Thoracic Spine Anatomy Overview

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Questions and Answers

What is the primary purpose of the structures mentioned in the content?

To enhance strength

To offer relief (correct)

To improve flexibility

To promote balance

Which of the following is associated with frontal plane deviation?

Pelvic tilt

Structural scoliosis (correct)

Hip abduction

Shoulder elevation

Which plane is mentioned as having the vertebrae that should be fairly vertical?

Frontal plane (correct)

Transverse plane

Sagittal plane

Oblique plane

What issue is likely to occur due to compression in the left side?

Left IV foraminal issues Signup and view all the answers

What type of studies show disagreement about coupling patterns?

Movement coupling studies Signup and view all the answers

Which structure mentioned is positively affected by the passive mechanisms?

Ligaments Signup and view all the answers

What condition is commonly known as T-spin in the context of movement?

Frontal plane deviation Signup and view all the answers

What is likely compressed according to the study of aorta mentioned?

Left IV Signup and view all the answers

What is the primary role of the parasternals in respiration?

Stabilizing the rib cage Signup and view all the answers

Which muscles are primarily responsible for elevating the 1st and 2nd ribs?

Scalene muscles Signup and view all the answers

How does motion in the thoracic region impact respiration?

It is critical for vital functions such as respiration. Signup and view all the answers

What happens to the forces acting on the spine due to abnormal postures?

They can significantly alter due to changed dynamics. Signup and view all the answers

Which structure is located in the scalene interval?

Brachial plexus and subclavian artery Signup and view all the answers

What is the primary function of the thoracic cage?

To protect the heart and lungs Signup and view all the answers

What aspect of the thoracic spine contributes to its stability?

Minimal mobility at individual segments Signup and view all the answers

In which thoracic region is rotation the dominant motion?

Upper thoracic region Signup and view all the answers

What shape is the thoracic vertebrae in the transverse plane?

Heart-shaped Signup and view all the answers

Which ligament provides support to the anterior aspect of the vertebral column in the thoracic spine?

Anterior longitudinal ligament Signup and view all the answers

What is the surrounding structure that supports the thoracic spine under compressive loads?

Thoracic cage Signup and view all the answers

Which joint is formed by the articulation between the ribs and thoracic vertebrae?

Costovertebral joint Signup and view all the answers

Which of the following describes the facet orientation in the upper to mid thoracic spine?

Oriented between transverse and frontal planes Signup and view all the answers

What is indicated if tissue pain is perceived during a strain of the Erector Spinae?

A non-contractile issue might be present. Signup and view all the answers

What kind of mobility do multiple thoracic segments exhibit when moving in concert?

Larger range of motion Signup and view all the answers

What happens to torque as the thoracic kyphosis increases?

Torque increases progressively. Signup and view all the answers

What does the normal movement of the thoracic spine primarily involve?

Extensive rotation Signup and view all the answers

Which statement best describes the condition of tissues during strain?

The condition may affect non-contractile tissues. Signup and view all the answers

What effect does straining the Erector Spinae have on pain perception?

It may increase pain if non-contractile tissues are involved. Signup and view all the answers

How does increased thoracic kyphosis affect the overall kinetic function?

It decreases mechanical advantage. Signup and view all the answers

Which of the following statements about tissue tension is accurate during strain?

Non-contractile tissues might not generate sufficient tension. Signup and view all the answers

What might indicate a significant issue during an Erector Spinae strain?

Persistent muscle contraction. Signup and view all the answers

What role does torque play in relation to the body's kinetic function?

Torque influences body movements and mechanics. Signup and view all the answers

What occurs when the ribs are elevated in the sagittal plane?

Increases the anteroposterior dimension of the thorax Signup and view all the answers

What is the result of torsion in rib motion during ventilation?

Allows for energy storage and elastic recoil Signup and view all the answers

How does the descent of the diaphragm affect intraabdominal pressure?

Increases intraabdominal pressure Signup and view all the answers

What impact does spinal cord injury have on abdominal musculature and compliance?

Increases compliance in pre-existing conditions Signup and view all the answers

Which condition tends to decrease abdominal wall compliance?

Pregnancy and abdominal obesity Signup and view all the answers

What is the primary function of the diaphragm during inspiration?

To create negative pressure in the thoracic cavity Signup and view all the answers

What happens to the lower ribs during the bucket handle action of respiration?

They move laterally during expiration Signup and view all the answers

In patients with Chronic Obstructive Pulmonary Disease (COPD), how does the diaphragm's contraction affect lung volume?

Decreases lung volume despite contraction Signup and view all the answers

Which anatomical motion occurs in both the frontal and sagittal planes in lower ribs?

Both elevation and lateral movement Signup and view all the answers

What happens to the muscle fiber orientation in hyperinflated lungs?

Muscle fibers are oriented horizontally Signup and view all the answers

Study Notes

Thoracic Spine Overview

Most stable vertebral region due to long spinous processes, thoracic cage articulations, numerous ligaments, and facet joints.
Longest vertebral region, minimal individual segmental mobility, but multiple segments moving together allows for larger ROM.
Serves as a stable base for head and arms, supporting upper extremity movements.
Provides protection for the spinal cord and internal organs.

Thoracic Cage

Composed of thoracic vertebrae, 12 pairs of ribs, and sternum.
Functions in:
- Protection of heart and lungs.
- Flexibility for respiration and spinal motion.
- Supporting the entire thoracic spine, able to sustain 4x compressive load with intact cage; without cage, T/S vertebrae alone would struggle to support head weight.

Thoracic Spine - Facet Orientation

Upper to mid thoracic:
- Between transverse and frontal planes, similar to lower cervical facets.
- Dominant motion is rotation in upper and mid thoracic region.
- Ribs limit side bending and rotation.
Mid to lower thoracic:
- Oriented more in sagittal plane, similar to upper lumbar facets.
- Flexion/extension bias.

Thoracic Vertebrae Shape

Sagittal plane: wedge-shaped, contributing to normal kyphosis.
Transverse plane: heart-shaped.

Key Thoracic Joints

Intervertebral discs (IVDs): provide shock absorption and flexibility.
Costovertebral joints: articulation between ribs and vertebrae, allowing for rib movement during respiration.
Costotransverse joints: articulation of ribs with transverse processes, supporting rib movement.
Costosternal joints: articulation of ribs with sternum, contributing to chest expansion during breathing.

Key Support Structures

Anterior longitudinal ligament (ALL): runs along the front of the vertebral bodies, providing stability and preventing hyperextension.
Posterior longitudinal ligament (PLL): runs along the back of vertebral bodies, limiting flexion.
Ligamentum flavum (LF): connects vertebral laminae, providing elastic support.
Intertransverse ligaments (ITL): connect transverse processes, stabilizing the spine.
Interspinous ligaments (ISL): connect spinous processes, limiting flexion and rotation.
Supraspinous ligaments (SSL): connects spinous processes, providing additional support.

Normal Thoracic Movement

Passive structures are elongated during extension, including the PLL and SSL.
Vertebrae in frontal plane should be fairly vertical.
Vertebral motion is coupled, but studies disagree on specific patterns.

Thoracic Scoliosis

Scoliosis in the frontal plane can affect aorta location and potentially compress it.
Scoliosis can impact the left intervertebral foramen and left IVD compression, potentially causing pain and muscle spasms.
Pain on the right side could involve non-contractile tissue and could potentially indicate a nerve issue.

Normal Kinetics

Thoracic kyphosis is largely due to the wedge-shaped vertebrae.
The axis of rotation for kyphosis is going backward due to the moment of inertia of the head, increasing the flexion torque created by the muscles.

Kinematics of Ventilation

Rib Motion
- Elevation in sagittal plane increases anterior-posterior dimension of the thorax.
- Elevation in frontal plane increases the transverse dimension of the thoracic cage via lateral rib movement.
- Both frontal and sagittal plane motion occurs in lower ribs.
- Torsion allows for energy storage & release during exhalation without muscle contraction, relying on elastic recoil of connective tissues.

Mechanics of Ventilation - The Diaphragm

Diaphragm descent increases intra-abdominal pressure, stabilizing the central tendon of diaphragm.
Continued costal fiber contraction creates "bucket handle" action in lower ribs.
Diaphragm contraction pulls downward and increases the chest cavity volume.
Increased intra-abdominal pressure necessitates abdominal muscle contraction for stability.

Normal Mechanics of Inspiration

Normal compliance of the abdominal wall is vital for efficient inspiration.
Conditions that increase abdominal wall compliance (spinal cord injury, pregnancy, obesity) can make efficient breathing more challenging.
Conditions that decrease compliance (pregnancy, abdominal obesity) increase tension in abdominal tissues due to over-elongation.

Pulmonary Conditions - Diaphragm Function

Hyperinflated lungs (COPD) flatten the diaphragm, altering muscle fiber orientation and potentially decreasing thoracic cavity size with diaphragmatic contraction.
Diaphragmatic fibers are oriented horizontally in chronically hyperinflated lungs.

Intercostal Muscles

Intercostal muscles are activated from cranial to caudal.
Lower intercostals are typically activated during deep inspiration.
Primary function of parasternals is probably stabilizing the rib cage

Scalene Muscles

Play a role in elevating the first and second ribs and the sternum, creating the “pump handle” motion.
Anterior and middle scalenes attach to the first rib.
Posterior scalenes attach to the second rib.
The scalene interval houses the brachial plexus and subclavian artery.

Conclusion: Thoracic Spine Importance

Thoracic region has subtle, yet critical, motion for respiration and overall function.
The entire thoracic cage and its joints contribute to complex motion.
Abnormal postures can significantly alter forces on the spine.

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Description

Explore the fundamentals of the thoracic spine and its components, including the thoracic cage and facet orientation. This quiz covers stability, mobility, and the protective functions of this crucial vertebral region. Understand how the thoracic spine supports upper body movement and protects vital organs.