In an adult there are typically 33 individual vertebrae arranged in 26 moveable parts in the spinal column

• Vertebrae– 7 cervical – 12 thoracic – 5 lumbar– 5 fused sacral– 4 fused coccygeal

The vertebral column helps to provide vertical support for the body, supports the head, aides in maintaining an upright position, helps transfer weight to appendicular skeleton, and protects the delicate spinal cord.

Cervical curvature

Thoracic curvature

Lumbar curvature

Sacral curvature

Read about spinal curvature abnormalities in clinical view in text

ACCORDING TO THE CLINICAL VIEW IN YOUR TEXT, WHAT CAN CAUSE KYPHOSIS?

A OSTEOMALACIA

B OBESITY

C PREGNANCY

D PULLING ON ROPES IN BELL TOWERS

E ALL OF THE ABOVE

The vertebral foramen is the opening through which the spinal cord passes while the intervertebral foramen allows the spinal nerves to branch off laterally.

Intervertebral foraminae allow for lateral exit of spinal nerves

There is one spinous process, two transverse processes (left and right), two superior articular processes that interlock with the vertebra above, and two inferior articular processes (not shown) that interlock with the vertebra below.

The interlocking of the superior and inferior articular processes limits the twisting of the vertebral column.

Fibrocartilage intervertebral disc

Soft pulpy core of disc is nucleus pulposus surrounded by the annulus fibrosis

Demonstration of proper way of lifting heavy loads so as to minimize injury to lower back.

Herniated disc

The seven cervical vertebrae allow for the most flexibility, and the least stability, in the entire vertebral column.

Cervical vertebrae have transverse foramenae and bifurcated spinous processes, except for C1, which has a minimal spinous process.

Whiplash of the neck

Whiplash of the neck may injure the spinal cord

Atlas supports the heavens, not the Earth.

The first cervical vertebra (the atlas) articulates with the occipital condyles of the skull on the inferior surface of the occipital bone.

Superior view of atlas. Note lack of a body, minimal spinous process (#1), superior articular processes (#3), and transverse foramen (#4).

Nodding “yes” movement made possible by articulation of occipital condyles rocking in superior articular processes of the atlas. This articulation is called the atlantooccipital joint.

Anterior view of second cervical vertebrae, the axis. Note the odontoid process (dens) labeled #5.

Anterior x- ray through open mouth. Note odontoid process (dens) of axis (#9).

Atlantoaxial joint

The atlantoaxial joint allows the atlas to pivot around the odontoid process so the head can make a side-to-side “no” movement.

Method of fracturing odontoid process (dens).

Note locations of the atlantoocipital and atlantoaxial joints.

WHICH OF THE FOLLOWING IS CORRECT ABOUT THE ATLAS?

A ITS ARTICULATION WITH THE SKULL ALLOWS SIDE-TO-SIDE “NO” MOTIONS

B ITS MOST SUPERIOR PART IS CALLED THE DENS

C IT ARTICULATES WITH THE TEMPORAL BONE

D IT HAS A PROMINENT SPINOUS PROCESS, HENCE THE TERM “VERTEBRA PROMINENS”

E IT HAS HOLES IN ITS TRANSVERSE PROCESSES

The spinous process of C7

(vertebra prominens) is an easily palpable prominence felt at the base of the neck.

The classical hangman’s fracture of the cervical vertebrae severs the spinal cord. The large knot is typically positioned just behind the left ear.

The thoracic vertebrae serve as attachments for the ribs so as to form the posterior anchor of the thoracic cage.

Thoracic vertebrae have costal facets or costal demifacets on their bodies and transverse processes for attachment of the ribs

Note ribs attach to bodies and transverse processes of thoracic vertebrae

Lumbar vertebrae have massive bodies and thick blunt spinous processes. They are the largest vertebrae of the spinal column.

(L3 and L4)

The L3/L4 intervertebral space is level with the iliac crests of the pelvis

The sacrum consists of five fused vertebrae. The sacrum atriculates with the ilia of the pelvis.

The sacrum articulates with L5 superiorly, with the bones of the os coxae laterally, and with the coccyx inferiorly.

The coccyx consists of four fused vertebrae

Human tails rarely occur and are easily removed surgically.

The coccyx is easily fractured, particularly by Master Long.

Palpation of fractured coccyx by inserting index finger in the rectum and applying pressure.

Childbirth can injure both the perineum and the coccyx

coccyx

WHICH OF THE FOLLOWING ARTICULATES WITH THE BONY PELVIS (OSSA COXAE)?

A COCCYX

B L5

C SACRUM

D AURICLE

E NONE OF THE ABOVE

The thoracic cage is formed by thoracic vertebrae, ribs, costal cartilages, and sternum

Contents of thoracic (chest) cavity.

(gladiolus)

Sternum

Costal notches for rib attachment

(Sternal notch)

Suprasternal fossa is just superior to jugular notch (sternal notch). Note large rope-like muscles that form lateral boundaries of suprasternal fossa.

(gladiolus)

Sternum

Costal notches for rib attachment

(Sternal notch)

Sternal angle

Read about sternal foramina in the clinical view in your text.

Xiphoid process

Master Long knows where your heart is located!

An upward and inward blow to the xiphoid can fracture it off and drive it into the heart (a directly inward blow will drive it into the liver)

Master Long delivering the potentially fatal blow to his opponent’s xiphoid.

Human sacrifice in Central America

Human sacrifice in Central America. Note the sacrificial altar that is reminiscent of a USU parking barricade. This allows the victim to be bent backwards.

A curious mind might ask why Utah State University chose this particular design for use around the campus as a traffic barricade? Was it just by mere chance that it mimics the design of sacrificial altar stones of Aztecs?

I urge caution if you should see wild-eyed and bare-breasted collegians with red stained hands! (or with runny cheeseburgers)

Ribs #1-7 are “true ribs” and are directly attached to the sternum. Ribs #8-10 share the costal cartilage attachment of rib #7, while ribs #11-12 don’t attach anteriorly at all. So ribs #8-12 are also called “false ribs.”

Posterior view

Ribs #11 and #12 not only are false ribs, they are also floating ribs because they have no attachment to the sternum whatsoever

Shaft or

Typical rib

Cervical rib on C7

Elongated transverse processElongated transverse process on C7

Read about variations in rib development in clinical view in text

IF A WANDERING BUG STARTED ON THE OCCIPITAL BONE OF A SKELETON, TRAVELED DOWN 18 VERTEBRAE, AND THEN MOVED ANTERIORLY ALONG A BONE, WHAT BONE WHOULD THE BUG BE WALKING ON?

A FLOATING RIB

B FALSE RIB

C BONE WITH NO COSTAL CARTILAGE

D BONE OF THORACIC CAGE

E ALL OF THE ABOVE

Christopher Reeve in his role as Superman

Christopher Reeve became a famous respirator-dependent quadriplegic

Christopher Reeve eventually died from an infection that began in a diseased bed sore (decubitus ulcer). He did much to promote research in treatment for spinal injuries.

There are many ways to suffer a flail chest. One is shown here.

Paradoxical motion occurs when the fractured segment of ribs moves in a direction that is opposite from the rest of the chest wall when the injured person inhales or exhales.

Paradoxical motion

Spina bifida

• Spina bifida is caused by a failure of the neural tube to close completely during the first month of embryonic development

Infants born with spina bifida are typically paralyzed distal from the defect.

Chiropractors have been shown to statistically have the best success with most lower back pain. More so than other healthcare providers.

Abdominal crunches that flex the spine strengthen the anterior muscles (such as the rectus abdominus) that help stabilize the spine

Arching or extension of the spine strengthens the posterior muscles (such as the erector spinae muscles) that help stabilize the spine.

Back surgery should be the last resort as outcome is uncertain.

WHICH OF THE FOLLOWING HAS BEEN SHOWN TO REDUCE THE RISK OF NEURAL TUBE DEFECTS, SUCH AS ANENCEPHALY?

A B VITAMIN

B SUNLIGHT

C VITAMIN A

D FOLIC ACID WITHIN THE FIRST WEEK AFTER BIRTH

E ACCUPUNCTURE

• This data indicate that since the addition of folic acid in grain-based foods as mandated by the Food and Drug Administration, the rate of neural tube defects dropped by 25% in the United States.