Test 4 Lecture 1 Flashcards
Midsternal Line
line coursing down the median portion of the sternum.`
Midclavicular Line
Find the mid portion of the left and right clavicle, drop a line down on the left and drop a line down on the right. –
line coursing down the anterior thorax, which forms a perpendicular relationship with the midpoint of the clavicle.
In males it is usually medial to the nipple, in females it varies
Midaxillary Line
line down the midaxillary (Armpit) region
Anterior and Posterior Axillary Lines
line which courses down the anterior axilla (Armpit) (formed by the pectoralis major) and posterior axilla (armpit) (formed by the latissimus dorsi and teres major) axillary folds, respectively.
Paravertebral Line
a line down either side of the posterior thorax just lateral to the transverse processes of the thoracic vertebrae.
2 lines that are on each side of the spine, just lateral to transverse processes)
The thorax is
a bony cage that gives protection to the major thoracic viscera, i.e. the heart, large blood vessels, and lungs.
Boundaries of the thorax
ANTERIOR ASPECT:
- 12 pairs of ribs with 11 intercostal spaces and costal cartilages (hyaline);
- Sternum (3 parts)
POSTERIOR ASPECT (also has 12 pairs of ribs and 11 intercostal spaces)
- 12 thoracic vertebrae;
- Scapula- covers ~ ribs 2-6
SUPERIOR ASPECT
5. Superior thoracic inlet (bean shaped- Rib 1 articulates with sternum and both sides of rib 1 meet at vertebral column in the back) (looking down inside from above thorax);
INFERIOR ASPECT
6. Inferior thoracic inlet - subcostal margins, diaphragm. (Costal margin is formed by the costal cartilages of ribs 7-10, where they all connect to the 7th rib)
3 Parts of the sternum
- Manubrium (the most superior portion of the sternum
- Body (the elongated middle portion of the sternum)
- Xiphoid Process
Parts of the Manubrium (the most superior portion of the sternum):
a. has suprasternal notch aka the jugular notch on top;
b. has a clavicular notch on either side of the sternal notch for articulation with the medial clavicle;
c. has a notch (or facet) for the articulation of the costal cartilage of the first rib.
About where is L2
It is medial to the end of the boney thorax
Iliac crest = what level vertebrae?
L4
the diaphragm covers/ lines the
inferior thoracic outlet. It kind of looks like a parachute inside of it
What structures are on top, or ride, on the diaphragm?
the heart and lungs are superior to it
As you exhale the diaphragm will
ascend
As you inhale the diaphragm will
descend
What is the clavicular notch for?
the clavicular notch is found on the manubrium of the sternum, and it is where the clavicle articulates
What muscle is found between the clavicular notch and the jugular notch (on that edge in between)
SCM (sternocleidomastoid)
Parts of the Body of the Sternum (the elongated middle portion of the sternum)
a. articulates with manubrium at the Sternal Angle of Louis;
b. accommodates the costal cartilage of the second rib, which articulates with the manubrium and the sternal body at the sternal angle (of Louis);
c. has articular facets that accommodate the costal cartilages of ribs 3-6. The articular facet for the costal cartilage of rib 7 is a demifacet arrangement, located at the xiphisternal joint and partially on the sternal body and partially on the xiphoid process.
what is the sternal angle of Louis?
the junction between manubrium and the body of the sternum
What happens at the sternal angle of Louis?
Rib #2 has two little demifaucets (one on the superior aspect of the body, and one on the inferior aspect of the manubrium) that attach to costal cartilage of the rib. This costal cartilage articulates with the articular facet of the sternum
sternal angle of Louis is also called
the manubriosternal joint
Xiphoid Process –
the lower, terminal portion of the sternum that articulates with the body of the sternum at the xiphisternal joint and has an articular demifacet to help in accommodating the costal cartilage of rib 7.
Ossifies between 15-30 years of age
Where/what is the xiphisternal joint
Between the body of the sternum and the xyphoid process of the sternum.
It is where the costal cartilage of rib #7 articulates
Where do ribs 3-6 articulate?
the body of the sternum
Where does rib 1 articulate?
the manubrium of the sternum
Where does rib 2 articulate?
between the manubrium and the body of the sternum at the angle of Louis
Where does rib 7 articulate?
between the body of the sternum and the xyphoid of the sternum at the xiphisternal joint
True Ribs
- which ribs?
- why are they true ribs?
- what do they articulate with posteriorly?
- True Ribs: 1-7
- True Ribs each attach (via costal cartilage) directly to the sternum.
-Posteriorly their heads articulate with their respective thoracic vertebral bodies, i.e. the thoracic vertebral body above, the intervertebral disc, and the vertebral body of the same numbered thoracic vertebral body below via demifacets on each vertebral body.
False Ribs
- which ribs?
- why are they false ribs?
- what do they articulate with posteriorly?
- False Ribs: 8-10
- Attach to the sternum via the costal cartilage of the 7th rib
-Posteriorly their heads articulate with their respective thoracic vertebral bodies, i.e. the thoracic vertebral body above, the intervertebral disc, and the vertebral body of the same numbered thoracic vertebral body below via demifacets on each vertebral body.
Floating Ribs
- which ribs?
- why are they floating ribs?
- what do they articulate with posteriorly?
- Floating Ribs: 11-12
- Do not attach to the sternum
Posteriorly their heads articulate with their respective thoracic vertebral bodies, i.e. the thoracic vertebral body above, the intervertebral disc, and the vertebral body of the same numbered thoracic vertebral body below via demifacets on each vertebral body.
Are Ribs 11 and 12 False Ribs
NOOO! Floating ribs
What # Ribs are Typical?
3-9
What # Ribs are Atypical
1-2, 10-12
What makes ribs 3-9 typical ribs?
They all have the following:
- head (articulates w/ vertebral column)
- neck
- tubercle with articular facet (articular facet articulates w/ transverse process of lower vertebrae.)
- angle
- shaft with costal groove (intercostal n, artery, and vein run underneath)
What kind of facets do the thoracic vertebral columns have for the head of the ribs?
demifacets
sternal extremity is?
the end of the rib that attaches into the costal cartilage which then attaches to the sternum
Why is Rib #1 Atypical?
- It is flat
- -It does not have a Costal Groove*
- -It does not have an angle (its a C, but there is no sharp turn)*
- It has a scalene tubercle- a roughed up edge where the ant. scalene will attach
- it has a groove for the subclavian artery
1st rib relationship
first rib sweeps under clavicle
the subclavian vein goes up and over the first rib
the anterior scalene muscle attaches
the subclavian artery exits out up and over first rib (more lateral to vein)
the brachial plexus runs over it, lateral to the sub. art and vein
the middle and post scalene are around here too
Why is it important to note the 1st rib relationships?
if this area is compressed- there could be numbness and tingling in some of the nerves of the brachial plexus, or they could have diminished pulses due to the constriction of the subclavian artery
-sometimes people have a 13th rib that is above the 1st rib, and it can lead to compression of this region
anterior to posterior the relationships of around the 1st rib
most anterior = subclavian v over 1st rib
posterior/ lateral to that = ant scalene attaches
posterior/ lateral to that = subclavian artery over 1st rib
posterior/ lateral to that = brachial plexus runs over 1st rib
post/ lateral to that = middle and post scalene muscles
Why is rib #2 atypical?
- flattened (by comparison to other ribs), and it’s angle is closer to the tubercle, *
- I think it’s the first rib which does have demifacets (sup & infer attachments to vertebrae)
Why is rib #10 atypical?
- lacks an articular facet on the tubercle, because it does not attach to transverse process of any vertebrae
- it has a singular articular facet on head- so it only articulates with T10
Atypical Ribs: 11-12
No Tubercle
12th has no Costal Groove
-both have a single articular facet on head to articulate with vertebrae of same number
vertebrocostal joints
These are the joints formed by the heads of the ribs with the vertebral body demifacets. They are synovial (gliding) joints.
Ribs tubercle articulate to the ____ transverse process # as the rib #
same
If you look at the head of the rib, it is named how?
it is named for for the lower vertebrae
Transversocostal joints
describe, what kind of joint, and which ribs do not have this joint?
These joints are formed by the articulation of the tubercular facet on the rib with the corresponding vertebral transverse process (transverse costal facet). They are synovial (gliding) joints.
These joints are absent on ribs 10-12.
How much movement does a gliding joint have?
not much individually, but when you put these kinds of joints together there is a good amount of movement (hence why we can take deep breaths!)
Sternocostal joints (aka?)
- articulation btwn?
- type of joint? amount of movement?
aka - Chondrosternal
- Articulations between the ribs and sternum.
- These are cartilaginous joints;
- Allow minimal movement. to allow us to inhale and exhale
Costochondritis
inflammation of the costal cartilage
The 11 pairs of intercostal nerves and vessels are cradled in the___ ___ of the __ through the ___ ribs,
costal grooves
1st through 11th ribs
ventral root combines with dorsal root to make
spinal nerve
spinal nerve splits into
dorsal primary ramus and
ventral primary ramus
VPR becomes ?
the intercostal nerves
The ventral primary rami breaks off into
a lateral cutaneous branch and an anterior cutaneous branch
the lateral cutaneous branch is
sensory to the side of the chest
the anterior cutaneous branch
sensory to anterior sternum
The 2 subcostal nerves (T12) lie below the ___ ribs, and help to supply innervation to the ___ ____
12
supply innervation to the abdominal muscles
shingles =
an issue at the spinal level where intercostal n initiates
Intercostal nerves run in
the intercostal space
the intercostal nerves supply
general sensation to the boney thorax and innervation to the intercostal muscles
In the intercostal space in the following manner:
Vein > Artery > Nerve.
How many pairs of posterior intercostal arteries are there
11 pairs because there are 11 spaces
posterior intercostal arteries 3-11 arise from
the thoracic artery (a huge vessel found in the thorax, kind of behind sternum)
posterior intercostal arteries 1-2 arise from
the costocervical trunk, which is a branch of the subclavian artery
posterior intercostal arteries 3-11 direction of travel
they go back and curve so they they are coming anterior and medially in intercostal space, but they taper off around the anterior axillary wall… They do not profuse all the way anteriorly
posterior intercostal arteries are ___ than anterior intercostal arteries
longer
the anterior intercostal arteries UPPER 6 PAIRS arise from
the internal thoracic artery, which is a branch of the subclavian artery
as the internal thoracic artery streams down the thorax it….
bifricates into a superiorepigastric artery and a musculophrenic artery
the LOWER 5 PAIRS of the anterior intercostal arteries arise from
the interior thoracic artery’s Musculophrenic branch
The posterior intercostal arteries form ______ with the anterior intercostal arteries
anastomoses
the subclavian artery travels between
under the clavicle, over rib 1
the internal thoracic artery is a branch of the
subclavian artery
the internal thoracic artery travels
immediately downward and runs on either side of the sternum (one on right, and one on left)
the 6 anterior intercostal arteries are branches of the
internal thoracic artery
there are the 6 anterior intercostal arteries supplied by the internal thoracic artery, and what are the lower 5 anterior intercostal arteries from?
the musculophrenic artery
the thyrocervical trunk is a branch of
the subclavian artery
the three branches of the thyrocervical trunk?
- Inferior Thyroid Artery
- Transverse Cervical Artery
- Suprascapular Artery
Inferior Thyroid Artery supplies
the thyroid gland
Transverse Cervical Artery supplies
it travels around the neck in posterior direction so:
supplies levator scapulae, upper trapezius, supraspinatus and infraspinatus
Suprascapular Artery
travels over scapular ligament so it supplies above and below the spine of the scapula
vertebral artery
travels in transverse foramen, enters at C6 and travels up and into head
costocervical trunk
has 2 branches, one of which is costal branch which gives off the supreme costal artery which gives off 1st and 2nd anterior intercostal
Dorsal Scapular Artery
60% of the time its present as a branch off of the subclavian artery
External Intercostal Muscles Direction/Face
fibers pass downward and forward
External Intercostal Muscles do what?
These muscles raise the ribs, and thus facilitate INSPIRATION by increasing the anteroposterior and transverse diameters of the thorax. Beginning along the spinal column, these muscles course around the thorax in the intercostal spaces
internal intercostal muscles direction/ face -
these fibers pass downward and backward
Internal Intercostal muscles do what?
The muscles thus pull the ribs down, which decreases the anteroposterior and transverse diameters of the thorax. This facilitates active, or forced EXPIRATION.
anterior and posterior intercostal veins run with
the ant or post intercostal artery and intercostal n
if you see an artery that is more by the axillary fold it is more likely to be the anterior or posterior intercostal artery?
posterior intercostal artery because they’re longer
External Intercostal Muscles O/I
origin = rib above insert = rib below)
Begin at the Spine and
End in the Parasternal Area-Anterior Axillary Line
External Intercostal Muscles Inhale or Exhale
Inhalation
Inhalation is ____, whereas exhalation is
voluntary, involuntary or forced
How many pairs of external intercostal muscles
11
External Intercostal membrane
the intercostal muscle tissue that attaches to the sternum
the internal intercostal muscle O/I
O= rib below, I rib above- so pull the rib down. So they are our muscles for forced expiration
muscles for forced exhalation?
internal intercostal muscle and Innermost Intercostals
internal intercostal muscle start and end?
start at the Sternum
End in the Posterolateral Thoracic Area-Post. Axillary Line
Internal Intercostals attach to vertebra by
Internal Intercostal Membrane
The internal intercostal muscle is deep to
the external intercostal muscle
The deepest Layer of the intercostal muscles?
Innermost Intercostals
Innermost Intercostals fibers run in the same direction as
Internal Intercostals
Which muscles are as deep as the innermost intercostals muscles
the transverse throracic
the innermost intercostals layer begins anteriorly right next to the sternum with the little muscle called
the transverse throracic
the transverse thoracic ends at
the paravertebral area
the transverse thoracic picks back up as
fascial tissue and continues back as the innermost intercostal muscle which continues on as innermost intercostal MEMBRANE which attaches to the spine
between what two layers of intercostal muscle does the nerve, artery and vein highway run?
between the innermost intercostal layer and the internal intercostal muscle layer
the diaphragm does between ___ or ____ % of the work for breathing
75%-85% of the work for breathing
what does the diaphragm cover?
the inferior thoracic aperture
what does the diaphragm attach to?
costal attachment (ribs)
sternal attachment
vertebral attachment
keep it in place so it can do it’s job
the central tendon
the aponeurotic attachment where the muscle fibers of the Diaphragm all come in together (if it contracts, it causes the diaphragm to contract so the fibers will pull, and cause the diaphragm to flatten out and the lungs will expand and create a negative pressure so that the air can fill in the lungs
The main vertebral attachments of the diaphragm are formed by the
left and right diaphragmatic crus
the right diaphragmatic crus arises from
L4 (longer)
the right diaphragmatic crus (slip of fibers) arises from
(longer than left)
starts on L4 and goes up to CREATES AN ARCH AND OPENING FOR AORTA (AORTIC HIATUS)
the left diaphragmatic crus arises from
(shorter than right)
starts on L3 and goes up to meet with the right diaphragmatic crus to help form aortic hiatus
Contraction of the diaphragm about the central tendon for inspiration causes the thoracic vertical distance to ____ , thus allowing the lungs to _____. This decreases the pressure within the lungs and allows air to flow in.
thoracic vertebral distance INCREASE, thus allowing the lungs to EXPAND
Diaphragm can be split into
right and left hemidiaphragm
right hemidapragm goes up to the
4th rib interspace
left hemidiapragm goes up to
5th rib
Why is the right side of the diaphragm higher than the left?
It has the liver pushing it up
medial arcuate ligament
begins at body of L2 attaches to transverse process of L1
-it’s an arch that allows the psoas major to pass under the diaphragm. It also acts as an attachment point for the diaphragm to the vertebrae
lateral arcuate ligament
- runs from transverse process of L1 to 12th rib
- needed for the Quadratus lumborum muscle to go under the diaphragm to attach to lumbar vertebra
as soon as thoracic aorta goes through the aorta hiatus it becomes
the abdominal aorta
the esophageal hiatus
also formed by the right crus
-where the esophagus passes through the thorax into the abdomen
hiatal herniation
occurs through the esophageal hiatus
- the upper portion of stomach herniates up and through the esophageal hiatus into your thorax
- with stomach protruding, the esophageal sphincter will remain open so the acidic contents come up and into the lower esophagus and can create esophageal cancer
- burning and chest pain
aortic hiatus location
T12
Esophageal hiatus location
T10
Caval Hiatus location and what goes through it?
T8-T9
-transmits inferior vena cava
innervation of diapragm
It is innervated bilaterally by the Ventral Primary Rami of Phrenic nerve.
C3-C5
phrenic nerve always passes over
the anterior belly of the anterior scalene muscle,
Path of phrenic nerve after anterior belly of scalene?
it then passes through superior thoracic aperture created by 1st rib, then goes to thorax and passes anteriorly to the 2 mainstream bronchi coming off of the trachea, and it bulges to cover the diaphragm
the aortic hiatus is formed by the
right crus as it arches around to meet the left crus
the esophageal hiatus is formed by
muscle fibers of the right crus as they recur around the esophagus
the caval hiatus is
a perforation through the diaphragm lying in the right portion of the central tendon
