Anatomy thoracic wall Sept27 M3 Flashcards
thoracic cage top and bottom openings
superior thoracic aperture (thoracic inlet) and inferior thoracic aperture (thoracic outlet)
Structure in front and in back of thoracic cage
Front: sternum (or breast bone)
Back: Thoracic spine
Total number of ribs
12
Angle at bottom of rib cage in front below sternum
Infrasternal angle
3 categories of ribs
True ribs, false ribs, floating ribs
which ribs are true + definition
I to VII. Direct insertion to sternum via costal cartilage
which ribs are false + definition
VIII to X. Indirect insertion on sternum via costal margin
def. of costal margin
Merging of costal cartilage of ribs VII to X
which ribs are floating + def
XI and XII. No insertion on sternum
3 portions of a rib from posterior to anterior
Head (and neck), body, costal cartilage
Structure found on rib’s neck + its def
Tubercle: protrusion to the back where there’s an articular facet
How many articular FACETS and where
- One on tubercle and two on head, separated by crest
Two things to denote on body of rib and where
Costal angle (initial curling of the rib in the back) Costal groove on interior and inferior surface
3 articular surfaces of ribs and where attach (+ anterior or posterior)
costal cartilage (A, sternum)
head of the rib (P, vertebrae)
Tubercle of the rib (P, vertebrae)
4 gross structures of a vertebra
Spinous process (back, goes downwards), transverse process (back, one on each side, horizontal) vertebral foramen (middle hole) vertebral body (front)
How many thoracic vertebrae
12
how many facets on one side of a vertebra for RIB articulation and where
three. two on side in middle between VB and TP (one upwards, one downwards)
third on one TP (transverse process)
Posterior joint def
joint between rib and vertebra
two posterior joints names
costovertebral joint and costotransverse joint
costovertebral joint def + where are facets
articulation of rib with vertebral body of rib on same level and the VB of one above it (vertebral facets behind VB, rib facets of the head)
costotransverse joint def + where are facets
between tubercle of rib and transverse process of vertebra on same level.
name of ligament near costotransverse joint and what it does
Superior costotransverse ligament joins transverse process and head-neck or rib
which ribs are atypical ribs
I,II,X,XI,XII
why rib I atypical (4)
Short, flat, horizontal
No costal groove
Grooves and scalene tubercle on top
Only articulates with vertebra at same level
Special structures found only on rib 1 (3)
two grooves on superior surface for large arteries and veins to pass separated by scalene tubercle
why rib II atypical (1) + how compares to rib I’s length
short, flat, horizontal.
Twice length of rib I but still not enough to be normal
why rib X atypical (1)
only articulates with vertebra at same level (not also with one above it)
why ribs XI and XII atypical (4)
no tubercles or necks
short
no costotransverse joint
Only articulates with vertebra at same level
which ribs articulate only with vertebra at same level
I, X, XI, XII
II is only atypical that doesn’t fit here
which ribs have no costal groove
I
which ribs are short
I,II,XI,XII
which ribs are flat and horizontal
I, II
which ribs have no tubercle and neck and costotransverse joint
XI, XII
sternum three parts top to bottom
manubrium, body of the sternum, xiphoid process
characteristic on top of manubrium and its level
Jugular notch (TII)
joint between manubrium and body of sternum (two names) + level
Manubriosternal joint (or sternal angle) (TIV/TV)
Joint between body of sternum and xiphoid process: name and level
Xiphisternal joint (TIX)
3 muscle layers of intercostal muscles and orientation
External intercostal muscles (inf, ant)
Internal intercostal muscles (sup, ant)
Innermost intercostal muscles (sup, ant)
where external intercostal muscles start and end
inferior surface of a rib and superior surface of rib below
where internal and innermost intercostal muscles start and end
superior surface of a rib and inferior surface of one above
what external intercostal transform into as you move to front
transform into external intercostal membrane
Muscle in rib cage other than intercostals and goes from where to where
Transversus thoracis: goes from body of sternum and xiphoid process to ribs 2 to 6
diaphragm three portions
right dome, central tendon, left dome
diaphragm particularity about levels of domes
right dome a little above rib 5 (bc of liver)
left dome a little below rib 5
Innervation of diaphragm
Right phrenic nerve: right dome
Left phrenic nerve: left dome
origin of the right and left phrenic nerves
nerves on levels C3,C4 and C5 of spinal cord join to form right and left phrenic nerves
Primary muscle involved in resting inspiration
diaphragm
mechanic movement axis in respiration allowed by diaphragm
superior inferior movement
primary muscle involved in resting expiration
none
muscles involved in forced inspiration and what they do to rib cage
external intercostal muscles - increase volume
muscles involved in forced expiration and what they do to rib cage
internal and innermost intercostal muscles and transversus thoracis
how external intercostals work (given their orientation)
their orientation allows them to pull on rib below to elevate it
two axes of movement allowed by intercostal muscles and transversus thoracis
allow anterior posterior movement (elevation, depression) and lateral movement (expansion and compression on the side)
Disposition of neurovascular supply between intercostal muscles. MAIN branches (not forget there are other ones)
On inferior surface of rib, between innermost and internal muscles, from top to bottom, vein and artery protected by costal groove and then nerve
Arterial supply to front of rib cage (start from left ventricle)
left ventricle-arch of aorta-thoracic aorta and subclavian artery on each side-internal thoracic artery on each side
rib 1 to 7: internal thoracic artery-anterior intercostal artery
rib 8 to 11: internal thoracic artery-musculophrenic artery-anterior intercostal artery
rib 12-thoracic aorta-subcostal artery
other name for internal thoracic artery
mammary artery
name of artery that goes from bottom of internal thoracic artery (its continuation) to the gut
superior epigastric artery
arterial supply to posterior rib cage (start from left ventricle)
left ventricle-arch of aorta-thoracic aorta-posterior intercostal artery
Interaction between anterior and posterior intercostal arteries
Have anastomoses, linking it into one circular supply to a rib
direction in which anterior and posterior arteries travel between ribs
anterior artery: front to back
posterior artery: back to front
venous drainage of anterior rib cage
rib 1-7: anterior intercostal vein, internal thoracic vein, brachiocephalic trunk, superior VC
rib 8-11: anterior intercostal vein-musculophrenic vein
rib 12: subcostal vein(?) or musculophrenic vein(?)
venous drainage of posterior rib cage on left and right side
left: left posterior intercostal veins-hemiazygos vein (on left side)-azygos vein (on right side)-SVC
right: right posterior intercostal veins-azygos vein (on right side)-SVC
name of vein on the front of the body that comes from gut to join interior thoracic vein
superior epigastric vein
name of spinal nerves emerging at a vertebral level and which one goes to rib
dorsal ramus and ventral ramus (which goes to rib)
Name of nerve travelling between ribs the rib
intercostal nerve
Name of two nerves that emerge and deviate from between ribs and where they do so
Lateral cutaneous nerve (between back and the side of the rib)
Anterior cutaneous nerve
What cutaneous nerves do
Provide sensory info to skin of chest
which nerves are intercostal and which are subcostal + their spinal level
intercostal from one below rib 1 to one below rib 11 (T1-T11)
subcostal for 1 below rib 12 (T12)
how many cervical levels to the spinal cord
7
How many spinal nerves emerge from cervical vertebrae
8
Transition in location of spinal nerves explanation
Cervical spinal nerves emerge above the cervical vertebra of their level (number)
Thoracic spinal nerves emerge below spinal vertebra of their level
Nerve emerging between C7 and T1 is called C8
how to differentiate nerve numbers from bones numbers
bones: roman numerals
name of hole from which a spinal nerve emerges
intervertebral foramen
location of intervertebral foramen
right above a vertebra, between the VB and the transverse process of the one above
Dermatome def
Area of skin innervated by single spinal nerve
Area of skin innervated by T4
Nipple
Area of skin innervated by T6
Skin over xiphoid process
Area of skin innervated by T10
Umbilicus
What causes shingles and how
varicella-zoster virus, attacks T5, rash on T5 level below nipple
