Module 2: The Back
how are the cervical vertebrae characterized?
by their small size and by the presence of a foramen in each transverse process.
Spinal cord blood supply
-longitudinally oriented vessels arising superior to the cervical portion of the cord, which descend on the surface of the cord ~single anterior spinal artery: originates within cranial cavity as the union of 2 vessels that arise from the vertebral arteries ~2 posterior spinal arteries: originate from cranial cavity -feeder arteries (AKA segmental spinal arteries) that enter the vertebral canal through intervertebral foramen at every level; arise mainly from the vertebrae and deep cervical arteries in the neck ~posterior intercostal arteries in thorax ~lumbar arteries in abdomen
3 routes deoxygenated blood can leave spinal cord via veins:
1. via 2 pairs of veins on each side of cord, connected to intervertebral plexus in the extradural space 2. via anterior spinal vein, runs parallel to the anterior median fischer 3. via posterior spinal vein, runs parallel to the posterior medial sulcus
The number of thoracic vertebrae is: 5 7 10 12
12
A typical vertebra has a total of __ joints how many synovial and symphysis?
6 joints with adjacent vertebrae: 4 synovial joints (two above and two below) and 2 symphyses (one above and one below). Each symphysis includes an intervertebral disc.
articulates with the head and its major distinguishing factor is that it lacks a vertebral body
Atlas (C1)
known by the dens that project superiorly from the vertebral body and is held in place by a strong transverse ligament of the Atlas (C1)
Axis (C2)
The dens is found on the first cervical vertebra or atlas. True or False
FALSE
The five sacral vertebrae remain separate until about 40 years of age; at that point they fuse to form one wedge-shaped bone. True or False
FALSE
Segmental back muscles -Subdivisons -Function
Interspinales - stabilize adjoining vertebrae during movement of vertebral column Intertransversaraii - samd as interspinales Levatores Costarum - elevates the ribs -Deepest of the deep back muscles
Where does the spinal cord end?
L1-L2 vertebrae
suboccipital muscles
Obliquus capitis superior - extends the head and bends it to the same side of the muscle that is contracting Obliquus capitis inferior - rotates the face to the same side that is contracting Rectus capitis posterior major - extends the head and rotates the face to the same side of the muscle that is contracting Rectus capitis posterior minor - extends the head
A "slipped disk" is the result of deterioration of the annulus fibrosis. True or False
TRUE
A dermatome is the skin surface area supplied by a single spinal nerve. True or False
TRUE
A physician can use a lumbar puncture to withdraw cerebrospinal fluid from the subarachnoid space in the lumbar region of the spinal cord. True or False
TRUE
All spinal nerves are mixed nerves. True or False
TRUE
Even though there are only seven cervical vertebra, this region generates eight cervical nerves. True or False
TRUE
Examining the spine from its posterior side, the normal curvature is convex through the thoracic region and concave through the cervical and lumbar regions. True or False
TRUE
The sacral plexus is found deep within the shoulder. True or False
TRUE
The vertebral column contains both cartilaginous joints and synovial joints. True or False
TRUE
are the discs between vertebrae considered joints?
YES
Functions of Erector Spinae Muscles
all act bilaterally to straighten back, returning to upright position from flex position and pull head posteriorly help control vertebral column flexion by contracting/relaxing in a coordinated way they unilaterally bend the vertebral column laterally and turn the head to the actively contracting side
List the 5 sections of the vertebral column.
cervical - in neck, 7 vertebrae thoracic - in thorax/rib region, 12 vertebrae lumbar - in lower back, 5 vertebrae sacrum - below lumbar, 5 vertebrae coccyx - below sacrum (tail bone), 4 vertebrae
What is NOT a part of the axial skeleton? rib vertebral column mandible clavicle
clavicle
During development, the vertebral column grows much faster than the spinal cord. As a result, the spinal cord ...
does not extend the entire length of the vertebral canal
superficial to deep structures of spinal cord:
extradural space dura mater (1st membrane around spinal cord) subdural space arachnoid mater subarachnoid mater (contains cerebral spinal fluid) pia mater spinal cord
vertebrae (except sacrum and coccyx) are separate bones separated by intervertebral discs made of a flexible form of cartilage called:
fibrocartilage
define transverse process and function
function as site of attachment for muscles and ligaments of the spine, and point of articulation for ribs and thoracic region looks like horns/arms jutting from pedicle
erector spinae group
iliocostalis lumborum, thoracis and cervicis longissimus thoracis, cervicis and capitis spinalis thoracis, cervicis and capitis
where are the largest vertebrae?
in lower back responsible for bearing bulk of weight
Each spinal nerve exits the vertebral canal laterally through
intervertebral foramen
The ligamenta flava is located in the: shoulder hip knee none of the above
none of the above
define pedicles
on the posterior side of the vertebrae and attach the vertebral arch to the vertebral body
Vertebral bodies are connected together by the: ligamenta flava ligamentum nuchae posterior longitudinal ligament intertransverse ligaments
posterior longitudinal ligament
Which vertebrae are fused and when does this occur?
sacrum and coccyx during embryologic development
define extradural space
same thing as epidural space sits around spinal cord where there's los of padding via adipose tissue
Lateral curvature of the spine is called: scoliosis lordosis kyphosis convexity
scoliosis
Transversospinalis muscles
semispinalis thoracis, cervicis and capitis multifidus rotatores thoracis, cervicis and lumborum
If the dorsal root ganglia of the spinal nerve were destroyed, a person would lose: sensory input to the CNS related to that pathway willed movement related to the pathway reflex activity only, related to that pathway both reflex activity and sensation related to that pathway
sensory input to the CNS related to that pathway
intermediate (respiratory) group of back muscles
serratus posterior superior serratus posterior inferior
Spinotransversales muscles of the back
splenius capitis splenius cervicis
Functions of the back
support, movement, protection
two major types of JOINTS between vertebrae:
symphyses between vertebral bodies synovial joints between articular processes
A way to distinguish between the anterior and posterior part of the spinal cord is: the dura mater is thickest on the posterior side the posterior fissure is deeper and wider than the anterior fissure the anterior fissure is deeper and wider than the posterior fissure a and b are correct
the anterior fissure is deeper and wider than the posterior fissure
Which of the following is NOT true? The spinal cord completely fill the vertebral canal The spinal cord extends from the foramen magnum to the first lumbar vertebra One bundle of nerve fibers (nerve roots) projects from each side of the spinal cord The spinal cord has anterior and posterior grooves that almost divide the cord into symmetrical halves
the spinal cord completely fill the vertebral canal
what do the superior and inferior articular processes articulate with?
the vertebrae above and below them
Which of the following is not a plexus of the spinal nerves? cervical brachial lumbar thoracic
thoracic
function of transversopinalis muscles
to extend the vertebral column BUT when muscles on only 1 side contract they pull the spins process towards the transverse processes on that side, causing the trunk to turn/rotate towards that direction
Superficial group of back muscles
trapezius and latissimus dorsi, with rhomboid major, rhomboid minor, and levator scapulae located deep to trapezius in the superior part of the back
All vertebrae, except the sacrum and coccyx, have a central opening called the: spinous process vertebral foramen dens transverse process
vertebral foramen