Lesson 4: Cartilage and Bone Tissue Flashcards
Describe the FIVE STRUCTURAL COMPONENTS OF CARTILAGE.
1) CHONDROBLASTS: cells that produce cartilage matrix
2) CONDROCYTES: mature cells that reside in lacunae
3) LACUNAE: caves where chondrocytes live
4) EXTRACELLULAR MATRIX: protein fibers embedded in a gel-like ground substance (everything outside of and between cells
5) PERICHONDRIUM: dense irregular connective tissue membrane that surroundings cartilage
- CHONDRO = Cartilage
What are the THREE TYPES OF CARTILAGE? Which one is thickest?
F.H.E.!
1) Fibrocartilage (most thick)
2) Hyaline Cartilage
3) Elastic Cartilage (least thick)
Describe the composition, function, and distribution of FIBROCARTILAGE.
Composition:
- contains thick collagen fibers
Function:
- shock absorber
(forceful movements attacks JOINTS!)
Distribution (locations):
- intervertebral discs
- menisci of knee
- pubic symphysis
- articular disks of jaw
Describe the composition, function, and distribution of HYALINE CARTILAGE.
Composition:
- type II collagen and proteoglycans
- significant amount of water
* the MOST COMMON type of cartilage in the human body
Function:
- flexible but resilient
Distribution (locations):
* EVERYTHING ELSE
- respiratory system
(larynx, trachea, bronchi)
- costal cartilage
- nose
- articular cartilage
- epiphyseal plate
- fetal skeleton
Describe the composition, function, and distribution of ELASTIC CARTILAGE.
Composition:
- contains elastic fibers
Function:
- provides elasticity
Distribution (locations):
- epiglottis (covers respiratory tract when we swallow food and water: AKA THE WRONG PIPE!)
- auricle (external) of the ear
What are the MAJOR (CHARACTERISTICS) and FUNCTIONS OF CARTILAGE?
Characteristics:
* Semirigid, weaker than bone
* Flexible and resilient due to elastic fibers and water content
* Avascular
* Receives nutrient supply through diffusion
Functions:
* Support soft tissues
* Articular surfaces for joints
* Provide a model for endochondral bone formation
What are the MAJOR (CHARACTERISTICS) and FUNCTIONS OF BONE?
Characteristics:
* Osseous connective tissue
* Bone cells (Osteocytes)
* Extracellular matrix made of:
- osteoid (Collagen)
- calcium phosphate
Functions:
* Support and protect:
- Create framework of the body
- Protect vital organs from injury
* Movement:
- Attachment sites for muscles
* Hemopoiesis (Hematopoiesis):
- Red bone marrow
* Storage of minerals and energy:
- Calcium phosphate
- Yellow bone marrow
What are the TWO TYPES OF BONE?
1) Compact (cancellous/trabecular)
2) Spongy (cortical)
What is the DISTINGUISHING FEATURE OF “LONG” BONES?
Provide examples!
- Longer than they are wide:
- Humerus
- Radius
- Ulna
- Metacarpals
- Phalanges
- Femur
- Tibia
- Fibula - Metatarsals
What is the DISTINGUISHING FEATURE OF “SHORT” BONES?
Provide examples!
- Width and length are similar
- Carpals
- Tarsals
- Sesamoid Bones (Patella)
What is the DISTINGUISHING FEATURE OF “FLAT” BONES?
Provide examples!
- Generally flat and rounded
- Most of bones in skull
- Scapulae
- Sternum
- Ribs
(not considered long bones because of how flat and rounded they are!)
What is the DISTINGUISHING FEATURE OF “IRREGULAR” BONES?
Provide examples!
- Don’t fit into other categories haha
- Vertebrae
- Sacrum
- Coccyx
- Os Coxa
- Ethmoid
- Sphenoid
Diagram of a TYPICAL LONG BONE including the following structures:
o Compact bone
o Spongy bone
o Proximal epiphysis
o Distal epiphysis
o Diaphysis
o Metaphysis
o Epiphyseal line
o Articular cartilage
o Medullary cavity
o Endosteum
o Periosteum
o Perforating fibers
o Nutrient foramen
o Yellow bone marrow
o Red bone marrow
- In your diagram, state the function of each long bone structure.
- COMPACT BONE (dense outer layer)
- SPONGY BONE (lighter inner layer)
- EPIPHYSIS (end-point of bone)
- Proximal Epiphysis & Distal Epiphysis - DIAPHYSIS (shaft of the bone)
- METAPHYSIS (meta = change)
- Location of EPIPHYSEAL PLATE (in children) or EPIPHYSEAL LINE (in adults) which indicate how much more a bone will grow! :) - ARTICULAR CARTILAGE (reduce the rubbing between bones near joints)
- MEDULLARY CAVITY (medulla = inner)
- Contains RED BONE MARROW (in children) and YELLOW BONE MARROW (in adults) - ENDOSTEUM (inner wallpaper)
- Layer of cells lining the spongy bone and medullary cavity (not bone!!) - PERIOSTEUM (outer carpet)
- Membrane made of Dense Irregular CT outer covering of bone (not bone!!) - PERFORATING FIBERS (hold periosteum to the bone)
- NUTRIENT FORAMEN (where blood vessels enter the bone)
List the LAYERS OF BONE from superficial to deep.
Superficial –> Deep
Periosteum ->
Compact Bone ->
Spongy Bone ->
Endosteum
What are the CELLS OF BONE? Differentiate between each in terms of FUNCTION and LOCATION.
1) Osteoprogenitor cells
* STEM cells of bone (genesis = origin)
* Found in the periosteum (outer bone layer) and endosteum (inner bone layer lining the medullary cavity)
–> become –>
2) Osteoblasts
* BUILD bone by secreting osteoid
* Found on the bone surfaces (periosteum and endosteum) where bone formation is actively occurring
–> become –>
3) Osteocytes
* MATURE bone cells that maintain bone matrix
* Reside in lacunae, small spaces within the bone matrix.
4) Osteoclasts (multiple nuclei)
* CONSUME bone (bone resorption)
* Found in Howship’s lacunae (resorption bays) on the surfaces of bones undergoing active resorption.
Describe the COMPOSITION OF THE BONE MATRIX, including both ORGANIC and INORGANIC components.
Extracellular Matrix:
* OSTEOID (Collagen)
- Organic component (body naturally produces this)
* CALCIUM PHOSPHATE
- Inorganic component (depends on our diet
Diagram of a TYPICAL LONG BONE including the following structures:
o Compact bone
o Spongy bone
o Red bone marrow
o Endosteum
o Periosteum
- In your diagram, state the function of each long bone structure.
COMPACT BONE (cortical bone)
- Lined by the Periosteum
- Contains Osteons
SPONGY BONE (cancellous/trabecular)
- Lined by Endosteum
- Often contains Red Bone Marrow
Draw a cross-section of a COMPACT BONE (microscopic view) with the following structures:
o Osteon
o Central canal
o Blood vessels
o Lamellae
o Osteocytes
o Lacunae
o Canaliculi
o Perforating canal
- In your diagram, state the functions of each labeled structure.
- OSTEON (Haversian system)
- tree trunk-like structure - CENTRAL CANAL (Haversian canal)
- inside of trunk containing blood vessels - CONCENTRIC LAMELLAE
- rings of the trunk - OSTEOCYTES
- maintain bone health - LACUNAE
- little caves where osteocytes live - CANALICULI
- tiny canals that connect to the lacunae allowing osteocytes to receive blood - PERFORATING (Volkmann’s) CANALS
- connections between central canals (horizontal pathways connecting osteons)
Draw a diagram of SPONGY BONE (microscopic view) with the following structures:
o Trabeculae
o Lamellae
o Osteocytes
o Lacunae
o Canaliculi
NO OSTEONS! (spongy bone does not have a central canal)
* Instead –>
TRABECULAE (beam)
Crisscrossing bars and plates that help maintain bone structure between compact bone (H)
PARALLEL LAMELLAE
OSTEOCYTES within lacunae
CANALICULI (different than canaliculi in compact bone because spongy bone is surrounded by bone marrow–rather than nutrients coming from blood vessels in central canal)
What are the TWO TYPES OF OSSIFICATION?
1) Intramembranous Ossification
2) Endochondral Ossification
What is the process of INTRAMEMBRANOUS OSSIFICATION? Where does this process happen in relation to the clavicle?
Intramembranous = Within Membrane:
* Bone growth within a membrane
* Forms flat bones of the skull, some facial bones, mandible, and clavicle
(CLAVICAL AND UP)
What is the process of ENDROCHONDRAL OSSIFICATION? Where does this process happen in relation to the clavicle?
Endochondral = Within Cartilage:
* Bone growth within cartilage
* Turns fetal framework of hyaline cartilage into bone (ossification)
* Formation of most bones
(BELOW THE CLAVICAL
HOW DO BONES GROW (both lengthwise and in thickness or width) DURING CHILDHOOD?
Interstitial growth (length)
- occurs at epiphysial plates
Appositional growth (thickness)
- occurs at periosteum and endosteum
What are the FOUR DIFFERENT TYPES OF BONE FRACTURES?
1) Simple fracture
* Bone doesn’t pierce the skin
2) Open or compound fracture
* Bone pierces the skin
3) Stress fracture
* Thin break from repetitive loads
4) Pathologic fracture
* Disease weakens bones
