Unit 1 Objectives Flashcards
What are the muscles of the back?
Trapezius - Transverse cervical a. - Spinal Accessory n. Levator Scapulae, Rhomboid Minor, Rhomboid Major - Dorsal Scapular a. - Dorsal Scapular n. Serratus Posterior Superior - Ventral Rami of intercostal n. Latissimus Dorsi - Thoracodorsal a. - Thoracodorsal n. Serratus Posterior Inferior - Ventral Rami of intercostal n. Erector Spinae - Dorsal Rami of segmental spinal n.
What do Dorsal Rami innervate?
Skin of Back and epaxial (dorsal side) muscles
How do the dorsal and ventral primary rami form?
Off of each side of the spinal cord:
- Dorsal/Ventral Rootlets form Dorsal/Ventral Roots
- Dorsal/Ventral Roots combine to form Spinal Nerve (DRG 1st)
- Spinal nerve splits to form Primary Dorsal Rami and Primary Ventral Rami
The Dorsal Rootlets/Roots are only sensory neurons
The Ventral Rootlets/Roots are only motor neurons
- Sensory/Motor becomes combined in the spinal nerve and then afterwards into the rami
What are the vertebral characteristics associated w/ kyphoplasty?
Vertebral Body, Pedicles Transverse Processes Lamina Spinous Process Superior/Inferior Articular Processes Intervertebral Foramina Superior, Inferior, Transverse Costal Facets (Thoracic only) Transverse Foramina (Cervical Only)
For kyphoplasty, have to insert needle at 45 degree angle between transverse Process and Spinous process into compressed Vertebrae
- expand balloon and inject the glue which fixes compression
What are the planes of the body?
Coronal (frontal)
Sagittal (median)
Transverse (horizontal)
Describe the nervous system components present in the vertebral canal and intervertebral foramen.
Vertebral Canal
- Spinal cord
- Meninges
- Epidural Fat
- Internal Vertebral (Epidural) Venous Plexus
In the Intervertebral Foramina
- Dorsal (and DRG) and ventral nerve roots
- Spinal Nerve
- if the disc is herniated it will be in there too compressing nerve root
Describe the boundaries of the intervertebral foramen and the structures which may cause stenosis of the foramen.
Boundaries of the intervertebral Foramen are the Superior and Inferior vertebral notches
- Anterior border is the vertebral body
- Posterior border is the ligamentum flavum
Stenosis can be caused by:
- Facet inflammation
- Ligamentum flavum hypertrophy
- Disc pathology
Describe the dural layers of the spinal cord, and the spaces associated with them.
Dura Mater
- subdural space and epidural space
Arachnoid Mater
- Subarachnoid space that contains CSF
Pia Mater
- denticulate ligaments
Describe safe anatomical areas for spinal taps and epidural injections.
To Draw sample of CSF for spinal tap you have to enter below LV2
- above LV2 risks damaging spinal cord
- below LV2 the cauda equina can accommodate needle
For Epidurals:
- enter the epidural space before the dura mater
Describe the structures penetrated during a spinal tap procedure.
Skin Epidural Fat Supraspinous Ligament Ligamentum Flavum Epidural Space Dura Mater Subdural Space Arachnoid Mater Subarachnoid space for CSF!
Describe the anatomy relevant to common sites of intervertebral disc protrusion
99% of disc hernations occur at LV 4/5, LV5/SV1, CV4/5 or CV5/6
- CV herniations affect spinal nerve of higher # CV
- LV herniations affect spinal nerve of lower # LV
Define “dermatome”, “autonomous zone” and “myotome”.
dermatome
- area of skin innervated by single spinal nerve
autonomous zone
- area of skin where overlap of dermatomes not likely
Myotome
- A group of muscles that a single spinal nerve root innervates
• Ex. C5 = shoulder abduction o C6 = elbow flexion/wrist extension o C7 = elbow extension/wrist flexion o C8 = finger flexion o T1 = finger abduction
Use dermatome and myotome signs to localize a spinal cord/nerve lesion.
Study the dermatome & myotome chart for arm.
Discuss the curvatures of the spine in normal and abnormal states
Normal
Primary curvatures (kyphotic)
• Thoracic and sacral
Secondary curvatures (lordotic)
• Cervical and lumbar
Abnormal
Scoliosis
• Lateral curvature of the spine
• Discuss kyphoplasty in the context of severe osteoporosis
o Used to repair compressed vertebral bodies
o Surgical
Enter through pedicle to avoid puncturing spinal cord
Inflate balloon and inject material to return vertebral body to normal shape
Describe the components of the spinal cord/spinal nerve?
Spinal segment Ex. T1 - Dorsal/Ventral Rootlets =>Roots Dorsal - Sensory • Dorsal root ganglion Ventral - Motor
Combine to make a spinal nerve
One pair of spinal nerves for each spinal segment
- Exit vertebral canal below vertebra of the same number EXCEPT in the cervical region which exit above vertebra of the same number (C8 exits above T1)
Split into a dorsal primary ramus and ventral primary ramus
- this is mixed at this point (sensory/motor)
Which structures may impinge on the spinal nerve?
Pathological IV disc
• Nucleus pulposes is what herniates after bulging and breakdown of the annulus fibrosis
Stenosis of vertebral canal
• Facet inflammation
• Ligamentum flavum hypertrophy
Describe the basic anatomy, blood supply, and lymphatic drainage of the breast.
Anatomy Overlies ribs 2-6 Suspensory ligaments (of Cooper) Lactiferous ducts empty into lactiferous sinuses, then out the nipple Areola Nipple
Blood supply
Internal thoracic (mammary) a. and lateral thoracic a.
Lymphatic drainage
Axillary nodes (75% of lymph drains here)
Supraclavicular nodes
Parasternal nodes
• Describe the anatomical mechanisms of mastectomy-induced lymphedema and winging of the scapula.
Lymphedema
Side effect of removing lymph nodes because the channels may not drain correctly or connect so lymph accumulates in the arms
Winging of the scapula
Because the long thoracic n. is superficial to the serratus anterior m. it can be cut or injured during mastectomy, which paralyzes the serratus anterior m. causing winging of the scapula.
• Learn how to perform the Neer Sign and Hawkins test in a physical exam.
Neer sign
Internally rotate humerus and lift arm above shoulder
Hawkins test
Flex elbow and internally rotate humerus
Explain the sub-acromial space and its role in shoulder pain.
Between acromion and head of the humerus
Contents
Subacromial bursa
Supraspinatus tendon
Capsular ligaments
Space can be reduced by
Inflammation of bursa, tendon, muscle tear
Instability of the humeral head
Bone spur
Perform Neer sign and Hawkins test to determine impingement syndrome
Weakened rotator cuff caused the humeral head to displace superiorly by the pull of the deltoid m.
Relate shoulder dystocia to Erb’s palsy, and describe the functional deficits associated with upper brachial plexus injury
Shoulder dystocia occurs during delivery of a fetus when the shoulders get stuck behind the pubic symphysis and the head is pulled with the shoulders stationary, stretching the upper trunk of the brachial plexus
o Erb’s palsy Internally rotated arm • “waiter’s tip” hand • Nothing is opposing them o The external rotators are nonfunctional Numbness around shoulder and anterolateral aspect of arm and forearm, thumb • C5-C6 Weakness abducting arm
Compare and contrast upper and lower brachial plexus injuries
Upper C5-C6 • Difficulty abducting arm • Arm medially rotated • No sensory to lateral part of arm and thumb
Lower C8-T1 • Claw hand o Ulnar n. problem • Klumpke’s palsy • No sensation on pinky
• Describe the distal attachment pattern of the rotator cuff muscles, and the two main functions of the rotator cuff.
Greater tubercle
Supraspinatus
Infraspinatus
Teres minor
Lesser tubercle
Subscapularis
Primary functions of rotator cuff muscles
Stabilize head of humerus in glenoid fossa
Assist in abduction and rotation of humeral head
Describe the difference between “shoulder separation and shoulder dislocation”
Shoulder separation
Torn ligaments around shoulder
• Weight of arm can pull scapula downward, looking like dislocation
Shoulder dislocation
Displacement of the humeral head out of the glenoid fossa
Describe the anatomical difference between central and peripheral nervous systems
CNS
Brain and spinal cord
Ogliodendrocytes
• Myelinating cells of the CNS
PNS 31 pairs of spinal nerves 12 cranial nerves Peripheral autonomic ganglia and nerves Schwann cells • Myelinating cells of the PNS
Describe the embryological origin of the neural tube and neural crest
Neuroectoderm
Notochord induces formation of neuroectoderm
Neural tube
Cell bodies inside the brain and spinal cord
Neural crest
Cell bodies outside the brain or spinal cord
Describe the nerve components and reflex arcs of somatic innervation
GSE
Motor
Innervates skeletal muscles
Cell bodies found in the ventral horn
GSA
Sensory
Pain, touch temperature from somatic structures
Cell bodies found in the DRG
Reflex arcs Monosynaptic • One motor neuron • 1 GSA (PUN) neuron in to ventral horn • 1 GSE neuron from ventral horn to target structure
Bisynaptic
• 1 GSA neuron to dorsal horn
• 1 interneuron from dorsal to ventral horn
o Secondary sensory neuron
• 1 GSE neuron from ventral horn to target
Describe the difference between upper motor neurons and lower motor neurons and recognize clinical signs of damage to each
UMN CNS No direct contact with target structure Communicate with LMN • Often inhibitory Damage causes • Hyperreflexia o Random muscle jerking b/c loss of inhibitory fxn • Hypertonia • Muscle weakness • Ex. CP, stroke,
LMN Directly contacts target structure All spinal motor neurons and some cranial nerves are LMNs Damage • Muscle weakness/paralysis • Atrophy • Hyporeflexia • Atonia • Ex. Polio, ALS
Describe the characteristics and sequelae of compartment syndrome.
Case Study Initial findings:
• Sensation is present in all fingers
• He cannot actively extend wrist or fingers
• Severe pain with passive extension of wrist
• Finger and thumb flexion weak
• Radial and ulnar pulse present
1 hr later • Pain is worse • Loss of all sensation in hand • Loss of motor function • Fingers are cool • No radial pulse
Describe the major nerves and arteries in each compartment of the arm.
Arm Anterior • Musculocutaneous n. • Brachial a. Posterior • Radial n. • Deep brachial a./profunda brachii
Forearm
Anterior
• Median n. and ulnar n.
• Radial a., ulnar a., anterior interosseous a.
Posterior
• Deep branch of radial n. / posterior interosseous n.
• Posterior interosseous a.
Describe general sites of frequent nerve and artery damage
Sites of: Tethering by soft tissues Passage through tunnels Crossing joints injured by dislocation In near contact with bone Superficial location
Describe specific sites of frequent damage to the radial n., ulnar n., and median n.
Radial n. Supinator tethers, laying against lateral epicondyle Mid-shaft break of humerus • Lies in radial groove Wrist drop
Ulnar n. Medial epicondyle of humerus • Cubital tunnel Guyon’s canal in wrist Claw hand!
Median n.
Supracondylar fracture
Crosses elbow joint
Carpal tunnel
Contrast acute compartment syndrome with chronic exertional compartment syndrome
Acute compartment syndrome
Medical emergency
• 4-8 hours of ischemia leads to irreversible damage
Inc. pressure in compartment (in antebrachial fasica)
Occlusion of capillary flow
• Muscle and nerve ischemia
Inc. intracompartmental tissue swelling
• Secondary trauma and ischemia
Inc. pressure in compartments
Ischemic necrosis of muscle and nerve
Chronic exertional compartment syndrome
NOT a medical emergency
Pain during exercise (usually repetitive activities)
• Can be caused by hypertrophy and inc. blood flow to muscles
Refactory cases may require fascial release surgery
Describe the joints of the hand and the muscle/nerve combinations that move them.
Metacarpophalangeal joint (MCP)
Flexor – Lumbricals
• Median n. EXCEPT for medial ½ innervated by ulnar n. (4th and 5th digit)
Extensor – extensor digitorum
• Deep radial n.
Abduction and Adduction – palmar and dorsal interossei m.
• Ulnar n.
Proximal interphalangeal joint (PIP)
Flexor – flexor digitorum superficialis
• Median n.
Extensor – lumbricals (median n. and ulnar n.) and interossei m. (ulnar n.)
Distal interphalangeal joint (DIP)
Flexor – flexor digitorum profundus
• Median n. and ulnar n. (medial half)
Extensor – lumbricals (median n. and ulnar (medial ½) and interossei m. (ulnar n.)
Digit 1 Thumb abduction • Abductor pollicis longus o Radial n. • Abductor pollicis brevis o Recurrent branch of median n. Thumb adduction • Adductor pollicis o Ulnar n.
How can you test a functioning adductor policis m.?
Froment’s sign (ulnar n. palsy)
Cannot grip paper strongly, must compensate with flexor pollicis longus and flexor pollicis brevis
Describe the vascular supply to the hand and one test of anastomotic flow of the hand.
Superficial palmar arch
Primarily supplied by ulnar a.
Anastomoses with superficial branch of radial a.
Deep palmar arch
Primarily supplied by radial a.
Anastomoses with deep branch of ulnar a.
Allen’s test
Occlude, pump hand, release one artery, see if hand “pinks up”, repeat
Describe tests to assess ulnar nerve function
Froment’s sign Grip paper with thumb • Adductor pollicis paralyzed • Compensates with FPL and FPB o Weakened grip and thumb sticks up
Abduction and adduction of the fingers
Interossei m.
Sensation on medial side of hand or 5th digit
Describe the “carpal tunnel syndrome” and one test of median nerve dysfunction
Carpal tunnel
Transverse carpal ligament => compression of median n.
Contents • Median nerve • Tendons of flexor digitorum superficialis • Tendons of flexor digitorum profundus • Tendon of flexor pollicis longus
Symptoms • Pain • Paresthesia • Sensory loss • Weakness • Muscle atrophy
Tinel’s sign
Tap on transverse carpal ligament, will elicit tingling down hand and first three digits
Sign of nerve irritability
Describe the two divisions of the autonomic nervous system.
Sympathetic
Most travel with spinal n. or arteries
“Fight or flight”
• Increased heart rate
• Vasodilation in heart and muscles
• Vasoconstriction in skin and viscera
• Dilated pupils
Parasympathetic
Not found in limbs/body wall
“Rest and digest”
• Decreased HR
• Promotion of peristalsis
• Bronchoconstriction
• Salivation
These two systems are sometimes, but not always, antagonistic.
Describe the general pattern of autonomic innervation (i.e. 2 neuron motor system)
2 neuron motor system from lateral horn (IML) of spinal levels T1-L2 and S2-S4
Pre-ganglionic motor neuron from spinal cord grey matter sends out axon to peripheral ganglion where it synapses onto a post-ganglion neuron, which then goes to target structure
DRGs at ONLY these spinal levels carry autonomic sensory
PUNs
Describe the neurotransmitters used by pre-ganglionic and post-ganglionic neurons for both sympathetic and parasympathetic systems.
Sympathetics
Pre-ganglionic
• Acetylcholine
Post-ganglionic
• Noradrenaline
o EXCEPT for sweat glands which are also cholinergic (AcH)
Parasympathetics
Acetylcholine for both
Describe the parts of the sympathetic chain and what types of fibers travel in each.
Chain ganglion
And chain
Connected to spinal nerve by
White ramus
• Pre-ganglionic neuron
Grey ramus
• Post-ganglionic neuron
Splanchnic nerve
Out to viscera
Describe what is meant by the “thoracolumbar” and “craniosacral” outflow of the sympathetic and parasympathetic systems, respectively.
Thoracolumbar
Cell bodies of PRE-GANGLIONIC sympathetic neurons located only in the IML (or lateral horn) of spinal levels T1-L2
T1-L2
• Sympathetics
Craniosacral
Cell bodies of PRE-GANGLIONIC parasympathetic neurons are located only in the brain (for cranial nerves) or in the IML of spinal levels S2-S4
S2-S4
• Parasympathetics
Describe the gluteal region including muscles and their function and the major nerves and vessels located in this region
Superior
Function: extension of the hip
Gluteus maximus m.
• Inferior gluteal n.
• And lateral rotator of the hip
• Origin: sacroiliac tendon
• Insertion: IT band and gluteal tubercle
Gluteus medius and minimus m.
• Superior gluteal n.
• Not as strong extensor of the hip
• Medial rotation of hip
• Insertion: greater trochanter of the femur
Tensor fascia lata m.
• Superior gluteal n.
Deep
Function: lateral rotators of the thigh
Piriformis m.
• Nerve to piriformis
Superior gemellus m.
• Nerve to obturator internus
Obturator internus m.
• Nerve to obturator internus
Inferior gemellus m.
• Nerve to quadratus femoris
Quadratus femoris m.
• Nerve to quadratus femoris
Nervascular bundles
Superior gluteal
Inferior gluteal
Pudendal
Sciatic n.
Tibial n.
Common fibular (peroneal) n.
• Superficial fibular (peroneal) n.
• Deep fibular (peroneal) n.
Describe the basic distribution of the spinal level dermatomes of the lower extremity and clinically relevant autonomous zones to test function of these levels.
Anterior Thigh mid level = L3
Kneecap and directly above = L4
Lateral Leg (knee down)/in between Toes 1/2 = L5
Describe the functional groups of muscles of the thigh and identify the nerves and major vessels which supply them.
Anterior
Femoral n.
Femoral a.
Sartorius m.
• Function: flexes hip, flexes knee, medial/internal rotation of the leg at knee
Quadraceps femoris m.
Function: All extend knee
• Vastus lateralis m.
• Vastus medialis m.
• Vastus intermedius m.
• Rectus femoris m.
o Also flexes the hip
Femoral triangle
• Borders
o Inguinal ligament
o Sartorius m.
o Adductor longus m.
• NAVE(L)
o Femoral nerve, artery, vein, superficial inguinal lymph nodes
Medial
Obturator n.
Deep femoral a.
Function: Adduction of thigh, stabilizers of hip (working with gluteus medius and minimus)
Pectineus m.
• Femoral and obturator n.
Illiopsoas m.
Obturator externus m.
Adductor longus m.
Adductor brevis m.
Adductor magnus m.
• Obturator n. and tibial n.
Gracillis m.
Posterior
Function: extension of the hip and flexion of the knee
Sciatic n. (mostly tibial branch of sciatic n.)
Hamstrings
• Biceps femoris m.
o Long head
o Short head
Innv by common fibular (peroneal) branch of sciatic n.
• Semitendinosus m.
• Semimembranosis m.
Describe the spinal levels associated with tests of the myotactic reflexes in the lower extremity.
HIP
- Flexion = L2, 3
- Extension = L5, S1
KNEE
- Flexion = L5, S1
- Extension = L3, 4
ANKLE
- Dorsiflexion = L4, 5
- Plantarflexion = S1, 2
FOOT
- Inversion = L4, 5
- Eversion = L5, S1
Describe the anatomical reasons for a Trendelenburg sign
Can be caused by hip dislocation, surgery, or poliomyelitis
Gluteus medius m. and gluteus minimus m. are paralyzed (superior gluteal n.) and cannot abduct thigh or hip.
Causes hips to tilt, injured side rising (because abductors cannot pull it down to level), and leaning to the injured side to compensate so that you don’t fall over
