Flashcards in Unit 1 Objectives Deck (49)
What are the muscles of the back?
- 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.
- Thoracodorsal a.
- Thoracodorsal n.
Serratus Posterior Inferior
- Ventral Rami of intercostal n.
- 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?
Superior/Inferior Articular Processes
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?
Describe the nervous system components present in the vertebral canal and intervertebral foramen.
- Spinal cord
- 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.
- subdural space and epidural space
- Subarachnoid space that contains CSF
- 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
- enter the epidural space before the dura mater
Describe the structures penetrated during a spinal tap procedure.
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”.
- area of skin innervated by single spinal nerve
- area of skin where overlap of dermatomes not likely
- 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
Primary curvatures (kyphotic)
• Thoracic and sacral
Secondary curvatures (lordotic)
• Cervical and lumbar
• Lateral curvature of the spine
• Discuss kyphoplasty in the context of severe osteoporosis
o Used to repair compressed vertebral bodies
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.
Overlies ribs 2-6
Suspensory ligaments (of Cooper)
Lactiferous ducts empty into lactiferous sinuses, then out the nipple
Internal thoracic (mammary) a. and lateral thoracic a.
Axillary nodes (75% of lymph drains here)
• Describe the anatomical mechanisms of mastectomy-induced lymphedema and winging of the scapula.
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.
Internally rotate humerus and lift arm above shoulder
Flex elbow and internally rotate humerus
Explain the sub-acromial space and its role in shoulder pain.
Between acromion and head of the humerus
Space can be reduced by
Inflammation of bursa, tendon, muscle tear
Instability of the humeral head
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
Weakness abducting arm
Compare and contrast upper and lower brachial plexus injuries
• Difficulty abducting arm
• Arm medially rotated
• No sensory to lateral part of arm and thumb
• 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.
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”
Torn ligaments around shoulder
• Weight of arm can pull scapula downward, looking like dislocation
Displacement of the humeral head out of the glenoid fossa
Describe the anatomical difference between central and peripheral nervous systems
Brain and spinal cord
• Myelinating cells of the CNS
31 pairs of spinal nerves
12 cranial nerves
Peripheral autonomic ganglia and nerves
• Myelinating cells of the PNS
Describe the embryological origin of the neural tube and neural crest
Notochord induces formation of neuroectoderm
Cell bodies inside the brain and spinal cord
Cell bodies outside the brain or spinal cord
Describe the nerve components and reflex arcs of somatic innervation
Innervates skeletal muscles
Cell bodies found in the ventral horn
Pain, touch temperature from somatic structures
Cell bodies found in the DRG
• One motor neuron
• 1 GSA (PUN) neuron in to ventral horn
• 1 GSE neuron from ventral horn to target structure
• 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
No direct contact with target structure
Communicate with LMN
• Often inhibitory
o Random muscle jerking b/c loss of inhibitory fxn
• Muscle weakness
• Ex. CP, stroke,
Directly contacts target structure
All spinal motor neurons and some cranial nerves are LMNs
• Muscle weakness/paralysis
• Ex. Polio, ALS