Bone -REYNOLD Flashcards
What is the difference between the ground subtance of cartilage and bone?
Cartilage:
- Gel type
- For shock absorption and protections (joints)
Bone:
- Calcified
- For weight support
Discuss cartilage matrix:
- The ground substance is composed of what 3 things?
- What collagen type does cartilage contain in the extracellular matrix?
- What two cells can be found in cartilage?
Cartilage Matrix
- Ground substance: GAGs, proteoglycans, glycoproteins
- Cartilage = Type II collagen
- Cartilage cells:
- Chondrocytes: surrounded by lacunae
- Chondroblasts
What are the 3 types of cartilage? (discuss each)
Hyaline cartilage: (most common)
- Type II collagen fibers, proteoglycans and hyaluronic acid
- Stiff, flexible support
- Reduces friction between bones
- Found in synovial joints, rib tips, sternum and trachea
Elastic cartilage: hyaline cartilage plus elastic fibers
- Supportive but bends easily
- Found in external ear and epiglottis
Fibrocartilage:
- hyaline cartilage plus abundant type I collagen fibers- causing an acidophilic appearance
- Limits movement
- Prevents bone-bone contact
- Pads knee joints
- Found between pubic bones and intervertebral discs
Which of the following has abundant type I collagen to prevent bone-bone contact?
A. Hyaline cartilage
B. Elastic cartilage
C. Fibrocartilage
C. Fibrocartilage
Which of the following would be found in external ear and epiglottis?
A. Hyaline cartilage
B. Elastic cartilage
C. Fibrocartilage
B. Elastic cartilage
Hyaline = synovial joints, rib tips, sternum and trachea
Elastic = external ear and epiglottis
Fibrocartilage = between pubic bones and intervertebral discs
Which of the following would be found between pubic bones and intervertebral discs?
A. Hyaline cartilage
B. Elastic cartilage
C. Fibrocartilage
C. Fibrocartilage
Hyaline cartilage can be found in all of the following EXCEPT:
A. Synovial joints
B. Epiglottis
C. Rib tips
D. Sternum
E. Trachea
B. Epiglottis
Which of the following is surrounded by a lacunae?
A. Chondroblasts
B. Osteoblasts
C. Chondrocytes
D. Osteoprogenitor cells
D. Chondrocytes
Which of the following is arranged around central canals and are connected by cytoplasmic extensions called canaliculi?
A. Chondroblasts
B. Osteoblasts
C. Osteocytes
D. Chondrocytes
C. Osteocytes
The minerals calcium phosphate and calcium hydroxide combine to form ______, which is the main component of bone.
Hydroxyapatite
What two minerals located in the ground substance of bone combine to form hydroxyapatite?
Calcium phosphate and calcium hydroxide
Which of the following is dominant in bone?
A. Type I collagen
B. Type II collagen
C. Type III collagen
A. Type I collagen
What are the four cells that are associated with bone?
- Osteoblast
- Osteoclast
- Osteocytes
- Osteoprogenitor cells
Discuss each of the following cells associated with bone:
- Osteoblast
- Osteoclast
- Osteocyte
- Osteoprogenitor cells
Osteoblast:
- Mesenchyme —> osteoprogenitor cells —> osteoblasts
- immature bone cell that secretes organic components of matrix
- Produces Osteoid which is the uncalcified form of bone
- Mononucleated
Osteoclast:
- Mesenchyme —> Myeloid —> Monocytes —> osteoclast
- Multinucleated
Osteocyte:
- Mesenchyme —> osteoprogenitor cells —> osteoblast —> Osteocyte
- Are between layers (lamellae) of matrix
- Connected by cytoplasmic extensions through canaliculi in lamellae
- Do not divide
- Functions: maintain protein and mineral content of matrix and to help repair damaged one
Osteoprogenitor cells:
- located in endosteum, the inner cellular layer of periosteum
- Assist in fracture repair
Monocytes are a precursor of which of the following?
A. Osteoblast
B. Osteoclast
C. Osteocyte
D. Osteoprogenitor cells
B. Osteoclast
Which of the following live in between lamellae and connect by cytoplasmic extensions called canaliculi?
A. Osteoblast
B. Osteoclast
C. Osteocyte
D. Osteoprogenitor cells
C. Osteocyte
Which of the following bone cells is multinucleated?
A. Osteoblast
B. Osteoclast
C. Osteocyte
D. Osteoprogenitor cells
B. Osteoclast
Osteoclast are derived from monocytes (which are multinucleated)
Compare and contrast the extracellular matrix of cartilage and bone:
Carilage:
- Ground substance:
- Gel-type
- For shock absorption and protection (joints)
- GAGs, proteoglycans, glycoproteins
- Extracellular fibers
- Type II collagen
Bone:
- Ground substance
- calcium phosphate + calcium hydroxide = hydroxyapatite
- Type I collagen
Which of the following is located in endosteum, the inner cellular layer of periosteum?
A. Osteoprogenitor cells
B. Osteocytes
C. Osteoblasts
D. Osteoclasts
A. Osteoprogenitor cells
Which of the following is found in the skull, sternum, ribs and scapulae?
A. Sutural bones
B. Irregular bones
C. Short bones
D. Flat bones
E. Long bones
D. Flat bones
Found between flat bones of the skull:
A. Sutural bones
B. Irregular bones
C. Short bones
D. Flat bones
E. Long bones
A. Sutural bones
Ankle and wrist bones are examples of which of the following?
A. Sutural bones
B. Irregular bones
C. Short bones
D. Flat bones
E. Long bones
C. Short bones
Spinal vertebrae and pelvic bones are examples of which of the following?
A. Sutural bones
B. Irregular bones
C. Short bones
D. Flat bones
E. Long bones
B. Irregular bones
_____ are found inside tendons near joints of knees, hands and feet.
A. Sutural bone
B. Irregular bone
C. Short bone
D. Sesamoid bone
E. Long bone
D. Sesamoid bones
Sutural bone = found between flat bones of skull
Irregular bone = spinal vertebrae and pelvic bones
Short bone = ankle and wrist
Flat bone = skull, sternum, ribs and scapulae
Long bone = arms, legs, hands, feet, fingers and toes
Sesamoid bone = inside tendons near joints of knees, hands and feet
Flat bone can be found in all of the following EXCEPT:
A. Skull
B. Sternum
C. Scapulae
D. Ribs
E. Spinal vertebrae
E. Spinal vertebrae
Flat bone = skull, sternum, scapulae and ribs
Long bone can be found in all of the following EXCEPT:
A. Arms
B. Legs
C. Wrist
D. Hands
E. Toes
C. Wrist
Short bone = ankle and wrist
Discuss each of the following:
- Epiphysis
- Metaphysis
- Diaphysis
Epiphysis:
- wide part at each end
- articulation with other bones
- mostly spongy (cancellous) bone
- covered with compact bone (cortex)
Metaphysis:
- where diaphysis and epiphysis meet
Diaphysis:
- the shaft
- a heavy wall of compact bone, or dense bone
- a central space called medullary (marrow) cavity
Which of the following is mostly composed of spongy (cancellous) bone?
A. Epiphysis
B. Metaphysis
C. Diaphysis
A. Epiphysis
Epiphysis = spongy bone
Diaphysis = compact bone
Which of the following is mostly composed of compact bone?
A. Epiphysis
B. Metaphysis
C. Diaphysis
C. Diaphysis
Epiphysis = spongy bone
Diaphysis = compact bone
Which of the following is the part of bone that articulates with other bones?
A. Epiphysis
B. Metaphysis
C. Diaphysis
A. Epiphysis
Epipysis = End of bone
Metaphysis = between epiphysis and diaphysis
Diaphysis = the shaft
Which of the following is the part of bone that is known as the shaft?
A. Epiphysis
B. Metaphysis
C. Diaphysis
C. Diaphysis
______ is a thin layer of cartilage that covers area of epiphysis where bones form a joint. This structure reduces friction and shock.
A. Articular cartilage
B. Periosteum
C. Endosteum
A. Articular cartilage
______ is a thin membrane that lines medullary cavity that contains a single layer of endosteal or osteoprogenitor cells (resemble fibroblasts).
A. Articular cartilage
B. Periosteum
C. Endosteum
C. Endosteum
_______ is a sheath of connective tissue, containing osteoprogenitor cells, covering bone surface everywhere except where articular cartilage is present.
A. Articular cartilage
B. Periosteum
C. Endosteum
B. Periosteum
The amount of calcified matrix determines which category a region of bone is assigned to. Spongy bone is 40% calcified and compact bone is 60% calcified.
A. both statements are true
B. both statements are false
C. First statement is true, second is false
D. First statement is false, second is true
C. First statement is true, second is false
Spongy (cancellous) bone = 20% calcified
Compact (cortical) bone = 80% calcified
Discuss the structure of compact (cortical) bone:
- ____ is the basic unit
- Discuss this basic unit
Compact bone
-
Osteon is the basic unit
- Osteocytes are arranged in concentric lamellae
- Around a central canal containing blood vessels
- Perforating canals are perpendicular to central canal and carry blood vessels into bone and marrow
- Circumferential lamellae is wrapped around long bone and bind osteons together
Discuss the structure of Spongy bone:
Spongy bone
- Does NOT contain osteons
- The matrix forms an open network of trabeculae
- Trabeculae have no blood vessels
- The space between trabeculae is filled with Red bone marrow
- Red Bone Marrow
- contains blood vessels
- forms RBCs
- supplies nutrients to osteocytes
- Yellow Bone Marrow
- stores fat
All of the following are structural components of spongy bone EXCEPT:
A. Red bone marrow
B. Osteons
C. Trabeculae
D. Yellow bone marrow
B. Osteons
Compact bone:
- Osteons
- Central canal
- Perforating canals
- Circumferential lamellae
All of the following are structural components of Compact bone EXCEPT:
A. Osteons
B. Central canal
C. Perforating canals
D. Circumferential lamellae
E. Trabeculae (spicules)
E. Trabeculae (spicules)
Discuss Periosteum in regards to compact bone:
- What does it cover
- What are the two layers of the periosteum?
- What connects with collagen fibers in bone as well as joints, tendons and ligaments?
- What are the 3 main functions of the periosteum?
Periosteum
- A membrane that covers the outside of compact bone
- Outer fibrous layer and inner cellular layer
- Perforating fibers connect with collagen fibers as well as joints, tendons and ligaments
-
3 main functions of the periosteum
- isolates bone from surrounding tissues
- provides a route for circulatory and nervous supply
- participates in bone growth and repair
Which of the following is located on the inside?
A. Periosteum
B. Endosteum
B. Endosteum
Discuss Endosteum:
- is it located on the outside or inside?
- what two things does it line?
- covers _____ of spongy bone.
- what 3 cells does it contain?
- What is it’s function?
Endosteum
- Located on the inside
- An incomplete cellular layer
- Lines the medullary (marrow) cavity as well as the central canal
- Covers trabeculae of spongy bone
- Contains osteoprogenitor cells, osteoblasts and osteoclasts
- Functions in bone growth and repair (periosteum does this and more)
Which of the following is the function of the Endosteum?
A. Isolates bone from surrounding tissue
B. Provides a route for circulatory and nervous supply
C. Participates in bone growth and repair
D. All of the above
C. Participates in bone growth and repair
Endosteum function:
- bone growth and repair
Periosteum function:
- bone growth and repair
- isolates bone from surrounding tissue
- provides a route for circulatory and nervous supply
Which of the following is the function of the Periosteum?
A. Isolates bone from surrounding tissue
B. Provides a route for circulatory and nervous supply
C. Participates in bone growth and repair
D. All of the above
D. All of the above
Endosteum is only involved in bone growth and repair
All of the following effect bone development EXCEPT:
A. Gender
B. Diet
C. Health
D. Weight
E. Individual differences in bone
D. Weight
note: human bones grow until about age 25
Bone formation:
A. Ossification
B. Calcification
C. Osteogenesis
C. Osteogenesis
The process of replacing other tissues with bone is referred to as _______.
A. Ossification
B. Calcification
C. Osteogenesis
A. Ossification
Calcification:
- the process of depositing calcium salts
- Occurs during bone ossification and on other tissues
What are the two types of Ossification?
- Which one is derived from the neural crest?
- Which one is associated with long bones, vertebrae and ribs?
-
Intramembraneous Ossification (mesenchyme)
* skull bones derived from neural crest - Endochondral Ossification (cartilage)
- Vertebrae and ribs derived from sclerotome mesoderm
- long bones of limbs from lateral plate mesoderm
______ ossifies bones that originate as hyaline cartilage.
Endochondral ossification
note: most bones originate as hyaline cartilage
(T/F)
Most bones originate as fibrocartilage and undergo endochondral ossification.
False
correct answer: Most bones originate as hyaline cartilage
What are the 6 main steps of Endochondral ossification in the formation of bone?
- Chondrocytes begin to enlarge and the matrix will calcify and get more thin. Calcifying the matrix will deminish nutrients ultimately starving chondrocytes to death.
2. Bone collar formation
- Angiogenesis will occur recruiting blood vessels. The blood vessels will supply the cartilage with nutrients and bring mesenchymal cells, which will differentiate into osteoprogenitor cells and differentiate into osteoblasts.
- osteoblast will gather at the diaphysis and form the bone collar (this is the first evidence of bone formation)
3. Primary ossification center develops in diaphysis
- Periosteal bud invades the cavity (in the diaphysis) causing the formation of spongy bone. The periosteal bud will bring with it blood vessels supplying the future bone with osteoprogenitor cells (become osteoblasts) and monocytes (become osteoclasts). The osteoclasts will degrade the matrix leaving a space for the primary ossification center to develop in the diaphysis.
4. The primary ossification center continues to enlarge. Osteoclast continue to degrade the bone and the medullary cavity is on the verge of becoming fully formed. Cartilagenous growth is only occuring at the epiphysis at this stage.
5. Secondary ossification centers form at the epiphysis
- The epiphysis begins to ossify
- Cartilage in the metaphysis continues to grow
- The epiphyseal plate (cartilage) is the last site of active growing cartilage (known as the growth plate). Epiphyseal plates will fuse
Endochondrial ossification occurs in development of all of the following EXCEPT:
A. Skull bones
B. Vertebrae
C. Ribs
D. Long bones
A. Skull bones
Intramembranous ossification = skull bones (such as the mandible and clavicle)
Why is intramembranous ossification also called dermal ossification?
- What bones does intramembranous ossification form?
- What type of bone does intramembranous ossification produce? (compact/spongy)
- Called dermal ossification bc it occurs in the dermis
- produces dermal bones such as the mandible and clavical
- Intramembranous ossification produces spongy bone w/ trabeculae
What effect does exercise have on bone remodeling?
- Heavily stressed bones become thicker and stronger
- Mineral recycling allows bones to adapt to stress
- Up to a third of bone mass can be lost in a few weeks of activity
Discuss the role of nutrition in normal bone growth and maintanance?
- A dietary source of what two minerals is important in bone growth and maintanance?
- A dietary source of what 4 vitamins are required?
- Which of the 4 vitamins is involved in collagen synthesis and stimulation of osteoblast differentiation?
- What vitamin stimulates osteoblast activity?
- What 2 vitamins help synthesize bone proteins?
- A dietary source of calcium and phosphate salts
- plus small amounts of magnesium, fluoride, iron and manganese
- Vitamin C is required for collagen synthesis and stimulation of osteoblast differentiation
- Vitamin A stimulates osteoblast activity
- Vitamins K and B12 help synthesize bone proteins
Discuss hormones role in normal bone growth and maintenance:
- What hormone is synthesized in the kidney and functions to help absorb calcium and phosphorus from digestive tract?
- Synthesis requires vitamin _____.
- What 2 hormones stimulate bone growth?
- What 2 hormones stimulate osteoblasts
- What 2 hormones regulate calcium and phosphate levels?
Calcitriol:
- made in the kidneys
-
helps absorb calcium and phosphorus from digestive tract
- synthesis requires vitamin D3
Growth hormone and thyroxine:
- stimulate bone growth
Estrogen and androgens:
- stimulate osteoblasts
Calcitonin and PTH:
- regulate calcium and phosphate levels
Which of the following hormones helps absorb calcium and phosphorus from the digestive tract?
A. Calcitriol
B. Calcitonin
C. PTH
D. Estrogen
E. Thyroxine
A. Calcitriol
Which of the following hormones regulate calcium and phosphate levels?
(select all that apply)
A. Calcitriol
B. Calcitonin
C. PTH
D. Estrogen
E. Thyroxine
B. Calcitonin
C. PTH
Which of the following is the most abundant mineral in the human body?
A. iron
B. phosphate
C. calcium
D. fluoride
C. calcium
Calcium ions are vital to:
- membranes
- neurons
- muscles (especially heart cells)
Calcium ions are vital to all of the following EXCEPT:
A. epithelial cells
B. membranes
C. neurons
D. muscle cells
E. heart cells
A. epithelial cells
Calcium ions are vital to:
- membranes
- neurons
- muscle cells (especial heart cells)
