Thorax Flashcards
region of body between
neck and abdomen (aka the chest
thorax
The thorax contains the heart and the lungs
* Other major structures found in the
thorax include the ____ and
the aorta (through the thoracic
portion of descending aorta)
esophagus
Thoracic cavity and its walls have the
shape of a ___
truncated cone
T/F the walls of the thoracic cavity are thick
F; relatively thin
Thoracic cavity has a _____ superior opening (superior
thoracic aperture) and a ____ inferior
opening (inferior thoracic aperture)
Narrow. larger.
Narrow superior opening of the thorax
superior thoracic aperture
The muscular thoracic diaphragm
covers the ____,
creating a floor to the thoracic cavity
inferior thoracic aperture
Floor to the thorax
muscular thoracic diaphragm
Central compartment of the thorax
– houses the thoracic viscera except
for the lungs
mediastinum
Right and left pulmonary/pleural
cavities – house the ___
lungs
Functions of the thorax: protection of thoracic and ___ organs
abdominal
Functions of the thorax: Resistance against the ______ generated by the elastic recoil
of the lungs and inspiratory movements
negative internal pressures
negative internal pressures in thorax generated by the elastic recoil of the lungs and ___ movements
inspiratory
Attachment and supportive of the upper limbs
* Origin for groups of muscles of the upper limb, abdomen, back neck, and head
thorax
Functions of thorax: Muscles for breathing: ___ and diaphragm
intercostals
costal=
chondral=
osseous=
rib, cartilage, bone
Thoracic skeleton includes:
- 12 pairs of ribs and associated costal cartilages
- 12 thoracic vertebrae and the intervertebral (IV) discs
interposed between them - Sternum
Three types of ribs defined by how they articulate with
the sternum anteriorly:
true (1-7) false (8-10) floating (11-12)
ribs attaching directly to sternum through
their own costal cartilages
True Ribs (1-7)
attach to the cartilage of ribs
superior to them (indirect attachment)
False ribs (ribs 8-10) -
do not contact the sternum,
instead ending in the posterior abdominal musculature
- Floating ribs (ribs 11-12) –
- All ribs articulate posteriorly with ____
thoracic vertebrae
Atypical rib numbers
1, 2, 10, 12
The joining of the costal cartilages of
false ribs (8,9,10) form a
continuous, articulated, cartilaginous
____
costal margin
The infrasternal angle (subcostal
angle) is formed by the left and right
costal margins at the ___
xiphisternal joint
The _____ is formed by the left and right
costal margins at the xiphisternal joint
infrasternal angle (subcostal
angle)
_____ separate the ribs
and their costal cartilages from one
another
intercostal spaces
Intercostal spaces are named according to rib ___ them
above
Below rib 12 is called the ____
space
subcostal
trachea, esophagus,
nerves, and vessels that supply and drain the
head, neck, and upper limbs pass through the:
Superior thoracic aperture (thoracic
outlet/inlet)
Inferior thoracic aperture is closed by the
_____
diaphragm
Structures passing in
or out of thorax must pass through the
_____ or behind it
diaphragm
Structures passing through/behind diaphragm:
aorta, esophagus, inferior vena cava
(Rib) Connects the head with the body at the level of the
tubercle
neck
Most curved region of body where rib turns anterolaterally
Angle of rib
(rib) Location of intercostal vessels and nerve (same
number as intercostal space)
costal groove
rib end attached to costal cartilage
sternal end
The weakest part of a rib is ___ to its angle
anterior
articulation of head of rib
with the inferior and superior costal facets on
bodies of adjacent thoracic vertebrae
Costovertebral joint
articulation of tubercle
with costal facet of transverse process of
vertebrae of same number
costotransverse joint
–1st rib articulates with ____ only
–Ribs 11 and 12 only articulate with T11
and T12, respectively, but do not
articulate at costotransverse joint
T1
Upper ribs (1-7) rotate at the costotransverse joints
*–Results in _____movements of sternal ends of these ribs and sternum in
the ______ plane (pendulum movement)
elevation and depression. sagittal
Lower ribs (8-10) glide at the costotransverse joints
* Results in elevation and depression of ___ most portions of these ribs in the ____ plane (bucket-handle movement
lateral. transverse
Ribs ___ do not articulate with transverse processes
11 and 12
Ribs that are found outside of the thoracic region
Supernumerary Ribs
What is a potential consequence of Supernumerary Ribs?
Can lead to compression of neurovascular structures entering the superior
thoracic aperture
Supernumerary ribs in the lower cervical
region can cause irritation or injury to the
vessels and nerves supplying the shoulder and
upper limb CALLED
Thoracic Outlet Syndrome
Thoracic Outlet Syndrome can be caused by trauma, repetitive injuries, and ____
pregnancy
Thoracic Outlet Syndrome–Vulnerable structures: ____,
subclavian artery and vein
brachial plexus
______ occurs when blood vessels or nerves are compressed by the collar bone or muscles, leading to pain and numbness in upper back, neck, shoulder, arm, and hand
Thoracic Outlet Syndrome (TOS)
Parts of Sternum:
manubrium, body, sternal angle, xiphoid process
Manubrium: medial portion of superior border =
jugular notch (suprasternal notch)
Manubrium: lateral portion of superior border on each side
Clavicular notch (forming the sternoclavicular joints)
Manubrium: Lateral Border= notch for ___
1st costal cartilage
Body of the sternum acts as notches for __
costal cartilages
Sternal Angle is at this joint
manubriosternal joint
Xiphoid process is completely ossified by age ____ and is an important midline marker for the sternum
40 years old
Thoracic Wall joints: rib to costal
cartilage
Costochondral Joints
Costochondral Joints: Primarily ______ joints and
they usually do not experience movement
cartilaginous (hyaline)
T/F Costochondral Joints experience extensive movement
false
Thoracic Wall Joints: between
adjacent costal cartilage
Interchondral Joints
Interchondral Joints: Some are plane _____ joints (between
costal cartilages 6-9)
plane synovial joints
Interchondral Joints: Some are fibrous (between cartilages ____)
9-10
Thoracic Wall Joints: sternum to
costal cartilage
Sternocostal Joints
Sternocostal Joints: 1st joint is ____
* Joints 2-7 are synovial plane joints
cartilaginous
Sternocostal Joints: Joints 2-7 are ____ joints
synovial plane joints (movement!)
Location of costochondritis (inflammation of
________ –> sharp pain and
tenderness)
Sternocostal Joints
inflammation of
sternocostal joints –> sharp pain and
tenderness (What is this called?)
costochondritis
Mechanic of breathing: When the upper ribs are _____, the
anterior-posterior (AP) dimension of the
thorax increases. There is a greater
increase at the ____ end of sternum
elevated; inferior
The middle parts of the lower ribs move
_____when they are elevated,
increasing the ____ dimension
laterally; transverse
Combined movement during forced
____increases the AP and
transverse dimensions of thoracic rib
cage (C
inspiration
External Intercostals function in INSPIRTAIN
elevate ribs (thus increasing width of thoracic cavity and aiding deep inspiration)
Increase volume, decrease pressure:
air comes in with ____ (Boyle’s
Law
less effort
_____ muscles: Occupy the intercostal spaces and function
during respiration to move ribs and keep intercostal
spaces rigid
Intercostal Muscles
Run infero-anteriorly from the rib above to the
rib below (”hands in pockets”)
External Intercostal Muscles
External Intercostal Muscles: Most active during ____ to elevate ribs
inspiration
Attach superiorly to the inferior border of the
rib above and inferiorly to the superior border
of the rib below
External Intercostal Muscles
Run inferoposteriorly from the rib above to the
rib below (“hands toward mouth”)
Internal Intercostal Muscles
Attach superiorly to the inferior border of the
rib above and inferiorly to the superior border
of the rib below
Internal Intercostal Muscles
Internal Intercostal Muscles: Most active during ______ to depress the
ribs, especially interosseous portion
* Interchondral part can elevate ribs
expiration
Intercostal neurovascular bundle runs
in between the ____ and innermost
intercostal muscles
internal
Arrangement of neurovascular bundle in costal groove
Vein, Artery, Nerve (VAN) from superior to
inferior in costal groove
Innermost intercostal muscles: Same fiber direction as _______
muscles
* Likely same actions as well
internal intercostal muscles
–muscle functioning to depress ribs
–Attaches inferiorly on the posterior sternum and superiorly
on costal cartilages 2-6
Transversus Thoracis
Scalene Muscles action in INSPIRATION
elevate and fix upper (2) ribs
muscles of inspiration _____ the ribs
elevate
Principle muscle involved in respiration
diaphragm
Thin muscular and tendinous septum that separates
the thoracic cavity from the abdominal cavity
diaphragm
Is dome shaped (convex superiorly) and consists of
a peripheral muscular part, which arises from the
lateral walls of the thorax (sternal, costal, lumbar) &
a central tendon
diaphragm
Central tendon of the diaphragm is intertwined with _____
around heart and descends during inspiration (or
contraction of diaphragm)
pericardium
During inhalation the diaphragm ____
contracts (moves down/descends)
___pairs of thoracic spinal nerves
supply the thoracic wall
12
Intercostal Nerves: After passing through intervertebral
foramina, the ____ spinal nerves
divide into anterior and posterior rami
mixed
The ____rami of nerves T1-T11
form the intercostal nerves that run
along extent of intercostal spaces
anterior
Anterior ramus of nerve T12 is called the
___ (runs below 12 th rib
subcostal nerve
The _____ rami of thoracic spinal
nerves pass posteriorly to supply the
joints, deep back muscles, and skin of
the back in the thoracic region
posterior
area of the skin
supplied by the posterior and
anterior ramus of each pair of
thoracic spinal nerves
Dermatome
group of muscles
supplied by the posterior and
anterior ramus of each pair of
thoracic spinal nerves
Myotome =
(Thoracic Dermatomes and Myotomes) T1 and T2 supply ___
upper limb
(Thoracic Dermatomes and Myotomes) T2-T12 supply ____
trunk
What supplies the intercostal spaces?
Anterior intercostal Arteries
Internal thoracic aa. (spaces ___) and musculophrenic aa. (spaces ___) are the
source of anterior intercostal aa
1-6; 7-9
____ and _____ are the
source of anterior intercostal aa
Internal thoracic aa. (spaces 1-6) and musculophrenic aa. (spaces 7-9)
____ aa. (spaces 1-2) and ____ (spaces 3-11) are the
source of all posterior intercostal aa.
Supreme intercostal arteries; thoracic aorta
Spaces 10 and 11 are only supplied by ___
posterior intercostal aa
___ is also source of subcostal a. (below 12 th rib)
Thoracic aorta
Most of the posterior intercostal veins
return blood to the ____ on the
right and the ____veins on the left
azygos vein. hemiazygos/accessory
hemiazygos .
Azygos system of veins drains into the
___
superior vena cava
Left superior intercostal drains into the ___
left subclavian vein
Superior intercostal veins = posterior
intercostal veins of the 2nd and 3rd intercostal
spaces that unite to form a ___
trunk
Function of Interchondral parts of Internal Intercostals during INSPIRATION
elevate ribs and aid external intercostals with deep inspiration
function of respiratory diaphragm during INSPIRATION
domes decend, thus increasing vertical dimension of thoracic cavity; also elevates the lower ribs
Expiration results from ____ of lungs and rib cage
passive recoil
Internal intercostal muscles (except for interchondral part) aid in ______
forced expiration
During exhalation: diaphragm ______
relaxes (moves up) [decrease volume–> air out]
Name the origins of these arteries:
1) Internal Thoracic
2) Subcostal
1) Subclavian
2) Thoracic
