anatomy lec 5

8/3/2019 Anatomy Lec 5

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We finished with the bony part of the head which was the skull ,,today wewill speak about the bony framework in the neck ,,which is made by the cervical vertebrae

and as you all know that the cervical vertebrae are part of the vertebral column

,,vertebral column is made up of 33 vertebrae ..

they are divided into :

- 7 in the cervical region

- 12 thoracic

- 5 lumbar

- 5 sacral

- 4 coccygeal

The last two the sacral & coccygeal >> they usually fuse with each other ,,the sacral 5

vertebrae fuse to form the sacrum ,,& the coccygeal fuse to form the coccyx ..

So our lecture today will be related to those 7 cervical vertebrae ,,before we start we

have to know some general information about vertebral column to understand the

formation & the shape of cervical vertebrae ,,when we look to the vertebral column

development during fetal period as the fetus is sleeping over itself so the all vertebral

column will be carved more anteriorly (y3ne concave anteriorly ) ,,this is what we refer to

it as the primary curvature of vertebral column ( ) > when the kid start to left his head up


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**lumbar >> when the kid start to stand up on his legs

SO the primary curvatures remain after birth in two areas :

in the thoracic region it still concave anteriorly

in the sacral region ( pelvic region sacrum + coccyx) concave anteriorly

**thoracic & sacral (pelvic) >> PRIMARY curvatures

**cervical & lumbar >> SECONDARY curvatures

So the 7 cervical vertebrae are primary or secondary ?

secondary :)

In addition to these two normal curvatures,, they are normal because of the

resilience of the vertebral column ,,it must be resilience (mshan ysma7 b7rket

ljethe3)>> tlef ymen shmal tn7ne..

In addition to these normal there could be some abnormal curvatures ,, abnormal

m3nato yntoj bsabb developmental anomaly aw bsabb pathological process ,, (fe

mr9 adda lha aw fe anomaly genetic abnormalities ) lead to this kind of abnormal

curvatures..

Abnormal curvatures mainly 3 :1- Kyphosis ( ) ,,increase in thoracic curvature(hunch

back) bsabb t2akl al26raf alamamyeh mn lthoracic vertebrae,, there will

be an erosion of anterior part of the vertebrae in the thoracic region..

**this is because of osteoporosis (pathological process ) ,,

( ),,its mainly happen in the geriatric people(oldpeople)

2- Lordosis ,,increase lumbar curvature (secondary),, lmma bzed bsmohhollow back ,, hollow >> fa9e ,, the back of the patient is too much

concave posteriorly ..

Can be seen in temporary cases as in late pregnancies in women >> weight

of the fetus is very heavy producing pressure on the vertebral column


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increasing this kind of curvature temporary lordosis because after

delivery it will be demolished ..

also it can be seen in some people whose suffering from muscular weakness

>> especially in the anteriolateral abdominal muscles external oblique,

internal oblique, transverses abdominus those muscles come fromvertebral column all the way back then turn anteriorly to reach the rectus

abdominus muscle ,, homeh hdol shadat lvertebral column

>> when those muscles become weak they will relax paralysis r7 yr5o l

pulling of the vertebral column ,,so the vertebral column goes more

anteriorly ..

3- Scoliosis (curved back) : jeha a6wal mn jeha bl vertebral column ,,fbkon**** (sorry cant hear) patient..

for many causes :

** developmental anomaly : half of the vertebrae didnt developed .

** asymmetric paralysis : in one side of the intrinsic path muscles 39lat

shadeh l3mod lf8re ,, one side is paralysis so bn7ne to the opposite side .

** difference in the lengths of the lower limbs .

SO vertebral column is made up of 33 vertebrae & the joints between

them called secondary cartilaginous becausethere isintervertebral discsmade of fibrocartilage ,, located between each vertebrae & another ..

Intervertebral disc is very important because its function is shock

absorption ,,when we look at it superiorly it is made up of two parts :

1-Annulus fibrosus (fibrous) :external part 9lb jdn fibrocartilagenous ,,lefe

annulus >> da2re ,, concentric >> 7l8at ,,fibrosus >> fibrous

SO concentric layers of fibrocartilage to strengthen the disc .

2- Nucleus pulposus (gelatinous):

Inernal pulp of the disc made of gelatinous material( ) ,, nucleus pulposus located in this area is emptybecause we have open in the disc ,, it is the central core ofthe disc &moreelastic because of watery content (high water content)SO nucleus pulposus is the main part of shock absorption .


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SO the intervertebral disc btkawn mn 2 parts

annulus fibrosus & nucleus pulposus fra3 kamel y7twe madeh hlamyeh

Disc herniation : mar9 ldesk

Tearing in annulus fibrosus >> as a result the nucleus pulposus will bedrains out of the annulus fibrosus ..

**the disc anteriorly is made of a very thick layer of annulus fibrosus

however the posterior layer is thinner >>

Fl2shal etha 9ar tmzo8 bkon posteriorly so the herniation will happen

posteriorly ,,then nucleus pulposus will start to leak posteriorly where

there is the vertebral canal which contain the spinal cord ,,,,

SOO when the nucleus pulposus enter the vertebral canal it will pressure

on the spinal cord it will produce pain on the nerve that originating from

that area of the spinal cord .

Herniation usually happened between L4-L5 & L5-S1 >> because they are

the last two discs & most of the weight on them..

kl ma zad lwzen zad l pressure 3l disc wzad l ability eno ytmz8 l annulus

fibrosis

**why there are NO discs between the sacral vertebrae ?

Because they are fused & form the sacrum ,, they all as one piece ofbone .

SO the last disc is between L5 S1 .

Sciatic nerve originated from L4,L5,S1,S2,S3

Sciatica : 3er8 lnesa

Is happened because of pain in the sciatic nerve root ,, that pain is usually

happened because of disc herniation to L4-L5 OR L5-S1 the pain extend

from the back to the lower limbs

IVLigaments (intervertebral ligaments) :

To FIX the vertebrae & the discs in their positions ,,there are ligaments

supporting the vertebral bodies & ligaments supporting the vertebral

arches .


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Structure of the vertebra fe elha body mn lamam wby5tlf mn mn68a

lmn68a ,,rectangular in cervical ,, arch shape in thoracic ,, kidney shape in

lumbar ..

Behind the body there is arch composed of 2 pedicels & 2 laminae ,,over

them there are 7 processes: 2 transverse, 1 spinous , 2 sub articularprocesses , 2 inf articular processes

Ligaments between Vertebral Bodies :

1. Ant. longitudinal ligament:mn alamam 3la 6ol l3mod lf8re ,, its very strong & broadband (3re9)

,,3la 6ol l anterior surface of the vertebral column from up to down

2. Posterior longitudinal ligament:very narrow ligament posteriorly ,,on the middle aspect of the post.

vertebral bodies ,, ant. Ligament is stronger than post. Ligament .

Ligaments between arches & processes:

1. Ligamentum flavum:

Or flavae aktr mn wa7d

flavum mean yellowish >>because it has

elastic connective tissue mren ,, between the laminae of the

vertebra above & below .

2. Intertransverse lig. :

Between transverse process above & transverse process below .

3. Interspinous lig. :

Between spinous processes .

4. Supraspinous lig. :

On the tip the spinous processes,, between tips of spines .

2 lig. For bodies & 4 lig. For arches

**there is additional lig. ONLY in the cervical region :

5. Nuchal Ligament : or ligamentum nochaeNucha is French word means the back of the neck

Occipit is the back of the head

So this ligament as you see it here its located in the back of the neck

bnzel mn lskull from external occipital protuberance n86a wa97a jdn

fe nhayt lra2s


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Bebda mnha l nuchal lig. Wbenzel 3la 6ol lmnt9af tb3 l occipital bone

external occipital crest OR median nuchal line

SO it extend from external occipital protuberance & median nuchal line

,,,benzel all the way down wbrtabet m3 el supraspinous lig. Bs

bmn6e8et l cervical ,,,It merge with the supraspinous lig. Of the cervical region l7d C7

bynthe 3nd C7

Nuchal lig. >>> support the cervical vertebrae because they are small in

size post.

Cervical Vertebrae :

7 cervical vertebrae we classify them to typical & atypical upon to

specific characteristics as the ribs

4 main characteristics to classify the typical vertebrae if we miss one

of them it will be considered atypical ,,

Atypical vertebrae :

C1 the Atlas

C2the Axis

C7

Typical vertebrae :

C3 , C4 , C5 , C6

**Because they have :

1-rectangular shape body

2-transverse foramina

ft7at on the transverse

processes

Bifid : 2 heads ONLY exception is C7 it has

Long process & unifid (short bifid spinous process

3-short bifid spinous process

Bifid : 2 heads ONLY exception is C7 it has

Long process & unifid (1 head) process

Transverse processes of cervical

vertebrae have foramina not exist in

the remain vertebrae of the body,,

because of very important artery

ascending from the root of the neck

up into the skull to provide blood

supply to the post.inf. part of the

brain especially cerebellum ,,which iscalled vertebral artery inside the

vertebral column within the cervical

vertebrae ,,its a direct branch of

subclavian artery that enters the

transverse foramina & after passing

the first one it goes to foramen

magnum of the brain

This vertebral artery pass through cervical transverse foramina except C7,,

although C7 has transverse foramen the artery pass anterior to the transverseprocess ,, then it enters C6 foramen up to the brain .

The cause of that >> if the artery gonna pass in the transverse foramen of C7 it

has to make a sharp angle so it will block the blood supply to the brain


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4-large triangular vertebral foramen

vertebral foramen bemr feha l spinal cord ,, between the body & the

arch of the vertebrae ,,vertebral foramen akbar eshe btkon bl neck cervical

vertebrae,,b3den btbd2 tt9ya8 fl thoracic >>lumbar >>sacrum ,, become

narrower as you go down because of tapering of the spinal cord

Because of C7 has long spinous process the physicians count (be3edo) the vertebrae from

spinous process of C7 ,,in the root of the neck fe mn6e8a wa97a jdn (bony prominent

palpated easily ) >> which is the tip of the spinous process of C7

**SO C7 has along with one head spinous process ,,very easily palpated (bulging beneath

the skin),,thats why we depend on this spinous process in counting the vertebrae

Four main characteristics of a typical cervical vertebrae :

1- Rectangular body2- Transverse foramina3- Bifid spinous process & short4- Triangular & large vertebral foramenException C7 >> long unifid spious process & has foramen but the vertebral arterydoesnt pass in this foramen

AtlasC1 :

First cervical vertebra

Atypical >> fesh elo body ,,it is a ring shape bone ( ) ,,so NO body ,,NO spinous

process,, instead it has only anterior arch & posterior arch ,, & two lateral masses ofbone to allow it for articulation up & down,, Fhwa 7l8a (5atam) 3leh 2 small masses of

bone for articulatin

why do they call it Atlas ??

in the Greek mythology ,, Greek gad ATLAS ,, whose holding the whole earth in his

hands ,, SO referring to this kind of mythology or resembling ,, the Atlas is the first

vertebra holding the whole skull up .


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Atlas communicate superiorly by 2 joints (ahm 2 joints in cervical region) ,, the first

one with the skull superiorly m3 the occipital condyles occipital bone ,, forming

atlanto_occipital >> allow the head to move in anterior posterior directions flexion &

extension signifying YES ,, this is between the atlas & the skull

The other joint inferiorly of the atlas atlanto_axial joint >> for rotational movement of

the head signifying NO ,, ma elha 3la8a bl skull betm da5l lf8rat l3n8yeh nfsha ,, there

is no movment for the skull there ,,(between atlas & axis) ..

Most two important joint in the cervical vertebrae :

1- Atlanto_occipital >> flexion & extension2- Atlanto_axial >> lateral movement

AxisC2 :

Atypical because of one reason >> on its body it has dense , tooth , axis , Odontoid process

It is used to thought by some anatomists that the dense of axis actually used to be the

body of atlas but with development & with timeit has lost its communication & fusion withatlas to go & fuse with the axis to allow the rotational movement.

Atlas is a ring shape & this is the axis w6ale3 mno ldense ,, al atlas mrtabe6 bl dense wbelf

3leh ,, so the dense or the odontoid process acting as an axis for the atlas producing

rotational movement ,, saying NO >> so atlas rotating over the dense of the axis on the

atlanto_ axial joint .

Atlanto-Occipital Joint :

The type , articulation , supporting ligaments & the movement.

NOTE : Special characteristics for it not included :)

Type : condyloid synovial joint >> condyloid because of the occipital conyles are part of

articulation

Codyle : is a smooth round

surface ,,help in

articulation of the joint,,always present in the


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Articulations : atlas with occipital codyles

Movement : flexion & extension ,,also help in

lateral flexion ,,myzoha 3n elrotational flexion .

**lateral flexion : atlas btlef 3l axis wl axis 3l

C3 wl C3 3l C4 m3 b39 ,, btebda bl atlanto_occipital & continue

within the cervical vertebrae ,, bending of your head .

Ligaments :

Two important membranes :

1. Ant. atlanto-occipital memb.

from the anterior arch of atlas to anterior margin of foramen magnum

2. Post. atlanto-occipital memb.

From the posterior arch of atlas to the posterior margin of foramen magnum occipital

bone ,,B6al3 3leh mn wra b7me l joint post.

***SO both of them extend from the arches of atlas to the margins of foramen magnum

Atlanto-Axial Joints : 3

Atlas articulating with the axis in the 3 joints

**First 2 lateral atlanto_axial

laterally located between the lateral masses of atlas with superior articular facets of axis

,,

Type >> synovial gliding joints

Atlas with lateral masses & Axis with facets .

**Median atlanto_axial joint :


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In the middle ,, the most important ,, classified as pivot synovial joint ,, pivot means axial

,, so the movement is rotation ,, rotation start Between the anterior arch of atlas along

with the dense of axis

Articulation :

Anterior arch of atlas , the dense of axis , posterior there is a ligament >>transverse

ligament of atlas .

The transverse ligament of atlas begin from lateral mass of atlas in one side to the lateral

mass of atlas in the another side ,, so its the stick to keep the dense attached firmly

against the anterior arch of atlas ,, & thats why it considered as part of articulation .

SOOO :

1- Anterior arch of atlas2- The dense of axis3- Transverse ligament of atlas

Imagine this ligament is rupture ,,if there is tearing to this ligament that means the dense

will leave the anterior arch of atlas ,, so there will be a posterior displacement of the

dense of axis & HERE the dangerous situation

If it posteriorly displaced this is what we call it Atlanto-axial dislocation sometimes if

its minor >> subluxation

(again dense of axis go posteriorly away of the atlas)

Behind the dense of axis there is the spinal cord ,, & above the atlas directly the skull

(foramen magnum) ,, at the level of foramen magnum usually the last part of the brain

medulla oblongata

( ) benthe 3la 7eft l foramen magnum w bbda2 l spinal cord ,,, soif this tearing happen the dense will be go post. wby9rb emma l medulla oblongata aw

mmken y3ml enjry bl spinal cord .


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Medulla oblongata has a very important centers >> the cardiovascular center & the

respiratory center ,, if the tear hit those two centers that will result in direct death

Quadriplegia ( )More lucky situation if the dense go back & hit the spinal cord only that will result in

paralysis in all nerves that the spinal cord supply,, kl la6raf tb3 l person btnshal .

80% of car accidents death happen because of tearing in transverse ligament of atlas .

Web lash injuries ( ) : as the driver driving in very highspeed &he just hit the break ,, his head will go ant. & post.

web lashing ,,when the head comes back huge force has been gathered cause a tearing

in the transverse ligament & the dense hit the medulla oblongata .

Supporting Ligaments of atlanto_axial joint :

1- Cruciate LigOr cross ligament ,,Come posteriorly ,,howeh nfsoh l transverse ligament of atlas

,,the horizontal part of it is the transverseligament of atlas ,, but in order tostrengthen it by6l3 mno 2 vertical branches (2 lig. Attach to the skull ,,the ant.

Margin of foramen magnum) ,,one of them descend to attach the body of the dense

post. ,,,,,,SO one from above & another from below .

Just remember that this ligament mainly is an expansion of transverse ligament of

atlas .

2- Apical LigYou dont see it here,, you have to cut the cruciate lig.

,,its at the apex of the axis

Attach the tip of the dense along with the ant. Border offoramen magnum.

3-Alar Lig.s

they are going to the sides ,,dense of axis by6l3 mno lig. From the tip bro7 ll23al

called apical ,,by6l3 2 one to the RT & one to the LF those called the alars ,, so we

have apical & 2 alars .


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4-Tectorial MembraneBe36e all the ligaments ,,if you cut it you will see post. the cruciate lig. & when you

cut the cruciate you will see the alars & the apical

**tectorial membrane is a continuation of post. longitudinal lig.

Tb3 l vertebral column ,, when the post. longitudinal lig. Reach

Behind C2 & C1 then it name will be tectorial .

AGAIN the tectorial lig. Is the post. longitudinal lig. itself .


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Your colleague :)

Malak abuaqulah


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anatomy lec 5

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