Functional Anatomy 3rd exam

the end is in sight lads

Anatomical factors influencing curves of the spine

Wedge-shaped discs or bodies, Spatial orientation of apophyseal joints, Tension in ligaments, Degree of natural muscle stiffness

Line of gravity (promotes ideal posture)

passes near mastoid process, anterior to 2nd sacral vertebrae, knee and ankle, and posterior to hip

Factors affecting the spatial relationships between the Line of gravity and spinal curves

Fat deposition, specific shapes of regional spinal curvatures, static posture of the head and limbs, muscle strength, connective tissue extensibility, position and magnitude of loads supported by the body

Borders of vertebral foramen

anterior: body and disc, lateral: pedicle, posterior: lamina and ligamentum flavum

Lateral Recess

medial to intervertebral foramen, clinically an area of nerve root impingement, exclusive to lumbar region

Lateral recess borders

Anterior: body and annulus Superior / inferior: pedicles Posterior: ligamentum flavum and anterior facet capsule

Three components of intervertebral junction

AKA motion segment. transverse and spinous processes, apophyseal joints, interbody joint

Fucntion of interbody joints (23 joints)

force dissipation, promotes stabilization and mobility throughout the vertebral column

Combined heights of intervertebral disc accounts for ______ %

20-33

Intervertebral discs dynamic, day vs night

compression dehydrates disc during day, release during night causes imbibition (swelling) —> taller in the morning

Nucleus Pulposus

15-20 percent type ii collagen, allows disc to act as a modified hydraulic shock

Annulus fibrosus

Type 1 and Type 2 collagen makes up 50-60 percent of dry weight, constrain nucleus during compression —> increased hydrostatic pressure

End plate

thin cartilaginous caps that adhere discs to bodies and promote diffusion of nutrients

Extent and magnitude of compression depends on

amount of applied compressive force, disc height, cross-sectional area of disc

Disc height variations

Primary - age, gender, height Secondary- extrinsic, degeneration, abnormality, etc.

Intradiscal Pressure Study findings

Disc pressures large holding load in front of body even larger bending forward, Knee flexed lifting load less pressure on lumbar disc than knees straight, forward slouch = greater pressure than sitting erect

Zygapophyseal - Apophyseal - Facet

24 pairs, permit certain movements, prevent others

L1 - L4 region

most apophyseals oriented vertically

L5-S1

Interbody joint anteriorly, pair of apophyseal joints posteriorly

Lumbar spine motions

three degrees of freedom, facet joints oriented sagitally

Normal strategy of lumbopelvic rhythmn

40 deg flexion of lumbar spine and 70 deg hip flexion

Posterior Pelvic Tillt (and vice versa)

flexes lumbar spine, decreases lordosis, shifts nucleus posteriorly, increases diameter of intervertebral foramen

SI joint

modified synarthrodial joint, provides pelvic ring stress relief, stable means of load transfer

nutation vs. counter nutation

both are a simultaneous movement of pelvics, but nutation consists of iliac crest shifting posteriorly

Sacroiliac articular joint surfaces

Iliac - fibrocartilage, thin (0.5 mm), bluish, dull, rough Sacral surface - hyaline cartilage, thick (3mm), white, shiny, smooth

Thoracolumbar Fascia purpose

approximates spinous processes, increases intra-abdominal pressure, creates a ridged column due to muscular activation

Functions of thorax

stable base of muscles to control craniocervical region, protection, breathing

Thoracic Vertebrae Typical vs. Atypical, contact points

Typical (T2-T9), Atypical (1,10,11,12), 20 contact points - 2 other vertebrae via discs (synchondrosis) and zygapophyseal joints, 4 ribs via costovertebral and costotransverse joints, 4 sternocostal and costochrondral joints

Thoracic facet joints are oriented in the ____ plane

frontal

Bucket handle vs. Pump Handle

increase in transverse diameter vs. Increase in sagittal diameter

Muscles of forced inspiration

serratus posterior superior and inferior, levator costarum, scm, lat, iliocostalis thoracis and cervicis, pec major and minor, quad lumborum

Muscles of forced expiration

rectus abdominis, io, eo, ta, transversus thoracis, intercostales interni

Cervical vertebrae, Typical vs. atypical, special connection(s)

Typical - C3 - C6 (lower cervical), Uncinates at C3-C7, superior + inferior processes = articular pillar

Atlas C1 inferior articular facets face… so axis

inferior-medial, 20 deg from horizontal plane so axis superior-lateral 20 deg

Atlanto-occipital joint provides _________________ of the cranium relative to the atlas

independent movement

Posteriorly C0-C1 joint is covered by a thin, broad _______________ and _________ pierces it to enter foramen magnum

Posterior atlantooccipital membrane, vertebral a.

Function of Atlanto-occipital joint

provide independent movement of the cranium relative to atlas, convex on concave

Protraction vs. retraction

upper cervical extension and lower cervical flexion and vice versa

Atlanto-axial joint (C1-C2)

pivot joint, smaller anterior cavity, larger posterior cavity

Atlanto-axial joint

pivot joint 2 degrees of freedom, acts as as a spacer between cranium and axis, flexion is simply tilt forward, axial rotation takes curved path

Upper cervical spine exhibits _________ coupling

contralateral

Lower cervical spine is a

five-link kinematic chain: 2 zygapophyseal, 2 uncovertebral, 1 intrabody - disc

In the lower cervical spine, generally

anterior margin of disc attaches to ALL

Average joint angulation from horizontal plane of Zygapophyseal joint

upper = 35 middle = 45 lower = 65, clinically imagined as vertically through a patients nose

Lower cervical spine orientation and coupling

facets are halfway between frontal and horizontal plane at 45 deg, ipsilateral