110 terms

5 Cartilage and Bone Tissue

What are the 5 types of connective tissue?
Connective Tissue Proper
- Loose Connective Tissue
- Dense Connective Tissue
What are the types of cartilage?
Which is the most abundant type of cartilage?
How does hyaline cartilage provide support?
Through flexibility and resilience.
Where do you find hyaline cartliage?
Articular cartilage (found at joints)
Epiphyseal plate
Fetal skeleton
What does fibrocartilage contain?
Thick collagen fibers
What does fibrocartilage do?
It acts as a shock absorber.
Where do you find fibrocartilage?
Intervertebral discs
Menisci of knee
Pubic symphysis
What does elastic tissue contain?
Highly branched elastic fibers.
What does elastic tissue do?
It provides flexibility.
Where do you find elastic cartilage?
Auricle of the ear
Epiglottis (Determines what tube something goes down from your mouth)
What are the characteristics of cartilage?
Semirigid, weaker than bone.
Flexible and resilient due to elastic fibers and water content.
Avascular (recieves nutrient supply through diffusion.
What are the functions of cartilage?
Support soft tissues
Articular surfaces for joints
Provide a model for endochondral bone formation (making bone from cartilage)
What are the immature cartilage cells called?
What are the mature cartilage cells called?
What are the functions of cartilage?
Support of soft tissues
Articular surfaces for joints
Provide a model for endochondral (endo=inside/within, chondral= cartilage) bone formation. (Making bone from cartilage)
What do the chondroblasts do?
Produce the matrix of cartilage
Where do you find chondrocytes?
They reside in lacunae.
Describe the structure of cartilage.
Chondroblasts produce the matrix of the cartilage. Once they become encased within the matrix they have produced and secreted, the cells are called chondrocytes and occupy small spaces called lacunae.
Cartilage has an extracellular matrix.
Perichondrium surrounds pieces of cartilage.
What is perichondrium? What does it provide to the cartilage?
Perichondrium is dense connective tissue.
It provides mechanical support and protection.
What is the primary component of bone?
Osseous connective tissue (bone connective tissue)
What type of extracellular matrix does bone have?
Calcified extracellular matrix. (Calcium phosphate)
What are the functions of bone?
Support and protect
Hemophoiesis (Hematopoiesis)
Storage of minerals and energy reserves
How do the bones support?
They create the framework of the body.
How do bones protect the body?
They protect vital organs from injury and trauma.
e.g. cranial bones, rib cage, vertebrae, pelvis
How do the bones assist in movement?
They provide attachment points for muscles.
What is hemopoiesis (hematopoiesis)?
Hemo = blood, poiesis = creation/formation
Red bone marrow (making blood)
How do the bones assist in the storage of minerals and energy reserves?
Storage: Calcium phosphate
Energy: Yellow bone marrow (yellow because it contains fat)
Who has exclusively red bone marrow? Why?
Children, because they are growing and need to create more blood.
Who has yellow bone marrow? Why?
Adults, because they've stopped growing and start to store fat in their marrow.
What are the structural classifications of bone?
What are the characteristics of a long bone?
Longer than wide
Diaphysis (shaft) and epiphyses (end)
What are some examples of long bones?
Humerus, radius, ulna, metacarpals, phalanges, femur, tibia, fibula, metatarsals
What are the characteristics of short bones?
Length nearly equal to width
Covered by compact bone
Interior is mostly spongy bone
What are some examples of short bones?
Carpals, tarsals, sesamoid bones (bones you aren't born with e.g. patella)
What are the characteristics of flat bones?
Flat, thin surfaces
Roughly parallel surfaces of compact bone with a layer of internally placed spongy bone.
What are some examples of flat bones?
Skull, scapulae, sternum, ribs
What are the characteristics of irregular bones?
Elaborate, complex shapes
What are some examples of irregular bones?
Vertebrae, sacrum, coccyx, os coxa, ethmoid, sphenoid
In a long bone, where is the compact bone found?
It's the superficial bone tissue.
In a long bone, where is the spongy bone found?
It's the deep bone tissue.
In a long bone, where is the epiphysis found?
Ends of long bones.
In a long bone, where is the diaphysis?
It's the shaft.
In a long bone, where is the metaphysis?
Between the epiphysis and diaphysis.
What does the metaphysis contain?
Epiphyseal plate or line.
What is the epiphyseal plate made of?
Hyaline cartilage.
What is the epiphyseal line made of?
Bone that replaces the epiphyseal plate when a person stops growing.
In a long bone, where is the articular cartilage?
Hyaline cartilage covering the ends of bones within a joint.
In a long bone, where is the medullary cavity?
The middle of the bone. Medulla = middle, cavity = hollowed out
What does the medullary cavity contain?
Contains yellow marrow in adults and red marrow in children.
In a long bone, where and what is the endosteum?
Layer of cells lining the spongy bone and medullary cavity. (The first layer of cells inside the bone)
In a long bone, where and what is the periosteum?
Dense CT outer covering of bone.
In a long bone, where and what are the perforating fibers?
Attach the periosteum to compact bone.
In a long bone where and what are the nutrient foramina?
They contain the nutrient artery. Blood vessel travels through the nutrient foramen.
What are the stem cells of bones called?
Osteoprogenitor cells (bone stem cells)
Osteo = bone, pro = before, genitor = creation
Where do osteoprogenitor cells come from?
Mesenchyme (stem cells for all CT)
What do the osteoprogenitor cells turn into?
What are osteoblasts?
Cells that build bone.
How do osteoblasts build bone?
They secrete osteoid (organic part of bone matrix).
They take calcium from the blood stream and make the bone thicker. They decrease blood calcium.
What do the osteoblasts turn into?
What are osteocytes?
Mature bone cells that maintain bone matrix.
Where do the osteocytes reside?
Reside in lacunae (small spaces inside the bone matrix)
What are osteoclasts?
Cells that consume bone. They increase blood calcium levels.
What are the bone types classified by histology?
Compact bone
Spongy bone
What are the characteristics of compact bone (cortical bone)?
Solid, relatively dense
Lined by periosteum
Found in the superficial regions of bone
Contains osteons (functional unit of bone).
What are the other names for spongy bone?
Cancellous bone
Trabecular bone
What are the characteristics of spongy bone?
Lined by endosteum
Found in deeper regions of bone
What is the basic structural and functional unit of compact bone?
Osteon (Haversian system)
Where and what is the central (Haversian) canal in the osteon?
Cylindrical channel that lies in the center of the osteon and runs parallel to it. Blood vessels and nerves that supply the bone run through it.
Where and what are the concentric lamellae in the osteon?
Concentric rings of osseous connective tissue that surround the central canal.
Where are the osteocytes in the osteon?
Mature bone cells housed in lacunae found between adjacent concentric lamellae.
Where and what are the lacunae in the osteon?
Cavities which house the osteocytes. Found between adjacent concentric lamellae.
Where are what are the canaliculi in the osteon?
Connect neighboring lacunae. Allow nutrients, minerals, gases, and wastes to travel between the central canal and osteocytes.
Where and what are the perforating (Volkmann's) canals?
Connect blood and nerve supply to central canal. Perpendicular to central canal.
What is the main structural and functional component of spongy bone?
What do trabeculae look like?
Crisscrossing bars and plates. Strengthen spongy bone.
What and where are parallel lamellae in the trabeculae?
They are the concentric lamellae of tribeculae.
Where do the osteocytes reside in tribeculae?
In lacunae.
What structures provide nutrients to the osteocytes in tribeculae? What kind of process is this?
Canaliculi provide nutrients to cells through diffusion.
What does osteogenesis mean?
Bone Creation
Osteo = bone, genesis = creation
What are the two types of osteogenesis?
Intramembranous Ossification
Endochondral Ossification
What is Intramembranous Ossification?
Bone growth within a membrane (mesenchyme turns into a bone)
What are some examples of osteogenesis throgh intramembranous ossification?
Forms flat bones of the skull, some facial bones, mandible, and clavicle.
What is encochondral ossification?
Bone growth within cartilage.
Turns fetal framwork of hyaline cartilage into bone.
What are some examples of osteogenesis through enochondral ossification?
Formation of most bones.
Where are the ossification centers in endochondral ossification?
Primary ossification center in diaphysis, secondary ossification center in epiphysis.
When does bone growth occur?
During childhood and adolescence.
What does interstitial and appositional growth mean?
Interstitial growth = length
Appositional growth = width
Describe interstitial growth at the epiphyseal plates.
1. Chondroblasts near epiphyseal plate multiply; epiphysis is pushed away from diaphysis.
2. Chondrocytes enlarge; matrix calcifies.
3. Chondrocytes die and disintegrate.
4. Remodeling by osteoclasts.
What are the different types of bone fractures?
Simple fractures
Open or compound fractures
Stress fractures
Pathologic fractures
What is a simple fracture?
Bone doesn't pierce the skin.
What is a compound fracture?
Bone pierces the skin.
What is a stress fracture?
Thin break from repetitive loads (overuse injuries)
What is a pathologic fracture?
Disease weakens the bone. (breaking because of disease, e.g. osteoporosis)
What are the steps of bone repair?
1. Fracture hematoma forms (blood rushes in)
2. Fibrocartilage (soft) callus forms
3. Hard (bony) callus forms
4. Bone remodeled
What is osteomalacia?
Osteo = bone, malacia = soft
Called Rickets in children.
Soft bones
Leads to bowed legs
What causes osteomalacia?
Vitamin D deficiency
Calcium deficiency
What is osteoporosis?
Excessive bone resorption.
Porous bones.
What causes osteporosis?
What is osteitis deformans?
Excessive osteoclast and osteoblast function.
Bone is unstable and immature.
What is another name for osteitis deformans?
Paget's disease.
Where is the most common place to find osteitis deformans?
Os coxa
Name the three types of cartilage. Where do we find each type? Which type is on the end of long bones?
• Hyaline cartilage: Costal cartilage, fetal skeleton, epiphyseal plate, articular cartilage, trachea
• Fibrocartilage: Pubic symphysis, menisci of the knee and intervertebral discs
• Elastic cartilage: Ears and epiglottis
Hyaline cartilage is found on the ends of long bones (articular cartilage).
The names of mature chondro/osteo cells end with the suffix ____. Immature (building cells) end in ____.
Cyte; blast
What is the function of red bone marrow? Yellow bone marrow?
Red bone marrow performs hematopoiesis or the production of blood cells. Yellow bone marrow stores energy in the form of fat.
What are the four structural classifications of bones? What type of bone is the ox coxa? Humerus? Rib? Metacarpal?
Long, short, flat and irregular; os coxa = irregular, humerus = long, rib = flat, metacarpal = long
In what region of a long bone is the epiphyseal plate found?
Draw and label the canals of the osteon. Name the concentric rings and cavities containing osteocytes.
Concentric rings = concentric lamellae; cavities containing osteocytes = lacunae
What type of ossification forms the flat bones of the skull? Which begins with a hyaline model?
Intramembranous; endochrondral
What is the difference between osteoporosis and osteomalacia?
Osteoporosis typically occurs in older adults and is characterized by bone that has become less dense and more porous. Osteomalacia typically occurs in children when bone becomes softer and more flexible due to calcium and vitamin D deficiencies.