Physio Lecture Block 2 Flashcards
study lmao
What does the skeletal System contain
Bones
Cartilage
ligaments
connective Tissues
skeletal system functions
Support
protection
leverage (movement)
mineral homeostasis (storage and release)
triglyceride storage (yellow marrow)
Hemopoiesis (red and white blood cells formation) found in red marrow
Axial Skeleton
Skull
Hyoid
Auditory
Vertebral column
Thorax
only 80 bones total and appears more central
Appendicular
Pectoral Girdle (shoulder)- clavicle and scapula
Upper Limbs
Pelvic Girdle (hips etc.)
Lower Limbs (extremities)
126 total bones
Types of Bone/Bone classification
Long- humerus
Short - wrist bone
Flat - sternum
Irregular - vertebra
Sesamoid - patella
Sutural- fetal skeleton
pneumatized - ethmoid ??
layers of connective tissue that are important growth and remodeling
endosteum and periosteum
Periosteum
-connective tissue membrane covering the EXTERNAL SURFACE of a bone
-continuous with tendons and connective Tissues of joints
-attached to bone matrix via perforating fibers
Two layers of the periosteum
outer fibrous and inner osteogenic
Endosteum
Lines the INNER surface of bone: **marrow cavity, trabeculae of spongy bone, and canals of compact bone
**Contains Osteogenic cells (this is where it gets importance for bone growth and remodeling)
Short Bone Anatomy
Compact bone, the spongy bone, and then red blood marrow in between spongy bone
Anatomy of a flat bone
Periosteum, then compact, then spongy, endosteum lines inner space (kinda between spongy it looks like)
Are sutural bones part of the 206 bones of the body?
No they are in addition if present at al
Articulations (AKA JOINTS OR ARTHROSES) definition
a point of contact between
-Bones (elbow)
-Bones and Cartilage (epiphyseal plates)
-Bones and Teeth
Arthrology definition
Study of Teeth
Kinesiology definition
Study of the body in motion
How are joints classified (2 ways)?
What are the 3 types of each?
Based on anatomical structure!
Fibrous
Cartilaginous
Synovial
Based on Function!
Synarthrosis
Amphiarthrosis
Diarthrosis
Synarthrosis, Amphiarthrosis, and Diarthrosis explained
Syn= immovable
Amphi= Slightly movable
Di= Freely movable
Fibrous Joint
Dense Irregular CT between bones
What type of tissue is Cartilaginous
Hyaline Cartilage between Bones
Synovial
synovial fluid between bones
Synarthroses examples
Immovable
*sutures
*Gomphosis (fibrous and looks like root of tooth/alveoli area)
*Synchondrosis (cartilaginous joint idk where tho)
amphiarthrosis
slightly movable- examples: intervertebral discs
*Syndesmosis (fibrous)- between tibia and fibia
*Interosseous Membrane (fibrous) also between fibia and tibia?
*Symphysis (such as pubic) (is cartilaginous joint)
diarthroses (Name and describe all 6!)
Freely movable- examples
*Gliding Joint (back and forth side to side between navicular and cueniforms of tarsus.
*Hinge Joint (elbows, knees- monoaxial and only swing in one direction) specifically trochlea of humerus and trochlear notch of ulna
*Pivot Joint (head of radius and radial notch of ulna)
*Condyloid Joint- joint between radius and the scaphoid and lunate carpus
*Saddle Joint- between trapezium of carpus and metacarpal of the thumb
* Ball and Socket- (between head of femur and acetabulum of hip)
All diarthroses are what type of joints?
Synovial!
functions of synovial fluid
*lubrication of the joint
*provision of nutrients to articular cartilage
*shock absorption
accessory structures of synovial joints
*bursae (little pillows)
*menisci (articular discs)
*intra and extracapsular ligaments
*tendons (bone to muscle)
Two types of arthritis
osteoarthritis (degenerative)
-bone ends rub together and it is due to wear and tear over time
Rheumatoid Arthritis (inflammatory) basically auto immune and more typically older patients. Involves a swollen and inflamed synovial membrane because the body thinks it is a pathogen
Shoulder Joint is . . .
also called glenohumeral joint
diarthrosis- freely moveable
a ball and socket joint
tri-axial joint (more injury)
What is the shoulder joint stabilized by?
4 ligaments and the tendons of 4 muscles
Rotator cuff muscles:
-supraspinatus
-infraspinatus
-subscapularis
-Tres Minor
Knee Joint is . . .
also called tibiofemoral
diarthrosis, hinge joint, mono axial, and medial and lateral menisci cushion the joint
Ligaments that stabilize the knee joint
7!!
2 intracapsular
5 extracapsular
test for ACL vs PCL
ACL= anterior drawer test
PCL = posterior drawer test
where is yellow bone marrow found?
Diaphysis
Bone Cells
Osteogenic Cells
Osteoblasts
Osteocytes
Osteoclasts
Osteogenic Cells
what are they formed from?
What do they become?
AKA Osteoprogenitor Cells or “Bone Stem Cells”
formed from mesenchyme
differentiate into osteoblasts
Cycle example (need to be able to explain)
osteogenic Cells -> mitosis -> daughter osteogenic cells -> differentiation -> osteoblasts (some change and some do not)
Osteoblasts
cells that build bones (BONE FORMATION)
These are IMMATURE bone cells and the golgi folds on surface giveaway its role in secretion
*synthesize organic components (collagen fibers) of matrix
*Initiate calcification- take Ca from blood and put in matrix by exocytosis
Osteocytes
Mature Bone cells
Involved in MAINTENANCE of bone tissue
Senses microdamage and mechanical forces on bone- sends signals for repair (VIA DENDRITES)
Osteoclasts
what do they release and for what function?
Where are they derived from?
break down bone- RESORPTION
*Release proteolytic enzymes and acids to degrade collagen and release minerals to blood
*Derived from Myeloid Stem Cells NOT osteogenic cells
Osteoclasts parts and functions
Sealing Zone- Growth, depositing, and fixing
Ruffled Border- Secretory with “resorption lacuna” which are amino acids floating around
Functional Secretory Domain-releases out into blood
goal/s of bone remodeling
Achieve Strength for loading and lightness for mobility
Reach Peak Strength (during growth) and Maintain this by removing damaged bone in adulthood
How does bone modeling achieve Strength and lightness
-Strategically deposit bone where it is needed for strength
-Remove bone from where it is not needed to avoid bulk
Fatigue Damage and How the bone responds to it with each bone cell type
- detect location and magnitude of damage (osteoclast)
- remove damage (osteoclast)
- Replace it with new bone (osteoblast)
- Restore bone material composition, microarchitecture, and macroarchitecture
Extracellular Matrix of Bones
Ground Substance (GAG, water, minerals, noncollagenous proteins)
and Organic components- COLLAGEN FIBERS
Ground Substance
GAGS- glycosaminoglycans
Glycoproteins (polysaccharides and protein)
they are negatively charged so they trap water
Collagen Fibers
*fibrous protein arranged in a helical form (Type 1 collagen)
*Very resistant to pulling forces
*Provides flexibility and framework for deposition of calcium crystals
Hierarchial Organization of Collagen in Bone
osteoblast-tropocollagen-microfibril-fibril-fiiber-lamella-osteon- compact cortical bone-bone
Inorganic Components of ECM
- Water- 25% and is attracted to ground substance
- Hydroxyapatite Ca10(PO4)6OH2
Forms mineral plates that fill spaces within collagen fibers
What two things provide strength to the ECM??
Collagen and Minderals
collagen provides flexibility and minerals provide firmness
experiments to test the strength of collagen and then minerals
collagen- proteolytic enzymes applied and bone becomes brittle and crumbly
Minerals- soak in vinegar and it becomes flexible
Rickets
Children
Calcium deficiency due to lack of vitamin D
Flexible,bowed legs
Scurvy
problem with collagen synthesis due to vitamin C deficiency
brittle, easily broken bones
Spongy Bone organization
Irregular lattice of thin plates called trabeculae
osteocytes in lacunae
Spongy Bone Location
*Epiphyses of Long Bones
*Surrounds Marrow Cavities
*Flat, short, Irregular bones
Spongy Bone Functions
*Withstand forces from many directions- trabeculae arranged along lines of stress
*Lightens the skeleton- less strong than compact bone
*Contains red marrow for hemopoiesis
Compact Bone Organization
Solid network of bone organized in concentric ring structures called osteons
Compact Bone Location
-External layer of all bones
-Diaphysis of long bones
Compact Bone Function
Gives long Bones ability to withstand forces along longitudinal axis
Why is every bone not compact bone?
too heavy and too difficult to remodel
what is the functional unit of a compact bone?
osteon
What is the epiphyseal of the long bone made of in infants?
Cartilage
epiphyseal plates stay as what until the end of adulthood?
Cartilage
bones of a baby before birth are composed of:
1) loose connective tissue (messenchyme)
2) Hyaline Cartilage
Ossification
*Replacement of connective tissue by bone
*Begins during the second month of development
*Continues for many years after birth
two types of ossification
Intramembranous and Endochondral
intramembranous ossification
Within membrane
messenchyme becomes bone
Endochondral Ossification
Inside Cartilage
Messenchyme–>cartilage –> bone
Bones formed by intramembranous ossification
Cranial, Facial, Sternum, Clavicles
Heterotrophic Bone Formation
- Also considered intramembranous ossification
abnormal stresses can cause bone formation where it is not supposed to be
sesamoid bones
Sesamoid Vs. Bone spur
Intramembranous ossification Steps
1) Development of ossification center: Messenchymal cells become osteogenic cells, then blasts, then those secrete bone matrix
2) Calcification
osteoblasts deposit calcium in the matrix and then blasts diff. into cytes
3) Formation of Trabeculae- ECM develops into trabec that fuse to form spongy bone
4)Development of Periosteum- remodel of spongy bone to compact bone
what is an essential part of ossification?
Calcification
Endochondral Ossfication
Most bones formed this way
Growth in LENGTH at epiphyseal plate is triggered by this
Endochondral Ossification Steps
1, development of a cartilage model
2. growth of cartilage model
3. blasts create a primary ossification center
4. osteoclasts create a marrow cavity
5. around birth, secondary ossification centers form in the epiphyses
6. spongy bone replaces cartilage at epiphyses (except for plates)
Types of Endo ossification
Primary-
*marrow cavity formed
*replaces all cartilage with bone
*located in diaphysis and cocurs before birth
Secondary-
*no marrow cavity
*some cartilage left for growth plates and artic. cart.
*located in epiphyses
*occurs at time of birth
What are the two processes that occur at the growth of an epiphyseal plate
- interstitial growth of cartilage
- Endochondral ossification
What occurs/is meant by interstitial growth of cartilage
cartilage grows from within at the epiphyseal side of the epiphyseal plate
4 steps of interstitial growth
- Mesenchymal cells differentiate into chondroblasts
- chondroblasts build matrix and differentiate into chondrocytes
- chondrocytes divide and spread apart
- cartilage tissue grows from within
Endochondral Ossification is when
cartilage is replaced by bone on the diaphyseal side of the epiphyseal plate
Diaphysis grows in LENGTH but the thickness of what does not change
the thickness of the epiphyseal plate
Epiphyseal Plate growth (summary/should be able to roughly explain the steps)
*Diaphyseal osteoclasts breakdown calcified cartilage
*Osteoblasts lay down spongy bone
*Chondrocytes Continue to form cartilage matrix in prolif. region
*Length growth stops when clasts and blasts are working faster than chondrocytes in the proliferation zone- epiphyseal plate becomes the epiphys line
at what age for male and female do plates close?
18 females
21 males
why do epiphyseal plates close and what forms after?
epiphyseal cartilage stops dividing and are replaced by bone
the epiphyseal line forms
——- cannot occur after the epiphyseal plate closes
interstitial growth
Appositional growth is what? And what does it generated?
growth in width
It generates new osteons
What does appositional growth increase?
bone diameter
cortical width
medullary cavity size
Appositional growth steps
*periosteal osteogenic cells become osteoblasts
*these blasts build bone on outer surface of the bone
*endosteal osteoclasts increase the diameter of medullary by breaking down from the middle
4 steps leading to osteons being added on the periosteal side
1) ridges in Periosteum create groove for blood vessel
2) periosteal ridges fuse, making an endosteum lined tunnel
3) blasts in endosteum build concentric lamellae inward towards center of tunnel Foraming a new osteon
4) bone grows outward and osteon formation repeats
2 fracture classifications
Traumatic
Pathologic
Traumatic Fracture
normal bone experiencing abnormal force
pathologic fracture
abnormal bone experiencing normal forces
Gross classification of fractures
*Incomplete: partially broken “greenstick”
*Complete: all the way through, loss of continuity
*Displaced Vs. Non-displaced: separation between the broken pieces or not
*Open (Compound) Vs Closed (simple): open is where there is a complete displaced fracture in which one or more broken pieces break the surface
Comminuted Fracture
Think Finger example
hypertension from finger bent backwards too far, tendon tears and pulls off the bone
avulsion injury from Jersey finger
What is an epiphyseal fracture and why is this naming different from avulsion, spiral, etc.
it is different because it is named via location and not based off of the nature of the break
This fracture can be incomplete or complete and it is on the plate between diaphysis and epiphysis
3 steps of bone- repair
need to be able to explain each (double check on slide 39 of 2.6
1) formation of fracture hematoma (6-8 hours)
2a) fibrocartilage callus formation (3 weeks)
2b) bony callus formation(Endochondral ossification) (3-4 months)
3) Bone remodeling (6-9 months)
Bone Fracture Treatment
Immobilization
Reduction (open)- surgical use of rods, screws, etc.
reduction (closed)- manipulation of bone without surgery
3 Factors that Influence Bone
Diet
Hormones
Excercise
Minerals and Vitamis and what they do for your bones
Ca and K+ found in blood
Vitamin A Stimson osteoblast activity
Vitamin C needed for collagen synthesis
Vitamin D stimulates Ca absorption in GI tract (rickets)
Vitamins K and B12 needed for synthesis of bone proteins
What is the normal range of blood calcium?
8.5-11 mg/dL
Why is calcium important and what are some ways we control its entry and exit from the blood?
Membrane excitability
blood clotting
secondary messenger
Control entry and exit:
-Bone storage
-Kidney excretion
-Intestinal Absorption
What 3 hormones are involved in Ca homeostasis
Calcitonin
calcitrol (vitamin D)
Parathyroid hormone
What is Calcitonin’s
Stimulus
Source:
Target Tissue:
Action:
and End Result:
Stimulus: High blood Ca
Source: thyroid gland
Target Tissue: bone, kidney, intestine
Action:
inhibits clast activity
increases Ca excretion in kidneys
Inhibits absorption of Ca at intestine
End Result: decreased blood Ca levels (- Feedback Loop)
Parathyroid Hormone
Stimulus
Source:
Target Tissue:
Action:
and End Result:
Stimulus: low blood Ca
Source: parathyroid gland
Target Tissue: bone, kidney, intestine
Action:
-Stim clast activity
-decrease excretion of Ca at kidney
-Stimulates intestinal absorption of calcium and promotes Calcitrol action
End Result: Increase blood calcium levels
Calcitrol is what form of vitamin D
Active Form
When is vitamin D converted to the active Form only if what is present
PTH
Calcitrol
Stimulus
Source:
Target Tissue:
Action:
and End Result:
Stimulus: PTH, low blood Ca
Source: kidney
Target Tissue: bone, kidney, intestine
Action:
End Result:
How much calcium do you need per day
1000 ng Ca per day
What hormones act on osteoclasts?
calcitonin and parathyroid hormone
What hormones act on osteoblasts
GH and Estrogen/Test.
Growth Hormone (somatotropin) stimulates what?
cell growth and protein synthesis (collagen)
secretion of IGF’s that stim osteoblast activity
Pituitary Dwarfism
Children with low levels of GH- slow epiphyseal growth
Pituitary Gigantism
hypersecretion of GH in childhood
-accelerated epiphyseal growth
Acromegaly
Hypersecretion of GH AFTER puberty
leads to appositional growth in skull hands and feet and cartilage because epiphyseal plates of long bones are already closed
