Anatomy Lecture 1 Flashcards
What are the bones of the Thoracic Limb?
- Scapula
- Humerus
- Radius
- Ulna
- Intermediate Carpus
- Ulnar Carpal
- Accessory Carpal
- Carpal Bones I, II, III, and IV
- Metacarpal Bones I, II, III, IV, and V
- Phalanges (proximal, middle and distal)
What are the extrinsic muscles of the Thoracic limb? (8)
- Superficial Pectoral
- Deep Pectoral
- Brachiocephalicus (Cleidobrachialis and Cleidocephalicus)
- Omotransversarius
- Trapezius
- Rhomboideus
- Latissimus Dorsi
- Serratus Ventralis
What is included in the Axial Skeleton?
bones of the axis of the body: skull, thorax, vertebral column
What is included in the Appendicular Skeleton?
bones of the appendages (limbs)
What are the shapes of bones? (5)
- Long
- Short
- Flat
- Irregular
- Sesamoid
What makes a bone a long bone? (what are the required characteristics?)
The length of the bone must be greater than its diameter
What is the Diaphysis?
the long, straight main body of a long bone.
- location of primary ossification
What is the Epiphysis?
End regions of long bones
- Location of secondary ossification
What is the Metaphysis?
region of bone lying between the epiphysis and diaphysis
Where is the Metaphyseal growth plate and what is it made of?
located between the epiphysis and diaphysis in young animals. Comprised of cartilage cells
What is a short bone?
a bone that has approximately equal dimensions (cube-shaped)
- Only one center of ossification and no growth plates
What is a flat bone?
bones that are centrally compressed which are present either when extensive protection or large muscle attachment is necessary.
What is an irregular bone?
bones that cannot be classified under any of the other categories.
- formed by both endochondral ossification (body of bone) and intramembranous ossification (bony processes)
What is a sesamoid bone?
a small, seed-like bone that is embedded in muscle tendons
What do sesamoid bones do?
- eliminated tendon shear
- redirects lines of force
- increases torque
What is the Periosteum?
lines the outer surface of the bone.
- source of osteoblast progenitor cells (healing fractures)
- rich in nerves -> very sensitive
- blood supply
What is the Endosteum?
Lines the inner surface of bone.
What is the Medullary Cavity?
Where bone marrow is stored.
How are most bones formed?
Endochondrial ossification which is the ossification of a cartilage model
What is Intramembranous Ossification?
when mesenchymal cells become osteoblasts directly rather than becoming chondroblasts
What bones form by intramembranous ossification?
Flat bones including bones of the calvaria (top of skull) and face.
What is Chondrodystrophy?
Cartilage Maldevelopment. A genetic condition that affects secondary centers of ossification, resulting in arrested growth of long bones.
DISPROPORTIONATE DWARVES!
Where do nutritional vessels enter the bone?
through the Diaphysis and epiphysis with the majority of long bones having a single nutrient foramen entering mid-diaphysis.
How does the cortical bone get supplied with blood?
Vessels in the periosteum supply it
What is Wolff’s Law?
Normal bone remodels in response to stress placed upon it.
- If load in a particular area increases, the bone will remodel to become stronger to resist those forces.
What are the three types of muscle?
- Smooth (Involuntary)
- Cardiac (Involuntary)
- Skeletal (Voluntary)
What is the Epimysium?
the outermost connective tissue envelope surrounding the muscle belly
What is the Perimysium?
extends from the epimysium into the muscle and divides the muscle into smaller units
What are muscle fascicles?
the smaller units of muscle that has been divided up by the perimysium
What is the Endomysium?
extends from the perimysium to envelop individual muscle fibers (Cells)
Epimysium, Perimysium and Endomysium are all types of what?
Connective Tissue
What is the constituent material of muscle tendons that are attached to the bone?
the same connective tissue seen in the Epimysium, Perimysium and Endomysium.
What is the Tendon of origin?
usually the more proximal and/or fixed point of muscle attachment
What is an Aponeurosis?
A sheet-like tendon that allows muscles to have a broader attachment
What are structures that ease the effect of excessive pressure or friction associated with tendons?
- Sesamoid Bones
- Synovial Subtendinous Bursa
- Synovial Sheath
What is a Synovial Subtendinous Bursa?
A synovial fluid-filled bag positioned between a tendon and a bony process
What is a Synovial Sheath?
A synovial fluid-filled bag that wraps around a tendon
What do Tendons attach?
attach muscle to bone
What do Ligaments attach?
attach bone to bone
What is the tendon of insertion?
the more distal, peripheral or movable point of muscle attachment
How are fibers in a strap-like muscle arranged? Why?
The fibers run parallel to the long axis
- greater displacement
How are fibers in a spindle shaped muscle arranged?
the fibers are fusiform
What are three types of fiber arrangements that join the tendons at an angle?
- pennate
- bipennate
- multipennate
Why do more muscle fibers mean that the muscle is more powerful?
it has a greater cross sectional area