Musculoskeletal

• 1. CK-MB = heart muscle damage
• 2. CK-MM = skeletal muscle damage
• 3. CK-BB=   brain damage

• Osteoid - nonmineralized
• Organic- Collagen I & V, proteoglycan, glycoproteins
• Inorganic- Ca2+ & phosphorous

• It is an osteoblast that has been trapped in the same matrix that it has created.
• Space occupied by osteocyte is called lacuna
• Connected via cannaliculi to gap junctions

Splanchnic mesoderm -> gut tube

Somatic mesoderm -> blood vessels

ectoderm -> eye

This is Prune belly syndrome which is a result of the lack of myotome migration.

Wnts & Shh

• The hyaline cartilage grows
• osteoblasts invade -> death of chondrocytes and calcification of matrix -> large marrow spaces

osteoblasts produce primary bone on top of the calcified cartilage.

Osteoclasts come and break down for formation of secondary bone.

Vitamin D -> Ca2+ absorption

Vitamin C -> collagen formation

Vitamin A -> proper bone formation

• COMPOSED OF:
• - type II collagen, basophilic matrix, chondrocytes in isogenous groups.

PERICHONDRIUM: Present except on articular surfaces

• LOCATION:
• - articular ends of long bones, nose, larynx, trachea, bronchi, ventral ends of ribs, template for endochondral bone formation.

small Q angle which is caused by arthrosis of medial collateral ligament which will lead to stress on the Lateral collateral ligament.

• Anterior cruciate ligament
• Medial collateral ligament
• medial meniscus

To prevent hyperextension of the knee.

Tested with the anterior drawer test or Lachman's test

PASSIVE: bones, aponeurosis, plantar ligament, plantar calcaneocuboid ligament, plantar calcaneonavicular ligament.

• DYNAMIC: Intrinsic muscles, long tendons
• - Longitudinal- Flexor hallucis longus, Flexor digitorum longus
• - Transverse- Fibularis longus and Tibialis posterior

• 10th vertebrae
• - inferior limit of thoracic cavity
• - Superior border of liver
• - Central tendon of diaphragm
• - inferior border of heart
• - esophagus into the diaphragm

• 
• Costal pleura
• Cervical pleura (cupular pleura)
• mediastinal pleura
• Diaphragmatic pleura

• Intercostals (T1-T11)
• - costal pleura and diaphragmatic pleura
• - pain is sensed to originate from chest wall

• Phrenic Nerves (C3,4,5)
• - Mediastinal and rest of diaphragmatic
• - pain is sensed to come from the neck +/or shoulder (referred)

Potential pleura space where heart can touch posterior thoracic wall.

• 
• Terminal cisternae
• T tubules
• Terminal cisternae

Ap -> Ca influx -> Ach release -> sarcolemma deplolarization -> T tubules -> ca released from Sarcoplasmic reticulum -> cytosol troponin -> tropomyosin shift -> contraction

Glutamate and Acetylcholine -> Na+ in, Ca2+ in

Ionotropic - faster - Na influx

Metabotropic - slower - G protein - K efflux

• Fast Twitch glycolytic
• - fast fatigue
• - Fast velocity
• - large diameter

# of fibers per unit

# of active motor units

• contracted
• partially contracted(tone)
• phasically active
• relaxed

• Single unit has gap junctions and relies on 1 cell to produce the spontaneou AP to affect multiple cells.
• - small blood vessels, urinary, reproductive, GI tract

• Multi-unit involves specific innervation.
• - lung airways, blood vessels, eyes, hair follicles

MLCK leads to contracted state

MLCP leads to uncontracted state

• Spinal cord - L2
• Dura mater- S2
• Filum terminale - Coccyx 2

• Supraspinous
• interspinous
• ligamentum flavum
• posterior longitudinal ligament
• Dura mater
• Arachnoid mater
• Pia mater

Posterior fibrous annulus is the most common site for disc herniation where gelatin from the nucleus pulposus can escape leading to a pinched nerve that passes through and ends at a lower level.

Myoepithelial - glandular secretory units

Myofibroblast- decrease wound opening

T-tubules, sarcomeres, and troponin

• Anticholinesterases
• corticosteroids
• azathioprine (immunosuppressive)
• thymectomy

• Stress
• extreme temperatures
• fever
• illness
• hypokalemia
• relaxants
• overexertion

• Wrist drop
• sensory loss of the lower part of the dorsal aspect of the thumb, and proximal dorsal aspect of all the fingers except for the little finger and half of the ring finger.

Arises from the middle of the posterior tibia to the distal phalanges of 2-5.

• Flexes the toes and foot
• invert ankle

Adductor longus, adductor brevis, anterior portion of the adductor magnus, and gracillis

• Innervated by the ulnar nerve(3 and 4) and the median nerve (1 and 2)
• - extend fingers at the interphalangeal joints

Caused by deposition of monosodium urate crystals in the joints and soft tissue(tophi)

Aspiration of the joint shows negatively birefringent crystals, which are yellow in color when viewed parallel to the polarizer and blue when viewed perpendicular.

Casues: enzyme def, lifestyle, or drugs (chemotherapy)

• Deep peroneal nerve
• - supplies tibialis anterior, extensor hallucis, extensor digitorum, and peroneus tertius.
• - Action = dorsiflexion and digit extension.

Subclavius (occupies small groove on the undersurface of the clavicle)

Wrist and elbow flexion, elbow extension, and arm abduction.

Sensory innervation of the palmar surface of the first 3 digits and over the deltoid.

• Posterior auricular
• Temporal
• Zygomatic
• Buccal
• Marginal Mandibular
• Cervical

Please tell Ziggy Bob Marley called

Between the palmaris longus tendon and the flexor carpi radialis tendon.

The medial cord of the brachial plexus

• Caused by exogenous corticosteroid use or Cushing disease.
• Chronically characterized by the insidious onset of muslce weakness of the thighs and upper arms.
• Preferential atrophy of type II fibers.

• Repetitive cycles of osteolysis and disorganized osteoblastic activity -> thickened bone with haphazard lamellar orientation.
• Affects skull and axial skeleton
• Histologic jigsaw puzzle appearance of bone llamellae is pathognomonic.
• Presentation = pain, bone deformities, and chalkstick fractures.

• Rod like structure with globular strcutres at end
• amino terminal end binds to actin filaments of myofibrils
• cysteine carboxy end binds to beta-dystoglycan (anchors complex to basal lamina via laminin.)

• Disorder of type I collagen synthesis
• multiple fractures in the absence of overt soft tissue damage
• blue tinged sclera present in some types of OI

bony changes to lower ends of the radius and ulna, where the diaphyseal ends become fuzzy, cup-shaped, and may develop a spotty rarefaction.

• deformity of chest wall
• bowing of legs
• fractures

• Psoas major - lesser trochanter
• Gluteus maximus - gluteal tuberosity
• Gluteus medius, minimus, piriformis - greater trochanter