HSF I Unit II

How is the forearm compartmentalized? What is each compartment innervated by?

*Anterior Compartment (Flexor-Pronator):* Ulnar & Median Nerves *Posterior Compartment (Extensor-Supinator):* Radial Nerve

What is *myasthenia gravis*?

*Myasthenia gravis:* • Autoimmune disease caused by production of antibodies to Ach receptors => Muscle weakness • Treatment: Acetylcholinesterase inhibitors

What are fibroblasts with contractile ability called?

*Myofibroblasts*

What is skeletal muscle responsible for? What percentage of body mass is skeletal muscle?

- Responsible for movement of skeleton; under *voluntary* motor control - 40% of body mass = skeletal muscle

What are characteristics of synovial joints?

1) *Diarthroses:* Characterized by extensive movement 2) Surrounded by connective tissue capsule (joint capsule) 3) Lined by thin, discontinuous layer of cells, *synovium* that secrete *synovial fluid* which bathes articular surface 4) NO basement membrane, so not a true epithelium

What is cartilage relative to bone?

Bone Precursor

What is required for muscle contraction?

Ca

What are the cause, symptom, and treatment of myasthenia gravis?

Causes: Autoimmune disease that results in Ab production Ach nicotinic receptors on muscle (therefore not enough receptors to reach EPP and reach threshold to get AP) Symptom: Weakening of muscle Treatment: Achesterase inhibitors

How is the axillary vein formed?

Coming together of the brachial vein(s) and the *basilic vein*

What are the cephalic and basilic veins responsible for?

Draining *superficial* regions of the arm

What is the Triangle of Auscultation?

Have less tissue and is closer to the rib cage, can hear breath sounds much more clearly 1. Superior Border of Latissimus Dorsi 2. Medially, Trapezius 3. Inferior Angle of Scapula

What are the branches of radial a.?

Just ONE - Radial Recurrent A.

What is the *endosteum*?

Lines the marrow cavity

What are microfibrils composed of?

Many proteins including *fibrillin-1*

Define mechanoreceptors.

Modified skeletal muscle fibers called *intrafusal fibers* associated with modified nerve endings

What is d-tubocuranine?

Nicotinic receptor *antagonist* - blocks the receptor

What are the gaps in collagen fibrils?

Nucleation sites for *hydroxyapatite [Ca5(PO4)3OH] crystals*

INTERMEDIATE - What is the origin, insertion, action, and innervation of flexor digitorum superficialis?

ORIGIN: 1. *Medial epicondyle* of humerus 2. Superior ½ of anterior border of *radius* INSERTION: Shafts of middle phalanges of medial 4 digits ACTIONS: 1. Flexes middle phalanges at proximal interphalangeal joint 2. Flexes proximal phalanges at metacarpophalangeal joints INNERVATION: Median N.

What is the origin, insertion, action, and innervation of adductor pollicis (NOT thenar)?

ORIGIN: 1. 2nd + 3rd Metacarpals 2. Carpals (Capitate + others) INSERTION: Proximal phalanx of thumb ACTIONS: Adducts thumb INNERVATION: Deep branch of ulnar n.

HYPOTHENAR - What is the origin, insertion, action, and innervation of flexor digiti minimi brevis?

ORIGIN: 1. Flexor Retinaculum 2. Carpal Bones (Hamate) INSERTION: Proximal phalanx of 5th digit ACTION: Flexes proximal phalanx of 5th digit INNERVATION: Deep branch of ulnar n.

SUPERFICIAL - What is the origin, insertion, action, and innervation of flexor carpi ulnaris?

ORIGIN: Medial epicondyle of humerus INSERTION: 1. Pisiform 2. Hook of hamate 3. 5th metacarpal ACTIONS: Flexes and adducts hand at wrist INNERVATIONS: *Ulnar N.*

What are aggrecans?

One of the proteoglycans found predominantly in hyaline cartilage

What are *fibroblasts*?

Pointed, elongate, spindle-shaped cells that synthesize & maintain proteinaceous ground substance & connective tissue fibers (collagen, elastin, & reticular fibers)

What is the retromammary space?

Potential space between breast and pectoral fascia overlying pectoralis major muscle

What is dense connective tissue?

Provides structural support— abundant fibers, moderate # of cells, lesser ground substance

Most smooth muscle has dual...

Sympathetic & parasympathetic innervation & is *involuntary*

The median nerves passes through ___________________

The median nerve passes through the carpal tunnel with all of the tendons of f.d.s. and f.d.p.

If the epiphyseal plates have not fused in the hand....

The patient is a child - not fully developed

What are the 3rd and 4th lumbricals attached to? What are they innervated by? Describe their shape.

• Attachment: Attached to medial 3 tendons of FDP • Nerve: *Deep branch of ulnar nerve* • Shape: Bipennate

What is the role of vitamin C?

• Helps in collagen synthesis • Facilitates intestinal absorption of Fe • Antioxidant

What is interstitial growth?

• New cartilage forms *within mass* • Chondrocytes retain ability to divide

What is polymastia and polythelia?

*Accessory nipple and/or breast tissue* can occur in both males and females May include glandular tissue May be mistaken for a *mole* (nevus) Appear along the embryonic *mammary crest*, which extends from axilla to groin area A mammalian characteristic

What is the entire upper extremity covered in?

*Fascia:* Compartmentalizes the limb

Name the collagen types and where they can be found.

*Fibril-Forming:* • Type I: Skin, bone, tendon, blood vessels, cornea • Type II: Cartilage, vitreous humor • Type III: Skin, muscle *Network-Forming:* • Type IV: Basement Membrane

What is an alternative to general anesthesia that involves the brachial plexus?

*Interscalene Block:* • Typically guided by ultrasound, local anesthetic agents are injected close to the brachial plexus, temporarily blocking sensation and motor function to the upper limb. • *Knowledge of the anatomical relationships within the posterior triangle of the neck is essential* to the safety success of this procedure.

What are inactive Harvesian systems known as?

*Interstitial Systems*

What are the boundaries of the cubital fossa?

*Lateral:* Brachioradialis Muscle *Medial:* Pronator Teres Muscle *Superior:* Imaginary line between medial and lateral epicondyles of humerus *Roof:* Skin, superficial & deep fascia, bicipital aponeurosis *Floor:* Supinator and brachialis muscles

Where do the mammary gland lobules converge? What do the lactiferous ducts drain into? What is the nipple surrounded by?

*Mammary gland lobules* converge on the nipple *Lactiferous ducts* drain into *lactiferous sinuses* which open at nipple The nipple is surrounded by a *pigmented areola*

How many nuclei are found in skeletal muscle cells?

*Multinucleated* cells

What is *muscular dystrophy*?

*Muscular Dystrophy:* - Degenerative wasting disease => muscle weakness due to genetic defect in muscle protein => cell death - One form affects protein *dystrophin*

What is the brachial plexus surrounded in within the axilla?

*Neurovascular bundle* by the *axillary sheath*

Measure your resting HR before and 30 min after intense workout. Why is it different?

*O2 Deficit* - Need to replenish glycogen and phosphocreatinine

What does compact bone contain?

*Osteons* or *Harvesian Systems*

Muscular attachments to the clavicle can...

*Pull fractured portions out of alignment*

What type of nonsynovial joints are *intervertebral joints*?

*Special type of symphysis* • Contain *intervertebral discs*, evolutionarily derived from notochord in chordates • Formed of concentric layers of fibrocartilage • Forms *annulus fibrosus* around central core of viscous ground substance, *nucleus pulposus* • Damage to annulus fibrosus causes nucleus pulposus to *herniate* => *herniated disc*

How is the posterior forearm divided up?

*Superficial:* 1. Brachioradialis - *Flexes elbow* 2. Extensor Carpi Radialis Longus 3. Extensor Carpi Radialis Brevis 4. Extensor Digitorum 5. Extensor Digiti Minimi 6. Extensor Carpi Ulnaris *Deep:* 1. Supinator 2. Extensor Indicis 3. Abductor Pollicis Longus 4. Extensor Pollicis Longus 5. Extensor Pollicis Brevis

What are Harvesian canals connected by?

*Volkmann's Canals:* Transverse canals

What are signs on a SDS-PAGE gel that show you that an individual has a mutation in the C-terminal half of α1/2 chain (OI)?

- Compare to control - Sign: Higher up (larger) and more smeared => more post-translational modifications

What occurs during muscle contraction?

- During muscle contraction, sarcomeres shorten but myofilaments remain the same length - Due to thick & thin filaments sliding over one another via energy from ATP => shortening of sarcomere, via repeated binding & unbinding of actin & myosin filaments - Ratchet-like or "walk-along" mechanism

What is another name for radioulnar joint? What do muscles in the region do?

- Elbow Joint - Primarily flex or extend the elbow joint

Describe dislocation of the glenohumeral joint. Where do most dislocations occur? Which dislocations are the most rare?

- Freely mobile yet *relatively unstable joint* - Most dislocations occur in the *downward (inferior) direction* and are described as *anterior dislocations* - Posterior dislocations are more rare: The coracoacromial structures and the rotator cuff tend to prevent upward dislocation

What are muscle fibers composed of? What are those components composed of?

- Individual muscle *fibers* composed of *myofibrils* - Myofibrils composed of numerous *myofilaments*, or *contractile proteins*, in parallel bundles

What do fractures of the scapula usually result from?

- Injury or trauma - Falling on outstretched hand or landing on shoulder - Direct blow to shoulder or upper back area

Which features of the scapular are often fractured?

- Most fractures occur across the *body of the scapula* but scapular neck can be fractured - The acromion is often involved

Where do actin and myosin overlap?

- Overlap in the A band (dark band) - DO NOT overlap in the I band (light band)

What are osteoprogenitor cells?

- Resting mesenchymal cells that reside in the *periosteum* and *endosteum* - Can differentiate into *osteoblasts* and *osteocytes*

What are the two ways that lamellar bone can appear?

1) *Dense & Compact:* (e.g. cortex of long bones) 2) *Cancellous:* • *Spongy* (e.g. ends of bones) • Contains network of thin, bony *trabeculae* (aka *spicules*) and open spaces (marrow cavity)

What are the different parts of a long bone?

1) *Diaphysis:* • Shaft that is composed of dense, *compact* bone in *cortex* and spongy, *cancellous* bone in *medullary* cavity • Medullary cavity contains red (hematopoietic) marrow or yellow (fatty) marrow 2) *Epiphyses:* • Ends of bone • Composed of spongy, *cancellous* bone covered with *hyaline articular cartilage* 3) *Metaphysis:* • Flared region between epiphysis and diaphysis • Contains *epiphyseal plate* ("physis" of radiologists)

CLINICAL CORRELATION: What does a genetic deficiency in α-1 antitrypsin result in?

1) *Emphysema (Lung Damage)* 2) *Liver Damage:* Secondary effect in which α-1 antitrypsin gets stuck in the liver

What are the 2 regions that the radial nerve can be injured?

1) Axillary Region: Nerve injured before it supplies triceps 2) Spiral Groove of Humerus

List step-by-step the process of bone repair.

1) Blood fills fracture site => hematoma 2) Immediately after fracture, inflammatory response develops—pain, swelling, redness, & heat 3) In acute phase (first few days) neutrophils first to arrive, infiltrate hematoma, then macrophages, (both phagocytic) to clean up site of injury 4) After ~1 wk, fibroblasts & capillaries proliferate & grow into site 5) Forms *granulation tissue* (vascular collagenous tissue) 6) Tissue becomes progressively more fibrous in chronic phase to form *fibrous granulation tissue* 7) Mesenchymal cells differentiate into chondroblasts, secrete matrix => progressive replacement of granulation tissue by hyaline cartilage (= *provisional callous*) 8) Next, osteoprogenitor cells & osteoblasts from endosteum & periosteum at edge of wound grow inward, produce meshwork of *woven bone* within provisional callous, deposit calcium salts in collagen matrix 9) Transforms into *bony callous* (helps stabilize & bind fracture together) 10) Bony callous progressively *remodelled* => mature lamellar bone

What does the apex of the axilla consist of?

1) Clavicle 2) Scapula 3) 1st rib 4) *Cervicoaxillary Canal:* Passageway for *neurovascular structures* (axillary vessels and brachial plexus components) from the neck to the upper limb

List the cutaneous (sensory) nerves of the arm.

1) Intercostobrachial n 2) Medial Brachial Cutaneous n. 3) Posterior Brachial Cutaneous n. (from *radial n*) 4) Superior Lateral Brachial Cutaneous n. (from *axillary n.*)

What are the two types of cartilage growth?

1) Interstitial Growth 2) Appositional Growth

What are 4 types of bone cells?

1) Osteoprogenitor Cells 2) Osteoblasts 3) Osteocytes 4) Osteoclasts

How do muscles defend against disease?

1) Produce *myokines* (antiinflammatory) that interact with all types of tissues (e.g. adipose) and inhibit type 2 diabetes, CV, cancer, and osteroporosis (Side Note: Adipose releases *adipokines* that are *proinflammatory* and stimulate diabetes, CV, cancer, and osteoporosis) 2) Muscle is a giant *reservoir* for blood sugar, thereby lowering blood sugar levels. In addition, when insulin binds to receptor on muscle it translocates more *GLUT4* to the membrane) to bring more glucose into the muscle

What does the base of the axilla consist of?

1) Skin & superficial fascia 2) *Anterior Axillary Fold:* • Pectoralis major muscle 3) *Posterior Axillary Fold:* • Latissimus dorsi • Teres major 4) *Chest Wall* • Serratus anterior

List step-by-step the process of cartilage formation.

1) Stellate mesenchymal cells, differentiate into rounded *chondroblasts* 2) Chondroblasts grow & synthesize ground substance & fibrous extracellular matrix, trapping chondroblasts in *lacunae* 3) Further mitotic divisions produce clusters of mature *chondrocytes*, referred to as *isogenous groups*, separated by extracellular matrix— territorial (matrix around clusters of cell) vs. interterritorial (matrix around few cells)

What are the ligaments involved in the sternoclavicular joint?

1) Sternoclavicular Ligaments 2) Interclavicular Ligaments 3) Costoclavicular Ligaments

What are the two branches of radial n.? What do they innervate?

1) Superficial Radial N. (Runs Beneath Brachioradialis) -*Skin* 2) Deep Radial N. (Becomes Posterior Interosseous N.) - *Muscles*

Explain the sliding filament mechanism.

1. *ATP Binds:* Myosin heads *detach* 2. *Hydrolysis of ATP:* *Cocks* myosin heads so ready to bind to next binding site 3. *Pi Released:* *Power Stroke* 4. *ADP Released:* Remains in attached phase - No function; released due to the conformational change in myosin heads from doing power stroke

How is muscle contraction terminated?

1. *Acetylcholinesterase* breaks down Ach into choline and acetic acid. 2a. SR/ER Ca ATPase (*SERCA*) pumps Ca into SR. Then *calsequestrin* sequesters and binds Ca in order to pack even more into SR (primary mechanism) 2b. Use *Ca ATPase* to pump Ca extracellularly 2c. *Na Ca exchanger* brings in 3 Na+ in and 2 Ca out

What are the 2 types of myofilaments?

1. *Actin:* Thin Filament 2. *Myosin:* Thick Filament

What are the major gland functional groups?

1. *Endocrine Glands:* - Lack ducts - Secrete products (hormones) directly into bloodstream 2. *Exocrine Glands:* - Secrete product onto epithelial surface via ducts - Contain specialized contractile cells called *myoepithelial cells* that lie between secretory cells & basement membrane, assist in secretion

What are the 2 types of mechanoreceptors located within muscle?

1. *Neuromuscular Spindles* (AKA Muscle Spindles): • Located within the belly of muscle • Sensitive to changes in *length* 2. *Neurotendinous Spindles* (AKA *Golgi Tendon Organs*): • Located within tendon • Sensitive to changes in *tension* ***NOTE: Both prevent overstretching and tearing of muscle; used in postural reflexes and coordination

What are the types of secretory products (e.g. salivary glands)?

1. *Serous:* Watery; basophilic acini (e.g., parotid) 2. *Mucous:* Thick, viscid secretion (mucus); *clear on H&E* (e.g., palatal) 3.. *Mixed (Seromucous):* Contain both mucous & serous acini, often include *serous demilunes* (e.g. sublingual, submandibular)

What are the the different parts of the axillary artery?

1. *Superior Thoracic Artery* 2. *Thoracoacromial Trunk* -pectoral branch -deltoid branch -acromial branch (clavicular branch) 3. *Subscapular Artery* - circumflex scapular - thoracodorsal 4. *Anterior/Posterior Circumflex Humeral* 5. *Lateral Thoracic Artery*

What are the anastomosing arterial branches?

1. *Suprascapular Artery:* From subclavian artery 2. *Dorsal Scapular Artery:* Deep branch of transverse cervical a. from subclavian a. 3. *Posterior Intercostal Arteries:* From thoracic aorta) 4. *Circumflex Scapular Artery:* Division of subscapular artery from axillary artery 5. *Thoracodorsal Artery:* Division of subscapular artery from axillary artery

FOREARM REVIEW: What is the origin of: 1. Anterior Interosseous N. 2. Posterior Interosseous N.?

1. Anterior Interosseous N: Median N 2. Posterior Interosseous N: Deep Branch of Radial N

What are the different scapular motions?

1. Elevation/Depression 2. Protraction/Retraction 3. Upward Rotation/Downward Rotation

What does mesoderm give rise to?

1. Epithelium of kidneys & gonads 2. Mesothelium (lining pleura, peritoneal, & pericardial cavities) 3. Endothelium (blood & lymph vessels) 4. Adrenal cortex

What are the movements that can occur at the interphalangeal joints?

1. Flexion/Extension

What are the movements that can occur at the metacarpophalangeal joints?

1. Flexion/Extension 2. Abduction/Adduction

What are the motions you can do with the glenohumeral joint?

1. Flexion/Extension 2. Adduction/Abduction 3. Medial/Lateral Rotation 4. Circumduction

What are the movements that occur at the thumb?

1. Flexion/Extension 2. Adduction/Abduction 3. Opposition/Retroposition

What are the fascial compartments of the hand and wrist? Which nerves and muscles can be found each?

1. Hypothenar: • Nerve: *Deep ulnar n.* • Muscle: Intrinsic muscles of 5th digit 2. Thenar: • Nerve: *Recurrent branch of medial n* • Muscle: Intrinsic muscles of thumb 3. Central (Carpal Tunnel): • Nerve: *Median n.* • Muscle: Tendons of FDS, FDP, and flexor pollicis longus 4. Adductor: • Nerve: *Deep ulnar n.* • Muscle: Adductor pollicis muscle 5. Interosseous: • Nerve: *Deep ulnar n.* (between metacarpals) • Muscles: Palmar & Dorsal interosseous muscles

What are the 2 different types of ossifications?

1. Intramembranous Ossification 2. Endochondral Ossification

What are the forms of connective tissue?

1. Loose (Areolar) CT 2. Dense • Regular • Irregular

Describe the development of muscle fibers.

1. Muscle cells form *synctia* (a multinucleate mass of cytoplasm) due to the fusion of *myoblasts* into a multinucleate *myotube* during development 2. Myotubes synthesize *contractile proteins* which assemble into sarcomeres 3. Nuclei migrate to the periphery of the cell, lose ability to proliferate

In hypertrophy you get more...

1. Myofibrils 2. Sarcoplasm 3. Connective Tissue OR combination of those

What are the 3 criteria of epithelial classification?

1. Number of Cell Layers • *Simple*—1 cell layer thick • *Stratified*—2 or more cell layers • *Pseudostratified*—looks stratified, but isn't; all cells rest on basement membrane, but not all cells extend to epithelial surface 2. Shape Of Cells (At Epithelial Surface) *Squamous:* Flattened, width > height *Cuboidal:* Width = depth = height *Columnar:* Height > width 3. Surface Specializations (e.g. cilia, keratin)

What are 6 diseases associated with the skeletal system?

1. Osteoarthritis 2. Rheumatoid Arthritis 3. Gout 4. Rickets/Osteomalacia 5. Osteoporosis 6. Scurvy

What are the movements associated with the radiocarpal and midcarpal joints?

1. Palmar Flexion/Dorsal Flexion 2. Radial/Ulnar Abduction

What are the different parts of deep fascia of the pectoral region?

1. Pectoral Fascia 2. Axillary Fascia 3. Clavipectoral Fascia 4. Deltoid Fascia

What are the 4 muscles of the pectoral region?

1. Pectoralis major 2. Pectoralis minor 3. Subclavius 4. Serratus anterior

What are the 3 energy sources?

1. Phosphocreatine & Creatine Kinase (8-10 sec) 2. Glycogen - Anaerobic Glycolytic Metabolism (1+ min) 3. Oxidative Metabolism (unlimited with nutrients)

What are the branches of the brachial artery?

1. Profunda Brachii (Deep Brachial Artery) • Middle Collateral (Posterior Descending Branch) • Radial Collateral (Anterior Descending Branch) 2. Superior Ulnar Collateral 3. Inferior Ulnar Collateral Other (Not Part of Brachial A): Nutrient Arteries To Humerus & Muscular Branches To Muscle

What is the basement membrane functions?

1. Provides *structural support, scaffolding for growth, differentiation, & migration of cells* during embryonic growth & regeneration 2. Non-cellular, protein & polysaccharide-rich layer; *acts as filter* between epithelium & underlying connective tissue (e.g. in kidneys, glomerular basement membrane acts as highly selective filter for urine formation) 3. *SPM for nutrients & metabolites* to & from epithelium via maintaining negative charge

What is the purpose of connective tissue?

1. Provides structural support & metabolic support for other tissues & organs 2. Carries blood vessels; functions in tissue repair 3. Mediates exchange of nutrients/metabolites/waste products between tissue & circulation

What happens to the choline that is broken down from Ach?

1. Pumped back into cell via *Na choline cotransporter* 2. *ChAT* combines choline and acetyl CoA to make Ach 3. Ach is packaged into vesicle via *Ach transporter* 4. Quanta can be released

How is smooth muscle similar to skeletal muscle? (2)

1. Same organization of muscle fibers with *endo-*, *peri-*, and *epimysium* 2. Smooth muscle fibers bound together in highly irregular, branching *fascicles*, specialized for prolonged contractions with low force

There is a well know association between these 3 things. What are they?

1. Sarcopenia 2. Osteoporosis 3. Falls

What 2 structures act as Ca reservoirs when muscle is relaxed?

1. Sarcoplasmic reticulum 2. Terminal cisternae

What are the 3 types of muscle (all mesodermally derived)?

1. Skeletal Muscle 2. Smooth Muscle 3. Cardiac Muscle

Which bursa can be found in the glenohumeral joint?

1. Subscapular Bursa 2. Subacromial Bursa (Subdeltoid Bursa) 3. Subcoracoid Bursa 4. Synovial Sheath (Long Biceps Tendon)

What are the 2 types of fascia in the pectoral region?

1.) *Superficial Fascia:* - Subcutaneous; fatty 2.) *Deep Fascia:* - Compartmentalizing - Surrounds muscles - Attaches to bone in most cases

Which ligaments help to stabilize the acromioclavicular joint?

1.) Acromioclavicular Ligament (has *2 supporting sets of ligaments*) 2) Coracoclavicular Ligaments a. Trapezoid Ligament (lateral) b. Conoid Ligament (medial)

What are the 2 types of muscle relaxants?

1.) Depolarizing (e.g. succinylcholine) 2) Non-Depolarizing (e.g. d-tubocurarine)

What is Ca homeostasis regulated by?

2 Antagonistic Hormones 1) *Parathormone (Parathyroid Hormone):* • Secreted by parathyroid gland • Stimulates *osteoclast* activity => bone resorption • ↑ Blood Ca levels & ↓ renal excretion by kidneys 2) *Calcitonin:* • Secreted by thyroid gland • Stimulates *osteoblast* activity, *inhibits* osteoclasts => bone deposition • ↓ Blood Ca levels

Define myotomes.

A group of muscles that receive motor innervation from a single spinal nerve. Myotomes overlap; most muscles are made up of >1 myotome (one muscle is suppled by more than one spinal nerve).

What is the basal lamina composed primarily of?

All impart tissue specificity of the basal lamina 1. *Type IV collagen* 2. *Laminin* 3. Entactin (Nidogen) 4. Perlecan (Heparin Sulfate Proteoglycan) 5. Other Minor Proteins

What do arterial branches arising from the subclavian and axillary arteries form?

An *anastomosis* around the scapula, allowing collateral circulation to the upper limb

What is TGFβ?

An important factor regulating production and maintenance of ECM

Which artery is serving the anterior compartment? Posterior compartment?

Anterior: Brachial Posterior: Profunda Brachii (Deep Brachial)

What does thick cartilage contain?

Blood vessels in *2' cartilage canals*

What are bone and cartilage both derived from?

Bone (rigid) and cartilage (semi-rigid) are both derived from *primitive mesenchymal cells*

Bone serves as a ___________ for Ca and functions in _____________________

Bone serves as a reservoir for Ca & functions in Ca homeostasis

What do the divisions contribute to?

Branches that correspond anterior parts of the limb or posterior parts of the limb

What is a unique feature of the C7 root of the brachial plexus?

C7 *DOES NOT contribute to the medial cord*. However, C7 does typically contribute to the *Ulnar Nerve*

What are characteristics of nonsynovial joints? What are 3 types of nonsynovial joints?

Characteristics: 1) Limited movement 2) Joined by dense connective tissue 3) Lacks articular surface Types: 1) Syndesmosis 2) Synchondrosis 3) Symphysis

What is rickets?

Characteristics: • Bone matrix doesn't calcify normally in children during growth => *soft, deformed bones* • Can be permanent Cause: Due to insufficient dietary Ca or Vitamin D

What is gout?

Characteristics: • Deposit of *urates and uric acid crystals in joints* (especially fingers & toes) • Extremely painful Causes: 1.) Consumption of *large quantities of red wine, meat, and certain vegetables* (e.g. asparagus, broccoli, cauliflower, Brussel's sprouts) => All represent new plant growth, high in protein & [N] 2.) Some *diuretics used to treat hypertension* can also cause gout

What are osteoclasts? Where are they normally found? What is their function?

Characteristics: • Large, multinucleate cells derived from monocyte-macrophage lineage; phagocytic Location: • Usually found on endosteal/ periosteal surface in depressions, called *Howship's lacunae*, or *resorption bays* Functions: • Actively involved in resorption & remodeling of bone • Function in Ca homeostasis by producing organic acids & lysozymes that digest bone—secreted into ECS by *ruffled border* (modified, folded plasma membrane, containing microvilli-like structures)

List the two types of fractures of the distal radius as well as their characteristics.

Colle's Fracture: - Distal fragment of radius displaces *dorsally* - Shaft of radius displaces *ventrally* - Cause: *Forced extension* while FOOSH - Appearance: *"Dinner Fork"* Deformity Smith's Fracture - Distal fragment displaced *ventrally* - Shaft of radius displaced *dorsally* - Cause: *Forced flexion* while FOOSH - Appearance: *Garden Spade* Deformity

What is the common flexor origin? What is the common extensor origin?

Common Flexor Origin: Medial Epicondyle Common Extensor Origin: Lateral Epicondyle

GAGs do not...

Compact Well - Negatively charged due to sulfate & carboxyl side groups => hydrophilic => gel formation

Connective tissue may be classified as ________________. All of these but _________, share __________________________.

Connective tissue may be classified as dense, loose, cartilage, bone, or blood. All of these but blood share some common proteins, with the different tissue types having different distributions of various protein isoforms.

What does stimulation of a motor neuron result in?

Contraction of muscle fibers within that motor unit

Explain why people who have passed away demonstrate rigamortis.

Dead cells cannot make ATP, therefore they are unable to release the myosin heads from actin filaments (until proteins break down).

What is invasion of the site of damage by blood vessels frequently result in?

Death of chondrocytes and formation of bone

What are the anastomoses between the *deep brachial artery* and the *radial & interosseous arteries*?

Deep Brachial Artery - Radial & Interosseous Arteries 1) *Radial* Collateral - *Radial* Recurrent 2) Middle Collateral - Recurrent Interosseous

Describe the inheritance pattern of OI if the defect is in the COL gene vs. if in a collagen-modifying protein.

Defects in COL Genes: • Autosomal Dominant • Range in severity of phenotype (haploinsufficiency v. dominant negative) Defects in Collagen-Modifying Proteins: • Autosomal Recessive • Severe phenotype

What do glycine mutations do?

Delay collagen folding, and result in overmodified collagen, which may compromise secretion and/or processing.

What are the differences in terms of development for the 2 types of twitch fibers?

Early in development of myotubes, "fast" Mm fibers are innervated by "fast" Nn & "slow" Mm fibers by "slow" Nn Also differences in development of contractile proteins => "fast" myosin & "slow" myosin

Where do the brachial plexus trunks emerge (supraclavicular)?

Emerge *posteriolateral to the sternocleidomastoid muscle* in the *lateral neck region*, in an area called the *posterior triangle*, through the *interscalene space* (between the middle and anterior scalene muscles) at approximately the level of the *cricoid cartilage of the larynx*. The brachial plexus maintains an *anatomical relationship with vascular structures* emerging from the root of the neck *(subclavian a. and v.)* as it *travels posterior to the omohyoid muscle and the clavicle* on its way into the axilla.

What are the ends of T-tubules bounded by?

Enlarged terminal cisternae of ER on either side; forms *triad*

What do the blood vessels and nerves tend to follow?

Epimysium and Perimysium for support

What are glands composed of?

Epithelial cells specialized for synthesis and secretion

Explain the lymph drainage of the breast and its importance.

Especially *important* due to its role in *metastasis of cancer cells*; most mestasis is to *axillary lymph nodes* >75% of lymph from breast: *Axillary Lymph Nodes* 1) Pectoral 2) Central 3) Apical Nipple, Areola, Lactiferous Lobules: *Subareolar Lymph Nodes* Remaining Lymph: *Parasternal* (internal mammary) and *Abdominal Lymph Nodes*

In a mammography, what is the breast tissue examined for?

Evaluated for asymmetry, breast density, calcifications, masses (cystic or solid)

Which muscles are innervated by the brachial plexus?

Every muscle of the upper extremity with the exception of 2 muscles

What is the transverse tubule system (T-tubules)?

Extensive network of tubules continuous with sarcolemma that indirectly links extracellular space with ER & intracellular environment

What is the extensor expansion/hood?

Extensor Expansion: *The extensor tendons form a moveable hood* over the *metacarpophalangeal (MP) joints* The arrangement of both extensor muscles and intrinsic hand muscles that attach to this dorsal digital expansion *enable the uncoupling of flexion & extension* This mechanism enables the long extensor tendons to strongly *extend the MP* joint and allows *extension of IP joints when MP joints are flexed by lumbricals*, which also attach to the "hood" part of the extensor expansion. This is also aided by contraction of dorsal interosseous muscles

Compare muscle areas in need of fine motor control and muscle areas that do not require fine motor control (e.g. antigravity muscles, back muscles)

Fine Motor Muscles: 1 motor neuron synapses with as few as 4/5 muscle fibers Antigravity/Back Muscles: 1 motor neuron synapses with 100s of muscle fibers

What do some of these ligaments of hand/wrist contribute to?

Formation of spaces within the wrist and hand through which tendons, nerves, and arteries must pass

What is the axillary fascia?

Forms floor of axilla

What do most sternoclavicular dislocations result from?

Fractures through epiphyseal plate at the sternal end of the clavicle in individuals >25 yrs of age

A newborn displays the symptoms of a moderate case of osteogenesis imperfecta. Analysis of the child's collagen by SDS-PAGE indicates a molecular species with a greater-than-normal molecular weight. Treatment of the child's collagen with b-mercaptoethanol prior to SDS-PAGE results in a normal-sized collagen. The mutation in this child is most likely which one of the following?

Glycine To Cysteine Explanation: Mercaptoethanol is a reducing agent that has ability to break disulfide bonds. 2 cys link together which gives forth a "greater-than-normal molecular weight." The treatment then breaks this bond so it runs at normal size.

What is special about the *subscapular artery* and its branches (circumflex scapular and thoracodorsal)?

Have particular importance in circulation around the shoulder and scapula

What is one key type of post-translational modification?

Hydroxylation: • Pro and Lys residues on the a chains are hydroxylated by *hydroxylases* that *require ascorbic acid (vitamin C)* • *Hydroxylation is a key contributor to collagen stability; it provides polar groups for H-bonding, and is required for glycosylation, which further stabilizes structure.* • Prolyl Hydroxylase: Proline => Hydroxyproline (Hyp) • Lysyl Hydroxylase: Lysine => Hydroxylysine (Hyl)

Explain the composition and the changes in the following parts: I Band, A Band, H Band.

I Band: • Composition: Actin ONLY • Change: Disappears A Band: • Composition: Actin + Myosin • Change: None; remains the same H Band: • Composition: Myosin ONLY • Change: Disappears

What are the 3 divisions of the subclavian artery?

In relation to the *anterior scalene muscle* - Part 1: *Medial* to the anterior scalene muscle - Part 2: *Posterior* to the anterior scalene muscle - Part 3: *Lateral* to the anterior scalene muscle

What happens in the absence of vitamin C?

In the absence of vitamin C, the melting temperature of collagen drops from 42ºC to 24ºC (protein will denature at a lower temperature)

What is reduced muscle strength with aging associated with?

Increased risk of disability and mortality

What do lumbricals insert on? What are their actions?

Insertion: Lateral sides of the extensor expansions of digits 2-5 Actions: 1. *Flex the metacarpophalangeal joints* 2. *Extend interphalangeal joints* (via the extensor expansion & extensor hood) of digits 2-5

What are integrins and fibronectins?

Integrins: • Facilitate connections between the cell membrane and the ECM • Link ECM proteins such as fibronectin, laminin, and collagen to the internal cytoskeleton. • At least 24 unique isoforms Fibronectin: • Like laminin, facilitates connections between ECM components • Important adhesion protein • Adhesion proteins connect integrin to other components of the ECM.

Where are the following located: lamina lucida, densa, and reticularis?

Lamina Lucida: In contact with basal cell membrane Lamina Densa: Anchored to underlying connective tissue by *microfibrils* of Type IV collagen (anchoring filaments) Lamina Reticularis: Merges with surrounding tissue

What does entactin bind with?

Laminin

What is laminin the major component of? What is it produced by?

Laminin: • Major component of basement membrane • Produced by most epithelial & endothelial cells

What are the origins of the following nerves that provide sensory innervation to the forearm: a. lateral cutaneous n. b. medial cutaneous n. c. posterior cutaneous n.

Lateral Cutaneous N: Terminal branch of musculocutaneous Medial Cutaneous N: Coming off medial cord of brachial plexus Posterior Cutaneous N: Radial nerve

List the extrinsic back muscles in each layer (layer 1-3 from superficial to deep).

Layer 1: 1) Trapezius 2) Latissimus Dorsi Layer 2: 1) Levator Scapulae 2) Rhomboid Minor/Major Layer 3: 1) Serratus Posterior Superior/Inferior - move the ribs (NOT the limbs)

What do *sebaceous glands* of the skin secrete?

Lipids in the form of *sebum*

A 50 year-old woman undergoes surgery to remove a mass in her left breast. The surgeons also remove several axillary lymph nodes. The patient experiences a complication-free recovery but has difficulty raising her left arm over her head during routine daily activities. She is examined by her primary care physician who finds that the medial border of her left scapula sticks out posteriorly when she pushes on a wall with both arms, indicating that she is unable to maintain protraction of her left scapula. What nerve was likely damaged during her recent surgery?

Long thoracic nerve

What does non-functional or insufficient lysosomal enzymes lead to?

Lysosomal storage diseases, aka "mucopolysaccharidoses"

What are the blood supply branches that go to the breast?

Medial & Lateral Mammary Branches (from *internal thoracic a.*)

What do the following nerves in the forearm innervate: a. Median Nerve b. Ulnar Nerve c. Radial Nerve?

Median Nerve: • *Anterior compartment* of forearm; all muscles except 1 and ½ Ulnar Nerve: • 1 and ½ muscles in *anterior compartment* of forearm Radial Nerve: All muscles in *posterior compartment* of forearm

Define motor unit.

Motor neuron and all the fibers it innervates

Which veins drain *deeper* parts of the arm region?

Multiple *brachial veins* and *profunda brachii*

What occurs during normal exercise?

Muscle fibers develop micro-tears

Which muscle(s) and nerve(s) can be found in the superficial fascia of the pectoral region?

Muscle: *Platsyma Muscle:* Muscle over lower mandible, neck and upper thoracic/shoulder region; a very superficial skeletal muscle that is mostly subcutaneous Nerves: 1. *Supraclavicular Nerves* (cutaneous branches from C3 & C4 cervical spinal nerves) 2. *Anterior & Lateral Branches of Intercostal Nerves* (come up through deeper layers of fascia to subcutaneous layers)

DEEP - What is the origin, insertion, action, and innervation of supinator?

ORIGIN: 1. Lateral epicondyle of humerus 2. Radial collateral & anular ligaments 3. Ulnar crest INSERTION: Proximal 1/3 of radius (nearly all surfaces, as it wraps around the bone) ACTIONS: Supinates forearm INNERVATION: Deep branch of radial nerve

DEEP - What is the origin, insertion, action, and innervation of flexor pollicis longus?

ORIGIN: Anterior surface of radius and interosseous membrane INSERTION: Distal phalanx of thumb ACTIONS: Flexes thumb INNERVATION: Median N. - Anterior Interosseous N.

What is the origin, insertion, action, and innervation of palmar interossei?

ORIGIN: Attach to palmar surfaces of 2nd, 4th, & 5th metacarpals INSERTION: Proximal phalanges and the extensor expansions of digits 2nd, 4th, & 5th digits ACTION: 1. *PAD* - Adducts 2nd, 4th, & 5th fingers toward axial line 2. Also assist lumbricals INNERVATION: Deep branch of ulnar n.

DEEP - What is the origin, insertion, action, and innervation of pronator quadratus?

ORIGIN: Distal ¼ of anterior surface of *ulna* INSERTION: Distal ¼ of anterior surface of *radius* ACTIONS: 1. Pronates forearm 2. Deep fibers bind radius & ulna together INNERVATION: Median N. - Anterior Interosseous N.

SUPERFICIAL - What is the origin, insertion, action, and innervation of extensor carpi radialis brevis?

ORIGIN: Lateral epicondyle of humerus INSERTION: 3rd Metacarpal ACTIONS: Extend and abduct hand at wrist INNERVATIONS: Deep branch of radial nerve

SUPERFICIAL - What is the origin, insertion, action, and innervation of extensor carpi ulnaris?

ORIGIN: Lateral epicondyle of humerus and posterior border of ulna INSERTION: 5th metacarpal ACTIONS: Extends and adducts hand at wrist INNERVATIONS: Posterior Interosseous N.

Describe the axillary region of radial nerve injury.

Possible Cause: Improper use of crutches can compress and injure the nerve in the axilla Clinical Presentation (posterior compartment affected) 1. Weakness when trying to push something away with arm 2. Difficulty extending the wrist 3. Difficulty extending the fingers and opening the hand 4. *"Wrist Drop"* posture

Describe the ulnar nerve relationships.

Posterior to the medial epicondyle Runs along the medial forearm under the flexor carpi ulnaris Goes through Guyon's canal lateral to the pisiform bone Enters the hand and supplies most of the intrinsic muscles of the hand

What is the primary and secondary functions of bone & cartilage?

Primary Functions: 1. Support 2. Locomotion/movement Secondary Functions: 1. Protection 2. Mineral Storage 3. Hemopoiesis (formation of blood)

What is the relative strength of bone and cartilage due to?

Properties of ground substance and extracellular fibers

What is the brachial plexus responsible for?

Provides *somatomotor* and *somatosensory* innervation to the *upper extremity*

What is the purpose of hyaline cartilage? What is it characterized by? Where is hyaline found?

Purpose: Precursor for bone in most of skeleton Characterization: Small aggregates of chondrocytes in amorphous matrix of ground substance, reinforced with *Type II* collagen fibers Locations: 1. Articular surfaces 2. Growth plates 3. Nasal septum 4. Costal cartilage (ribs) 5. Tracheal and bronchial rings

How is pronation obtained?

Radial head stays stationary while the distal end of radius flips over the ulna • Supinated = Anatomical Position • Pronated = How we naturally tend to hold our forearms

Radial nerve does not _____________________. Superficial radial nerve provides ___________ to ___________________

Radial nerve supplies NO muscles in hand. Superficial radial nerve provides sensation to dorsum of hand on thumb side

What is the origin of the subclavian artery on the right and left?

Right: Brachiocephalic Trunk Left: Aortic Arch (arises posterior to sternoclavicular joint)

What is the purpose of microfibrils?

Serve as guides for the deposition of elastin

A 65 year old female goes in for a routine annual mammogram, the results of which indicate abnormal tissue growth in the upper quadrant of her left breast. As a result she has a biopsy performed and also undergoes surgery to remove a number of lymph nodes from her left axilla. During the procedure her left long thoracic nerve is torn. What post-surgery functional deficit(s) will she likely experience?

She will not be able to lift her left arm up over her head

What is another word for acromioclavicular joint dislocation?

Shoulder separation

What is osteoid similar to?

Similar to *cartilage* - both are later mineralized to form new bone

How do we treat fractures of the scapula?

Since the scapula is invested in muscle and soft tissue, some fractures require *little treatment*

What is the size of an average Harvesian system?

Size of osteoclast

What can smooth muscle cells develop from? What can myoepithelial cells develop from?

Smooth muscle cells can develop from the following: 1. Endothelial Cells 2. Pericytes of Blood Vessels 3. Fibroblasts Glandular epithelial cell can differentiate into *myoepithelial* cells

How does smooth muscle respond to injury?

Smooth muscle retains ability to divide & repair itself following injury

What is bone?

Specialized support tissue— extracellular components are mineralized => rigidity & strength

What are goblet cells?

Specialized, unicellular exocrine glands located in epithelium that secrete mucus

What are the stages of breast cancer?

Stage 1: Early disease: tumor *confined to the breast* (node-negative) Stage 2: Early disease: tumor *spreads to* moveable ipsilateral axillary *nodes(s)* (node-positive) Stage 3: Locally advanced disease tumor *spreads to the superficial structures of the chest wall*; involvement of ipsilateral internal mammary lymph nodes Stage 4: Advanced (or metastatic) disease; *metastases present at distant sites*, such as bone, liver, lungs, and brain and including supraclavicular lymph node involvement

Describe the appearance in a cross section.

Stippled in cross-section due to hexagonal array of microfilaments

What are concentric bony lamellae laid down by?

Successive layers of osteoblasts

Cephalic and basilic veins are both...

Superficial veins of the upper limb

The motor end plates each...

Synapse with their own muscle fiber

What does fibrillin-1 interact with?

TGFβ-binding proteins

What do you do after you get a wound to the thenar eminence?

Test for function of *thenar muscles* - may have damaged *recurrent branch of median nerve* that supplies motor innervation to all those muscles

Where does the brachial plexus arise from? What is it formed by? Where do the spinal nerve roots emerge from and pass between?

The brachial plexus arises from the *cervical enlargement of the spinal cord* It is formed by the *VENTRAL RAMI of cervical spinal nerve roots C5-T1*. These spinal nerve roots *emerge from the intervertebral foramina (neural foramina)* of cervical vertebrae and pass between the *anterior and middle scalene muscles (interscalene space)* of the neck.

Explain how muscles from opposing functional compartments act as antagonists to each other, and why this is important.

The flexors in the anterior compartment of the arm and the extensors in the posterior compartment of the arm act as *antagonists* to each other. For example, biceps brachii opposed the action of triceps brachii when the elbow joint is extended. Biceps must relax in order for triceps to be able to extend The opposing action of the antagonist also ensures that the working muscle does not *over‐extend* or *over‐flex*

During the process of forming triple helix, you can still have post-translational modifications. Therefore, the longer it takes to wind....

The more modifications you will get

What is anterior interosseous nerve & anterior interosseous artery relationship to the pronator quadratus muscle?

The nerve and artery run deep (posterior) to the muscle

List the muscles involved in the scapulohumeral (intrinsic musculator). What is the action of all these muscles?

These muscles attach the scapula to the humerus. They move the humerus at the shoulder joint and contribute to the stabilization of this joint. They are all innervated by the *brachial plexus.* 1. Serratus Anterior (functionally) 2. Deltoid 3. Teres Major 4. *Rotator Cuff Muscles* - Subscapularis - Supraspinatus - Infraspinatus - Teres Minor

What are the extensor retinaculum and the flexor retinaculum?

Thickenings in the antebrachial fascia that help keeps things tight in the wrist as well as help with the efficiency of motion

What are the 3 types of troponin molecules?

Troponin T (TnT): Binds to *tropomyosin* Troponin C (TnC): Binds to *calcium* Troponin I (TnI): Binds *myosin binding site* ; *i*nhibitory

List the different types of collagen.

Type I Collagen: • 90% of collagen in body • Loose & dense connective tissue of skin, tendons, ligaments, bone & fibrocartilage Type II Collagen: • Found in hyaline and elastic cartilage Type III Collagen: • *Reticulin* fibers; thin, branching, net-like fibers • For structural support in organs (e.g., liver, spleen, lymph nodes, bone) • Produced by *reticular* cells in lymph nodes & bone marrow & by fibroblasts elsewhere • *Argyrophilic* (stains black with silver stain) Type IV Collagen: • Found in basement membrane • Doesn't form fibers Type V Collagen: • Cornea Type VII Collagen: • Dermo-epidermal Junctions

What are the 3 muscle fiber types and their characteristics: a. metabolism b. mitochondria c. myoglobin d. capillary density e. resistance to fatigue f. force/power

Type I, Slow Twitch (Red Meat): Metabolism: Oxidative Mitochondria: High Myoglobin: High Capillary density: High Resistance to Fatigue: High Force/Power: Low Type IIa, Fast Oxidative Twitch: Metabolism: Oxidative Mitochondria: High Myoglobin: High Capillary density: Intermediate Resistance to Fatigue: Intermediate Force/Power: High Type IIb, Fast Glycolytic (White Meat): Metabolism: Glycolytic Mitochondria: Low Myoglobin: Low Capillary density: Low Resistance to Fatigue: Low Force/Power: Very High

Ulnar nerve passes ______________ to ______________ and enters _____________________

Ulnar nerve passes superficial to flexor retinaculum and enters ulnar canal (Guyon's Canal) medial to ulnar artery

What is the basal surface of epithelial cells attached to?

Underlying *basement membrane* - extracellular matrix proteins => Referred to as *external lamina*

A 24 year old woman fell from a horse that she was riding and landed violently on her right shoulder and head, causing excessive separation. In the emergency department, upon examination her right limb, which she complained felt "weak", was held close to her body, rotated inward, with her forearm pronated and extended. She was unable to move her limb out of this position without assistance.

Upper Trunk Injury

What are the 3 types of cartilage?

Variable types and amounts of fibers embedded within matrix produce 3 types of cartilage 1. Hyaline Cartilage 2. Fibrocartilage 3. Elastic Cartilage

What are osteons produced via?

Via bony *remodeling*—removal of existing bone by osteoclasts and redeposition of new bone by osteoblasts

Can you change your fiber type?

Yes but not drastically

What is the term to describe the following: a. individual muscle cell b. muscle cytoplasm c. muscle plasma membrane/plasmalemma?

a. Individual Muscle Cell = *Myocyte*/ *Muscle Fiber* b. Muscle Cytoplasm = *Sarcoplasma* c. Muscle Plasma Membrane/Plasmalemma: *Sarcolemma*

What is ostrogenesis imperfecta (OI)?

• "Brittle Bone Disease" • Group of at least eight clinically, genetically, or biochemically distinguishable disorders in *collagen type I biosynthesis* Symptoms: 1. Varying degrees of bone fragility and deformity 2. Growth retardation 3. Hearing loss 4. Blue sclera

What are type II, fast twitch fibers?

• "Fast" myosin • *Large* fibers with less myoglobin & fewer mitochondria • Use 1' *anaerobic glycolysis* for energy production • Abundant glycogen • Extensive sarcoplasmic reticulum for rapid Ca release • Fatigue rapidly, but generate high M tension for short bursts of activity

What is osteoarthritis?

• *Arthritis:* *Inflammation* of joints • Progressive degeneration & loss of articular cartilage • Leads to *eburnation* (bone becomes hard and dense like ivory), pitting, erosion => pain, swelling, thickening of joint capsule • *Osteophytes:* Production of irregular new bone at edges of articular surfaces AKA "bone spurs" • Limits range of motion • Progressive build-up of osteophytes, osteoarthritis or trauma can lead to *ankylosis*—bony fusion of joint with loss of mobility

What are elastin chains cross-linked by?

• *Desmosine Units* • Use *lysyl oxidase* to oxidize lys residues in elastin to end up with cyclic structure = desmosine

What is the pectoral fascia?

• Attaches to clavicle and sternum; invests pectoralis major muscle; continuous with fascia of anterior abdominal wall • Pectoral fascia will become the *axillary fascia*

What are the 1st and 2nd lumbricals attached to? What are they innervated by? Describe their shape.

• Attachment: Attached to lateral 2 tendons of FDP • Nerve: *Median Nerve* • Shape: Unipennate

What is Marfan's syndrome?

• Autosomal dominant condition resulting in abnormal elastic fibers • Characterized by tall stature, long limbs, and long, thin fingers • Enlarged aorta, with ↑ regurgitation and ↑ risk of developing a dissecting aneurysm

How does cartilage receive nutrition?

• Cartilage is an *avascular connective tissue* => most cartilage lacks blood vessels • Exchange of metabolites occurs via diffusion through ground substance • Limits thickness of mature cartilage

What does the cephalic vein drain into? What does the basilic vein receive and later become?

• Cephalic vein (lateral) drains into the axillary vein • Basilic vein (medial) receives *deep* veins from the arm and then becomes the axillary vein

What post-translational modification occurs to collagen α-chains once secreted into extracellular space?

• Collagen lys side chains can be *oxidized by lysyl oxidase* which requires *O2 and Cu2+*. The resulting aldehyde (allysine) forms *inter-chain or inter-strand crosslinks*

What is the clinical correlation regarding ossification of the clavicle?

• Congenital *pseudoarthrosis* ("nonunion"; "false joint") of the clavicle • Sometimes the fusion of the different ossification centers of the clavicle fails • A congenital defect like this can present like a poorly healed fracture • Most often involves right clavicle but can be bilateral (rare)

What is elastin?

• Connective tissue protein with elastic-like properties • Primary component of elastic fibers, which are found in the large arteries, lungs, ligaments, elastic tendons, skin, and eleastic cartilage

What types of cells are found in adipose? Describe fat energetically? What does adipose tissue function in?

• Contains *adipocytes*, cells derived from *lipoblasts* —primitive mesenchyme adapted for storing fat (primarily TGs) • Fat *energetically very active*, has rich blood supply • Functions in energy storage, thermoregulation, & as a shock absorber

What is the axillary artery?

• Continuation of the subclavian artery • Has tributaries that provide blood to the shoulder, thorax, and axillary region. • Continues into the arm as the brachial artery.

What is medial winging of scapula? What are the causes and clinical presentation?

• Damage to *long thoracic nerve* • *Serratus anterior* affected Causes: 1. Penetrating wound to the axillary region 2. Surgical removal of axillary lymph nodes Clinical Presentation: 1. Medial border of scapula protrudes ("winged scapula") 2. Unable to raise arms above 90º

What is clavipectoral fascia?

• Deep to pectoralis major muscle • Invests *subclavius* and *pectoralis minor muscles* • *Costocoracoid membrane* connects subclavius to pectoralis minor • Attaches to clavicle • Becomes *suspensory ligament* of axilla

What is the anatomical snuff box? What are the borders? What structures can be found on the roof, floor, and running through it?

• Definition: Space that is both visible and palpable on the dorsal‐lateral aspect of the junction of the wrist and hand • Borders (Brevis Sandwich/Outcropping Muscles): 1. Abductor pollicis longus (APL) 2. Extensor pollicis brevis (EPB) 3. Extensor pollicis longus (EPL) • Roof: Skin and *superficial radial n* branches • Floor: *Scaphoid & Trapezium Bones* • Running Through It: *Radial Artery*

What are matrix metalloproteases?

• Degrade *several protein components*, including collagen (collagenases) • Clear the path for movement of cells through connective tissue and basement membranes which is necessary during growth and development • Require either *Zn+2 or Ca+2* • Secreted as *zymogens*, and are activated when needed.

What does Type IV collagen form? What does it not form?

• Forms triple helical structures (similar to Type I) • DOES NOT form fibrils (network forming collagen)

Describe the components of the myosin head.

• Heavy Chain: ATPase (binds and hydrolyzes ATP), dictates muscle fiber types • Regulatory Light Chain: Helps regulate muscle contraction - can augment it or decrease it

What happens to your hyaline cartilage as you age?

• Tendency for all hyaline cartilage to *calcify* with age, via deposition of calcium phosphate crystals within matrix • Eventually replaced by bone

What is pronator syndrome?

• The *median n* that runs between the 2 heads of pronator teres *becomes entrapped* as a result of: 1. Trauma 2. Muscular Hypertrophy or 3. Anomalous Fibrous Bands Associated w/ Muscle • Symptoms: 1. *Pain and tenderness* in the proximal aspect of the anterior forearm 2. *Decreased sensation (hypesthesia)* of the palmar aspect of hand and lateral 3 and ½ digits 3. *Pain with pronation against resistance* (handshake)

What is the standard terminology for collagen proteins and genes?

• n = Number for type of α-chain • # = Roman numeral for type of collagen that results from assembly of several a chains *Collagen Protein α-Chains:* º *αn(#)* º Ex: α2(IV) refers to the α2 chain that appears in collagen IV, which is composed of various combinations of 6 different α-chains *Collagen-Coding Genes:* º *COL#An* º Ex: COL4A2 is the gene encoding α2(IV)

Define bursa.

"Pillows" of synovial fluid between muscle and joint capsule and/or bone and joint capsule

Describe muscle glycogen replenishment length based on the following diets: a. high carb diet b. no food c. fat and protein diet

***Glycogen is depleted in 2 hrs of exercise a. High Carb Diet: 50 hours post recovery b. No Food: Never replenished? (double check) c. Fat and Protein Diet: 5 days post recovery

How many palmar interossei exist?

*3:* 2nd, 4th, & 5th fingers - Does not attach to thumb because has *adductor pollicis* - Does not attach to 3rd finger because it is the mid-line

How many dorsal interossei exist?

*4:* 2nd-4th finger; middle finger (3rd) has 2 (can abduct to both sides) - Does not attach to thumb because of abductor pollicis longus/brevis - Does not attach to pinky because of abductor digiti minimi

How can the breast be divided?

*5 regions:* 1. Upper Inner (UI) 2. Upper Outer (UO) 3. Lower Inner (LI) 4. Lower Outer (LO) 5. Axillary Tail

What is a common complication of interscalene block?

*Accidental partial anesthesia of the diaphragm and temporary respiratory depression* due to proximity of *phrenic nerve* (C3-C5; cervical plexus) to the anterior scalene m. and compartmentalization of fascia within the neck.

Which muscles fall in the anterior (flexor) compartment? What are they all innervated by?

*All innervated by musculocutaneous n!* 1) Biceps Brachii • Long Head • Short Head 2) Brachialis 3) Coracobrachialis

Which muscles fall in the posterior (extensor) compartment? What are they all innervated by?

*All innervated by radial nerve!* 1.) Triceps Brachii • Long Head • Lateral Head • Medial Head 2.) Aconeus

Each muscle fiber exhibits...

*All or none* response - either contracts or it doesn't

List the muscles associated with anterior, posterior, medial, and lateral borders of the axilla.

*Anterior Border:* Pectoralis major and minor *Posterior Border:* 1. Scapularis 2. Teres Major 3. Latissimus Dorsi *Medial Border:* Serratus anterior (and thoracic wall) *Lateral Border:* (Intertubercular Sulcus)

What is the anterior compartment of the arm innervated by? What is the action? What is the posterior compartment of the arm innervated by? What is the action?

*Anterior Compartment:* - Innervation: Musculocutaneous n. - Action: Flexors of elbow joint *Posterior Compartment:* - Innervation: Radial n. - Action: Extensors of elbow joint

What is the anterior compartment of the hand innervated by? What is the action? What is the posterior compartment of the hand innervated by? What is the action?

*Anterior Compartment:* - Innervation: Ulnar & Median Nn - Action: Flexors *Posterior Compartment:* - Innervation: Radial n. - Action: Extensors

The upper extremity can be divided into...

*Anterior Compartment:* Comprised of muscles that mainly *flex* the joints of the upper extremity *Posterior Compartment:* Comprised of muscles that mainly *extend* the joints of the upper extremity

Which arteries supply blood to the anterior forearm? Posterior forearm?

*Anterior Forearm:* 1. Ulnar Artery (proper) 2. Radial Artery (proper) 3. Anterior Interosseous Artery *Posterior Forearm:* 1. Radial Artery (proper) 2. Posterior Interosseous a. 3. Dorsal carpal branch (ulnar a.)

What is an important distal branch of the medial n.?

*Anterior Interosseous N.*

A 35 year-old male body builder has enlarged his shoulder musculature to such a degree that the size of the quadrangular space has been greatly reduced. Which of the following structures would most likely be compressed in this condition?

*Axillary Nerve*

What is a fracture site completely bridged by woven bone called?

*Bony Union*

What is the region of the arm mainly supplied by?

*Brachial Artery:* Continuation of the axillary artery that begins approximately at the *inferior border of teres major*

How do epithelial cells adhere to one another?

*Cell Junctions:* Intercellular epithelial attachment sites that allow communication between cells

What does mature connective tissue contain?

*Cells* and *extracellular material* secreted by cells

What is the axillary vein eventually joined by?

*Cephalic Vein* as it becomes the subclavian vein

What is the name of the trunk that is formed from the superficial and deep branches of the transverse cervical artery?

*Cervicodorsal Trunk*

What is the most common glycoprotein in cartilage?

*Chrondronectin*

What is the outer periphery of cortical bone arranged in?

*Circumferential lamellae*

What are lysosomal glycosylases?

*Degrade GAGs* after phagocytosis

What is dense regular CT and dense irregular CT?

*Dense Regular:* • Collagen fibers oriented *parallel* to each other • Densely packed fibers & cells arranged in fascicles • Examples: Ligaments, tendons, & aponeuroses *Dense Irregular:* • Collagen fibers oriented *randomly* • Moderate # of fibers and few cells

What is Ehlers-Danlos Syndrome?

*Ehlers-Danlos Syndrome:* A *collagenopathy* characterized by: 1. Hyperextension of joints 2. Skin fragility 3. Poor wound healing

What are the connective tissue layers that surround the muscle?

*Endomysium:* Connective tissue that surrounds individual muscle fibers *Fascicles:* Several fibers bound together in "bundles" • Many fascicles together form muscle *Perimysium:* Connective tissue that surrounds fascicles *Epimysium:* Connective tissue that surrounds the entire muscle; continuous with tendinous attachment

What is a unique feature of the *epiphyseal plate*?

*Epiphyseal Plate:* • In region of metaphysis, remains *"open"* (i.e., unmineralized) • *Allows continuous longitudinal growth* • At maturity, hormonal changes ↓ cartilage proliferation & cartilage plate replaced by bone • "Closure of epiphysis" => complete ossification, occurs at maturity • In humans, femur = last long bone to close (occurs ~ age 18-20) • After closure, growth plate persists as *epiphyseal line* in metaphysis (visible on X-rays)

What is a disease that deals with injury to the superior trunk? What are the symptoms?

*Erb's Palsey:* • At the shoulder and elbow: • Arm will be *adducted* (held close to body) • Arm will be internally (medially) rotated at the elbow • There will be pronation • There will be extension This describes the *"waiter's tip"* position of the affected upper limb.

Give examples of structural glycoproteins.

*Fibrillin* & *fibronectin* are structural glycoproteins—large polypeptides with branched polysaccharide side chains Non-Filamentous Molecules: 1. Laminin: Sulfated glycoprotein 2. Entactin: Sulfated glycoprotein 3. Tenascin

Where is fibronectin found? What was its function?

*Fibronectin:* • Found in basement membrane • Aids in adhesion between cell membrane & extracellular matrix via interaction of adhesion molecules known as integrins

Which joint is mainly responsible for flexion at the wrist joints? How about extension at the wrist joints?

*Flexion*: 40% occurs at radiocarpal joint, 60% occurs at *midcarpal joint* *Extension*: 33% occurs at midcarpal joint, 67% occurs at *radiocarpal joint*

What are the 2 common proteins found in connective tissue?

*Globular Proteins:* There are a number of globular proteins found in connective tissues. Some, like *metalloproteases*, have catalytic roles, while others, such as *fibronectin*, *integrin*, *fibrillogen*, and *laminin,* help to connect the various elements of the connective tissue to each other. *Fibrous Proteins:* Unlike globular proteins, these form long fibrous structures with unique mechanical properties. The main fibrous proteins in connective tissues are: *collagen* and *elastin*.

What are the Grades 1-3 of acromioclavicular joint dislocation?

*Grade 1:* Acromioclavicular ligament is stretch or "sprained" *Grade 2:* Acromioclavicular ligament is torn *Grade 3:* Acromioclavicular and coracoclavicular ligaments are torn

What is *graded response*?

*Graded Response:* Total # of muscle fibers contracting at any given time determines strength of overall contraction

Define haploinsufficiency and dominant negative effect.

*Haploinsufficiency:* A single functional copy of a gene is not sufficient for normal function. *Dominant Negative Effect:* An abnormal protein destroys the function of the normal protein (often seen in proteins that are active as multimers)

What is located in the center of each osteon?

*Harvesian Canal:* • Contains blood vessels and nerves • Exchange of waste & nutrients occurs via Haversian vessels • Haversian systems oriented parallel to long axis of bone

What is a type of GAG?

*Hyaluronic Acid (Hyaluronate):* • Predominant GAG in loose connective tissue • Lacks sulfated side groups • Several *thousand* sugars long • *NOT* bound to proteins • Ground substance is impervious barrier to microorganisms— • Pathogenic bacteria produce *hyaluronidase* to destroy this barrier & facilitate their spread

What are hyaluronidases and aggrecanases?

*Hydrolyze hyaluronate and aggrecan* respectively

What is a unique feature of smooth muscle?

*Inherent Contractibility:* Rhythmic, wave-like contractions independent of neurological stimulation

What is the mineralized component of bone formed by?

*Inorganic Salts:* - Primiarily Ca and phosphate in the form of *hydroxyapatite crystals* Ca10(PO4)6(OH)2

What is the name of condition associated with lower trunk injury (median + ulnar nerves affected)?

*Klumpke's Palsey:* • An avulsion injury that usually results from *excessive, forceful abduction* of the arm • Relatively rare obstetric injury • Often associated with Horner's Syndrome (T1 involvement may cause interruption of preganglionic sympathetic pathways) • Symptoms: 1. Wrist - Held in an extremely extended posture 2. Hand/Fingers - • All intrinsic muscles of hand affected • Joints between hand bones and finger bones will be hyperextended • Joints between finger segments will be flexed • *"Claw Hand"* posture associated with this injury

What is a unique characteristic of spongy and woven bone?

*Lack* Harvesian system; ONLY present in compact lamellar bone

Define the following terms: a. lumpectomy b. partial (segmented) mastectomy c. total (simple) mastectomy d. modified radical mastectomy e. radical mastectomy

*Lumpectomy:* Removes cancerous tissue and associated lymph nodes *Partial (Segmented) Mastectomy:* Removing only a small portion 1/4 of the breast. *Total (Simple) Mastectomy:* Entire breast is removed, including skin and nipple. No axillary lymph nodes are removed. *Modified Radical Mastectomy:* Breast, skin of breast, and nipple are removed. Some axillary lymph nodes are also removed. This is the *most commonly‐performed mastectomy procedure*. *Radical Mastectomy:* Entire breast, breast skin, nipple, and axillary lymph nodes. *Pectoral muscles are also removed.* This procedure is now *rarely* performed.

Describe the anatomical relationship of the median nerve relative to: a. pronator teres b. flexor digitorum superficialis c. flexor retinaculum

*Median Nerve To Pronator Teres:* -Runs through the two heads *Median Nerve To Flexor Digitorum Superficialis:* -Deep to it (runs between F.d. superficialis and F.d.profundus) *Median Nerve to Flexor Retinaculum:* -Deep to it (through carpal tunnel)

What is the primitive connective tissue derived from?

*Mesodermal Mesenchyme:* Contains stellate to spindle-shaped cells, jelly-like extracellular matrix, & occasional fibers

Define a *motor unit*.

*Motor Unit:* A group of muscle fibers supplied by a single motor neuron • Size of motor units vary

What is a clinical correlation linked to lysosomal glycosidases?

*Mucopolysaccharidoses:* - Genetic defects in lysosomal glycosidases responsible for degradation of proteoglycans - Most Common Type: *Hunter Disease* - Accumulation of un-degraded GAGs in various tissues Symptoms: 1. Development of coarse facial features 2. Skeletal abnormalities 3. Cardiovascular impairments 4. Behavioral changes (aggressiveness) 5. Mental retardation 6. Childhood mortality (progressive disease)

What does neuroectoderm give rise to?

*Neural tube (=> CNS):* 1. Pineal body 2. Posterior pituitary (neurohypophysis) 3. Sensory epithelium of eye, ear & nose *Neural crest (=> PNS):* 1. Ganglia 2. Nerves 3. Glial cells 4. Adrenal medulla 5. Melanocytes 6. Neuroendocrine cells

What is a neuromuscular junction? What is a motor plate? What is a synaptic cleft?

*Neuromuscular Junction:* - Site where skeletal muscle innervated by motor nerve *Motor End Plate:* - Dilated terminal portion of axon surrounded by myelin - Rests on sarcolemma - Similar to *terminal bouton* (difference: unmyelinated) *Synaptic Cleft:* - Space between motor end plate of nerves & sarcolemma of muscles - Bridged by chemical neurotransmitter, generally *acetylcholine*

What is the origin, insertion, action, and innervation of trapezius?

*Origin:* 1) External occipital protuberance of skull 2) Nuchal Ligament 3) Spinous Processes C7-T12 vertebrae *Insertion:* 1. Lateral 1/3 of clavicle (anterior) 2. Acromion 3. Spine of scapula *Actions:* 1. Elevates/Depresses scapula 2. Retract scapula 3. Rotate glenoid fossa superiorly *Innervation:* 1. Motor: Accessory n. (CNXI) 2. Pain & Proprioception: C3 & C4

What is the origin, insertion, action, and innervation of pectoralis major?

*Origin:* 1. Clavicular and sternocostal attachments • Anterior surface of medial ½ of clavicle • Anterior surface of sternum and superior 6 costal cartilages *Insertion:* Lateral lip of the intertubercular sulcus (bicipital groove) *Actions:* 1. Adducts & medial rotates humerus 2. Draws scapula anteriorly & inferiorly (via clavicle) 3. Clavicular portion flexes humerus 4. Sternal portion can extend humerus while it is in this flexed position *Innervation:* Lateral & medial pectoral nerves (C5, C6 clavicular portion, C7, C8, T1 sternocostal portion)

What is the origin, insertion, action, and innervation of latissimus dorsi?

*Origin:* 1. Spinous processes of inferior 6 thoracic vertebrae & Inferior 3 ribs 2. Thoracolumbar Fascia 3. Iliac Crest *Insertion:* Floor of intertubercular sulcus (bicipital groove) of humerus *Actions:* 1. Extends humerus 2. Adducts humerus 3. Medially rotates humerus 4. Rotates torso towards arms during climbing or doing pull up 5. Pulls humerus down when torso is fixed *Innervations:* Thoracodorsal nerve (C6, C7, C8)

What is the origin, insertion, action, and innervation of coracobrachialis?

*Origin:* Coracoid process of scapula *Insertion:* Middle 1/3 of medial humeral surface *Actions:* 1. Flexes & adducts arm at shoulder joint 2. Resists dislocation of shoulder joint *Innervation:* Musculocutaneous n.

What is the origin, insertion, action, and innervation of anconeus?

*Origin:* Lateral epicondyle of humerus *Insertion:* Lateral surface of olecranon, superior part of surface of ulna *Actions:* Assists triceps in extension of forearm and stabilizes elbow joint; also abducts ulna during pronation *Innervation:* Radial n.

What is the origin, insertion, action, and innervation of triceps brachii?

*Origin:* • Long Head: Infraglenoid tubercle • Lateral Head: Posterior surface of humerus • Medial Head: Posterior surface of humerus, inferior to radial groove (spiral groove) *Insertion:* Proximal end of olecranon and fascia of forearm *Actions:* 1. Extends forearm at elbow joint (main) 2. Resists dislocation of shoulder joint (long head) *Innervation:* Radial n.

What is the origin, insertion, action, and innervation of deltoid?

*Origin:* 1. Lateral 1/3 of clavicle 2. Acromion of scapula 2. Spine of scapula *Insertion:* Deltoid tuberosity of humerus *Actions:* 1. Flexes 2. Medially rotates 3. Abducts 4. Extends 5. Laterally rotates humerus *Innervation:* Axillary nerve (C5, C6)

What is the origin, insertion, action, and innervation of rhomboid minor?

*Origin:* 1. Nuchal ligament 2. Spinous processes of C7 and T1 *Insertion:* Medial end of scapular spine *Action:* SAME FOR BOTH - Retract, elevate, and rotate scapula downward as well as fix it to thoracic wall *Innervation:* SAME FOR BOTH - Dorsal scapular nerve (C4, C5)

What is the origin, insertion, action, and innervation of biceps brachii?

*Origin:* • Long Head: Supraglenoid tubercle of scapula • Short head: Coracoid process of scapula *Insertion:* Radial tuberosity and fascia of forearm via *bicipital aponeurosis* *Actions:* 1. Supinates forearm (when supine will flex forearm) 2. Resists dislocation of shoulder (short head) *Innervation:* Musculocutaneous n.

What is the origin, insertion, action, and innervation of pectoralis minor?

*Origin:* 3rd-5th ribs, near costal cartilages *Insertion:* Coracoid process of scapula *Actions:* Stabilizes scapula by pulling it anteriorly and inferiorly against posterior thoracic wall *Innervation:* Medial pectoral nerve (C8, T1) - usually pierced by this nerve

What is the origin, insertion, action, and innervation of serratus anterior?

*Origin:* External surfaces of lateral parts of ribs 1-9 *Insertion:* Anterior surface of medial border of scapula *Actions:* 1. Protracts scapula 2. Upward rotates scapula 3. Holds scapula against thorax 4. Abducts humerus *Innervation:* Long thoracic nerve (C5, C6, C7)

What is the origin, insertion, action, and innervation of infraspinatus?

*Origin:* Infraspinous fossa of scapula *Insertion:* Middle facet of greater tubercle of humerus *Actions:* 1. Laterally rotates humerus 2. Helps hold humeral head in place *Innervation:* Suprascapular nerve

What is the origin, insertion, action, and innervation of subclavius?

*Origin:* Junction of 1st rib and its costal cartilage *Insertion:* Inferior surface of middle 1/3 of clavicle *Actions:* Anchors and depresses clavicle *Innervation:* "Nerve to subclavius" (C5, C6)

What is the origin, insertion, action, and innervation of teres minor?

*Origin:* Middle part of lateral border of scapula *Insertion:* Inferior facet of greater tubercle of humerus *Actions:* 1. Laterally rotates humerus 2. Helps hold humeral head in place *Innervation:* Axillary Nerve (C5 & C6)

What is the origin, insertion, action, and innervation of teres major?

*Origin:* Posterior surface of inferior angle of scapula *Insertion:* Medial lip of intertubercular (bicipital) groove *Actions:* 1. Adducts 2. Medially rotates humerus *Innervation:* Lower subscapular nerve (C5, C6)

What is the origin, insertion, action, and innervation of levator scapulae?

*Origin:* Posterior tubercles of transverse processes of first 4 cervical vertebrae *Insertion:* Medial border of scapula, superior part of scapular spine *Actions:* 1. Elevates scapula 2. Tilts glenoid fossa inferiorly by rotating scapula (downward rotation) *Innervation:* 1. Dorsal Scapular Nerve (C5) 2. Cervical Spinal Nerves (C3, C4)

What is the origin, insertion, action, and innervation of rhomboid major?

*Origin:* Spinous processes of T2-T5 *Insertion:* Medial border of scapula from level of spine to inferior angle *Action:* SAME FOR BOTH - Retract, elevate, and rotate scapula downward as well as fix it to thoracic wall *Innervation:* SAME FOR BOTH - Dorsal scapular nerve (C4, C5)

What is the origin, insertion, action, and innervation of subscapularis?

*Origin:* Subscapular fossa *Insertion:* Lesser tubercle of humerus *Actions:* 1. Medially rotates humerus 2. Adducts humerus 3. Helps hold humeral head in place *Innervation:* Upper and lower subscapular nerves (C5, C6, and C7)

What is the origin, insertion, action, and innervation of supraspinatus?

*Origin:* Supraspinous fossa of scapula *Insertion:* Superior facet of greater tubercle of humerus *Actions:* 1. Works with deltoid in *abduction* of humerus, 2. Acts with other rotator cuff muscles in *stabilizing shoulder joint* *Innervation:* Suprascapular nerve (C4, C5, C6)

What is a clinical correlation of aggrecanases? What is the condition's cause?

*Osteoarthritis:* - Linked to excessive activity of the aggrecanases *ADAMTS4* and *ADAMTS5* - Possible Therapeutic Target: ADAMTS5

What occurs when you are not getting enough O2 to your muscle?

*Oxygen Deficit* • If severe, can lead to ischemia and muscle cramps, even cell death

What is cartilage surrounded by?

*Perichondrium:* Peripheral zone of dense connective tissue, containing fibroblasts, collagen, & immature chondroblasts

What is the external surface of bone covered by?

*Periosteum:* - Layer of fibrous/dense connective tissue - Contains fibroblasts & osteoprogenitor cells

Describe the anatomical relationship of the radial artery relative to: a. superficial branch of radial n b. brachioradialis

*Radial Artery To the Superficial Branch of the Radial Nerve:* - Artery is medial (nerve lateral) *Radial Artery To Brachioradialis:* - Under brachioradialis or just medial to it

What do the following nerves cutaneously innervate in the hand and wrist: radial nerve, ulnar nerve, and median nerve?

*Radial Nerve (superficial branch):* Lateral dorsum of wrist and hand, near thumb *Ulnar Nerve:* Medial aspect of wrist and hand, medial 1 and ½ digits *Median Nerve:* Lateral palmar aspect of wrist and hand, digits 1‐3 and ½ digit 4

What are all the muscles of the posterior forearm innervated by?

*Radial nerve* via the *deep branch* of the radial nerve or the *posterior interosseous nerve*

Define *recruitment*.

*Recruitment:* ↑ in # of motor units firing within a muscle

What are *reticular cells*?

*Reticular Cells:* - Type of fibroblast located in *lymph nodes and bone marrow* - Morphologically similar to primitive mesenchymal cells; look like *branched fibroblasts* - *Synthesize reticular fibers* (made of *reticulin*); may have phagocytic function - Reticular fibers also synthesized by regular fibroblasts in some tissues

What is the anatomical relationship of the ulnar artery?

*Runs together with ulnar nerve*

What is the origin, insertion, action, and innervation of brachialis?

*STRONGEST FLEXOR* of elbow joint *Origin:* Distal ½ of anterior surface of humerus *Insertion:* Coronoid process and tuberosity of ulna *Actions:* Flexes forearm at elbow joint *Innervation:* 1) Musculocutaneous n. 2) *Radial nerve - lateral portions*

What are myofibrils arranged in?

*Sarcomeres:* Functional units of muscle cells

Which bones encompass the pectoral girdle (AKA shoulder girdle)?

*Scapula and clavicle only!*

What do the short arms of laminin interact with? Long arms?

*Short Arms:* Interact with each other, collagen, and other minor proteins of the basal lamina *Long Arms:* Interacts with cell surface proteins including integrin

What are the following parts innervated by: shoulder, arm, forearm, and hand?

*Shoulder (Pectoral Girdle):* - Innervated by nerves that come directly from the *roots, trunks, or cords* of the brachial plexus (mostly) *Arm (Brachial):* - Innervated by the nerves from the medial cord (cutaneous), the musculocutaneous n. (anterior) and the radial n. (posterior) *Forearm (Antebrachial):* - Innervated by a branch from the medial cord (cutaneous), and the musculocutaneous n. (cutaneous), *the median and ulnar nerves (anterior)* and the radial n. (posterior) *Hand:* - Motor Innervation: Median & Ulnar Nerves - Sensation: Median, Ulnar, & Radial Nerves

What is *somatotropin*?

*Somatotropin (Pituitary Growth Hormone):* • Stimulates growth, especially epiphyseal cartilage & bone, ↓ blood Ca • Oversecretion can lead to gigantism or *acromegaly* • Undersecretion leads to *pituitary dwarfism*

How is the anterior forearm divided up?

*Superficial:* 1. Palmaris Longus 2. Pronator Teres 3. Flexor Carpi Radialis 4. Flexor Carpi Ulnaris *Intermediate:* 1. Flexor Digitorum Superficialis *Deep:* 1. Flexor Digitorum Profundus 2. Flexor Pollicis Longus 3. Pronator Quadratus

What are the different parts of the brachial plexus?

*Supraclavicular:* - 5 Roots (ventral rami of spinal nerves) - 3 Trunks *Infraclavicular:* - 3 Anterior & 3 Posterior Divisions - 3 Cords - 5 Main Terminal Branches

How does the breast attach to the dermis?

*Suspensory Ligaments* (AKA Cooper's Ligaments)

What is symphysis?

*Symphysis:* • Secondary cartilage joint • Contains two hyaline cartilage surfaces connected by fibrocartilage plate

What is synchondrosis?

*Synchondrosis:* • Primary cartilage joint • Contains single layer of hyaline cartilage • Unites first rib with sternum; only one in human adult

What is a syndesmosis?

*Syndesmosis:* • Dense fibrous tissue between bones • In skull, progressively replaced by bone to become *synostosis* (aka "sutures")

What is Hilton's Law?

*The nerves that supply the muscles that cross a joint also innervate that joint.*

Describe the sternoclavicular joint.

*The only "true" boney articulation between upper limb & thorax.* 1. Synovial Joint 2. AKA "Double Saddle"/"Double Gliding"/ "Shallow Saddle" (called double saddle or double gliding bc of the inter-articular disc) 3. Has two separate synovial cavities

Define the following terms associated with the ulna (hypothenar side): a. trochlear notch b. coronoid process c. olecranon process d. ulnar shaft e. distal ulna

*Trochlear Notch (Semilunar Notch):* Articulates with trochlea of humerus to form the stable hinge joint of the elbow *Coronoid Process:* Provides insertion point for brachialis & origin for pronator teres *Olecranon Process ("Elbow"):* Provides insertion for the triceps tendon *Ulnar Shaft:* Provides origin for pronator quadratus and supinator as well as digital extensors *Distal Ulna:* Does not articulate with the carpal bones

Describe the organization of the hand in terms of synovial sheaths.

*Ulnar Bursa:* - The long tendons of: flexor digitorum superficialis and flexor digitorum profundus enters a common flexor sheath called the ulnar bursa. *Separate Synovial Sheath:* - Each of their 4 tendons then enters its own separate synovial sheath. This synovial sheath is within a *fibrous digital sheath*. - *The synovial sheath for the 5th digit is continuous with the ulnar bursae* *Radial Bursa:* - The long tendon of *flexor pollicis longus* has a synovial sheath that is separate from the ulnar bursa called the radial bursa.

What is the difference between white fat and brown fat?

*White Fat:* • *Uni*locular • Distributed in dermis & around intraperitoneal organs • Up to 20% of body weight in males, 25% in females Brown Fat: • *Multi*locular • Highly specialized • Present in infants & hibernating animals • Used in thermoregulation to maintain body temperature • In humans, located ~adrenals • Large #'s of mitochondria => heat

What occurs when you do the following: - Bunch up muscles completely - Bunch up muscles a bit - Overstretch muscles a bit - Overstretch muscles completely

*You get the best contraction with optimal overlap* Bunch Up: Too much overlap => takes up some of the binding sites that would normally exist • Contraction strength is *NOT optimal* Overstretch: Pulling away actin filaments from myosin => some myosin heads have no actin filament to bind to • Contraction strength is *NOT optimal* Completely For Either: *NO contraction*

What is the activity of elastase inhibited by?

*α-1 Antitrypsin:* Produced by the liver and circulates in the bloodstream

What is the outer margin of osteon delimited by?

- *"Cement Line":* The boundaries of the tunnel made by osteoclasts - Followed by invasion of empty canal by osteoblasts

What is subclavian venipuncture?

- *Axillary vein* plays a role - Common procedure - Central venous catheterization or central line placement - Placement of a catheter or defibrillation leads into the subclavian vein

What is adhesive capsulitis of the glenohumeral joint?

- AKA "Frozen Shoulder" - Chronic inflammation in the glenohumeral joint to the extent that it leads to *fibrosis* between the joint capsule, rotator cuff muscles and synovial bursa

What is the clavipectoral triangle (AKA deltopectoral triangle)?

- Allows passage of neurovascular structures between axilla and pectoral region - Borders: Deltoid, pectoralis major, middle 1/3 of clavicle - Contents: Cephalic vein, deltopectoral lymph nodes, deltoid branch of thoracoacromial a. (from axillary a.)

What is transverse carpal ligament?

- Forms *roof of the carpal tunnel* - Also referred to as the *flexor retinaculum*

What is *lymphangitis/lymphedema* with respect to breast cancer? How is it diagnosed?

- Inflammation of lymphatic vessels, specificially axillary lump nodes - Biopsied in Breast Cancer to determine possible spread of cancer because nodes receive lymph (& cancer) in a specific order - Diagnostic Tests: Sentinel Node Biopsy/Axillary Node Dissection

Describe anterior dislocation.

- Occurs most often in young adults, especially athletes - *Hyperextension with lateral rotation* - Humeral head is forced in an infero-anterior direction; hard blow to the humerus while fully abducted - Fibrous layer of joint capsule and glenoid labrum may tear such that the humeral head is positioned *inferior* to the glenoid cavity and anterior to the infraglenoid tubercle

What are adipocytes responsible for? Describe their shape.

- Responsible for storage & metabolism of lipids - Generally large, balloon-shaped, clear spaces filled with "lipid"

How does skeletal muscle respond to injury?

- Skeletal muscle has limited ability to regenerate following injury - Regeneration primarily is due to *satellite cells*, which proliferate following injury by differentiating into *myoblasts*

Describe the synovial capsule in the glenohumeral joint. What are the synovial capsules reinforced by? Which muscle tendon pierces the capsule?

-Filled with synovial fluid that helps to lubricate the joint - Weak but very mobile - Reinforced by the tendons of the rotator cuff muscles - *Long tendon of biceps brachii* pierces the capsule and attaches to supraglenoid tubercle of *scapula* and *glenoid labrum*

What are the 3 joints associated with the shoulder? List the articulating bones, structural type, and movements of each.

1) *Acromioclavicular Joint:* - Articulating Bones: Acromion process of scapula and clavicle -Structural Type: Synovial plane joint - Movements: Diarthrotic 2) *Glenohumeral Joint:* - Articulating Bones: Scapula and humerus - Structural Type: Synovial; ball and socket - Movements: Diarthrotic; multiaxial (flexion, extension, abduction, adduction, circumduction, rotation of humerus) 3) *Sternoclavicular Joint:* - Articulating Bones: Sternum and clavicle - Structural Type: Synovial (shallow) saddle joint; has articular disc - Movements: Diarthrotic, multiaxial

Explain the vasculature of the arm and forearm.

1) *Axillary a.* becomes *brachial a.* at the inferior border of teres major 2) Brachial a branches into: profunda brachii (w/ two branches = middle collateral and radial collateral), superior ulnar collateral, and inferior ulnar collateral 3) In the cubital region, the brachial a. branches into *radial a. and ulnar a.* which anastomose with the branches of the brachial a.

What are example of retraction signs to demonstrate cancer of breast (carcinoma)?

1) *Lymphedema (Pea d' orange Sign):* Due to the block in flow of lymph 2) *Dimpling of Skin:* Caused by lymphedema OR invasion of *glandular tissue and fibrosis* 3) *Elevation of Breast When Pectoral Muscles Contract:* Due to invasion of *retromammary pace and pectoral fascia*; clinical sign of advanced cancer 4) *Abnormal Contours* 5) *Nipple Retraction*

List step-by-step the process of intramembranous ossification.

1) *Mesenchymal cells differentiate* directly into osteoblasts, begin synthesizing osteoid at multiple sites, (multiple centers of ossification) within membrane—no cartilage precursor 2) *Mineralization* follows with subsequent fusion of adjacent centers of ossification 3) Osteoblasts trapped within lacunae of osteoid, *become osteocytes* 4) Osteoprogenitor cells at periphery continue to divide, *provide replacements* 5) Bone produced is woven bone—*later remodeled* by osteoclasts & osteoblasts to form compact bone

What are the 3 types of bone fractures?

1) *Simple/Closed Fracture:* No break in skin 2) *Compound/Open Fracture:* Damage to skin exposing bone 3) *Comminuted Fracture:* Bone broken in several pieces

What are the types of smooth muscle units?

1) *Single Unit (Tonic Smooth Muscle):* • Fibers contract as a unit • Ex) Visceral smooth muscle of gut; most common 2) *Multi Unit (Phasic Smooth Muscle):* • Individual muscle fibers contract independently • Ex) Ciliary body of iris, Erector pili Mm

What are the actions of the following muscles on the clavicle: sternocleidomastoid, trapezius, adductors of the arm, and coracoclavicular ligament?

1) *Sternocleidomastoid:* Elevates medial fragment 2) *Trapezius:* Action is counteracted by weight of limb 3) *Adductors of the Arm (e.g., deltoid, pectoralis major):* Can pull lateral fragment medially 4) *Coracoclavicular Ligament* Prevents dislocation of acromioclavicular joint

What are 3 types of specialized epithelia?

1) *Transitional Epithelia:* • Lines most of urinary tract (except for parts of urethra) • Stratified epithelium, modified for distensibility • Varies from squamous to cuboidal 2) *Endothelium:* Epithelium lining blood vessels & lymphatics; simple squamous 3) *Mesothelium:* Epithelium lining closed body cavities (i.e., thoracic, pericardial, & abdominal cavities); simple squamous

What are the ligaments that help stabilize the fibrous capsule of the elbow joint?

1) *Ulnar Collateral Ligament:* Holds trochlea of humerus against the trochlear notch of ulna 2) *Radial Collateral Ligament:* Holds radial head against capitulum 3) *Anular Ligament:* Encircles and holds head of radius in the radial notch of ulna thereby reinfocing the *proximal radioulnar joint* (important for stability during pronation/supination of forearm)

What are the 2 main forms of bone?

1) *Woven:* Immature form characterized by random orientation of collagen fibers (later remodeled to lamellar bone) 2) *Lamellar:* Contains *circumferential lamellae* (concentric layers) with parallel collagen fibers

The epiphyseal growth plate consists of several distinct zones in transition from cartilage to bone. List the zones and their characteristics.

1) *Zone of Reserve Cartilage:* • Hyaline cartilage with clusters of chondrocytes • NO cell proliferation 2) *Zone of Proliferation:* • Successive mitotic division of chondrocytes => columns of chondrocytes 3) *Zone of Maturation:* • Division ceases • Chondrocytes ↑ in size 4) *Zone of Hypertrophy:* • Chondrocytes greatly enlarge, contain large amounts of glycogen, become vacuolated & calcify 5) *Zone of (Cartilage) Degeneration:* • Capillaries of marrow cavity grow from diaphysis into growth plate • Chondrocytes degenerate • Lacunae invaded by osteogenic cells 6) *Zone of Ossification:* • Blood vessels from marrow cavity grow into cartilage mass • Osteogenic cells differentiate into osteoblasts, congregate on spicules of calcified cartilage matrix to form bony *trabeculae*

What are the branches of the ulnar a.?

1) Anterior Ulnar Recurrent A. 2) Posterior Ulnar Recurrent A. 3) Common Interosseous A. (3 sub-branches) • Anterior Interosseous A. • Posterior Interosseous A. • Recurrent Interosseous A.

What are some of the effects of hyperfolding or poor folding?

1) Modified collagen can be *degraded* by the cell (proteasomal degadation, autophagy, proteases), resulting in *lower quantities of collagen being secreted* 2) Secreted mutant collagen may *not be able to interact correctly with other extracellular matrix components* (due to its excessive modification). 3) It may also *not be able to support matrix mineralization*. 4) Finally, it may *disrupt normal cell-cell and cell-matrix interactions*.

List step-by-step the process of endochondral ossification.

1) Precursor of long bone formed of hyaline cartilage 2) *Primary center of ossification* occurs in mid-diaphysis: • Osteoprogenitor cells and osteoblasts secrete osteoid, which mineralizes, forming *periosteal cuff* • Calcification of cartilage matrix inhibits diffusion of nutrients => death of chondrocytes & spread of osteoblasts 3) Osteoprogenitor cells from periosteum migrate into medulla, along with growing blood vessels 4) Two *secondary centers of ossification occur in epiphyses*; mineralization spreads across cartilage matrix

What are the branches of the radial artery in the hand?

1. *Deep Palmar Arch* a. Princeps Pollicis A. b. Radialis Indicis A. (typically branches from princeps pollicis a.) 2. Superficial Palmar Branch of Radial A. (anastomoses with ulnar a. superficial palmar arch)

What are the 2 ways you can increase the force of muscle contraction?

1. *Fiber Summation:* Recruit additional *motor units* to activate more muscle fibers 2. *Frequency Summation:* Summation of *individual fibers* • Ca from previous contraction is still around in cytoplasm; hasn't had time to be pumped back into SR and now have another contraction • Ca is additive and keeps increasing in cytoplasm • Ultimately leads to *fused tetanus*

What are the major components of the basement membrane?

1. *GAG's* (Heparan Sulfate) 2. *Type IV Collagen* 3. Structural Glycoproteins (*laminin*, *fibronectin*, and *entactin*) - large polypeptides with branched, polysaccharide side chains

What are the 3 articulations that the elbow joint consists of?

1. *Humeroulnar Joint:* • Between trochlear notch of ulna articulates with trochlea of humerus • "Hinge" Joint; Uniaxial; Synovial • Flexion and Extension 2. *Humeroradial Joint:* • Between radial head and capitulum of humerus 3. *Proximal Radioulnar Joint:* • Between radial head and radial notch on ulna

What do the GAGs of ground substance in bone consist mostly of?

1. *Hyaluronic Acid* 2. *Chondroitin Sulfate*

List some examples of GAGs found in cartilage.

1. *Hyaluronic Acid* (non-sulfated) 2. *Chondroitin Sulfate* 3. *Heparin Sulfate*

What do post-translational modifications to collagen α chains provide?

1. *Hydroxyl groups for inter-chain hydrogen bonding interactions* that stabilize the triple helix 2. *Attachment sites for additional modifications* such as glycosylation

What are the 3 modes of discharge for a gland?

1. *Merocrine (Eccrine):* • Only secretory product released (generally proteins) • Most common; involves simple exocytosis 2. *Apocrine:* • Secrete membrane-bound vesicles • Product accompanied by *some* cytoplasm • Usually lipid products • Ex) Sweat & mammary glands 3. *Holocrine:* • Entire cell secreted (ruptures, releases contents) • Ex) Sebaceous glands

What are the categories of gland classification?

1. *Morphology* of gland/duct 2.*Type* of secretory pod 3. *Mode of discharge* of secretory pod

What are the 3 epithelial types?

1. *Mucous Membrane (Muscosa):* • Epithelium that lines cavities that connect with outside world, (e.g., alimentary, respiratory, or urogenital tracts) • Contains surface epithelium of ectoderm (or endoderm), basement membrane, supporting connective tissue (*lamina propria*), & sometimes layers of smooth Mm (muscularis mucosae) 2. *Serous Membrane (Serosa):* • Epithelium that lines closed body cavities (e.g., peritoneal, pleural, or pericardial cavities) • Consists of epithelial lining, the mesothelium, (mesodermally derived); basement membrane, & supporting connective tissue • *Lacks* muscularis mucosae 3. *Endothelium:* • Epithelium that lines blood & lymph vessels • Associated with variable #'s of Mm & connective tissue layers, or tunics • Most epithelial cells have finite lifespan

What are the changes in muscle with age?

1. *Muscle Performance* Declines 2. Age Associated *Atrophy* Due To: a. Loss Of Fibers (*irreversible*) b. Individual Fiber Atrophy (*partially preventable/reversible* w/ exercise) 3. *Muscle Mass* & *Contractile Force* Decline (w/o regular exercise)

What are the non-collagenous organic molecules found in bone matrix include?

1. *Osteocalcin:* Binds intracellular Ca during mineralization 2. *Osteonectin:* Bridges/binds collagen and minerals 3. *Sialoproteins:* Rich in sialic acid, concentrated from plasma

What are some other routes that metastatic cancer cells can also spread?

1. *Parasternal Lymph Node Communication w/ Internal Thoracic Vein* - Way in which cancers can *spread to thoracic and skeletal structues* 2. Involvement of *Vertebral Venous Plexus*: *Spread to the brain and cranium* 3. May also spread to *liver*

*The axillary lymph nodes can be grouped together based on their location within the pyramidal cone of the axilla.* Name the 5 groups.

1. *Pectoral (Anterior) Lymph Nodes (3‐5):* • Medial wall of axilla • Cluster around lateral thoracic vein 2. *Subscapular (Posterior) Lymph Nodes (6‐7)* • Posterior axillary fold • Cluster around subscaplular vessels 3. *Humeral (Lateral) Lymph Nodes (4‐6):* • Lateral wall of axilla • Near axillary vein 4. *Central (Center/Base) Lymph Nodes (3‐4):* • Base of axilla • Near axillary vein 5. *Apical (Apex) Lymph Nodes:* • Apex (cervicoaxillary canal) • Near axillary vein

What are the branches of the ulnar artery in the hand?

1. *Superficial Palmar Arch:* a. Common Palmar Digital Arteries (hand) • => Proper Palmar Digital Arteries (digits)

What are 3 functional types of cell junctions?

1. *Tight Junctions (Occluding Junctions)* 2. *Anchoring Junctions (Adhering Junctions)* 3. *Gap Junctions (Communicating Junctions)*

What are the branches off the thyrocervical arterial trunk?

1. *Transverse Cervical Artery* - Superficial Branch - Deep Branch (Dorsal Scapular Artery) 2. *Inferior Thyroid Artery* 3. *Ascending Cervical Artery* 4. *Suprascapular Artery*

What are the 3 arteries of particular importance in the circulation of the shoulder and scapular region?

1. *Transverse Cervical Artery* (cervicodorsal trunk) • *Superficial Cervical Artery* (superficial branch of transverse cervical artery) • *Dorsal Scapular Artery* (deep branch of transverse cervical artery) 2. *Suprascapular Artery* 3. *Subscapular Artery*

Which muscles make up the thenar eminence?

1. Abductor Pollicis Brevis 2. Flexor Pollicis Brevis • Superficial Head • Deep Head 3. Opponens Pollicis (deep to abductor pollicis brevis)

Which 3 muscles are grouped into the "outcropping muscles" group?

1. Abductor Pollicis Longus 2. Extensor Pollicis Longus 3. Extensor Pollicis Brevis

Explain step by step what happens at the neuromuscular junction.

1. Action potential travels down to axon terminal 2. Opens VG Ca channels 3. Ca interacts with synaptotagmin and causes the V SNARES and T SNARES to interact 4. Vesicle fuses with membrane and releases its NT Ach 5. Ach travels across synaptic cleft and binds to ionotrophic *nicotinic receptors* on skeletal muscle 6. (Normal) Muscle (ALWAYS) reaches threshold potential with *EPPs* (end plate potentials - called this instead of EPSPs) 7. VG Na+ channels are activated leading to an AP 8. AP is carried along the *sarcolemma* (similar to neuron - carried down axon) 9. AP moves down T tubules to the belly of the muscle 10. AP changes the conformational state of *DHPR* which then makes physical contact with *ryanodine receptor (RyR1)* 11. This causes Ca to be released from SR and increase the intracellular [Ca]. Ca can also trigger *CICR (calcium induced calcium release)* - open other RyR1 receptors thereby amplifying the effect. Ca is then used for muscle contraction.

What are smooth muscle contractions influenced by?

1. Autonomic Nervous System 2. Hormones 3. Local Metabolites

What are the functions of epithelia?

1. Barrier (e.g. skin) 2. Absorption (e.g. intestines) 3. Semipermeable Membrane 4. Transport (e.g. cilia in trachea) 5. Secretion (e.g. stomach) 6. Sensation (e.g. taste buds)

What do specialized connective tissue include?

1. Bone 2. Blood 3. Cartilage 4. Adipose Tissue 5. Hematopoietic Tissue 6. Lymphatic Tissue 7. Mesenchymal & Mucus CT (limited to embryo)

What is the sliding filament mechanism?

1. Ca causes conformational change in *troponin*, which interacts with *tropomyosin* molecules (bound to actin), exposing myosin-binding site on actin filament 2. Binding causes conformational change in myosin head & sliding of myosin past actin 3. Myosin heads repeatedly bind & unbind to actin in presence of Ca & Pi, causing contraction

How do you synthesize collagen?

1. Collagen is a *glycoprotein*; precursor proteins produced by fibroblasts 2. Initially synthesized as *procollagen*, composed of *3 α polypeptide chains*, form triple helix 3. Packed into secretory vesicles & secreted into extracellular space (ECS) 4. Followed by *extra*cellular enzymatic modification to form *tropocollagen* monomers 5. Polymerization of tropocollagen into larger bundles results in final formation of *collagen* microfibrils 6. Several microfibrils combine to form larger collagen *fiber*; several fibers make up collagen *bundle*

Describe the physiology of conductance through the neuron and muscle.

1. Electrical stimulation of neuron 2. Influx of Na+ into neuron 3. Wave of depolarization down axon 4. Release of neurotransmitter, binding to receptor proteins 5. Wave of depolarization of muscle fiber 6. Travels down *transverse tubule system* 7. Influx of Na+ ions into cytoplasm from T-tubules triggers depolarization of sarcolemma 8. Release of Ca from ER & terminal cisternae into cytoplasm during contraction 9. Ca ions activate *sliding filament mechanism* => contraction

What are the movements of the clavicle?

1. Elevation/Depression (clavicle & disc) 2. Protraction/Retraction (clavicle & sternum) 3. Rotation (both)

What is muscle fatigue due to?

1. Energy source depletion • Na/K ionic imbalance (high frequency action potentials cause Na+ and K+ movement to exceed capability of the Na/K pump- increase K+ outside of the cell. This change in K+ *decreases tetanic force*) • Metabolic products (Pi *reduces TnC affinity for Ca*) 2. Degradation of muscle membranes, proteins

What does ectoderm give rise to?

1. Epidermis (hair, nails, glands, mammary glands); oral & anal mucosa 2. Cornea & lens epithelia of eye 3. Enamel organ & enamel of teeth 4. Anterior pituitary (adenohypophysis) 5. Inner ear

Which muscles make up the hypothenar eminence?

1. Flexor Digiti Minimi 2. Abductor Digiti Minimi 3. Opponens Digiti Minimi (Palmaris Brevis lies superficial)

What are the ligaments that help stabilize the glenohumeral joint?

1. Glenohumeral Ligaments - Superior - Middle -Inferior 2. Coracohumeral Ligament

What is bone growth controlled by?

1. Growth Hormones 2. Thyroid Hormones 3. Sex Hormones

What does bone also have an affinity for?

1. Heavy Metals (e.g. Pb, Hg) 2. Radioactive Isotopes

What is contained in the cubital fossa?

1. Median Nerve 2. Brachial Artery with bifurcation of radial & ulnar arteries 3. Brachial Veins (venae comitantes) 4. Tendon of biceps brachii & bicipital aponeurosis 5. Radial Nerve • Deep Radial Nerve • Superficial Radial Nerve

Describe the glenohumeral joint.

1. Multiaxial Synovial Joint 2. Between glenoid of scapula and proximal end of humerus 3. Shallow joint; "ball & socket" joint

What are the boundaries of the axilla?

1. Pyramid-Shaped Space 2. Apex/Base 3.Anterior/Lateral/Medial/Posterior Wall

What does endoderm give rise to?

1. Respiratory epithelium 2. Alimentary epithelium (except oral & anal cavity) 3. Liver, pancreas, gallbladder, thyroid, parathyroid, & thymus 4. Epithelial lining of tympanic cavity & Eustacian tubes 5. Transitional epithelium of bladder

How does smooth muscle differ from skeletal muscle? (6)

1. Smaller muscle fibers 2. *Single*, *central* nucleus 3. Actin and myosin present in ~15:1 ratio - randomly arranged 4. Myofilaments are *NOT* arranged in sarcomeres, hence *NO* striations. Instead, have intracytoplasmic structures called *dense bodies* which are functionally equivalent to *Z discs* (provide attachment sites for actin) 5. Lacks *troponin* complex that controls myosin binding. Instead uses *calmodulin* - binds Ca and activates myosin cross-binding 6. Lacks T-tubule system and terminal cisternae of ER. Instead, cell membrane has *caveolae* which store the Ca extracellularly. Thus, relies on diffusion of extracellular Ca for contraction.

Which 2 joints involve the pectoral girdle?

1. Sternoclavicular Joint 2. Acromioclavicular Joint

Most GAGs have which properties?

1. Sulfated (e.g. chondroitin sulfate, heparan sulfate) 2. Covalently bind to protein molecules to form *proteoglycans* (mucoproteins)

List the anatomical structures located in the forearm from lateral to medial.

1. Superficial branch of the Radial nerve 2. Radial Artery 3. Median Nerve 4. Ulnar Artery 5. Ulnar Nerve

What are the 4 anatomical spaces?

1. Triangle of Auscultation 2. Quadrangular Space 3. Triangular Space 4. Triangular Interval Triangular *s*pace is superior. Triangular *i*nterval is *i*nferior. Quadrangular space is between the two.

Which anatomical structures are located posterior to the cubital region?

1. Triceps and Olecranon Process 2. Anconeus 3. Ulnar Nerve - Run posterior to medial epicondyle of humerus 4. *Posterior Ulnar Recurrent Artery - Run posterior to medial epicondyle of humerus*

What are the two major types of skeletal muscle?

1. Type I, Slow Twitch Fibers 2. Type II, Fast Twitch Fibers

What are the intermediate fibers?

1. Type IIA: Oxidative & Fatigue Resistant 2. Type IIB: Glycolytic & Fatigue Sensitive

Upward rotation of the scapula is due to the synergistic actions of which 3 muscles?

1. Upper Trapezius 2. Lower Trapezius 3. Serratus Anterior

How long does the bone repair process take?

6-12 wks depending on severity and location

What may extreme exertion lead to?

Acute *rhabdomyolysis* and subsequent *myoglobinuric nephrosis* (kidney failure) due to the breakdown of Type I muscle fibers and release of myoglobin, which gets stuck in the glomerulus/filter

What do collagen chain genes encode?

An α-chain of about 1000 amino acids with a large region of sequence containing *(Gly-X-Y)n* repeats • X = Any AA • Y = Proline or Hydroxyproline

What do Z discs act as?

Anchoring points for actin myofilaments

What is keratin?

Another fibrous protein found in epidermal cells

Explain the infraclavicular relationship of the brachial plexus.

As the brachial plexus travels posterior to the clavicle, it enters the axillary region and *travels posterior to the pectoralis minor m.* Here it forms an intimate relationship with the *axillary a.* such that *the artery itself runs in the middle of the plexus*, surrounded by the cords and terminal branches. The *axillary vein* and it's tributaries also seem to "entangle" themselves with the various branches of the brachial plexus.

What is Marfan syndrome?

Autosomal dominant disorder caused primarily by mutations in *fibrillin-1* Symptoms: 1. Lens Dislocation 2. Alteration in Spine Formation (scoliosis) 3. Long Limbs 4. Aortic Dilation

What does the subclavian artery continue its course as?

Axillary Artery

What would deficits in the following nerves cause: a. Axillary n. b. Suprascapular n. c. Musculocutaneous n. d. Radial n.

Axillary Nerve (C5): Weakness in *deltoid* and *teres minor* Suprascapular Nerve (C5): Weakness in *supraspinatus* and *infraspinatus* Musculocutaneous Nerve (C5): Weakness in *biceps* Radial Nerve (C6): Weakness in *brachioradialis*, *supinator*, and *wrist extensors*

How does the basement membrane appear in EM?

Basement membrane has electron dense layer (*lamina densa*) sandwiched between two electron- lucent layers, (*lamina lucida* & *lamina reticularis*)

What eventually happens to osteoblasts?

Become trapped in *lacunae* in osteoid matrix and mature into *osteocytes*

Which bones in your body are considered long bones?

Bones in limbs

During peak periods of exertion, both Type I and II fibers...

Both Type I and II fibers metabolize *glycogen* via *anaerobic glycolysis* to produce ATP => Intermediate metabolites (e.g. *lactic acid*) => precipitate as crystals in muscle => tearing of muscle fibers and pain after heavy exertion

What are the anastomoses between the *brachial artery* and *ulnar artery*?

Brachial Artery - Ulnar Artery 1) *S*uperior Ulnar Collateral - *P*osterior Ulnar Recurrent 2) *I*nferior Ulnar Collateral - *A*nterior Ulnar Recurrent

What occurs to the myofilaments when Ca is present? How about when Ca is absent?

Ca Present: Ca binds to TnC. This causes a conformational change so that TnC binds to TnI, moving it from the myosin binding site. Additionally, the tropomyosin and TnT also shift over. Ca Absent: Everything shifts back - bound to their correspondents

What is scurvy? (REVIEW)

Cause: - *Vitamin C Deficiency* - Many of the complications of scurvy result from deficiencies in the synthesis of collagen. Population: 1. *Alcoholics:* • Poor diets (inadequate vitamin C) • Alcohol impairs absorption of vitamin C 2. *Smokers:* • Smoking produces a lot of anti-oxidants which consumes the vitamin C 3. *College Students* Symptoms: 1. Bleeding 2. Tooth loss, gingivitis 3. Inability to limit infections 4. Poor wound healing 5. Arrested skeletal development 6. Anemia (due to Fe deficiency)

What is scurvy?

Cause: • Vitamin C Deficiency Symptoms: 1. Bone matrix not calcified 2. Weakening of collagen in ligaments (especially *periodontal ligament* => loose teeth) 3. Breakdown of scars/old wounds, which break open & bleed Treatment: Fruits & vegetables high in Vitamin C (e.g., citrus fruits—oranges, lemons, limes - also non-citrus fruit guava)

Describe injuries to the axillary nerve. What are the causes? What is the clinical presentation?

Causes: 1. Fracture to surgical neck of humerus 2. Anterior dislocation of glenohumeral joint 3. Rotator cuff repair surgery Clinical Presentation: 1. Numbness in posterior deltoid region 2. Difficulty *abducting* arm 3. Diminished *lateral rotation* of arm 4. Deltoid muscle wasting (prolonged injury)

Describe the spiral groove of humerus of radial nerve injury.

Causes: 1. Compression of the radial nerve along the midshaft of the humerus in certain positions ("Sleep Palsy", "Saturday Night Palsy") 2. Humeral fracture at midshaft (spiral groove fracture) Clinical Presentation: 1. Difficulty extending the wrist 2. Difficulty extending or straightening the fingers and opening the hand 3. *Triceps retains strength* because nerve fibers entering this muscle branch off proximal to the mid shaft of the humerus 4. Also causes *"wrist drop"* posture

What is osteoporosis?

Characteristics: • Loss of bone mass • *Resorption by osteoclasts exceeds deposition by osteoblasts* Population: • Common problem in *post-menopausal women*, possibly due to ↓ estrogen levels Treatment: • Treatment with *oral Ca supplementation & Vitamin D* for ↑ Ca absorption; chondroitin, glucosamine, gelatin also helpful • Newer osteoporosis meds, e.g., Fosamax, *bind phosphates in GI tract, minimize absorption* • Possible side effects include *mandibular necrosis*

What are osteoblasts? What are these cells responsible for?

Characteristics: • Roughly polygonal, mesenchymal cells *derived from osteoprogenitor cells* • *Very basophilic* due to synthesis of large amounts of protein & proteoglycans Responsibilities: • Responsible for *synthesis* of extracellular matrix & collagen, collectively referred to as *osteoid* • Also responsible for *calcification* of matrix via secretion of *matrix vesicles*

What is fibrocartilage characterized by? Where is fibrocartilage found?

Characterization: • Alternating layers of hyaline cartilage & dense connective tissue (contains *Type I* & *Type II* collagen) • Less cellular than either • *Lacks perichondrium* (because attached directly to bone) Locations: 1. Intervertebral Disks 2. Articular Areas - a. Knee b. Mandible (TMJ) c. Shoulder d. Sternum e. Ligaments , Tendons, Joint Capsules f. Pubic Symphysis

What are some characteristics of elastic cartilage? Where is it located?

Characterizations: • Histologically similar to hyaline cartilage with addition of large #'s of *elastic fibers* in ECM • Contains *Type II* collagen Locations: 1. External ear 2. Auditory & Eustachian canals 3. Epiglottis 4. Larynx

What are the 3 conditions associated with microtubules lacking dynein arms?

Ciliary mobility is impaired or absent 1) *Kartagener's Syndrome:* Causes sterility in males due to non- functional flagella on sperm 2) *Dextrocardia* OR *Situs Inversus:* Heart points towards right side instead of left side due to absence of ciliary activity during embryonic development 3) *Hydrocephalus:* Accumulation of CSF in brain; Due to non-functional cilia on ependymal cells unable to circulate CSF

The following diseases (hypochondroplasia, achondroplasia, scurvy, OI, and EDS) affect which part of the following pathway: collagen gene => collagen fibers = mineralized bone => degradation?

Collagen Gene => Collagen Fibers

What is the most abundant protein in the human body?

Collagen: • Forms long, rigid structures that play important extracellular structural roles • >28 different collagen types, each with its own characteristic amino acid sequence, properties, and functional role

What are the ligaments of the hand & wrist and their functions?

Collateral Ligaments: 1. *Radial Collateral Ligament:* Helps radius articulate with proximal row of carpals 2. *Ulnar Collateral Ligament:* Helps stabilize ulna's articulation with articulate disk 3. *Phalangeal Collateral Ligaments* 4. *Transverse Carpal Ligament:* Reinforces carpals and forms roof of carpal tunnel 5/6. *Metacarpal Ligaments/Intermetacarpal Ligaments:* Binds metacarpal together 7. *Carpometacarpal Ligaments:* Binds carpals to metacarpals 8. *Palmar Ligaments:* Binds metacarpals to proximal phalangeal segments

A 30-year-old woman presented with progressive shortness of breath. She denied the use of cigarettes. A family history revealed that her sister had suffered from unexplained lung disease. Which one of the following etiologies most likely explains this patient's pulmonary symptoms?

Deficiency of a1-antitrypsin

Define dermatome.

Definition: Area of cutaneous sensory innervation supplied by a single spinal nerve. For upper extremity this means *C3*, *C4* and the *brachial plexus (C5-T1)*, but some areas in the axilla are supplied by lower thoracic spinal nerves (T2-T5)

A 5-year-old boy is seen by a pediatrician because his parents are concerned about his aggressive behavior, hyperactivity, and loss of language skills. He also has recently become increasingly unsteady on his feet and has experienced a recent seizure. Slight facial feature coarsening is noted. In which of the following processes is this child most likely to have a disorder?

Degradation of glycosaminoglycans (GAGs)

What happens in certain cases of injury to, or ligation or occlusion of the axillary artery superior to the subscapular artery?

Direction of blood flow in the subscapular artery is *reversed*, allowing blood to flow to the distal portion of the axillary artery and the rest of the arm, forearm and hand

What is the clinical correlation associated with metalloproteases?

Disregulation of matrix metalloproteases may play important roles in some disease states including: 1. *Metastatic Cancer* 2. *Atherosclerosis* 3. *Bacterial Infection*

What can point mutations in COL1A1 or COL1A2 genes result in?

Disruption of triple helix interactions

What are the types of duct morphology? What are the types of gland morphology?

Duct: 1. *Simple Gland:* Unbranched ducts (straight or coiled) 2.. *Compound Gland:* Branched Ducts Gland: 1. *Tubular:* Tube-like (straight or coiled) 2. *Acinar/Aveolar:* Sac like or flask shaped, individual sac called *acinus* 3. *Tubuloacinar:* Intermediate, tube with dilated end

Which nerve roots supply the following muscles: a. Lateral Pectoral b. Thoracodorsal c. Lower Subscapular d. Upper Subscapular

Lateral Pectoral: C5-C7 Thoracodorsal: C6-C8 Lower Subscapular: C6 Upper Subscapular: C5

List step-by-step the process of collagen fibril biosynthesis.

Mnemonic: 1. *G*uests (gly) visit your home 2. You give them water with lemon (hydroxylation requires ascorbic acid) 3. You give them sweets (glycosylation, sugar is sticky, sweets = *C*andy) 4. They leave your house (exocytosis) 5. They no longer need to behave PROfessionally (procollagen is converted to tropocollagen) 6. They form tight bonds with each other (lysyl oxidase facilitates formation of covalent cross links) 1. *COL genes are transcribed*, and may undergo alternative splicing to make different variants. 2. *Prepro a-collagen peptides are translated* in the rough ER. The peptides undergo hydroxylation (LH, PH) and glycosylation (GT) 3. *Triple helix forms after nucleation of the C-terminal regions* (start at C terminus) by formation of disulfide bonds. 4. Procollagen is *secreted*. 5. The N- and C-terminal ends are cleaved by peptidases, *forming tropocollagen* 6. Some lys residues are *oxidized and form inter-strand crosslinks*. 7. Crosslinked collagen strands form *collagen fibrils* 8. Several microfibrils combine to form larger collagen fiber; several fibers make up collagen bundle

Mutations near the C-terminus are ____________ while mutations near the N-terminus are ______________

Mutations Near C-Terminus (Nucleation Center): - *Lethal* - Slow down formation of triple helix => more modifications => more disruptions in interactions Mutations Near N-Terminus: -*Non-Lethal* - Not as many post-translational modifications

What are the causes of the minority cases of non-classic EDS?

Mutations in: 1. N-terminal pro region of collagen type I 2. Procollagen peptidases 3. Lysyl oxidase 4. Collagen type III

A 55 year old woman visits her physician because of double vision, eyelid droop, difficulty chewing and swallowing, and general weakness in her limbs. Symptoms are made worse with exercise. The physician orders a tensilon test in which the patients perform repeated muscle movements before and after injection of tensilon or placebo (tensilon is an Ach esterase inhibitor). The woman performs the activities much better after the tensilon. Without other testing being performed which of the following is the most likely diagnoses?

Myasthenia Gravis

What can be upregulated with exercise?

Na/K pump

SUPERFICIAL - What is the origin, insertion, action, and innervation of pronator teres?

ORIGIN: 1. Coronoid process of ulna 2. Medial epicondyle of humerus INSERTION: Middle of lateral surface of radius ACTIONS: Pronates and flexes forearm at elbow INNERVATIONS: Median N.

HYPOTHENAR - What is the origin, insertion, action, and innervation of opponens digiti minimi?

ORIGIN: 1. Flexor Retinaculum 2. Carpal Bones (Hamate) INSERTION: 5th Metacarpal ACTION: Brings 5th metacarpal anterior & rotates it to bring it into opposition with thumb INNERVATION: Deep branch of ulnar n.

What is the origin, insertion, action, and innervation of dorsal interossei?

ORIGIN: Adjacent sides of 2 metacarpals INSERTION: Proximal phalanges and the extensor expansions of digits 2-4 ACTION: 1. *DAB* - Abduct 2nd-4th fingers toward axial line 2. Also assist lumbricals INNERVATION: Deep branch of ulnar n.

SUPERFICIAL - What is the origin, insertion, action, and innervation of extensor digitorum?

ORIGIN: Lateral epicondyle of humerus INSERTION: Extensor expansions of medial 4 fingers ACTIONS: Extends medial 4 fingers at metacarpophalangeal joints and somewhat at interphalangeal joints INNERVATION: Posterior interosseous nerve

SUPERFICIAL - What is the origin, insertion, action, and innervation of extensor digiti minimi?

ORIGIN: Lateral epicondyle of humerus INSERTION: Extensor expansion of 5th finger ACTIONS: Extends 5th finger at metacarpophalangeal joint and secondarily at interphalangeal joints INNERVATION: Posterior interosseous nerve

SUPERFICIAL - What is the origin, insertion, action, and innervation of extensor carpi radialis longus?

ORIGIN: Lateral supracondylar ridge of humerus INSERTION: 2nd Metacarpal ACTIONS: Extend and abduct hand at wrist INNERVATIONS: Radial N.

SUPERFICIAL - What is the origin, insertion, action, and innervation of flexor carpi radialis?

ORIGIN: Medial epicondyle of humerus INSERTION: 2nd Metacarpal ACTIONS: Flexes and abducts hand at wrist INNERVATIONS: Median N.

HYPOTHENAR - What is the origin, insertion, action, and innervation of abductor digiti minimi?

ORIGIN: Pisiform INSERTION: Proximal phalanx of 5th digit ACTION: 1. Abducts 5th digit 2. Aids in flexion of 5th proximal phalanx INNERVATION: Deep branch of ulnar n.

DEEP - What is the origin, insertion, action, and innervation of extensor pollicis brevis?

ORIGIN: Posterior surface of distal 1/3 of radius, interosseous membrane INSERTION: Proximal phalanx of thumb ACTIONS: Extends proximal phalanx of thumb at its metacarpophalangeal joint and carpometacarpal joint INNERVATION: Posterior interosseous nerve

DEEP - What is the origin, insertion, action, and innervation of extensor inidicis?

ORIGIN: Posterior surface of distal 1/3 of ulna and interosseous membrane INSERTION: Extensor expansion of 2nd finger ACTIONS: Independent extension of 2nd finger, but also helps with extension of wrist INNERVATION: Posterior interosseous nerve

DEEP - What is the origin, insertion, action, and innervation of extensor pollicis longus?

ORIGIN: Posterior surface of middle 1/3 of ulna, interosseous membrane INSERTION: Distal phalanx of thumb ACTIONS: Extends distal phalanx of thumb at its interphalangeal metacarpophalangeal, and carpometacarpal joints INNERVATION: Posterior interosseous nerve

DEEP - What is the origin, insertion, action, and innervation of abductor pollicis longus?

ORIGIN: Posterior surface of proximal ½ of ulna and radius, interosseous membrane INSERTION: 1st Metacarpal ACTIONS: Abducts thumb and extends it at carpometacarpal joint INNERVATIONS: Posterior interosseous nerve

SUPERFICIAL - What is the origin, insertion, action, and innervation of brachioradialis?

ORIGIN: Proximal 2/3 of *supraepicondylar ridge* of humerus INSERTION: *Distal radius*, proximal to styloid process ACTIONS: Flexes forearm when it is pronated (about midprone position) INNERVATIONS: Radial N.

DEEP - What is the origin, insertion, action, and innervation of flexor digitorum profundus?

ORIGIN: Proximal ¾ of medial and anterior surfaces of ulna and interosseous membrane INSERTION: Distal phalanges of 2nd-5th fingers ACTIONS: Flexes distal phalanges at interphalangeal joints (power grip) INNERVATION: 1. Median N. - Anterior Interosseous N. 2. Ulnar N.

SUPERFICIAL - What is the origin, insertion, action, and innervation of palmaris longus?

ORIGIN: *Medial epicondyle* of humerus INSERTION: *Flexor retinaculum*; continuous with palmar aponeurosis ACTIONS: Flexes hand at wrist, tenses palmar aponeurosis INNERVATION: Median N.

THENAR - What is the origin, insertion, action, and innervation of opponens pollicis?

ORIGIN: 1. Flexor Retinaculum 2. Carpal Bones (Scaphoid, Trapezium) INSERTION: 1st Metacarpal ACTIONS: 1. Oppose thumb 2. Medially rotate 1st Metacarpal INNERVATION: Recurrent branch of median n.

THENAR - What is the origin, insertion, action, and innervation of abductor pollicis brevis?

ORIGIN: 1. Flexor Retinaculum 2. Carpal Bones (Scaphoid, Trapezium) INSERTION: Proximal phalanx of thumb ACTIONS: 1. Abduct thumb 2. Aid in opposition INNERVATION: Recurrent branch of median n.

THENAR - What is the origin, insertion, action, and innervation of flexor pollicis brevis?

ORIGIN: 1. Flexor Retinaculum 2. Carpal Bones (Scaphoid, Trapezium) INSERTION: Proximal phalanx of thumb ACTIONS: Flexes thumb INNERVATIONS: • Superficial Head - Recurrent branch of median n. • Deep Head - Deep branch of ulnar n.

When do osteoblasts mature?

Osteoblasts mature into osteocytes within *lacunae* after matrix mineralizes

How are osteocytes connected?

Osteocytes connected by minute canals called *canaliculi* containing cytoplasmic extensions Communicate with each other via *gap junctions*

How often do dislocations of the sternoclavicular joint occur?

Rarely, because: 1.) Strong joint 2.) Direction of force transmission through clavicle prevents dislocation -Forces are usually transmitted along the length of the clavicle, such that the clavicle may fracture, but dislocation of the SC joint typically does not occur.

What is important to do before the *bony callous* forms?

Realign and stabilize (or set) fracture

What does smooth muscle response depend on?

Receptor Type (α vs. β)

What is the purpose of the recurrent branch of median nerve and the deep branch of ulnar nerve?

Recurrent Branch of Median Nerve: Supplies motor innervation to the muscles of the hand that are supplied by the median n (e.g. thenar muscles) Deep Branch of Ulnar Nerve: Supplies motor innervation to the muscles of the hand that are supplied by the ulnar n. (e.g. hypothenar muscles)

Recurrent branch of median nerve is very ___________________ as it enters ___________________

Recurrent branch of median nerve (motor) is very superficial (easily injured) as it enters the *thenar eminence*

Draw out the arteries blood flow chart to the shoulder/axilla.

Refer to Caroline's Picture (add lateral thoracic a. to axillary a.)

Describe the cutaneous innervation of the upper limb.

Refer to Slide 14 Brachial Plexus Slide

Draw the brachial plexus.

Refer to diagram.

What is congenital muscular dystrophy?

Results from deficiency in laminin 2, which links myocytes to the ECM

What is another name for saddle joint?

Sellar Joint

What do mutations in fibrillin-1 result in?

Structural defects in microfibrils, and alter signaling pathways involving TGFβ

What happens to the proteins and proteoglycans of connective tissue and basement membrane during remodeling?

Undergo regulated degradation via: 1. Matrix Metalloproteases 2. Elastase 3. Hyalyronidases & Aggrecanases 4. Lysosomal Hydroxylases

What is necessary for collagen synthesis?

Vitamin C

Define the following terms related to radius (thenar side): a. head of radius b. radial tuberosity c. radial shaft d. distal shaft

a. *Head of Radius:* Articulates with capitulum of humerus and radial notch on ulna b. *Radial Tuberosity:* Provides attachment site for biceps brachii tendon *Radial Shaft:* Provides attachment sites for pronators and supinators of the forearm, as well as some of the flexors and extensors of the wrist and fingers *Distal End:* Articulates with the scaphoid & lunate carpal bones

List the properties of the following amino acids: a. proline b. cysteine c. glycine d. serine e. lysine f. aspartate

a. *Proline:* α-helix breaker, puts kink in amino acid chain b. *Cysteine:* Able to form disulfide bonds in an oxidation reaction (if you put disulfide in reducing agent, it is likely to break) c. *Glycine:* Has the smallest side chain (H) d. *Serine:* Has -OH that can participate in H bonding interactions e. *Lysine:* Positive, basic amino acid (other: HArLy = histidine and arginine) f. *Aspartate:* Negative, acidic amino acid (other: glutamate)

What is the function of the following drugs on skeletal muscle contraction: a. tetrodotoxin b. ω-conotoxin c. acetylcholine and nicotine d. α-tubocuranine e. physostigmine f. nerve gas/insecticides g. botulism toxin

a. Tetrodotoxin: Inhibits *VG Na+ channels* b. ω-Conotoxin: Inhibits *VG Ca channels* c. Ach and Nicotine: Activates nicotinic *Ach receptors (AchR)* d. α-Tubocuranine: Inhibits *AchR* (poisonous arrows analogy) e. Physostigmine: Inhibits *Achesterase* f. Nerve Gas/Insecticides: Permenantly (binds to it irreversibly) inhibits *Achesterase* g. Botulism Toxin: Acts like protease, cleaves *V SNARES* & *T SNARES* to inhibit *Ach release*

A 32 year-old male is having a routine surgery to repair the anterior cruciate ligament in the right knee. After dosing with anesthetic (sevoflurane), the patient became rigid, heart rate rose to 130 bpm, blood pressure became 70/56, breathing rate of 20, and temperature was 106 F. The anesthesiologist indicated that this might be a case of malignant hyperthermia. A condition in which a patient has a mutation in the ryanodine receptor which causes the receptor to become active in the presence of certain anesthetics. What do you think was the primary cause for the 106 degree temperature during the crisis? Which of the following could be used to treat the patient?

d. Increase in muscle metabolism (more muscle contraction due to opening of RyR1 receptors) e. Block calcium release channels in skeletal muscle

What is lateral epicondylitis?

• "Tennis Elbow" • *Repetitive use of superficial extensor muscles in forearm* • *Pain over lateral epicondyle that radiates down* posterior surface of forearm • Pain is often exacerbated when patient opens a door or lifts an object • Common extensor tendon become strained and causes inflammation of the periosteum of the lateral epicondyle

What is the structure of collagen?

• *3 α-chains* twist together to form a supercoiled structure => The *high frequency of Pro* causes α-chains to adopt a *left-handed extended helical structure*. • Then, the 3 α-chains may form a *triple helix with the small glycine residues lining the inner core, and the more polar proline, hydroxyproline, hydroxylysine (and others) on the exterior*.

Describe the mechanism behind muscle building.

• *Actin and myosin become damaged* due to heavy weight, eccentric motion; ROS; or Ca-activated proteases • Have *inflammatory response* which leads to the production of even MORE actin and myosin filaments via cytokines and growth factors

What do matrix vesicles contain?

• *Alkaline phosphatase* • Matrix vesicles bud off osteoblasts into matrix => release enzymes => precipitation of mineral salts (e.g. Ca & PO4)

How does epithelia get nutrition?

• *Avascular* - *Never* penetrated by blood vessels • Supported by basement membrane, separates epithelium from underlying connective tissue & blood vessels • Cells of epithelium rely on *diffusion* of O2 & nutrients from underlying tissue

What is the breast defined as? What is the difference between the breast in males vs. females?

• *Bilateral glandular* structures found in both males and females; *modified sweat glands* • In females the breast is much more developed and is capable of producing nourishment for young.

What is the osteology of wrist and hand encompass?

• *Carpals:* 8 Bones • *Metacarpals:* 5 Bones • *Phalanges:* - 14 Bones - Thumb has 2 segments. Remaining 4 fingers have 3 segments each

What is the structure of laminin?

• *Heterotrimeric* structure with *cruciform shape* • At least 18 different isoforms

What is succinylcholine?

• *Partial agonist* • 2 Ach joined together • Binds to nicotinic receptors => initially some muscle contraction => activates receptor and maintains depolarization (cannot reopen the inactivation gates) => causes *paralysis* • SE: Muscle twitching, muscle paralysis for longer period, bradycardia (can also activate muscarinic receptors)

What is collagen?

• *Principle fiber in extracellular matrix* • Provides *tensile strength* • At least 28 different types identified, based on AA sequence • Most have distinct 67-68 nm banding pattern

What is the role of satellite cells?

• *Regenerate injured fibers* • Minor Damage => Incorporate satellite cells into existing fibers • Severe Damage => Satellite cells themselves form new fibers

Where is the breast located? What does the breast consist of?

• *Rests on pectoral fascia*, extends from 2nd to 6th ribs, sternum to midaxillary line • Consists of mammary gland tissue, fibrous & fatty tissue, blood and lymph vessels and nerves

What is the *axillary sheath* and what does it consist of?

• *Separate fascial compartment* within axilla • *Extension of the prevertebral layer of deep cervical fascia* into the *cervicoaxillary canal* (apex) of the axilla • Contents: 1. Vascular: Axillary Artery & Vein 2. Neurological: Cords of the Brachial Plexus 3. Lymphatic: Axillary Lymph Nodes

Incompressibility of water provides...

• *Turgor Pressure* of connective tissue • Reinforced with fibrous proteins

Which has a greater range of deviation: radial or ulnar deviation? Why?

• *Ulnar Deviation* = Adduction (30-45º) • Radial Deviation = Abduction (15-25º) • Reason: *Radial styloid process* limits movement!

What does mature compact bone consist of?

• 70% inorganic salts & 30% organic matrix • > 90% of organic component is *Type I collagen* synthesized by *osteoblasts*

What is zonula adherens?

• A continuous band characterized by transmembrane glycoproteins called *cadherins* (class of cell adhesion molecules, or *integrins*) • Adjacent cell membranes *not fused*

What is subluxation/dislocation of radial head also called? Which population is at risk? What occurs?

• AKA "Nursemaid's Elbow" • Vulnerable Population: Preschool age children - suddenly lifted by their upper limb in a jerking motion • Subluxation: Anular ligament tears and the radial head slips out of the annular ligament • Dislocation: Anular ligament tears and the whole radius moves out of position

What is the extracellular organic matrix also known as? What is embedded in it?

• AKA *ground substance* • Various fibers embedded within matrix like *collagen*, *reticulin*, & *elastin* • Each type of fiber has different chemical make-up and characteristics

What are gap junctions?

• AKA communicating junctions; nexus junctions • Focal, or regional adherent zones located on lateral border of cell • Roughly circular, intercellular contact areas containing hundreds of individual channels, called *connexons*, formed by ring of 6 integral proteins called *connexins* surrounding 2 nm diameter pores • Permit passage of small molecules between adjacent cells, allow transport of information & metabolites between cells

What two structures limit the range of motion of the glenohumeral joint? What is stability of this joint primarily maintained by?

• Acromion and Coracoid • Maintained by muscles and tendons that cross this joint

What is the actin/myosin ratio in skeletal muscle? Describe the arrangement of the contractile proteins.

• Actin and myosin are present in a *2:1 ratio* in skeletal muscle • Parallel arrangement of contractile proteins => *striated* appearance in longitudinal section (*striated* muscle)

In which ages is adhesive capsulitis of glenohumeral joint common? How is it initiated? What are the effects?

• Age: 40-60 yrs • Initiated by: 1. Glenohumeral dislocation 2. Supraspinatus or bicipital tendonitis 3. Rotator cuff tears • Effects: 1. Abduction affected; compensatory scapular movements 2. Acromioclavicular joint may become strained

What is ground substance? What does it contain?

• Amorphous, transparent material with properties of a semi-fluid gel • One of the two sugars is always an amino sugar (either n-acetyl glucosamine or galactosamine)— *glucosaminoglycan (GAG)* AKA *mucopolysaccharide (MPS)* which are long, unbranched polysaccharide chains of repeating disaccharide units • Consists mostly of GAGs (primarily hyaluronic acid), proteoglycans, and water

What is aneurysm of the axillary artery?

• Aneurysm Definition: Blood gets stuck in one of the layers of the arteries and blows out in a bubble which can then burst and cause a lot of bleeding • Causes: The first part of the axillary artery may enlarge and compress the trunks of the Brachial Plexus • Effects: Causes pain & anesthesia (loss of sensation) • Common In: Baseball pitchers & football quarterbacks because of their *rapid and forceful arm movements*

Where is the articular surface located in the glenohumeral joint?

• Articular surface is between the head of humerus and glenoid fossa • *Glenoid Labrum:* Cartilaginous rim that extends the surface area of the glenoid

What are anchoring junctions (adhering junctions)?

• Bind cells together, act as anchoring points for cell cytoskeleton • 2 Morphological Types: 1) *Zonula Adherens* 2) *Mascula Adherens* (*Desmosomes*) • 2 Specialized Types: 1) *Hemidesmosomes* 2) *Junctional Complex (Terminal Bar)*

What is tenascin's purpose?

• Binds cells to extracellular matrix • Thought to be important in cell migration in developing nervous system

How is the breast supplied with blood? What is the breast innervated mainly by?

• Blood Supply: From tributaries of *subclavian* and *axillary arteries* • Innervated *mainly* by *intercostal nerves* (4th-6th) • May also receive innervation from *supraclavicular nerve* branches as well as branches of other intercostal nerves

What are the radius and ulna bound by? What is the function of the proximal end of the ulna? What is the function of the distal end of the radius?

• Bound by *interosseous membrane* • Ulna: Elbow Joint • Radius: Radiocarpal Joint (has articular spots for scaphoid and lunate)

What do the C-terminal ends of the triple helices of Type IV collagen do? What do the N-terminal ends do?

• C-Terminus: Forms dimers (NC1 hexamers) with other type IV collagen helices • N-Terminus: Forms *tetramers* (7S domains) with other type IV collagen helices

Define axilla.

• Deep compartment of armpit • *Inferior to the glenohumeral joint*, at *the junction of the arm and the thorax* • Important *passageway for neurovascular structures* to the upper limb • *"Pyramid‐shaped"* space that invested in *layers of fascia*

What is intramembranous ossification?

• Direct replacement of mesenchyme by bone; *no cartilage precursor* • Mesenchymal cells differentiate into osteoblasts, produce osteoid, later mineralizes into bone (e.g., vault of skull)

What are the variations of collagen found in different tissues?

• Each collagen type is composed of different combinations of alpha chains. (e.g. Type I collagen has 2 α1 chains and 1 α2 chains.) • Different collagen types contain different amounts of triple helical structure; type I is almost entirely triple helical, while type XII contains only a small triple helical region

What does cartilage contain?

• Extracellular matrix of amorphous ground substance containing collagen • Matrix is *hydrated* (also bound to proteoglycans) => accounts for its flexibility and incompressibility

What is rhabdomyolysis?

• Extreme breakdown of muscle fibers due to extreme exertion or trauma Results: • Releases Myoglobin: Kidney Damage • Blood serum (outside) has: 1. High K+ (hyperkalemia) 2. Myoglobin 3. Creatine kinase/ creatinine (breakdown product of creatine) 4. Uric acid and lactic acid (hyperuricemia/acidosis) 5. Phosphate (hyperphosphatemia) • Inside the cell has influx in: 1. Calcium (hypoocalcemia) 2. ECF leaking in (*BP decreases*) 3. Albumin (hypoalbuminemia albumin) Symptoms: 1. *Reddish/brown urine* 2. Muscle pain/weakness/fatigue

What is microvilli?

• Finger-like cytoplasmic projections, extend from cell surface • Contain *actin* filaments • ↑ surface area for absorption or secretion (= *striated border* in intestine & *brush border* in renal tubules) • Supported by *terminal web*, network of *actin* microfilaments at base of microvilli; provide support

Describe the ossification of the clavicle.

• First long bone to completely ossify (embryonic weeks 5-6; *intramembranous ossification*) • Ends of clavicle then go through a *cartilagenous phase* (endochondral ossification) • Complete fusion of intramembranous and endochondral portions completes at *25-31 years*

What are hemidesmosomes?

• Found on basal surface of cell only, anchoring it to basement membrane via *integrins* (transmembrane receptor proteins) • Associated with high mechanical abrasion/ shearing forces (e.g., skin)

What is Ehlers-Danlos Syndrome (EDS)?

• Group of at least six clinically, genetically, or biochemically distinguishable disorders in *collagen biosynthesis* • Classic cases often involve mutations in *Collagen Type V* Symptoms: "Varying degrees of structural weakness in the skin, joints, and vasculature" 1. Hyperextensible Skin 2. Joint Hypermobility 3. Abnormal Wound Healing 4. GI and Aortic Ruptures 5. Chronic Pain

What is the morphology of elastic fibers? What is it synthesized as? What are the components of elastic fibers?

• Highly branched; random coiling pattern allows stretching; arranged in fibers & sheets; refractile • Synthesized by fibroblasts as *tropoelastin* precursor; polymerizes in ECM to form elastin • Two components of elastic fibers: 1) *Elastin:* Protein core similar to collagen, surrounded by microfibrils of fibrillin (structural glycoprotein) 2) *Fibrillin*

What is infectious tenosynovitis?

• Infection of *flexor tendon sheaths* • Infections of 5th digit can spread to ulnar bursa and carpal tunnel • Infections of 1st digit can also spread to carpal tunnel and flexor carpi radialis tendon (radial bursa) • *Kanavel's Four Cardinal Signs" ("Kanavel's Sign"):* 1. Flexed position 2. Pain with any attempt at extending affected digit 3. Uniform swelling involving entire digit 4. Percussion tenderness along course of tendon sheath

What is rheumatoid arthritis?

• Local, *autoimmune reaction in joints* => body produces Abs that attack joints => pain, damage to articular cartilage • Thickening, *inflammation of synovial membrane* • *Pannus:* Replacement of articular cartilage with fibrovascular tissue

What are tight junctions (occluding junctions)?

• Located immediately beneath luminal surface of simple columnar epithelia • Act as gaskets • Portions of opposing cell membranes fuse together, forming continuous, circumferential band around cell, called *zonula occludens* • *Fascia occludens* present between endothelial cells in wall of blood vessels

What is stereocilia?

• Long microvilli, not cilia • Found only in epididymis of males & sensory cells of inner ear • Non-motile, also contain *actin* filaments

What is cilia?

• Long, motile, cytoplasmic extensions • Possess *axoneme* ("9 + 2" arrangement of *microtubules*) • Each cilium arises from individual *basal body*; develop from centrioles • Cilia beat in synchronous, *metachronal rhythm*; has rapid, rigid, *effective stroke* & slower, flexible *recovery stroke* • Normally contain microtubule doublets with dynein arms

How many layers of *synovial cells* are found in joints? How many cell types and what are the types?

• Made of up to 4 cell layers of synovial cells of mesenchymal origin • 2 Types of Cells: A & B 1) *Type A:* Synoviocytes resemble macrophages 2) *Type B:* Synoviocytes resemble fibroblasts

Where is the breast blood mainly drained to?

• Mainly: *Axillary vein* via lateral thoracic veins and medial mammary veins • Some drainage to the internal thoracic vein via anterior intercostal veins

What are proteoglycans?

• Major components of the basal lamina, extracellular space, and connective tissue • Have a polypeptide core attached to GAG chains • Form brush-like structures that *originate from a hyaluronic acid chain* (only non-sulfated GAG) • Often interact with various proteins

What are osteocytes?

• Mature "bone cells"

What is appositional growth?

• More common • New cartilage forms at surface of pre-existing cartilage • New chondrocytes derived from mesenchymal cells of inner perichondrium—differentiate first into chondroblasts • More mature chondrocytes present at center of cartilage mass, with younger cells at periphery

What is mascula adherens (desmosomes)?

• Most common type of cell junction • Small, circular patches • Located on lateral surface of cell • Associated with attachment plaques containing attachment proteins, including *desmoplakins*, *desmogleins*, & *tonofilaments*

What is scaphoid fracture?

• Most frequently fractured carpal bone • Pain is produced during *palpation of the anatomical snuffbox* during *dorsiflexion and abduction* of wrist • Fracture of scaphoid is sometimes *not visible* on initial radiograph; misdiagnosis as sprain • Fractured scaphoid sometimes *associated with tear to arterial branch (radial a.) that supplies it; avascular necrosis of scaphoid*

Describe the muscle organization. What do nebulin and titin do?

• Muscle => Muscle Fibers => Myofibrils => Myofilaments (Actin & Myosin) • Organized into sarcomeres (unit of contraction), which are arranged around *Z-discs* • *Nebulin* and *titin* help to align actin and myosin respectively; thereby keeping the sarcomere organized

What is achondroplasia and hypochondroplasia caused by?

• Mutation in *fibroblast growth factor receptor 3 (FGF3)* • These activating mutations *inhibit growth of collagen-producing chondrocytes*, and are the leading cause of markedly *short stature*.

The scapulothoracic joint is not...

• NOT a *true joint* • *"Physiological" joint* • Joint is musculotendinous only • Scapula has *no bony articulation with thorax*; invested in muscle and fascia

What is the brachial plexus?

• Network of spinal nerves C5‐T1 that emerge from the neck and travel into the axilla • *Innervation to the shoulder, pectoral region, scapular region and upper limb*

What happens in the relaxed state of elastic fibers?

• Non-polar regions are sequestered from water (hide from water on inside) - this is the driving force for relaxation of the fiber after stretching

What is the function laminin?

• Other major protein of the basal lamina • Adhesion protein that forms extensive networks that interact, via linker proteins such as nidogen and integrin, with the collagen type IV network, other extracellular proteins, and the cell surface

What are *Sharpey's fibers*?

• Parallel bundles of *collagen fibers* that provide *anchorage & support* • Extend from periosteum or muscle tendon & insert into superficial layer of bone

What is osteomalacia?

• Population: Adults • Cause: Insufficient Ca & Vitamin D => Failure of Mineralization => Softening of Bones

What is ADAMTS?

• Protein family includes several proteases that play important roles in remodeling of the extracellular matrix, as well as other important physiological phenomena

What is myoglobin?

• Protein in striated muscle • Binds O2 with high affinity • Helps increase O2 in muscle cells

What is the purpose of epithelia? How are epithelial cells characterized by? Which layers of the germ layers is epithelial derived from?

• Purpose: Covers body surfaces, lines body cavities, & forms glands • Characterization: Epithelial cells are characterized by production of *keratin* intermediate filaments (different epithelia produce different keratin which can be useful in tumor ID) • Derivation: Derived from all 3 layers (ectoderm, mesoderm, endoderm)

What do the rotator cuff muscle tendons do? What can injury to the rotator cuff muscles affect?

• Reinforce and strengthen the glenohumeral joint • Can affect glenohumeral joint stability

Describe fractures of the clavicle.

• Relatively frequent • Common in children (often as a greenstick fracture - bends before breaking) •Weakest part of clavicle is between middle and lateral third • Fractures to middle 1/3 reported to be most common

Describe cartilage repair.

• Repair in cartilage is *limited*, because repair requires blood flow • Results in production of dense connective tissue = *fibrosis*

Describe the structure of GAGs (mucopolysaccharides).

• Repeating disaccharide units: • One sugar is either N-acetylglucosamine or N-acetylgalactosamine. • The second sugar is usually oxidized to the uronic acid. • Highly negatively charged • Bind cations and water, forming a gel-like substance that resists compression

What is the primary structure of elastin composed of?

• Repeating segments of polar (lys and ala rich) and non-polar (val and gly rich) amino acids. • Quite stable (1/2 life is about 70 yrs)

What is endochondral ossification?

• Replacement of *cartilage precursor* by bone • Resulting woven bone is extensively remodeled by resorption & appostional growth => lamellar bone (e.g., long bones, vertebrae, pelvis, & base of skull)

Describe the veins in the forearm.

• Same‐named veins accompany arteries of forearm • Arise from *deep palmar venous arch in hand* • Radial veins laterally • Ulnar veins medially • Posterior and anterior interosseous veins follow interosseous arteries • Some deep veins merge with median cubital vein (a superficial vein) • Most merge with brachial vein

What is elastase?

• Serine protease produced ONLY by *neutrophils* to facilitate the *destruction of invading bacteria and wound healing* • *Degrades elastase*

What is the Quadrangle Space?

• Significance: *Axillary n.* (innervates teres minor and deltoid) and *posterior circumflex humeral a.* emerge 1. Bordered *superiorly* by *teres minor* 2. Bordered *inferiorly* by *teres major* 3. Bordered *medially and laterally* by the long head and lateral head of *triceps brachii* respectively

What is the Triangular Space?

• Significance: *Circumflex scapular a.* (branch of subscapular a. involved in subscapular anastomose) emerges •Bordered by *teres minor* and *teres major* and *long head of triceps brachii*

What is the Triangular Interval?

• Significance: *Deep brachial a.* and *radial n.* emerge • Bordered superiorly by teres major, medially and laterally by long and lateral heads of *triceps brachii*

What is loose (areolar) CT? Where is it located?

• Sparse fibers & abundant ground substance => viscous, gel-like consistency • Supportive function • Located beneath epithelia & around nerves & vessels

What is the junctional complex (terminal bar)?

• Specialized, circumferential, intercellular connection • Hybrid between adhering & occluding junctions—forms diffusion barrier between cells • Three separate zones, circumferentially arranged: 1) zonula occludens (tight junction) 2) zonula adherens (adherent junction) 3) macula adherens (desmosomes)

What is Sentinel Lymph Node Biopsy (SLNB)?

• Standard of care for axillary management in breast cancer patients with negative nodes • Use in people w/ positive sentinel lymph nodes (SLNs) is increasing.

What is deltoid fascia?

• Surface of deltoid muscle • Attaches to clavicle, acromion & spine of scapula • Continuous with pectoralis fascia • Compartmentalizes scapular muscles

What is the antebrachial fascia?

• Surrounds and invests the forearm • Continuous with the brachial fascia of the arm

In the gut, sympathetic stimulation is ________________ and parasympathetic stimulation is ___________________ to smooth muscle.

• Sympathetic = *Inhibitory* • Parasympathetic = *Stimulatory*

What is the clinical correlation associated with the cubital region?

• The cubital region is used for *peripheral venous access* • *Cephalic* and *median cubital veins* are commonly used for venous blood draw and intravenous (IV) access • *Basilic vein* may also be used but tends to be avoided due to its position to the underlying *brachial artery* • In addition, 3% of patients exhibit a *superficial ulnar artery*, which lies in an unprotected position in the cubital region. If this artery is mistaken for a vein, it can be *damaged*, *bleed*, and *certain drugs* injected into the artery could be *fatal*.

What are type I, slow twitch fibers?

•"Slow" myosin • *Small* fibers with large amount of *myoglobin* • Use primarily *aerobic respiration* for oxidative metabolism • Large # of mitochondria (=> ATP for energy) • Resistant to fatigue, but generate only moderate M tension • Common in peripheral limbs