Back: MsK Basics Flashcards
What are the (2) categories of back muscles?
- Superficial (Extrinsic) muscles
- 1st layer:
- Trapezius
- Latissimus Dorsi
- 2nd layer:
- Levator Scapulae
- Rhomboid Major
- Rhomboid Minor
- 3rd Layer:
- Serratus Posterior Superior
- Serratus Posterior Inferior
- Deep (Intrinsic) (Epaxial) Muscles
- Superficial
- Splenius muscles:
- Splenius Capitis
- Splenius Cervicis
- Splenius muscles:
- Intermediate
- Erector Spinae:
- Spinalis
- Longissimus
- Iliocostalis
- Erector Spinae:
- Deep
- Semispinalis muscles
- Semispinalis cervicis
- Semispinalis capitis
- Rotatores
- Multifidus
- Semispinalis muscles
- Deep Minor
- Interspinales
- Intertransversarii
- Levatores Costarum
- Suboccipital muscles
- Obliquus Capitis Inferior
- Obliquus Capitis Superior
- Rectus Capitis Posterior Major
- Rectus Capitis Posterior Minor
Whats is the general function of the Superficial (Extrinsic) muscles?
Innervation?
Move the upper limb & retraction of the scapula
Primarily innervated by the anterior rami of cervical spinal nerves
Whats is the general function of the Deep (Intrinsic; Epaxial) muscles?
Innervation?
Move & stabilize the vertebral column; Primarily extension of the trunk
Innervated by Dorsal Rami of spinal nerves
What is the function of the Trapezius Muscle?
What letter represents this muscle group?
Elevate/Depresses/Retracts the Scapula
A
What is the function of the Latissimus Dorsi Muscle?
What letter represents this muscle group?
Extends, adducts, and medially rotates the arm
B
What is the function of the Levator Scapulae Muscle?
What letter represents this muscle group?
Elevates the Scapula
C
What is the function of the Rhomboid Muscles (Major & Minor)?
What letter represents these muscle groups?
Retraction of the scapula
Minor: D
Major: E
ID the superficial muscles.
- Trapezius
- Latissimus Dorsi
- Levator Scapulae
- Rhomboid Minor
- Rhomboid Major
What muscles fall under Intermediate muscles?
A. Serratus Posterior Superior
B. Serratus Posterior Inferior
What covers the deep muscles?
ID the deep back muscles
Thoracolumbar Fascia covers the deep back muscles.
-
Splenius muscles:
- Splenius Capitis
- Splenis Cervicis
-
Erector Spinae muscles:
- Spinalis
- Longissimus
- Iliocostalis
-
Transversospinalis muscles:
- Semispinalis capitis
- *more
Innervation of the Trapezius muscle
CN XI: Accessory Nerve
Innervation of the Latissimus Dorsi muscle
Thoracodorsal n.
Innervation of the Levator Scapulae muscle
Dorsal Scapular n. (off brachial plexus)
Innervation of the Rhomboid muscles
Dorsal Scapular n. (off brachial plexus)
What is the function of the intermediate muscles (Serratus Posterior Superior & Inferior)?
What is the innervation?
Move the ribs during respiration
Intercostal n. (anterior rami of thoracic spinal nerves)
ID the Splenius muscles.
What are their function?
Splenius Capitis & Cervicis
Function:
- Unilaterally: Laterally flex the head and neck
- Bilaterally: Extend the head and neck
What are the (3) Erector Spinae muscles?
Compare their positions medial to lateral
Erector Spinae muscles
- Spinalis
- Longissimus
- Iliocostalis
Medial to Lateral: Spinalis > Longissimus > Iliocostalis
ID the Transversospinalis muscle being covered.
What is its function?
Semispinalis Capitis
Extends & rotates the head
Which letter Identifies Levator Scapulae?
C.
Which letter identifies Rhomboid Major? Rhomboid Minor?
D. Minor
E. Major
A & B Identify which muscle groups?
A. Serratus Posterior Superior
B. Serratus Posterior Inferior
The arrow points to which structure?
Thoracolumbar Fascia
The letters identify which muscles groups?
What are their function?
A. Splenius Capitis
B. Splenius Cervicis
–
Unilaterally; Flex the head/neck laterally
Bilaterally; Extend the head and neck
What muscle is depicted here?
Erector Spinae- Spinalis
Which muscle is depicted here?
Erector Spinae- Longissimus
Which muscle is depicted here?
Erector Spinae- iliocostalis
What muscle is depicted here?
What is it’s function?
Semispinalis Capitis
Extend & Rotate the head
Input comes through what type of neurons?
Sensory (Afferent) Neurons
An aggregation of functionally related nerve cell bodies INSIDE the CNS are referred to as
A Nucleus
An aggregation of functionally related nerve cell bodies OUTSIDE the CNS
Ganglion
Output travels through what type of neurons?
Motor (Efferent) Neurons
What is a nerve?
A bundle of axons
Depending on the location a nerve can be called;
Rootlet, root, trunk, division, cord, ramus, nerve, or branch.
While the CNS is composed of the brain and spinal cord, the PNS is comprised of what components?
Cranial nerves, Spinal nerves, and ganglia
The Spinal Cord is composed of what?
Outer: White Matter (Myelinated Axons)
Inner: Gray Matter (Neuron Cell bodies, dendrites, and unmyelinated nerve processes)
What part resembles a Horse Tail?
Cauda Equina; collection of anterior/posterior nerve roots extending inferiorly below the terminal end of the spinal cord
What is the continuation of the Pia Mater extending to the coccyx? What is it’s function?
Filum Terminale: Anchors the Spinal Cord
The cone-shaped terminal portion of the spinal cord is referred to as what?
Conus Medullaris
Collection of nerve axons extending off the spinal cord are referred to as
Roots
Anterior Roots are what type of nerves?
Posterior Roots?
Anterior: Output | Motor (efferent) nerves
Posterior: Input | Sensory (Afferent) nerves
How does the length of the spinal cord change from embryo to adulthood?
Embryo: Extends entire length of vertebral canal
Infant: Ends around L3
Adult: Ends around L1-L2 (w/ variation)
What are the (3) meningeal layers from superficial to deep
- Dura Mater
- Arachnoid Mater
- Pia Mater
- Arachnoid Mater
What is the space between the Vertebra and the Dura Mater?
What does it consist of?
Epidural Space; contains fat, blood vessels, etc.
What space lies between the Dura and Arachnoid Mater?
SubDural Space
Which space lies between the Arachnoid and Pia Mater?
What does it consist of?
Subarachnoid Space; Filled with CSF
How do the Dorsal roots differ from the Ventral roots after they split from the Dorsal/Ventral Rami?
There is a Dorsal Root Ganglia between the Dorsal Root and the spinal nerve formation
How many pairs of Spinal Nerves are there?
How many are in each sub category?
A. 31
B.
(8) Cervical (C1-C8)
(12) Thoracic (T1-T12)
(5) Lumbar (L1-L5)
(5) Sacral (S1-S5)
(1) Coccygeal (Coc1)
Rehearse
How do Somatic Motor & Autonomic Motor pathways Differ?
Somatic Motor: Single neuron from the spinal cord to skeletal muscle
Autonomic Motor: Two Neurons from the spinal cord to the target tissue
What are the neurons involved in the Autonomic Motor circuit? Where do they associate?
Spinal Cord > Pre-Ganglionic > Autonomic Ganglion > Post Ganglionic > Target Tissue
How does the Sympathetic chain associate with the nerve pathway?
Through grey & white rami communicates to the Ventral Ramus
Describe the pathway of Sympathetic Innervation
- Grey Mater of the spinal cord (levels T1 -L2)
- Leave Spinal cord via Anterior Ramus
- Enter White Ramus
- Travel to Sympathetic Trunk
- Enter White Ramus
- Leave Spinal cord via Anterior Ramus
Possible routes from the Sympathetic Trunk;
- Ascend and then Synapse
- Synapse at the level entry
- Descend and then Synapse
- Pass through trunk w/o synapsing
What are the functions of the Vertebral Column? (4)
- Protects the spinal cord and spinal nerves
- Supports the weight of the body superior to the pelvis
- Provides a partly rigid and flexible axis for the body and pivot point for the head
- Role in posture and locomotion
- Adults have how many vertebra?
- What are the (5) regions?
- How many vertebra are in each region?
- 33 Vertebrae
- (7) Cervical
(12) Thoracic
(5) Lumbar
(5) Sacral
(4) Coccygeal
What are the Primary Curvatures?
When do they develop?
Primary Curvatures develop during the fetal period and include;
Thoracic & Sacral Kyphosis
How can can you differentiate Cervical Vertebra
- Transverse Foramina
- Smaller Spinous processes, bifid from C2-C6
- Triangular Vertabral Foramen
How can Thoracic Vertebra be differentiated?
- Lacking Transverse Foramen
- Transverse processes are long/strong
- Costal Facets on Transverse processes and body
- Spinous Processes are long, angled inferiorly, and overlap the inferior vertebra
- Heart-Shaped Body
How are Lumbar Vertebra differentiated?
- Lack of transverse foramina
- Lack of Facets on Transverse process and body
- Larger body size
- Spinous process is short, broad, and blunt
- Kidney-Shaped Body
What are Secondary curvatures?
How do they arise?
Secondary curvatures develop separately during infancy;
Cervical lordosis develops when infants begin raising their head
Lumbar lordosis develops when infants begin walking
The Head of the Rib articulates where?
The head of the ribs articulate at the articular facets located on the body of Thoracic vertebra
This is an example of what type of vertebra?
Thoracic Vertebra
This is an example of what type of vertebra?
Lumbar Vertebra
This is an example of what type of vertebra?
Cervical Vertebra
The question mark refers to what region?
Pars Interarticularis
This refers to what articulation?
Atlanto-Occipital Articulation
Identify A, B, & C
What is the significance of C?
A: Inferior Notch
B: Superior Notch
C: Intervertebral Foramen
This is the location where spinal nerves exit the spinal cord
Identify A & B
Where is there no IV disc present within the vertebral column?
A: Anulus Fibrosus
B: Nucleus Pulposus
There is no IV disc present between C1 & C2
This is an example of what condition?
Thoracic Kyphosis
This is an example of what condition?
Lumbar Lordosis
This is an example of what condition?
Scoliosis
Identify the Laminae
B
What is Clinical Kyphosis? Lordosis?
- Clinical Kyphosis is EXCESSIVE Thoracic curvature
- Clinical Lordosis is EXCESSIVE Lumbar curvature
What is Scoliosis?
Abnormal lateral curvature and rotation of the vertebral column
