General Osteology, Arthrology, and Myology Flashcards
What are the 7 primary functions of bones?
support, movement, protection, growth, storage of minerals (Ca and P), storage of fat (yellow marrow cavities), blood cell formation (hematopoiesis) (red marrow cavities)
What is osteology?
the study of bones
How is the skeleton divided?
Appendicular (bones of the appendages) and axial skeleton (bones of the axis of the body: skull, thorax, vertebral column)
What are the five categories of bones?
long, short, sesamoid, flat, irregular
What is the dominating characteristic of long bones?
length
Where are long bones located?
In the appendages
How many ossification centers do long bones have?
At least 3 (2 growth plates or more)
What is the diaphysis?
long, straight bone shaft that contains medullary cavity
What is the medullary cavity?
located inside the diaphysis, contains bone marrow, reduces weight of bone
What is the epiphysis?
end regions of bone
What are the sections of long bones
diaphysis, medullary cavity, epiphysis, metaphysis, and metaphyseal growth plate
What is the metaphysis?
region of bone lying between epiphysis and diaphysis
What is the metaphyseal growth plate?
located between epiphyses and diaphysis in young animals; comprised of cartilage cells
Why are growth plates clinically relevant?
They are often a primary site for infection, metastasis, fractures, and the effects of endocrine bone disorders.
They can cause genetic conditions such as chondrodystrophy, achondroplasia, and result in dwarfism
Where are short bones located?
carpal bones, sesamoid bones
How many ossification centers do short bones have?
One (no growth plates)
Describe the shape of short bones.
Approximate equal dimensions, cube shaped
What are the 3 purposes of sesamoid bones?
eliminate tendon shear, redirect lines of force, increase torque of joint
What type of bone is the patella?
sesamoid
Sesamoid bones are a subcategory of _______ bones.
Short
Describe sesamoid bones.
Seed-like bones embedded in muscle tendons
What are the purposes of flat bones?
protection or large muscle attachment area
What are examples of flat bones?
scapula, bones of the skull
Where are irregular bones found?
vertebrae
Irregular bones are a subcategory of _________ bones.
Short
Name some examples of protrusions on articular surfaces and non-articular surfaces.
articular - head, condyle, trochlea
non- articular - process, tuberosity, spine, crest
Name some examples of depressions/openings on articular surfaces and non-articular surfaces.
articular - glenoid cavity, acetabulum, cochlea
non- articular - fossa, fovea, foramen
What is Wolff’s Law?
Bony prominences will vary to some extent because bones are alive too. Normal bone remodels in response to stress placed upon it.
If a load on a particular area increases, the bone will remodel to become stronger to resist those forces (weight gain and muscle building)
The point of the shoulder and the point of the elbow are examples of what in applied anatomy?
Palpable or visual landmarks
How can normal bony landmarks and fractures/other pathology be differentiated?
radiographs
What is arthrology?
the study of structure and function of joints
What is a joint?
The point of contact, or articulation, between two or more bones/cartilages
Are all joints movable?
No
What is the purpose of a joint?
to provide support and movement to the skeleton
What are the two main classifications of joints?
functional and structural
What are the three types of functional joints? Are they movable? Give brief description.
synarthroses- immovable, most refer to fibrous joints
amphiarthroses- semimovable, most refer to cartilaginous joints
diarthroses- freely movable joints, synovial joints
What are the three types of structural joints? Give brief description.
fibrous- strong fibrous CT between articulatig bones; bones can even fuse
cartilaginous- cartilage (hyaline or fibrocartilage) between articulating bones; limited movement
synovial- joint cavity between articulating bones lined with synovial membrane
What is synostosis?
bones can fuse into a bony joint (associated with fibrous joint)
All synovial joints are ______.
Diarthroses joints
What are the three types of fibrous joint types?
suture, gomphosis, syndesmosis
What are suture joints?
fibrous joint, seams (interdigitation) of the bones of the skull
What is interdigitation?
Seams in bone
What joint is gradually eliminated via ossification and why?
suture joint, result of synostosis
What are gomphosis joints?
fibrous joint, tooth in alveolus united by periodontal ligament; technically not a classic joint because teeth are technically not considered bones
What are syndesmosis joints?
bones joined by interosseous ligaments (radius/ ulna, tibia/fibula)
How would you describe the connective tissue of a fibrous joint?
connecting medium = dense irregular connective tissue
What are two types of cartilaginous joints?
synchondrosis, symphysis
How would you describe the connective tissue of a cartilaginous joint?
connecting medium = hyaline or fibrocartilage
What are synchondrosis joints?
hyaline cartilage union
What are examples of synchondrosis joints?
coastal cartilages connecting ribs to sternum, growth plates
What are symphysis joints?
occur in the midline of the body where articulatig bones are connected via a flat disc of fibrocartilage
What are examples of symphysis joints?
pelvic symphysis, intevertebral discs
Which joint is freely movable?
Diarthrotic joints
Which bone surfaces are enclosed in a fluid-filled cavity?
articulating surfaces
How are fluid-filled cavities around articulating joints defined?
By a multilayered joint capsule
How many compartments are in a single joint capsule?
May have multiple
What covers bony articulating surfaces?
articular (hyaline) cartilage
What does a joint capsule consist of?
outer fibrous layer and inner synovial membrane
Describe the outer fibrous layer.
It blends with the periosteum and is thickened in some joints to form ligaments
What is the role of synoviocytes and where are they located?
Produce synovial fluid for lubrication and nutrition of the bone surfaces, found in inner synovial membrane
Is the innter synovial membrane vascularized? Does it have nerves?
Vascular with nerves
What is the purpose of intra-articular injections?
anesthetics for lameness evaluations; treatment for osteoarthritis
Are intra-articular injections only given in horses?
No, can be done in canine joints as well
What are the two accessory structures of the synovial joints?
meniscus/ menisci and ligaments
What cartilage makes up the meniscus and where is it located?
fibrocartilage located within the synovial cavity
What joints can menisci be found?
temporomandibular joint, stifle joint
What are two types of ligaments and where are they located?
extracapsular - located outside of the joint capsule
intracapsular - occur within the joint capsule, but are excluded from the synovial cavity by folds of the synovial membrane; not technically within the joint itself, but it does appear to be so
How can synovial joints be classified?
by number of articulating bones, how well the bones fit together, by shape and permitted motions
How are synovial joints classified by number of articulating bones?
simple joint: formed by two bones
compound joint: formed by two or more bones
How can synovial joints be classified by how well they fit together?
congruent joint: two articular surfaces fit each other
incongruent joint: two articular surfaces do not fit each other
Name the types of movement in a synovial joints.
gliding/translation motion and angular motion
What are the different types of angular motion?
flexion, extension, hyperextension, abduction, adduction, circumduction, rotation, pronation/supination
flexion
decreasing angle between bones
extension
increasing angle between bones to approximate 180 degrees
hyperextension
increasing angle past anatomical position of 180 degrees
abduction
moving away from median plane
adduction
moving towards median plane
circumduction
movement circumscribing a cone shape
rotation
medial or lateral
What are the 7 different motions in regards to shape and motion? Describe them briefly.
plane: permits gliding
hinge: flexion & extension/hyperextension only
spheroidal (ball & socket): permits rotation and other movements
pivot: permits rotation around the longitudinal axis of a bone
condylar: flexion & extension/hyperextension mostly, some rotation, gliding allowed
ellipsoidal: flexion & extension/hyperextension mostly, some rotation
saddle: flexion & extension/hyperextension mostly, some abduction & adduction, rotation permitted
What is the tradeoff in extracapsular ligments?
Trade off range of movement for stability
What is myology?
the study of muscles
What is the locomotor system?
bones and joints (passive) and muscles (active)
What is the tendon of origin?
proximal attachment, usually fixed point of muscle attachment
What is the tendon of insertion?
distal attachment, usually movable point of muscle attachment
What is aponeurosis?
a sheet-like tendon; allows muscle to have a broader attachment
What is the difference between a tendon and a ligament?
Tendons attach muscle to bone (or skin or another muscle)
Ligaments attach bone to bone
What are the 6 accessory structures to muscles?
sesmoid bones synovial bursa/bursae synovial tendon sheath fasciae and fascial planes superficial fascia deep fascia
What is superficial fascia?
loose CT
What is a synovial bursa?
synovial fluid-filled bag often positioned between a tendon and a bony process; can be subcutaneous, subtendinous, or intertendinous
What is a synovial tendon sheath?
synovial fluid-filled sacs that surround muscle tendons
What are fascial planes?
deep fascia septa (walls) that separate muscles groups/layers; allow muscle groups to functions as units
What is deep fascia?
dense collagenous connective tissue from which some muscles may originate or insert; attaches to bone
Why is it important to know muscle action>
diagnose lameness, gait analysis
What is gait analysis?
investigation of lameness, with swing and stance phases
In what way can some muscle actions be contradictory?
Contradictory actions on a given joint are dependent on weight bearing vs non weight bearing.
How are the origin and insertion interchangeable for some muscles?
Interchangeable depending on weight bearing vs non weight bearing
