Interval 6: Back and Gluteal Region Flashcards
What nerves innervate the upper limbs? How about the lower limbs?
- Upper: C5-T1
- Lower: L2-S2
What are the 4 curvatures of the adult back?
- Cervical: secondary curvature directed anteriorly
- Thoracic: primary curvature directed posteriorly
- Lumbar: secondary curvature directed anteriorly
- Sacral: primary curvature directed posteriorly
Movements between vertebrae occur at their ___________
- Zygapophyseal joints.
- Also by compression and traction of the discs
Zygapophyseal (facet) joints are formed between the _____________ at the junction of each ________ and __________.
- Superior and inferior articular processes
- each pedicle and lamina
What muscles act on facet joints?
-Deep or intrinsic back muscles
Describe the structure of intervertebral discs
-consists of fibrocartilaginous annulus fibrosus that surrounds a nucleus pulposus
What is the nucleus pulposus a remnant of?
-Fetal notochord
The anterior longitudinal ligament functions to limit ___________ and the posterior longitudinal ligament functions to limit ________.
- Extension of vertebra
- Flexion of vertebra
Individual vertebrae are separated by ___________.
-Intervertebral foramina
What are the anterior and posterior borders of intervertebral foramina?
- Anterior: bodies and intervertebral joints
- Posterior: facet joints
Elastic ligamentum flavum
- extends between the laminae of adjacent vertebrae
- limits vertebral flexion and helps maintain normal vertebral curvature
Which ligament of the vertebral column is yellow?
-Ligamentum flavum: yellow due to high content of elastic fibers
What ligaments of the vertebral bodies and what are ligaments of the vertebral arches?
- Bodies: anterior and posterior longitudinal ligaments
- Arches: ligamentum flava
Cervical vertebrae morphology
- small bodies
- short spinous processes with bifid tips
- transverse processes that transmit the vertebral arteries
Facet joints of cervical vertebrae
- C3-C7
- oriented at 45-degree angle relative to the transverse plane
- allows flexion, extension, lateral bending, and rotation
Uncinate processes of bodies of cervical vertebrae
- C3-C7 bodies
- form uncovertebral synovial joints with the vertebral bodies superior to them
- osteoarthritis in these joints make result in compression of the roots of C3-C7 spinal nerves
Atlas
- C1 vertebrae
- posterior arch and anterior arch
- no body or spinous process
- Yes joints found here
yes joints
- found between superior articular processes of atlas as they articulate with the occipital condyles of the skull
- permit flexion and extension
Axis
-C2 vertebra
Dens of axis
- stolen body of C1
- articulates with anterior arch of atlas and forms “no” joint
“no” joint
- where dens of axis articulates with anterior arch of the atlas
- permits rotation of the atlas and skull
What holds the dens in place and what happens if this ruptures?
- transverse ligament of the atlas
- rupture of this ligament causes dislocation of the atlantoaxial joint and displacement of dens posteriorly into cervical spinal cord which may lead to quadriplegia
What ligament keeps the dens from excessively rotating?
-Attached to the margins of the foramen magnum by alar ligaments
What is unique about C7?
- vertrebra prominens
- has long spinous process and small transverse foramina that do not transmit the vertebral arteries
Thoracic vertebrae morphology
- heart-shaped bodies
- long,obliquely oriented, spinous processes
- costal facets on the bodies and on the transverse processes for articulation with ribs
Facet joints of thoracic vertebrae
-60-degree angle relative to transverse plane
-permits lateral bending and rotation
(flexion and extension limited by ribs)
Lumbar vertebrae morphology
- large, kidney-shaped bodies
- short, horizontally oriented spinous processes
- long transverse processes
facet joints of lumbar vertebrae
- oriented perpendicular to the transverse plane
- permits flexion and extension and lateral bending
- limited rotation
The sacrum contains the sacral canal, which ends at the sacral hiatus in the dorsal midline; the canal contauns the ___________ and the sacral hiatus transmits_________.
- Canal: roots of the S1-coccygeal spinal nerves
- Hiatus: S5 and coccyeal spinal nerves
The coccyx is formed by 3-5 fused coccygeal vertebrae. It is an attachment site for what?
- gluteus maximus
- anococcygeal ligament (attachment site for muscles of pelvic diaphragm)
Foramen magnum
- boundary between brain and spinal cord
- where skull articulates with atlas
Meninge layers
Dura mater: exterior, tough, fibrous
Arachnoid mater: delicate, avascular, not adherent to dura
Pia mater: innermost layer; covers SC and roots of nerves; contains blood vessels and is indissectible from the spinal cord
Subarachnoid space
- space between pia and arachnoid membranes
- contains CSF
CSF
- derived from blood
- devoids of cells and proteins, and less glucose
- salt composition different from serum indicating it is secreted and not filtered
- secreted into ventricles of the brain, circulated in subarachnoid space, and is returned via venous system
The spinal cord ends at what vertebral level and what is the tapered structure called?
- L2
- Conus medularis
Denticulate ligament
-small, saw-tooth shaped extension of pia mater run to dura mater and serve to support cord within its sheath of dura
3 exits for spinal nerves
- intervertebral foramina
- sacral foramina
- sacral hiatus
1st 7 cranial nerves exit _____ to cervical vertebrae for which they are named.
- Superior
- Ex. C4 exits between C3 and C4
Beginning with T1, all other spinal nerves exit ______ to the vertebrae for which they are named.
- Inferior
- Ex: L4 exits between L4 and L5
C8 spinal nerve exits….
-through intervertebral foramina between C7 and T1 because there are 8 cervical nerves but only 7 cervical vertebrae
Cauda equina
-formed by dorsal and ventral roots of lumbar ans sacral spinal nerves that extend inferior to end of SC at L2
With a lumbar disk herniation, what muscles contribute to reducing the curvature of the spine?
- Psoas major
- Rectus abdominus
Muscles of rotator cuff
SITS Supraspinatus Infraspinatus Teres minor Subscapularis
4 actions the pelvic girdle can do on the chest wall
- elevate
- depress
- protract
- retract
What is the glenohumeral joint and what actions does it permit?
- Ball and socket joint where the head of the humerus articulates with the glenoid fossa of the scapula
- flexion and extension
- abduction and adduction
- medial and lateral rotation
The scapula is moved in what direction during abduction and adduction of the humerus at the glenohumeral joint?
- Laterally (upwardly) or medially (downwardly)
- Lateral during abduction and medial rotation during adduction
What 2 ligaments strengthen the glenohumeral joint?
- Glenohumeral bands strengthen anterior aspect of the joint
- Coracohumeral ligament strengthens the superior aspect of the joint
What is the function of the coracoacromial ligament?
-prevents superior displacement of the head of the humerus
Superior muscles of the back
- Trapezius
- Latissimus dorsi
- rhomboid major
- rhomboid minor
- levator scapulae
Innervation of the superior muscles of the back
-Innervated by ventral rami of spinal nerves through branches of brachial plexus, EXCEPT for the trapezius which is supplied by CN XI, the accessory nerve
Major functions (with what exception) of superficial muscles of the back
- to move the scapula which itself is part of the upper extremity
- Latissimus dorsi is different
What are the intermediate muscles of the back?
- serratus posterior superior
- serratus posterior inferior
- 12 pairs of levator costarum muscles
- attach to ribs and act as accessory muscles of respiration
Innervation of intermediate muscles of the back?
-Ventral rami of spinal nerves
Deep or intrinsic muscles of the back
- erector spinae muscles
- splenius capitis and splenius cervicis
- transversospinalis muscles
Erector spinae muscles
- 3 parallel muscle groups
- iliocostalis (most lateral)
- longissimus (middle)
- spinalis (medial)
Where can one find the splenius capitis and splenius cervicis?
-lie superficial to components of the erector spinae in the neck
function of splenius capitis and splenius cervicis
splenius capitis: extends the head
splenius cervicis: rotates the head
Transversospinalis muscles
- lie deep to the erector spinae
- semispinalis (superficial most)
- multifidus (middle)
- rotatores (deep)
Innervation of deep muscles of the back
-dorsal rami of spinal nerves
2 functions of muscles of rotator cuff
- rotate arm at shoulder
- maintain integrity of the shoulder joint and keep head of the humerus closely opposed to the glenoid fossa of the scapula throughout the full range of arm motion
Joints of the pelvic girdle
- Sacroiliac joints
- Hip joints
___________ resist rotation at the sacroiliac joints.
-Posterior sacroiliac ligaments
What forms the hip joint?
-head of femur and acetabulum
3 ligaments that strengthen articular capsule of hip joint
- iliofemoral ligament: strongest, reinforces anterior part of capsule and resists extension
- pubofemoral ligament: reinforces anterior and inferior parts of capsule and resists abduction
- ischiofemoral ligament: reinforces posterior part of capsule and resists extension by screwing head of femur into acetabulum
Main source of blood supply to head and neck of femur
-Medial circumflex artery
In patients with fractures of the femoral neck, the thigh is _____________ by the short lateral rotators of the thigh at the hip and by the gluteus maximus
-laterally rotated
Superior gluteal artery supplies
-gluteus maximus, medius, minimus
When does one experience the Trendelenburg gait?
- patients with lesion to superior gluteal nerve
- weakness if ability to abduct the thigh at the hip
- waddling in which the pelvis sags on the side of the unsupported limb–sags on side opposite the side of the lesioned superior gluteal nerve
What occurs when patients have lesioned inferior gluteal nerve?
-weakness in ability to laterally rotate and extend the thigh at the hip
Major muscles of the gluteal region
- Gluteus maximus
- Gluteus medius
- Gluteus minimus
- Tensor fascia lata
- Deep hip rotators
Name the deep hip rotators and what their function is.
- Piriformis
- Superior gemellus
- Obturator internus
- Inferior gemellus
- Quadratus femoris
- All LATERAL rotators of the femur at hip joint
What muscles are involved in “lateral balance control”?
- Gluteus medius
- Gluteus minimus
- Tensor fasciae latae
-These are the hip abductors that when a patient is instructed to stand with total body weight on one limb, act with such a force that the pelvis rises on the opposite side
What does a positive Trendelenburg test indicate?
-osseomuscular stability defect of the hip joint
Hamstrings and which are true
- Biceps femoris
- Semitendinosus
- Semimembranosus
- All are true except for the short head of the biceps femoris
Innervation of the hamstrings
- All but short head of biceps femoris are innervated by tibial nerve
- Short head is innervated by common fibular nerve
Long vs. Short head of femoris
- long head: crosses both the hop and knee joint
- short head: only crosses the knee joint
What is found in the triangular space?
-Circumflex scapular artery
-What is found in quadrangular space?
- Axillary nerve
- Posterior circumflex humeral artery
The vertebral arch consists of __________. Where do the individual parts attach and form?
- 2 pedicles and 2 laminae
- the pedicles attach to the body, and the laminae unite to form the spinous process
Most vertebra are composed of what 3 things?
- vertebral body
- vertebral arch
- pair of costal processes: form transverse processes
What parts of the vertebra form the spinous process and the transverse process?
- spinous process is the laminae
- transverse process is the costal processes
3 types of abnormal curvatures of the spine
- kyphosis
- lordosis
- scoliosis
Kyphosis definition and causes
- abnormal increase in the posterior curvature of the spine
- most common form is postural kyphosis
- cause be anterior wedge-shaped thoracic vertebrae and by resoprtion of anterior parts of the thoracic vertebral bodies from osteoporosis
Lordosis definition and causes
-abnormal increase in the anterior curvature of the spine that may be caused by a weakening of the anterior abdominal wall musculature as a result of weight gain
Scoliosis definition and causes
-abnormal lateral curvature that may be caused by an absent half of a vertebrae or a wedge-shaped vertebrae or by an asymmetric weakness of back musculature
Individual vertebrae articulate at _______ and through _________ and are supported by ligaments.
- facet joints
- intervertebral disks
What types of motions do facet joints allow?
-gliding motions
What are the functions of intervertebral disks?
-absorb shock and distribute weight over the entire surface of the vertebral bodies
The posterior longitudinal ligament is _____________ than the anterior longitudinal ligament.
-narrower and weaker
3 things that make up the vertebral canal
- meninges
- spinal cord
- root of spinal nerves
Where is the epidural space found and what does it contain?
- outside the meninges
- contains fat and internal vertebral venous plexus
What does the internal vertebral venous plexus do? How can this be pathologic?
- connects veins that drain the thorax, abdomen, and pelvis with dural venous sinuses of the cranial cavity
- also provides a route for metastasis for tumors of prostate, uterus, and rectum to the cranial cavity
Dura mater is continuous with the meningeal dural of the cranial cavity and ends at the lever of the _______ vertebra. Lateral extensions of the dural sac contain ________.
- S2
- roots of spinal nerves
Subdural space
-potential space between dura and arachnoid mater
Arachnoid mater extends to level of S2 and is pressed against the dura by _______.
-pressure of CSF
Function of CSF
-cushions the brain and spinal cord, absorbs waste products, and transports hormones
Filum terminale
-consists of pia that extends from the inferior end of the cord at level of L2 and joins the dura and arachnoid to end in the sacral canal at level of S2
Conus medullaris is the tapered inferior end of the spinal cord that contains the ____________ segments and is located at level of L2.
-sacral and coccygeal cord segments
What is a lumbar puncture used for and where is it usually done?
- procedure used to sample CSF or to introduce anesthetic agents into the subarachnoid space
- typically performed between the L4 and L5 vertebrae well below the inferior end of the spinal cord
In a midline lumbar puncture a needle will traverse what layers? What about in a lumbar puncture off the midline?
- midline: skin, superficial and deep fascia, supraspinous and interspinous ligaments, intralaminar space, epidural space, dura, arachnoid
- off midline: needle will traverse a ligamentum flavum instead of the supraspinous and interspinous ligaments and the intralaminar space
Radiculopathies result from ___________. What are the typical symptoms?
- compression of the roots of spinal nerves in the intervertebral foramina or in the vertebral cord
- typical symptoms are pain and parasthesias (altered sensations usually in form of tingling or numbness) in dermatomes supplied by the compressed sensory roots
- may also have weakness of skeletal muscles in myotomes supplied by compressed motor roots
4 ways to cause a radiculopathy
- osteroarthritis
- spondylitis
- spondylosis
- herniated disk
Osteoarthritis
-inflammation that results in additional bone growth by osteophytes at facet joints
Spondylitis
- inflammation that results in additional bone growth by osteophytes at margins of the vertebral bodies
- anterior longitudinal ligament and SI joints may undergo calcification
What do patients with spondylitis exhibit?
-ankylosis (joint stiffening) and a “bamboo spine” (marie strumpell disease)
Spondylosis
-degenerative changes in intervertebral disks which are usually combined with additional bone growth by osteophytes at margins of vertebral bodies
Herniated disk
-exists when nucleus pulposus protrudes at the posterolateral part of an annulus fibrosis resulting in the compression of roots of lower cervical or lower lumbar spinal nerves
What roots are compressed by a herniated disk?
-those of the more inferior spinal nerve
EX: C5, C6 herniation compresses C6 roots
