Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
104 Cards in this Set
- Front
- Back
|
What is ossification or osteogenesis?
|
The process of bone formation in embryos that leads to the formation of the bony skeleton.
|
|
|
What are the 2 kinds of bone development?
|
Bone formation:embryonic osteogenesis,aka ossification, occurs between fertilization & birth as bones form; Bone growth or oss. postnat ostogenesis18-21
|
|
|
Before week 8 what is the skeleton of the embryo composed of?
|
Hyaline cartilage and fibrous membranes.
|
|
|
What is embryonic formation?
|
Tissue that is formed in the fetus
|
|
|
What is stage 1 of embryonic formation?
|
Mesoderm differentiates into mesenchyme @ the 8th week of gestation.
|
|
|
What is the 2nd stage of embryonic formation?
|
Mesenchyme then differentiates into etiher fibrous membrane or into hyaline cartilage (the model for which future bone is formed)
|
|
|
When a bone develops from fibrous membranes what is the process called?
|
Intramembraneous ossification
|
|
|
What is the resulting bone called that is formed from intra-membranous ossification?
|
It is called a membrane bone or a flat bone
|
|
|
Which specific bones are formed as a result of intra-membranous ossification?
|
The cranial (frontal, parietal, occipital, temporal) bones of the skull, and the clavicle bones.
|
|
|
What is endochondral ossification?
|
It is bone development that happens by replacing hyaline cartilage resulting in endochondral bone or cartilage, a flexible resilient bone for growth.
|
|
|
What happens in stage 1 of intramembranous ossification?
|
Mesenchymal cells cluster and differentiate into osteoblasts forming an ossification center.
|
|
|
What happens in stage 2 of intramembranous ossification?
|
Bone matrix is secreted in fibrous membrane:osteoblasts secrete osteoid,that mineralizes in few days & trapped osteoblasts becomosteocytes.
|
|
|
What happens in stage 3 of intramembranous ossification?
|
Woven bone & periosteum form: accumulating osteoid laid arnd blood vessels- trabiculae;vascular mesenchyme condenses toperiosteum
|
|
|
What happens in stage 4 of intramembranous ossification?
|
Bone collar of compact bone forms, red marrow appears:Trabiculae deep to periosteum thicken, later form lamellar bone, diploe becomes red marrow.
|
|
|
Does intramembranous ossification involve osteons?
|
No, intramembranous ossification does not have osteons, its bone collar is simply lamellated layers.
|
|
|
Where are the 2 ossification centers in located in the long bones during endochondral ossification?
|
Primary ossification center in stage 1 of long bone form., in center of hyaline cartilage shaft. After birth 2ndary oss center in 1/ 2 epipheses of long bone
|
|
|
What is involved in the 1st stage of Endochondral ossification?
|
Stage 1:Osteoblasts from periosteum secrete osteoid around diaphysis, forming bone collar & encasing the hyaline cartilage
|
|
|
What is involved in the 2nd stage of endochondral ossification?
|
Stage 2: Chondroclasts break down cartilage matrix within the cartilage model, and make it calcify, opening up cavities.
|
|
|
What is involved in the 3rd stage of endochondral ossification?
|
3:Periosteal bud (nutrient artery nerves.red mrw,&osteoblas& osteo clasts);Osteoblasts secrete osteoid around remain cart.,forms trabiculae
|
|
|
What is involved in the 4th stage of endochondral ossification?
|
Stage 4: The diaphysis elongates & medullary cavity forms. Osteoclasts break down new formed spongy bone forms medullary cavity. 2nd oss. centers form before/after birth in epiphyses, calcify & then ossify
|
|
|
What happens in the 5th stage of Endochondral ossification?
|
5th stage: Ossification of the epiphyses, then hyaline cartilage remains only in epi. plates or articular cartilages. Blood vess. bring ylw. mar.
|
|
|
What are the 2types of growth in postnatal ossification?
|
Epiphesial plate growth and Recontour of the bone.
|
|
|
When does bone growth happen?
|
Postnatally
|
|
|
What happens in epiphesial plate growth?
|
Grow up/down,chondrocytes do mitosis push epiphesis up. Cartilage cells proliferate(increase #) 1st,then hytrophy (larger),induces osteogrwth
|
|
|
What makes up the epiphesial plate?
|
Hyaline cartilage
|
|
|
Where does endochondral ossification occur.
|
Apositionally at the articular cartilages and diaphysis, happens interstitally at the epiphesial plates? Ask Dr. Mehm
|
|
|
What is involved in Re-contouring (the first part of remodeling)?
|
Bone Deposition: w/osteoblasts and Resorption: w/ osteoclasts. Constant Bone deposition is building bone & resorption is breaking down bone.
|
|
|
Remodeling stage (after age 21) happens the rest of your life?
T/f |
True. 5-7% of all bone mass is broken and and built everyweek, 3-4 years all spongy bone replaced, every 10 years compact bone is replaced.
|
|
|
Where does remodeling happen?
|
Periosteum and endosteum
|
|
|
Is bone resorption osteoclastic or osteoblastic?
|
Bone resorption is osteoclastic.
|
|
|
What 2 components are involved in the bone resorption (osteoclastic) stage of remodeling?
|
1)the release of lysosomal enzymes that digest the (organic) matrix 2) release of hydrochloric acid which digests calcium salts.
|
|
|
What components are involved in the Bone deposition (osteoblast) part of Remodeling
|
Secretion of osteoid by osteocytes of gauzy-looking bone matrix.
|
|
|
What gets and sends messages of how and where to remodel or turn things off and on?
|
Cytokines communicate.
|
|
|
How is remodeling controlled or affected?
|
Hormonal mechanism and Mechanical stress.
|
|
|
What is PTH?
|
Parathyroid hormone releas by parathyroid gland-back of thyroid, when Ca+ levels low. PTH induce osteoclast resorbbn/releasCa in blood.
|
|
|
What is calcitonin?
|
Calcitonin is released by thyroid gland responding to high calcium blood levels and encourages calcium deposits in bone matrix to build bone
|
|
|
Is the release of calcitonin inducing an osteoblastic or osteoclastic response?
|
It induces an osteoblastic response.
|
|
|
Is the release of PTH inducing an osteoblastic or osteoclastic response?
|
An osteoclastic response.
|
|
|
Besides hormonal what is another way that remodeling is controlled?
|
By Wolfe's Law or Mechanical stress
|
|
|
State wolff's law
|
Bone grows in response to the stresses put upon it. Gravitational stress.
|
|
|
Is mechanical stress osteoblastic or osteoclastic?
|
osteoblastic
|
|
|
Vascularized mesenchyme condenses on the external face of the woven bone (trabiculae) becoming...
|
Periosteum
|
|
|
The accumulating osteoid that is layed down between embryonic blood vessels forms a random network called...
|
trabeculae
|
|
|
What is endochondrial ossification?
|
Replacement of hyaline cartilage
|
|
|
Which bones are formed through endochondrial ossification?
|
All bones below the skull with exception to clavicles-specifically long bones beginnin in 2nd month. It uses hyaline cartilage bones as the pattern.
|
|
|
Blood vessel infiltration changes nutritional status inducing mesenchymal cells to specialize into
|
osteoblasts
|
|
|
Which enters the cavity first- periosteal bud or trabeculae?
|
Periosteal bud enters first and then ossification is laid down around blood vessel.
|
|
|
What is another name for joints and what is their definition?
|
Also called articulations, they are sites where 2 or more bones meet
|
|
|
What are the 3 types of joints?
|
1) Fibrous (CT)
2) Cartilaginous 3) Synovial |
|
|
What are the characteristics of fibrous joints?
|
They have no cavity, are synarthrotic (immovable), made of dense irreg.con. tissue, sutures are examples.
|
|
|
What are the 3 types of fibrous joints and their characteristics and examples
|
Sutures-synarthrotic-immovable-dense irr.-skull;Syndesmoses amphiarthrotic-more give,dense reg-tibiofibular or interosseus memb; Gomphoses, synarthrotic, CT, peg in socket joint, periodontal ligament
|
|
|
Are fetus sutures tight or loose and big?
|
Loose and big. Adult's are tight.
|
|
|
What does synarthrotic, amphiarthrotic, and mean?
|
Synarthrotic means immovable. Amphiarthrotic means slight to considerable movement.
|
|
|
How do sutures tighten?
|
They ossify during middle age, after which they are called syntoses.
|
|
|
What tissue is a suture made from?
|
Dense irregular tissue.
|
|
|
What is interosseus membrane and where is it found?
|
It is a type of syndesmosis joint that is amphiarthrotic
|
|
|
How are joints typically classified?
|
According their amount of movement. Synarthrotic, Amphiarthrotic, or Diarthrotic
|
|
|
Where are sutures found?
|
Only in the skull.
|
|
|
What is another name for a peg-in-socket and what is the name of the ligament involved?
|
Gomphoses. Only example is in the bony alveolar socket for the tooth. Embedded by the short periodontal ligament.
|
|
|
What are the 3 types of fibrous joints?
|
Sutures, Syndesmoses, Gomphoses
|
|
|
What are the 2 types of cartilaginous joints?
|
Synchondroses and Symphyses
|
|
|
T/F All synchondroses are synarthrotic.
|
True.
|
|
|
Where are synchondroses found in the body? Where are symphyses found?
|
Synchondroses found in epiphesial plates and between the first costal rib and manubrium. Symphyses found in intervetebral discs and pubic area.
|
|
|
Are symphyses amphiarthrotic or synarthrotic?
|
They are amphiarthrotic allowing some body movement.
|
|
|
Out of the 3 types of joints,(fibrous, cartilaginous, and synovial) which is the most abundant class?
|
Synovial joints are the most abundant in the body.
|
|
|
Where are synovial joints found and what are their characteristics & structure?
|
All limbs that have joints are synovial jointed. Hyaline articular cartilage, synovial joint cavity, articular capsule, synovial fluid and reinforcing ligaments
|
|
|
What is the name of the type of movement for synovial joints?
|
They are diarthrotic-freely moving joints
|
|
|
Describe articular cartilage found in a synovial joint
|
Thin spongy cushion that absorbs compression placed on the joint that is made of hyaline cartilage
|
|
|
Describe the joint cavity in a synovial joint
|
This feature is unique to synovial joints. A potential space for synovial fluid.
|
|
|
Describe the articular capsule
|
Encloses jnt cavity, 2 layr, aka joint capsule.Ext.lyr tuf fibrous capsule DICTcontinues as periostea of artic bones.Inr. layr synov.memb. LCareolr
|
|
|
Describe synovial fluid
|
In free spaces of joint capsule,aka artlr capsule,prod.of syn.membrane, frm blood filtrate of capillaries, viscous, hyaluronic acid, wbc, phagocytes, prevents friction, warmth is good!
|
|
|
What type of membrane is found between the radius and ulna allowing for pronation and supination.
|
Interosseous membrane
|
|
|
What type of tissue is the periodontal ligament made of?
|
D R C T
|
|
|
Describe the external layer of articular capsule (joint capsule)
|
External layer is tough fibrous capsule, dense irreg ct., continuous with periosteum, strengthens joint so bones aren't pulled apart
|
|
|
Describe the internal layer of the articular capsule (joint capsule)
|
Synovial memb.,(loose areolar ct) lines inside of fibrous capsule, covers all internal joint surf. that aren't hyaline cart,continuous w/art. cart
|
|
|
What is the weight-bearing, shock absorbant film that reduces frictions between cartilages
|
Synovial fluid
|
|
|
How does our body recognize body position?
|
By proprioceptors found in joints, muscles or tendons that help the body to recognize body position based on positional detectors sent by nerve end.
|
|
|
Why is the articular capsule able to help with proprioception?
|
Because it is highly innervated with sensory nerves.
|
|
|
What is arthritis?
|
Inflammation of hyaline articular cartilage of joints
|
|
|
What are the extra fibrous sacs that are often found in synovial joints (not strictly) that help with shock absorbancy?
|
Bursae and tendon sheaths
|
|
|
Describe the bursae.
|
Bursae are flattened fibrous sacs filled with synovial membrane, and thin film of synovial fluid, common where lig., mus, skin, tend.,bones rub together
|
|
|
Describe the tendon sheath.
|
Essentially elongated bursa that wraps completely around a tendon subjected to friction, like a bun around a hotdog
|
|
|
What is the disadvantage of bursae and tendon sheaths?
|
They are not well vascularized. They heal slowly because the immune sysem can't get in.
|
|
|
What are some factors that influence the stability of synovial joints?
|
Shapes of articlr surf., number & positioning of ligaments, & muscle tone. Joints are unstable alone because constantly stretched & comp.
|
|
|
What do articular surfaces have to do with joint stability?
|
There shape in regards to location on body and joint assoication dictate stability:shoulder w/more mobility is unstable misfit, or hip/socket is good fit
|
|
|
What do ligaments have to do with joint stability?
|
Capsules & ligaments of synovial joints unite bones & prevent excessive or undesirable movement, except when relied on too much; like knee
|
|
|
What are the disadvantages of ligaments and instability?
|
Can become overstretched and snap, can be considered instable as in the knee ligaments.
|
|
|
What does muscle tone have to do with joint stability?
|
Muscles are in a constant state of low-level contractility to help maintain joint stability. Muscles pull on ligaments & tendons to help in movement.
|
|
|
What is behind our ability to have movement?
|
Synovial Joints give us our movement and fliexibility.
|
|
|
Describe muscle attachment
|
Muscles attach a min. of 2 places. Muscles origin attach. to immovable bone. Muscle's insertion attach. to movable bone;part moves is location of insertion
|
|
|
As a muscle contracts the insertion of muscle moves toward or away from origin?
|
Insertion toward origin
|
|
|
What are 3 types of joint movements?
|
Gliding, Angular, Rotation
|
|
|
Describe gliding movement in joints
|
Gliding occurs when flat bone surfaces glides or slips over another as in the carpals and tarsals, or flat articular processes of vertebral column.
|
|
|
Describe angular movements
|
They increase or decrease the angle between 2 bones allowing flexion, extension, hyperextension, abduction adduction & circumduction
|
|
|
What is flexion?
|
Flexion decreases angle of joint & brings artic. bones closer together: head forward on chest; flex shoulder (arm forward) flex knee (ankle to gluts)
|
|
|
What is extension
|
Reverse of flexion, increases the angle between articulating bones.
ex. arm @shoulder toward back |
|
|
What is dorsiflexion and plantar flexion?
|
Dorsiflexion-toes pointing up toward shin.
Plantarflexion-toes pointing down, wrist too |
|
|
What is Abduction and Adduction?
|
Abduction: Move a limb laterally away from the midline, ie, raise arm laterally; Adduction: Adding or moving toward midline of body
|
|
|
What is circumduction
|
Circular movements in joints; moving a limb in a conal shape that includes movements: extension, flexion, abduction,& adduction in succession
|
|
|
In reference to movement one must always reference the body part or the joint that is being moved?
|
The joint.
|
|
|
What is rotation?
|
Rotation is turning of long bone around own long axis.Only movement allowed between 1st 2 cervical vertebrae,ball & socket joints, goes lateral or medial
|
|
|
What few joints dictate special movements?
|
supination-pronation:radius rotation; inversion-eversion:sole ft. turns medial-lateral;elevation-depression: shrugshoulder,open mouth; protract-retract.:chinforward-back, oppositon -thumb& fingers
|
|
|
Name the 7 types of joints
|
plane: no axis, carpals..; hinge: exten-flexion only, straighten elbow; pivot: rounded end in sleeve of point atlas/axis; condyloid: oval arti surf fits in depression of other-knuckles; saddle: art.surf have concave& convex,shape likesaddle, thumbs? ball/socket: head articulate w/? socket of another, hip/shoulder, knee joint, largest, 3joints in one-femoralpatellar, tibiofemoral, menisci
|
|
|
What movements would be involved with TMJ
|
elevation, depression, protraction, retraction
|
