Nervous System
MSK
Axilla + Shoulder
Back + Spine
Arm + Forearm
100

Why are compressed nerve injuries easier to regenerate than transected? (2 reasons, just need 1 for points)

Axons are damaged, not severed

Connective Tissue Tubes guiding recovery are still intact

100

Describe the defining quality of each type of bone formation (50 pts each)

Intramembranous ossification: Mesenchymal cells give rise to osteoblasts directly (no cartilage intermediate)

Endochondral Ossification: Mesenchymal cells --> chondroblasts --> cartilage --> eventual bone replacement

100

What are the two branches of the 2nd part of the Axillary Artery? Which muscles do each vascularize

Thoracoacromial Trunk: Pec major and minor (delts + traps also accepted)

Lateral Thoracic: Serratus Anterior

100

The AC Joint connects which two bones. What is an injury to this region called (50 pts each)

Clavicle to Scapula. Separated shoulder

100

After a long night at Queens, patient Z falls asleep with their armpit draped over a wooden chair. What is this called, what nerve is compressed, and what is the effect?

Saturday night palsy, radial nerve compressed, wrist drop

200

Somatic Motor Pathways use a one motor neuron pathway to control voluntary skeletal muscle contractions. Autonomic Pathways use two. 

Describe the Following: (75 points each)

Pre vs. Postganglionic Neuron Length in the two branches of the ANS

Where the ganglia are located for each branch

Where the spinal nerves originate for each branch

The pre and post ganglionic neurotransmitter used in each


Sympathetic: Short pre / Long post 

Para: Long pre / short post

Ganglia in Sym: Right outside the CNS (SC) 

Ganglia in Para: Closer to effectors

Origin of Sym: Thoracodorsal

Origin of Para: Craniosacral

Sym Pre: Ach // Sym Post: Ach OR NE

Para Pre: Ach // Para Post: Ach

200

The gluteus maximus is an important muscle in hip extension. Hamstrings also assist with hip extensions. The hamstrings are a ___ to the glutes

Synergist

200

What muscle stabiliizes the scapula to the posterior wall, especially during a push-up? 

What is its innervation and vasculature? Which root does its innervation stem from?

Pec Minor, medial pectoral nerve, C8-T1

200
Functions of each:

Anterior Longitudinal Ligament

Post. Longitudinal Ligament

Ligamentum Flavum

Supraspinous Ligament

Limit hyperextension

Limit hyperflexion

Limit hyperextension

Limit hyperflexion

200

Patient Q was peacefully trying to eat their food outside when a bug came and decided to join the party. Which muscles were involved with: 

a) rotating the hand in a position to swat (palm downward)

b) snapping the hand outward

4 muscles total, 50 points each

Pronator quadratus and teres

Extensor Carpi Radialis and E.C. Ulnaris

300

For each: Their function (7 words or less) and whether they work in CNS or PNS (50 pts each):

Oligodendrocyte, satellite cells, astrocyte, ependymal cells, Schwann Cells, microglia


Oligodendrocyte: Myelin producers of CNS

Satellite: Insulate PNS soma, nutrient/waste exchange

Astrocyte: BBB in CNS

Ependymal: Prod/circulate CSF in CNS

Microglia: Phagocytes/immune cells of CNS

Schwann Cells: Myelin makers of PNS (one axon at a time)

300

Describe each type of joints and somewhere you'd find each type (100 pts each)

Synovial: Movement b/w bones (many types)

Cartilaginous: Bones conn by cartilage, some mvmt sometimes, but not always; epiphyseal growth plates or intervertebral discs

Fibrous Joints: No mvmt at all; sutures, flat bones of cranium

300

How does the distribution of blood after being pumped out by the aorta differ beetween the right and left side of the body? 

No brachiocephalic trunk on the left side, straight to carotid artery. 

300

The erector spinae is located __(superficial, intermediate, deep)__ an important muscle in ____ and is innervated by ___

Deep

Extending the spinal column

Dorsal rami of the back

300

What's the name of the ligament that holds the radius and ulna together? What happens if this ligament is damaged?

Annular Ligament

Nursemaid's Elbow 

400

As you move caudally, gray matter begins to outnumber the white matter. Why?

What type of neurons are present in the pathway from the brain to the ventral horn in the motor pathway? From ventral horn to effector? 

Patient Y refuses to hang out with anyone after sunset because she "can't drive at night." Which type of neurons are disrupting this sensory capability

What are the most common type of neurons in the body

When you are closer to the brain, you have more myelinated ascending & descending fibers (white mattter). When you are more caudal (farther from brain), already given off lot of descending fibers and haven't started accumulating ascending fibers.

Multipolar and Multipolar

Bipolar

Interneurons (multipolar)

400

Why is my thumb on the right side but my big toe on the left side?

Why are my fingers not fused? 

What's the purpose of the AER during Lower Limb Development

Which somites are responsible for upper limb vs. lower limb development

Medial rotation of upper limbs, lateral rotation of left

Apoptosis during development

Proliferation of distal mesenchyme by releasing fibroblast growth factors

C5-T1; L2-S2

400

What makes up each side of the quadrangular space? What passes through the quadrangular space? 

Superior: Teres Minor

Inferior: Teres Major

Medial: Long head of triceps brachii

Lateral: Surgical neck of humerus

Axillary nerve and posterior circumflex humeral artery

400

An injury to the nerve branching anteriorly off the C5 nerve root before it becomes the superior trunk is damaged. Which muscles and actions would be affected? 

Rhomboids + Levator Scapulae. Retraction of scap, rotation of scap, heavy lifting, elevate scapulae. 

400

A patient sustains an injury to the musculocutaneous nerve shortly after it pierces the coracobrachialis. What is the motor and sensory implication

Weakened elbow flexion, sensory loss over lateral forearm

500

Describe the sympathetic chain. Including the possible outcomes after.

No partial credit, all or nothing. 

Info from brain --> T1-L2, synapse with presynaptic sympathetic neurons in lateral horns

Presynaptic neurons leave ventral root, pass into spinal nerve, into ramus of respective spinal cord

Go to white rami communicans (junction b/w ramus & chain) 

Once on chain, either: synapse on same level, ascend/descend then synapse, or pass w/o synapse 

Those that did synapse --> gray rami communicans --> target

Those that did not --> splanchnic --> target

500

During Sohan's PR bench press of 45 lbs, what are all the muscle movements involved during the eccentric and concentric motions? 

Concentric: Shoulder Adduction, flexion; Elbow extension, Scapular protraction

Eccentric: Shoulder abduction extension, elbow flexion, scapular retraction

If you don't get the shoulder abduction that's fine

500

Patient X's podiatrist tells her that her foot is healed and she can finally take her boot and brace off for good. Yippee! To celebrate, she throws her arms in the air. What is every muscle involved with this action? 

Raising the humerus: Supraspinatus, deltoid

Rotating the scapula upward: Serratus anterior, trapezius