LRC Exam I - Thoracic Limb Flashcards
Define Saggittal Plane, Midsaggittal Plane and Parasaggittal Plane.
Divides body into left and right halves; median plane (divides body into equal parts); divides body into unequal parts
What is the term for a structure located in between 2 other structures in the medial to lateral orientation? In the proximal to distal orientation?
Intermediate; middle
What are the primary functions of bone?
Support weight, movement in concert with muscles, protection of internal organs, growth, storage of minerals (calcium and phosphorus), storage of fat (in yellow marrow cavities), blood cell formation (hematopoiesis; in red marrow cavities)
What is included in the axial skeleton? The appendicular?
Axial: skull, thorax, vertebral column; Appendicular: limbs
Define Diaphysis, Epiphysis, Metaphysis, Metaphyseal growth plate
Main body of long bone; end parts; between diaphysis and epiphysis; between epiphysis and diaphysis in young animals (made of cartilage cells)
List some key features of long bones and give examples of long bones in the body.
Located in appendages, multiple ossification centers. Eg: humerus, radius, ulna, femur, tibia, fibula, metacarpals
List some key features of short bones and give examples of short bones in the body.
Cube-shaped, one center of ossification, no growth plates. Eg: Carpal bones, sesamoid bones.
List some key features of flat bones and give examples of flat bones in the body.
For extensive protection or large muscle attachments, intramembranous ossification, diploe. Eg: scapula, skull bones
List some key features of irregular bones and give examples of irregular bones in the body.
Short bones with multiple processes, formed by both endochondral and intramembranous ossification. Eg: Vertebrae
List some key features of sesamoid bones and give examples of sesamoid bones in the body.
Small seed like bones embedded in muscle tendons, type of short bone. Eg: proximal sesamoid bones of manus and pes, patella
What is purpose of sesamoid bones?
Increase torque, redirect line of force, eliminate tendon shear.
List the 5 types of bones
Long bones, short bones, flat bones, irregular bones, sesamoid bones
Define periosteum, endosteum, medullary cavity
Periosteum: Lines outer surface, source of osteoblast progenitor cells, rich in nerves, blood supply
Endosteum: Lines inner surface
Medullary Cavity: Storage for bone marrow
Discuss the difference between intramembranous and endochondral ossification.
Intramembranous: osteoblast with connective tissue accumulate, replaces thin connective tissue membrane with bone (eg flat bones)
Endochondral: destroys cartilage before ossification, replaces fetal cartilage skeleton with bone (eg most bones)
What is chondrodystrophy?
Genetic condition. Affects secondary centers of ossification that results in cartilage maldevelopment and stunted growth of long bones (eg dachshunds)
Discuss bone blood supply.
Nutritional vessels enter the diaphysis and epiphysis, most long bones have a single nutrient foramen (around mid-diaphysis), vessels in the periosteum supply the cortical bone.
What is a cortical bone?
Hard bone between the periosteum and endosteum
What is a diploe?
Cancellous tissue enclosed by two thin layers of cortical bone. In some areas of the skull, this is absorbed to form air sinuses.
What is Wolff’s Law?
Normal bones will remodel itself in response to the stress placed on it. If load increases on a particular area the bone will remodel to resist those forces (eg with body weight gain, muscle building)
List the 3 types of muscle tissue in the body, describe where they are in the body and whether their action is voluntary or involuntary.
Smooth Muscle: organs, blood vessels. Action is involuntary (ANS)
Cardiac Muscle: musculature of the heart. Action is involuntary (ANS).
Skeletal Muscle: attached to the skeleton. Action is voluntary (SNS).
Describe the 2 aspects of the musculoskeletal system.
Muscular System: Active component. Skeletal muscles, muscles that move limbs, trunk, head.
Skeletal System: Passive component. Bones, joints.
List the 3 types of connective tissue found around skeletal muscle fibers and describe that they do.
Epimysium: surround muscle belly.
Perimysium: divides muscle into fasicles
Endomysium: surrounds muscle fibers.
Tendons attach _______ to _______. Ligaments attach _______ to _______.
Tendons attach muscle to bone. Ligaments attach bone to bone.
What is an aponeurosis? What is its purpose?
An aponeurosis is a sheet like tendon. Allows muscles to have a broader attachment.