Module 11: MSK (a) Flashcards
1
Q
MSK
-Sites of Blood cell formation?
A
- Skull
- Pelvis
- Sternum
- Femur
2
Q
Functions of the bones?
-Mineral storage
A
- Bones store
- Calcium
- Phosphate
- Carbonate
- Magnesium
3
Q
Bone
-Make up?
A
- Connective tissue that is rigid and flexible
- Made of
- Crystallized minerals (calcium) — Rigidity
- Collagen fibers — Flexibility - Tensile strength refers to the bones being Strong AND flexible
4
Q
Absorption Vs Resorption
A
- Absorption — taking up of tissues or fluids originating OUTSIDE the body
- Resorption — Taking of of products or tissues originating INSIDE the body
5
Q
Bone Cells
-3 Types
A
- Osteocytes — Start as osteoblasts — most abundant cells in the bone — MAINTAIN bone matrix — Respond to parathyroid hormone signals —Coordinate osteoblasts and osteoclasts to form and resort bone
- Osteoblasts — Form New bone — Synthesis of osteoid which is non-mineralized bone matrix — Synthesize osteoid
- Become osteocytes that are imbedded in bone — synthesize collagen and proteoglicans - Osteoclasts — Bone resorption — Release hydrogen chloride to breakdown bone tissue — body takes this back up and uses it to regulate serum calcium or to build new bone
6
Q
Bone Cells
-Osteocytes
A
- Osteocytes — Start as osteoblasts — most abundant cells in the bone — MAINTAIN bone matrix — Respond to parathyroid hormone signals —Coordinate osteoblasts and osteoclasts to form and resort bone
7
Q
Bone Cells
-Osteoblasts
A
- Osteoblasts — Form New bone — Synthesis of osteoid which is non-mineralized bone matrix — Synthesize osteoid
- Become osteocytes that are imbedded in bone — synthesize collagen and proteoglicans
8
Q
Bone Cells
-Osteoclasts
A
- Osteoclasts — Bone resorption — Release hydrogen chloride to breakdown bone tissue — body takes this back up and uses it to regulate serum calcium or to build new bone
9
Q
Bone matrix
-Organic Vs Inorganic
A
- 35% Organic — Proteoglycans & Albumin (Collagen fibers are synthesized & secreted by osteoblasts)
- 65% inorganic — Calcium & Phosphate
10
Q
Bone Matrix
-Proteoglycans
A
- Polysaccharides — Glucosamine & Chondroitin
- Strengthen the bone by forming compression resistant networks between COLLAGEN & CALCIUM
- Help deposit calcium in the bone
11
Q
Bone Matrix
-Albumin
A
- Albumin is a type of glycoproteins (identical to serum albumin)
- Transports essential elements such as hormones, ions, and other metabolites to and from the bone cells (matrix)
12
Q
Bone Matrix
-Calcium & Phosphate
A
- Calcium and phosphate are minerals
- Calcium — Regulates vitamin D and thereby promotes mineralization
- Phosphate — Balance of organic and inorganic phosphate required for proper bone mineralization — regulates vitamin D
13
Q
Compact Bone
-Info
A
- 85% of skeleton — Forms outer layer of all bones — Extremely strong & main weight bearing structure in long bones
- Haversian System (Osteon) is the basic structure all unit of compact bone
- Concentric lamellar form the central Haversian canal which runs longitudinally down the length of the bone and contains nerves and blood vessels - Volkmann’s canals —Run perpendicular (transverse) to the Haversian canals and interconnect them with each other
- Connections to the periosteum allow blood and nerves to travel to and from the bone
- Periosteum is the outer portion of the bone
14
Q
Spongy Bone
-Info
A
- 15% of skeleton & forms the inner layer of bone — Found in the epiphysis and metaphysics of long bones & Vertebral bodies
- Spongy bone is stiff and ductile — Can be deformed w/out losing toughness — Pliable and not brittle - Trabeculae — transfers mechanical loads from the articular surface to cortical bone — Main load bearing structure in vertebrae
—Spaces between trabeculae are filled w/ red bone marrow - LACKS haversian system
15
Q
Long Bones
A
- Diaphysis — Shaft of long bone — may contain fat (yellow marrow) or red bone marrow.
- Metaphysis— Epiphyseal plate is where growth occurs
- Epiphysis — Red bone marrow — blood formation
16
Q
Joints
-Movement Classification (3)
A
- Synarthrosis —Fibrous — Immovable joints — Ex: Sutures in the skull —
- Amphiarthrosis — Cartilaginous — Slightly movable — Ex: Pubic symphysis & intervertebral discs —
- Diarthrosis — Synovial — Freely movable — Ex: Shoulders, hips, knees, wrists, ankle, etc. —
17
Q
Skeletal Muscle
-Longest muscle
A
- Sartorius muscle is the longest muscle in the body
- Attaches at anterior superior iliac spine and attaches to superior medial tibia
18
Q
Skeletal Muscle
-Fusiforme Muscles
A
- Long and strap-like — Runs in straight line between attachment points (tendons) — Ex: Biceps, triceps, quads
2.
19
Q
Skeletal Muscle
-Pennate Muscles
A
- Flat, broad, slightly “fan-shaped.” Ex: Deltoid, pectoralis muscles
20
Q
4 Phases of Muscle Contractions
-All Steps
A
- Excitation — Spread of action potential from nerve to neuromuscular junction. Acetylcholine is released
- Coupling —Calcium release leaves actin free to bind w/ myosin — Caused by binding of calcium to troponin
- Contraction — Thin filament, actin, slides over myosin (thick filament) — cross bridge causes muscle to shorten
- Relaxation — Cross bridge detaches and sarcomere lengthens as calcium is pumped back into sarcoplasmic reticulum
21
Q
Motor Unit
-Definition
A
- Functional unit of the neuromuscular system
- Consists of the lower motor neurons and the muscle fibers it innervated
- Motor unites contract as a whole when receiving electrical impulse - Neuromuscular Junction - Where the nerve synapses with muscle cells
- Acetylcholine will travel between the NM junction to conduct the signal
22
Q
Skeletal Muscle Innervation
-Innervation ratio
A
- ## Defined as the # of muscle fibers innervated by one lower motor neuron
- Lower Innervation ratios allow for more precise movementsTEST — Ex: Lateral rectum muscle has ratio of 3
- Higher Innervation ratios are for muscles that do not require precise movements but need GREATER ENDURANCE.
- Ex: Calf muscle has ratio of 2000
23
Q
Skeletal Muscle Innervation
-Muscle Fiber Types
A
- Type I — Slow Twitch — Greater endurance — Ex: marathoner or triathlete — higher Innervation ratios
- Type II — Fast Twitch — Part of motor units w/ lower Innervation ratios — Ex: Ocular muscles
- Type II has 2 subtypes
- Type IIa — fast twitch muscle fibers — quicker, more precise, and more powerful contraction but fatigue easier than type 1
- Type IIx — higher proportion in those with sedentary lifestyle — If they work out, even a little, these convert to IIa fibers
24
Q
Skeletal Muscle Innervation
-Strength of Contraction
A
- Motor Unit recruitment — When a motor neuron is activated, it creates an action potential.
- All muscle fibers innervated by the motor neuron are stimulated and contract
- Activation of one motor neuron results in a weak but distributed muscle contraction
- Activation of more motor neurons will result in more muscle fibers being activated — Stronger muscle contraction - Type I (slow twitch) motor units will be activated first and, if needed, the type IIa (fast-twitch) the nType IIx
25
Q
Aging and the MSK System
-Bones
A
- Significant bone loss
- Bone that is present becomes Stiff and brittle
- Bone remodeling takes longer
- Bone loss is caused by bone remodeling taking longer d/t slow mineralization and increased bone resorption - OSTEOPOROSIS will often result
26
Q
Aging and the MSK System
-Joints
A
- Cartilage becomes more rigid, fragile and stiff
2. Decreased ROM — Careful flexibility exercises are very important to stress to your older patients
27
Q
Aging and the MSK System
-Muscles
A
- Apoptosis of muscle cells — Oxidative stress causes mitochondrial dysfunction w/in cells & results in apoptosis of muscle cells
- Decreased muscle strength and bulk
28
Q
Aging and the MSK System
-Sarcopenia
A
- Age-related muscle loss — sedentary individuals can lose as much as 3-5% of muscle mass each decade after 30
- Type II cells decrease to a greater extent than slower Type I fibers
- Educate Older patient to exercise and include weight training to
- Improve, maintain, or slow low of muscle strength
- Help increase bone mineral density
- Improve balance, coordination and mobility
- Improve lean body mass & decrease risk for falls
