Lecture 1: Musculoskeletal 1 Flashcards
Structure + Formation of Bones
formation of RBC, attachment sites for muscles to facilitate movement, protection of vital organs, gives the human body form, mineral + hormonal homeostasis
Components in Bone Tissue
Components in Bone Tissue
cells, fibers, ground substance, crystallized minerals
Function of bone cells
enable bone to grow, repair, change, shape synthesize new bone tissue & reabsorb new tissue
Osteoblasts
formation of new bones
derived from mesenchymal stem cells
responds to parathyroid hormone (PTH)
synthesizes osteoids for the formation of new bones
Osteoclasts
breakdown of old bony tissue
from osteoblasts»_space;»> osteoblasts
Elements of Bone Tissue
Rigid connective tissue
cells, fibers, ground substance, bone matrix, calcification
The 2 types of bone cells
- longitudinal long bone-cancellous (solid & spongy fiber) & contact bone
- compact bone
Collagen Fibers (bone matrix)
bulk of bone matrix
backbone of bony tissue
provides some strength
Proteoglycans (bone matrix)
strengthen bone
plays a role in calcium deposition & calcifications
Glycoproteins (bone matrix)
controls collagen interactions»_space;> fibril formation
sialoprotein, osteocalcin, bone album, alpha-glycoprotein
bone minerals (bone matrix)
formation of initial mineral deposit, proliferation
calcium + phosphate
Number of bones in the body
206
Axial bones
skull, vertebrae
80
appendicular bones
peripheral bones, limbs, upper/lower extremities, shoulder girdle, pelvic girdle
(126)
Examples of long bones
diaphysis, metathesis, epiphysis, medullary (marrow) cavity, endosternum
Examples of Flat bones
skull, ribs, sternum, scapula
Examples of Short Bones
wrists and ankles
Examples of Irregular Bones
vertebrae, face, mandibles
What is bone remodeling?
- repair of microscopic bone injuries
- existing bone is reabsorbed and new bone is formed
- *is a continual process - always happening**
The stages of bone repair
- inflammation/hematomas form
- pro callus formation
- callus formation (cartilage forms + crystallizes matrix)
- remodelling
Joints (articulations)
sites where two or more bones meet
The function of joints
Allow for motion and movement, provide stability
Joint Classification based on mov: Synarthrosis
immovable
Joint Classification based on mov: amphiarthrosis
freely moveable
Joint Classification based on mov: amphiarthrosis
partially moveable
Joint Structure: fibrous
joins bone to bone
suture, syndesmosis, gomphosis
Joint Structure: Cartilaginous
symphysis & synchondrosis
Joint Structure: synovial
joint capsule, synovial membrane fluid, joint cavity, synovial membrane, articular cartilage (provides lubrication for joint to facilitate
joint capsule
fibrous tissue that encloses bone ends and other joint surfaces
synovial membrane
The lining of a joint that secretes synovial fluid into the joint space.
Joint cavity (synovial cavity)
small amount of synovial fluid which lubricates and bears weight
allows two bones to move against each other
synovial fluid
Secretion of synovial membranes that lubricates joints and nourishes articular cartilage
articular cartilage
hyaline cartilage that covers ends of bones in synovial joints
reduces friction, weight bearing
comprised of chondrocytes + intracellular matrix
% composition of skeletal muscles
75 % water, 20% proteins, 5% organic + inorganic compounds
Number of Muscle Fibers in the body + length
600, 2-60 cm long
Layers of skeletal muscle
epimysium (outermost layer) perimysium (middle layer), endomysium (inner layer)
function of skeletal muscles
motor units (functional unit of neuromuscular system), sensory receptors (spindles, Golgi tendon organs)
muscle fibers (myofibrils)
fibers functional subunits
muscle fibers (myoblasts)
precursor cells
main cell responsible for muscle growth + regeneration
Contraction of Muscles
excitation
coupling, contraction
relaxation
Metabolism of muscles
REQUIRES CONSTANT ATP + PHOSPHOCREATINE
glycogen + blood glycogen converted acerbically to sustain activity w/o increasing demand for o2
type 1 fibers can resist fatigue in comparison to type 2
Muscle Mechanics: repetitive discharge
allows the muscle to activate the # of motor units needed to generate the desired force
Muscle Mechanics: physiological tetanus
occurs when motor units are stimulated against the muscle unit that has not been able to relax between contractions
Types of muscle contractions
concentric (muscle shortening), eccentric (muscle lengthening), isometric
Types of muscle movement
antagonist (involuntary) and agonist (voluntary)
Tendons
attach muscle to bone
attach muscle to bone
Connect bone to bone
osteoporosis
A condition in which the body’s bones become weak and break easily
sarcopenia
the loss of muscle mass, strength, and function that comes with aging
