Exam I | Overview of Tissues and Systems Flashcards
Where are osteons located?
compact bone
What are the components of an oseton?
- Haversian canal
- lamellae
- lacunae
Which canals run parallel to the bone axis?
Haversian canals
Which canals run perpendicular to bone axis?
Volkmann’s canals
What are the rings of bone matrix that surround the Haversian canal?
lamellae
What are the spaces that contain the osteocytes?
lacunae
What are canaliculi?
- microscopic canals between the lacunae
- the radiating processes of the osteocytes project into these canals, joined together by gap junctions.
What does the endosteum do?
- lines the bone marrow cavity.
- lines the inner surfaces of the central canals
- covers the trabeculae of spongy bone
What are trabeculae, and where are they found?
- interconnecting plates that bear weight and help the bone resist bending and twisting
- found in spongey bone
What is the medullary cavity?
central cavity of bone shafts where red bone marrow and/or yellow bone marrow (adipose tissue) is stored
What is an osteocyte?
mature bone cell that maintains bone marrow matrix
Where is most of the neural innervation in bone?
periosteum
What do nutrient arteries supply?
- bone marrow
- spongy bone
- compact bone
What do periosteal arteries supply?
much of compact bone
What do metaphyseal and epiphyseal arteries supply?
extremities of bone
How can bones be made clear?
injecting ethyl cinnamate
where do nutrient arteries and veins enter the bone?
by way of nutrient foramina
Where do nutrient veins depart?
epiphyseal regions
Bones have blood vessels, nerves, ______, and ______.
lymphatic vessels; fibers
What is Wolff’s Law?
bones adapts to load (atrophy or hypertrophy)
What is avascular necrosis?
- loss of functional bone tissue following impaired blood supply
- small regions of necrosis occur with every fracture or significant trauma to bone
What is the concern with a compound fracture? Why?
infection, because bone breaks through skin (at least momentarily)
What type of fracture is typically associated with falling injuries?
impacted fracture. broken ends are driven together
What can cause a pathological fracture?
osteoporosis or osteopenia, which weaken bone
What is the difference between an compound and closed fracture?
in a closed fracture there is no perforation of skin
What is another name for closed fracture?
simple fracture
What is the difference between a complete and incomplete fracture?
complete fracture is bone broken into 2 or more parts; bone remains whole in incomplete fracture
What is the difference between a complete and comminuted fracture?
comminuted fracture is FRAGMENTATION of bone, complete fracture is into DISCRETE parts
What are 2 types of incomplete fractures?
- greenstick fracture
- stress fracture
what is a greenstick fracture?
incomplete fracture following distortion of bone
What is a transverse fracture?
a fracture at a right angle to bone axis
What is an impacted fracture?
broken ends driven together
What 5 things does proper healing of bones require?
1) that the broken ‘ends’ be set in normal apposition
2) that fibroblasts secrete sufficient collagen to form a CALLUS that holds ends together
3) that REMODELING occurs in order to ‘bridge’ the fracture
4) CALCIFICATION of fractured region
5) RESORPTION of callus and displacement of callus by bone
What is osteogenesis imperfecta?
a group of genetic disorders in which bones break easily (can be once a week or month) from mild trauma or no apparent reason
What is an ILIZAROV?
- a circular fixator used to stabilize and lengthen the tibia
- small wires and pins fix the bone to the frame until healing occurs
What is mesenchyme?
embryonic connective tissue
What is endochondral ossification?
-long bones originating from cartilage
What is intramembranous ossification?
fetal ossification of mesenchyme
How are bones derived from mesenchyme?
- intramembranous ossification
- endochondral ossification
What are the first 4 steps of endochondral ossification (before primary ossification)
- mesenchymal cells become chondroblasts, forming the cartilaginous model
- cartilage begins to ossify from central region of bone
- periosteal capillaries invade interior bone
- blood vessels and osteogenic cells form PERIOSTEAL BUD
Where does the primary ossification center generally appear?
in the shaft (diaphysis)
Where and when does the secondary ossification center appear?
epiphyses; after birth
When do primary and secondary ossification centers meet?
when lengthening ceases (epiphyseal plates close)
Determination of bone age is dependent on knowledge of what 3 things?
- sites of normal ossification
- rates of normal ossification
- normal progression of fusion of ossification centers
What is bone age generally estimated from?
- location and degree of ossification in ossification centers
- prominence of epiphyseal plate
- extent of fusion
How must chondrocytes receive nutrients?
diffusion from the perichondrium, since cartilage lacks blood vessels
What is the function of the perichondrium?
- to surround cartilage (except articular cartilage) and provides it with nutrients
- provides sites for attachment of binding tissues
Where in the body can you find elastic cartilage?
- epiglottis
- pinna (ear)
What fibers is fibrocartilage made up of?
collagen
Where in the body can you find fibrocartilage?
- intervertebral disks
- innermost pubic symphysis
Name 5 places in the body where you can find hyaline cartilage.
- nose
- bronchi
- costal cartilage
- articular cartilage
- embryonic model
What are 3 classes of skeletal joint?
- fibrous
- cartilage: primary, secondary (fibrocartilage layer)
- synovial
What are the 6 types of synovial joint?
- hinge
- ball and socket
- plane
- pivot
- condyloid
- saddle
Which joints are generally immoveable or partially moveable?
fibrous joints
What is a syndesmosis?
- partially moveable joint
- bones connected by fibrous tissue sheet
What is a gomphosis?
- dentoalveolar syndesmosis
- anchors tooth
What ties the tooth into the socket?
periodontium
Give 3 examples of syndesmoses.
- cranial sutures
- interosseous membrane (forearm, lower leg)
- bilateral costotransverse joints of rib 11 and 12
which joints are made by fibrocartilage?
-secondary cartilaginous joints
What type of joint is the epiphyseal plate?
primary cartilaginous joint (synchondrosis)
What are the functions of synovial fluid?
- lubricates surfaces of joint
- nourishes articular cartilage
What are extrinsic and intrinsic ligaments?
- reinforce synovial joints
- extrinsic bind exterior of joint
- intrinsic form part of joint capsule
The acromioclavicular joint is what kind of joint?
plane joint
What is an anastomose?
network of branching structures
What is an articular (joint) capsule, and what are its components?
- fibrous capsule lined by synovial membrane in synovial joints
- articular arteries and veins are commonly in synovial membrane
- nerve endings are abundant in fibrous layer, but sparse in synovial membrane
Hilton’s Law
nerves innervating a joint often innervate associated muscles and skin of distal attachments
what are osteophytes, and what causes them?
- bone spurs
- bone-on-bone osteoarthritis (when cartilage wears down)
what is the most common joint disease, and where does it commonly occur?
- osteoarthritis
- knees and hips
What areas are most susceptible to general joint disease?
- knees
- hips
- vertebral column
- hands
What are the symptoms of osteoarthritis?
- joint stiffness
- loss of mobility
- pain
What is deglutition?
process of swallowing
what is a skeletal muscle fiber?
skeletal muscle cell
What is a tuberosity?
large rounded projection; may be roughened
What is a tubercle?
small rounded projection or process
What is a fossa?
shallow, basin-like depression in a bone, often serving as an articular surface
what does latissimus mean?
wide and broad
What does piriformis mean
pear shaped
What is a condyle?
knob
What are 6 ways muscles can be attached to bones and other structures?
- tendons
- aponeuroses (sheet-like connective tissue)
- other muscles
- ligaments
- fascia
- mucous membranes
pennate muscles
feather-shaped
fusiform muscles
spindle-shaped (round with tapered ends)
bicipital muscles
2 heads
convergent muscles
muscle fascicles converge into a single tendon, have broad attachment
What make up the motor unit?
motor neuron and all muscle fibers innervated by that neuron
