Outside the capsule

Extracapsular Ligaments | Synovial Joints

i. Distinct dense regular CT band ii. Inside the capsule deep the capsule; within the synovial space; covered by synovial membrane

Intracapsular Ligametns | Synovial Joints

a. Rich supply to the capsule and synovial membrane b. Capillaries are the source of synovial fluid plasma c. Nerves detect pain and provide feedback on stretch and joint position

Nerve and Blood Vessels associated with ANY Synovial Joint

1. Fat pads 2. Fibrocartilage discs 3. Friction-Reduction Structures: Bursae and Tendon Sheaths

Associated with some synovial joints, but not all

a. For additional cushioning in some joints i. EX: 1. Suprapatellar 2. infrapatellar

Fat pads

i. For shock absorption and improved joint stability b. Ex: i. Meniscus of knee ii. Glenoid labrum of the shoulder

Fibrocartilage discs

i. Flattened, fibrous sac lined with synovial membranes and containing synovial fluid ii. Common where ligaments, muscles, skin, tendons or bone rub together Friction reducers

Bursa

i. Elongated bursa that wraps completely around a tendon | Friction reducer

Tendon Sheath

a. Lubricates and nourishes the articular cartilage.

Function of hyaluronic acid in the synovial fluid

2. Bursae found where these things rub together; Tendon sheaths are wrapped around a tendon

FACT

i. Plane ii. Hinge iii. Pivot iv. Condyloid v. Saddle vi. Ball and Socket

6 Types of Synovial Joints

1. Articular surfaces are essentially flat 2. Allow only slipping or gliding movements 3. Only example of nonaxial joints in the body a. Examples i. Between proximal and distal row of carpals ii. Facets(?) of vertebrae

Plane Joint

1. Cylindrical projections of one bone fits into a trough-shaped surface on another 2. Uniaxial joints which permits flexion and extension only a. Examples i. Elbow joint ii. Interphalangeal joints 1. Fingers and toes

Hinge

1. Rounded end of one bone protrudes into a ring of bone or ligament ring of another 2. Uniaxial joints which permit rotation only a. Examples i. Joint between the atlas and axis (AA) joint (?) ii. Proximal Radioulnar joint

Pivot

1. = Condylar = Ellipsoid Joints 2. Oval articular surface of one bone fits into a complementary oval depression in another a. Both articular surfaces are oval 3. Biaxial joints which permit all angular motions a. Flexion-Extension b. Abduction – Adduction c. Examples i. Radiocarpal (wrist) joints ii. Metacarpophalangeal (knuckles) joints

Condyloid

1. Each articular surface has both a concave and a convex surface 2. Biaxial joints similar to condyloid joints but with greater movement allowed a. ONLY example i. Carpometacarpal joint of the pollex

Saddle

1. A spherical/hemispherical head of one bone articulates with a cup-like socket 2. Multiaxial joints – most freely moving synovial joints; move in all planes a. ONLY example i. Glenhumeral joint (shouler) and ii. acetabulofemoral joint (hip)

Ball and Socket

i. Shape of Articular surfaces 1. Determines what movements are even possible ex: hip vs. elbow ii. Ligaments iii. Muscle Tone

how Joint STABILITY is determined

1. Def: unites bones are prevents excessive/undesirable motion via stretch receptors

Ligaments

2. Stretch receptors send signals to CNS a. Response: skeletal muscles surrounding the joint contract to provide increased stability by tightening the tendons 3. No elastic tissue a. So when stretched, ligaments remain stretched and stretch signals are now delayed i. So easier to overstress the joint ii. Joint becomes hypermobile 4. Will tear when > approximately 5% of resting length

Ligaments

1. Works at a baseline level of muscle co-contraction around a joint 2. Muscle tendons are crossing the joint, therefore act as stabilizing factors 3. Muscle contraction, and thus tendon stabilization, increases with ligament stretch receptor output 4. This is critical factor for stability of a. Shoulder joint b. Knee joint c. Arches of the foot

Muscle Tone

i. Muscle attachment arrangement across a joint | ii. Planes of motion permitted by joint shape

How Joint MOBILITY is determined

"Origin" O | "Insertion" I

i. Muscle attachment arrangement across a joint

where there is attachment to the stationary bone

1. Origin “O”

where the muscle attachment to the movable bone

Insertion "I"

Nonaxial Uniaxial Biaxial Multiaxial

The planes of motion permitted by joint shape

– slipping or gliding movements only (no axis of motion)

Nonaxial

1. – movement in one plane (one axis of motion)

Uniaxial

– movement in two planes ( two axis of motion)

Biaxial

– movement n or around all three planes (three axis of motion) a. Some muscle groups have divisons at different O&I attachment sites, allowing for movement in all 3 planes i. Ex: hamstrings

Multiaxial

Range of Motion i. One flat bone surface glides or slips over another similar surface 1. Ex: a. Intercarpal & Intertarsal joints b. Between the facets of the vertebrae

Gliding Movements

Range of Motion | bending movement that decreases the angle of the joint

Flexion

Range of Motion | – reverse of flexion; joint angle is increased

Extension

Range of Motion | movement beyond the normal range of motion

Hyperextension

Range of Motion | movement away from the midline

Abduction

Range of Motion | movement towards the midline

Adduction

Range of Motion 1. The turning of a bone around its own long axis 2. Occurs as right rotation and left rotation between Atlas and Axis (AA Joint- between the first and second cervical vertebrae) 3. Occurs as internal rotation & External rotation a. Hip b. Shoulder joints

Rotation

``` Range of Motion movement describes a cone in space 1. Occurs in all 3 planes so appears like a circle 2. Occurs at ball and socket joints only a. Shoulder b. Hips ```

Circumduction

1. Forearm palm up and palm down motions, respectively (radius and ulna are parallel) Palm down - radius rotates over ula 2. Occurs at the proximal radioulnar joint

Supination and Pronation

1. Up and down movement of the ankle joint

iii. Dorsiflexion and Plantarflexion

1. SUbtalar Joint (between talus and calcaneus) medial and lateral movement

Inversion and Eversion

1. Scapula or mandible anterior/posterior movement a. Ex: protraction = shoulders rounded anteriorly; mandible jaw juts anteriorly b. Retraction = boobs out for shoulder; underbite in mandible

v. Protraction and Retraction

1. Scapula or mandible superior/inferior movement | a. Ex: elevation = close jaw, shrug shoulders

vi. Elevation and Depression

1. Touching of the thumb to the tip of any other digit on the same hand

Opposition

i. Ball and socket joint in which mobility is sacrificed to obtain greater stability ii. Head of the femur articulates with the deep acetabulum of the os coxa iii. Overall, good range of motion, but limited (as compared to shoulder range of motion) by the deep socket, strong capsule and thick strong ligaments

Hip

1. Strong stability is maintained by a. Acetabular labrum (horseshoe-shaped fibrocartilage) i. Deepens the socket b. Strong and thick joint capsule i. Weakest posteriorly ii. Site of dislocations c. Multiple thick, heavy ligaments d. Tendons of 12+ muscles

Hip

2. Other ligamentum teres a. Attaches from head of femur to lower acetabulum b. Contains an artery which provides blood supply to the head of the femur c. No stabilizing function

Hip

i. Hinge joint that allows flexion and extension only ii. Strong capsule iii. Radius and ulna articulate with the humerus iv. Radius also articulates with the humerus 1. Annular ligament around radial head – creates the pivot joint (pronation-supination) v. Stabilizing Ligaments 1. Ulnar collateral ligament 2. Radial collateral ligament

Elbow

c. Temporomandibular Joint (TMJ highlights) i. Modified hinge joint ii. Mandibular condyle articulates with the mandibular fossa of the temporal bone iii. Two types of movement 1. Hinge shape permits depression and elevation of mandible (open-close jaw) 2. Condylar sape permts lateral excursion (side-to-side motion) = grinding teeth 3. Fibrocartilage disc can displace, causing “popping/clicking” or jaw stuck open/closed

TMJ

i. Ball and socket joint in which stability is sacrified to obtain greater mobility ii. Head of humerus articulartes with the shallow glenoid fossa of the scapula

Shoulder

(horseshoe shaped fibrocartilage) serves to deepen the socket

Shoulder | Glenoid labrum

Thin & loose joint capsule a. Four key ligaments b. Tendon of the long head of biceps c. Rotator cuff

Glenoid Labrum | Shoulder

(weakest anteriorly and inferiorly; site of dislocations)

a. Thin & loose joint capsule

b. Four key ligaments i. One coracohumeral ii. Three glenohumeral

of the Glenoid Labrum

i. Which travels through the intertubercular groove and secures the humerus to the glenoid cavity

c. Tendon of the long head of biceps Glenoid Labrum Shoulder

i. Made of tendons of 4 muscles ii. Encircles the shoulder joint and blends with the articular capsule 1. Muscle tendons a. Supraspinatus b. Infraspinatus c. Teres minor d. Subscapularis

Rotator Cuff Glenoid Labrum Shoulder

i. Largest and most complex joint of the body ii. Modified hinge joint (bicondylar) iii. Three joints in one surrounded by single joint cavity

Knee

1. Allows flexion 2. Extension 3. Some rotation at the end of extension a. “screw-home” mechanism

Knee | Modified hinge joint

1. Joint capsule only covers the posterior and medial/lateral aspects of the joint cavity 2. Merges anteriorly with the patellar tendon and patellar retinaculum a. Patellofemoral joint b. Medial and lateral joints

Three joints in one surrounded by single joint cavity | Also, the knee

a. Quadriceps femoris muscle tendon b. Patellar retinaculum i. Dense regular CT connecting the femur and tibia c. Patellar tendon i. Patellar ligament, per text, but actually sesamoid bone d. Medial and collateral ligaments

Stabilizing Structures | Knee Ligaments and Tendons - Anterior

a. Adductor magnus muscle tendon i. One of the Adductor muscles b. Semimembranousus muscle tendon i. One of the Hamstring muscles c. Gastrocnemius muscle tendon i. Of the calf muscle d. Popliteus muscle i. Small muscle in the popliteal region e. Multiple additional ligaments

Knee Ligaments and Tendons - Posterior View

a. Anterior cruciate ligament i. Stretch signals the muscle to decelerate internal rotation of the femur 1. Ex: lowering in a one-leg squat b. Posterior cruciate ligament i. Stretch signals the muscle to decelerate posterior translation of the tiba on the femur 1. Ex: walking down a steep hill

The Knee | 3. Intracapsular Supporting Structures

i. Stretch signals the muscle to decelerate internal rotation of the femur 1. Ex: lowering in a one-leg squat

Anterior Cruciate Ligament (ACL)

i. Stretch signals the muscle to decelerate posterior translation of the tiba on the femur 1. Ex: walking down a steep hill

Posterior Cruciate ligament

semilunar cartilages that serve to deepen tibial articular surfaces (better fit)

Knee | Medial/Lateral Meniscus

Common Sports Injury 1. The ligaments reinforcing a joint are stretched or torn a. Once stretched, remain stretched 2. Partially torn ligaments slowly repair themselves and fill with poorly organized scar tissue 3. Completely torn ligaments require prompt surgical repair for re-attachment to bone

Sprain

whereas | 1. A muscle with torn fibers (mild, moderate, severe)

Strain

1. There is often a snap and a pop of overstressed cartilage 2. Common high-impact injury a. Especially the meniscus 3. The meniscus, glenoid and acetabular labra and posterior patellar hyaline cartilage are frequently damaged 4. Typically repaired with arthroscopic surgery

Cartilage Injuries

1. Occur when bones are forced completely out of alignment a. No contact of joint surfaces 2. Tend to occur at weakest point of a joint capsule 3. Usually accompanied by sprains, strains, inflammation, and pain-induced joint immobilization 4. Usually caused by serious falls that are common sports injuries

Dislocations

1. Partial dislocation of a joint | 2. Bone surfaces are still congruous but not in the correct position

Subluxation

Inflammatory Joint Conditions 1. An inflammation of the bursa, usually caused by a blow or overuse a. Creates friction 2. Symptoms a. Pain swelling 3. Treatment a. Anti-inflammatory drugs b. Anti-inflammatory modalities i. Rest ii. Ice iii. Ultrasound c. Excessive fluid may be aspirated to prevent further frictiion

Bursitis

Inflammatory Joint Conditions 1. Inflammation of tendon sheaths (like a Panini) typically caused by over use (friction) 2. Symptoms treatment a. Similar to Bursitis

Tendonitis

1. A group of more than 100 different joint-damaging inflammatory or degenerative diseases 2. Most widespread crippling diseases in the U.S. 3. Symptoms a. Pain b. Stiffness c. And swelling of a joint 4. Acute forms a. Caused by bacteria and are treated with IV antibiotics Chronic Forms Osteo Rheumatoid Gouty

Arthritis

a. Most common chronic arthritis b. Often called “wear and tear” arthritis c. Affects women more than men d. Most individuals will develop some degree of OA i. Unless you are a total couch potato e. More prevalent in the aged, and is related to the normal aging process

Osteoarthritis

i. OA reflects the years of abrasion and compression causing increased production of metalloproteinase enzymes that break down articular cartilage faster than it can be replaced ii. Without protection of hyaline cartilage, the exposed bone ends thicken, enlarge from bone spurs=osteophytes and restrict movement due to a change of joint shape iii. Joints most affected are those that receive the most use on a daily basis 1. Cervical and lumbar spines 2. Fingers 3. Knuckles 4. Pollex 5. Knees 6. And hips

Osteoarthritis disease course

1. Slow and irreversible 2. Treatments are symptomatic a. Mild anti-inflammatory meds (NSAIDS) along with moderate activity to facilitate synovial fluid protection 3. Swimming ideal due to buoyancy effect of water and decreased gravity effect on joints 4. Magnetic therapy a. Some evidence of pain relief 5. Glucosamine and chondroitin sulfate supplements – no reproducible evidence 6. Surgical: shaving of bone spurs and total or partial joint replacements

Osteoarthritis Treatment

a. Chronic, Inflammatory autoimmune disease (viral vs. leaky gut trigger), with an insidiuous onset b. Usually arises between the ages of 30 to 50, but can occur at any age c. Signs and symptoms i. Joint tenderness ii. Bone fusion iii. Osteoporosis iv. Muscle atrophy due to disuse of bones, anemia, and cardiovascular problems often co-present v. The course of RA is marked with exacerbations and remissions

Rheumatoid Arthritis

i. RA begins with synovitis (inflammation of synovial membrane) of the affected joint ii. Inflammatory chemicals are insappropriately released (irritate nerves and cause pain) iii. Inflammatory blood cells migrate to joint, causing swelling 1. Increased permeability iv. Inflamed synovial membrane thickens into a pannus 1. Feels like hardening glue v. Pannus erodes cartilage vi. Scar tissue forms and the articulating bone ends connect vii. The end ossification result viii. Known as ankylosis produces bent, deformed joints

Rheumatoid Arthritis Disease Course

1. Conservative therapy a. Aspirin b. Gluten-free diet c. Physical/occupational therapy 2. Progressive treatment a. Strong anti inflammatory drugs or immunosuppressants i. Many classes of immunosuprresive drugs lead to liver failure 3. Newer drug (Enbrel) neutralizes the harmful properties of inflammatory chemicals a. Less toxic to the liver 4. Surgical a. Multiple total joint replacements (often of the fingers, too)

Rheumatoid Arthritis Treatment

a. Deposition of uric acid crystal in joints and soft tissue, followed by a localized inflammatory response i. Pain, redness, swelling b. Typically, affects the joint at the base of the hallux c. Affects men more than women (naturally higher uric acid levels) d. If untreated , the bone ends fuse (ankylose) and immobilize the joint e. Treatment i. Colchicine ii. NSAIDS iii. Glucocorticoids

Gouty Arthritis

a. By embryonic week 8, synovial joints resemble adult joints and are further modified after birth by the mechanical effects of loading

Embryonic Development of Joints

b. Fibrous and cartilaginous joints are not as well-developed i. Ex: 1. Infant skull has more bones than the adult skull 2. Connected by four fontanelles a. Unossified remnants of fibrous membranes between fetal skull bones ii. Most sutures ossify by age 40 and epiphyseal plates ossify at the end of puberty

Development of embryonic development

i. Ligaments and tendons shorten and weaken ii. Intervertebral discs lose water content with a resultant decrease in compressive load tolerance and become more likely to herniate iii. Most people in their 70s have some degree of OA

Few problems occur until late middle age when advancing year take the toll on joints

d. Prudent exercise that coaxes joints through their full range of motion (especially swimming once signs and symptoms of arthritis are apparent) is key to postponing joint problems

Straight up fact

Exam 2 Flashcards

(238 cards)