Module 05 - Back and Axila Flashcards
What is the sacrum
Large bone located at the terminal part of the vertebral column where it form the posterior aspect of the bony pelvis
Why is the sacrum remarkably thick?
It aids in supporting and transmitting the weight of the body
What is the sacrum composed of?
the 5 fused sacral vertebrae
What does the sacrum articulate with?
The fifth lumbar vertebra (L5) at its base
What is the sacral canal?
continuation of the vertebral canal terminating at the sacral hiatus
What are the sacral foramina?
There are 4, located lateral to the fused sacral bodies on both the anterior and posterior surface. The foramina decreased in size as you go inferior. (Most superior is the largest)
What are the sacral cornua?
there are 2, they are bony processes and are palpated by clinicians as an anatomical landmark when administering injections into the sacral hiatus
What is the promontory?
It the anterior face of the sacrum. It articulates superiorly with the L5 vertebral body. It projects forward and functions to decrease the anteroposterior diameter of the pelvic brim
Why is the sacral promontory of considerable obstetric importance?
Used when measuring the size of the pelvis
What is the coccyx?
It is made of four fused rudimentary coccygeal vertebrae. It articulates with the sacrum superiorly at the sacrococcygeal joint.
Much smaller in size than the sacrum
serves as an attachment site for ligaments and muscles, such as the muscles of the pelvic floor
A small and variable amount of flexion and extension occurs at the sacrococcygeal joint, especially when sitting
What is the sacrococcygeal joint?
Joints that articulate the sacrum and coccyx
What movements is the sacrococcygeal joint capable of?
Small and variable amount of flexion and extension
Neutral in standing position
Flexion (towards the body) when sitting
Moving superior to inferior down the vertebral column, the noticeable trends of the vertebrae are:
Vertebral body size increases
Vertebral Foramen size decreases
Why does the size of the vertebral body increases when moving superior to inferior down the vertebral column?
To support increasing weight
Why does the size of the vertebral foramen decreases when moving superior to inferior down the vertebral column?
To support the spinal cord diameter decreasing as spinal nerves exit to their respective regions of the body
What are accessory ligaments of the vertebral column and what is their function?
Strong fibrous bands of tissue that stabilize the vertebral column and protect the intervertebral discs
Involved in movements of flexion and extension of the back
What are the 3 major accessory ligaments of the vertebral column?
Ligamentum flavum
Anterior Longitudinal ligament
Posterior longitudinal ligament
What is lumbar stenosis?
Narrowing of the vertebral canal in the lumbar region
May be caused by calcification of the ligamentum flavum or bone outgrowth
It compresses the spinal cord which can cause numbness and weakness in the lower limb
What are the 5 extrinsic muscles of the back?
Latissimus dorsi Trapezium Rhomboid minor Levator scapulae Rhomboid major
Describe the location and anatomy of the latissimus dorsi
Broad, triangular-shaped extrinsic muscle of the back. It covers the lumbar region and inferior portion of the thoracic cage.
It has multiple points of origin and, as such, has varying muscle fiber directions
it inserts at the intertubercular sulcus (bicipital groove) of the humerus
What is one of the largest point of origin of the latissimus dorsi (for this course)?
Thoracolumbar fascia
broad fascial sheath
What is the function of the latissimus dorsi?
Extends, adducts and medially rotates the arm