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