thorax Flashcards
thorax
= chest
between neck and diaphragm
- cylinder that is more narrow at the top and wider at the bottom
thoracic cavity parts
pleural cavities -2
mediastinum
pleural cavities
right and left
each contain a lung
- each are separated one does not affect the other
mediastinum
thick soft tissue partition between 2 pleural cavities
- can enter without entering pleural cavity
what encloses the thoracic cavity ?
thoracic wall
superior thorax
superior thoracic aperture
inferior thorax
inferior thoracic aperture
- Filled by the diaphragm
anterior thorax
contains sternum and costal cartilages
posterior thorax
thoracic vertebrae and intervertebral discs and posterior portion of the ribs
lateral thorax
ribs
functions of thorax
ventilation
protection
conduit
ventilation
breathing
- inspirations and expiration
- both have to do with changing air volume via diaphragm moving up and down [sides of diaphragm also contribute]
protection
thoracic wall protects :
lungs, heart, liver, stomach, spleen, superior kidneys
conduit
multiple structures pass though here as they move from one part of the body to another
connection of the thoracic regions to other body parts
what are the bones that help make up the chest wall?
collectively called the thoracic/rib cage
- thoracic vertebrate = 2 and intervertebral disks
- ribs
- sternum
costae
ribs
sternum
hematopoietic structure
3 parts
3 part of the sternum
manubrium - superior part
body - main part
xiphoid process - inferior part
costal cartilage
connects the upper 10 ribs to sternum
floating ribs
last 2 ribs since they have no skeletal connections
manubrium
top part is called the sternal notch
bottom part touching body is Called the sternal angle
shoulder girdle
clavicle and scapulae
not part of the appendicular skeleton
pectoral region
“pecs”
outside the thoracic wall
contain breasts and other muscles
intercostal muscles
fill in the space between the ribs and gives structural support to the chest well
help resist the intrathoracic pressures that drive respiration
intercostal blood supply
same structure as the rib cage
run in the intercostal spaces b/w the ribs
intercostal arteries
branches of the thoracic aorta or internal thoracic artery
intercostal veins
drain blood from thoracic wall into the azygos venous system
thoracic nervous system
12 spinal nerves
- exit foramen and divide into anterior/ventral and posterior/dorsal ramus
spinal nerves
have grey and white communicates that connect the spinal nerve to to the sympathetic trunk
posterior rami
run posteriorly to supply skin, muscles and joints of back
anterior rami 1-11
1-11 form the intercostal nerves
each runs with intercostal artery and vein to supply anterior/lateral parts of the chest wall, skin and muscles
12th anterior ramus
forms the subcostal nerve
dermatome
in the embryo- the body was created in segments by somites.
somites are blocks of tissue that form the bone, muscle, and skin.
dermatomes follow this patten
it is conserved,
help diagnose neurologic problems of the spinal nerve and cord.
shingles
herpes zoster
- comes from previous varicella infection
- unilateral and affects a single dermatome
usually a thoracic one or around the eyes
diaphragm
dome shaped skeletal muscle sheet
-fills the inferior thoracic aperture
diaphragm separates
thoracic and abdominal cavities
muscles fibers of the diaphragm
peripherally attach to the boundaries of the inferior thoracic aperture and converge to attache to the central tendon
diaphragm layout
anterior attachments are higher than the posterior attachments
back of dome is lower than the front
lateral are lower than the central
what is the lowest part of the thoracic cavity?
located along the posterolateral attachments of the diaphragm to the ribs
openings of the diaphragm
vena caval foramen
esophageal hiatus
arotic hiatus
vena caval foramen
at the horizontal T8 vertebra inferior vena cava
right of the midline
esophageal hiatus
horizontal level of the 10th thoracic vertebra
in midline
- for the esophagus and vagus x nerves
esophageal hiatus diaphragm fibers
the fibers that form this, help prevent gastro-esophageal reflux
arotic hiatus
located at the horizontal level of the 12th thoracic vertebra
in midline and technically beihind the diaphragm
there are no muscle fibers of the diaphragm that run posterior to the aorta
- contains decending aorta
thoracic duct
hiatal hernia
abnormal protrusion of n organ or other body structure through a defect / natural opening in a covering membrane/muscle. bone.
usually stomach though the esophageal hiatus
hiccup
involuntary spasmic contraction of the diaphragm.
it is the start of inspiration, but is checked by a sudden close of the glottis causing a sound
home remedies try to break the neurologic cycle
trying not to breathe until it stops
glottis
controlled by vagus nerve 10
respiration
contraction - flattens [increases size of the thoracic cavity and lowers pressure]
relaxes- thoracic cavity pressure increses
quiet breathing
only muscle that is moving is diaphragm
only moves during inspiration
expiration is passive
forced inspiration
also uses intercostal muscles to move the ribs apart
forced expiration
intercostal muscles pull the ribs together to make the cavity smaller
what is the weakest side of the abdominal cavity
superior part, so the organs move in that direction which decreases size of the thoracic cavity
this happens when the abdominal muscles compress the abdominal cavity with increases the pressure on abdomen
phrenic nerves
motor supply for the diaphragm
supplies sensory innervation to Both the fibrous pericardium and the portion go the parietal pleura lining the mediastinal wall
where do the phrenic nerves arise from?
cervical spinal cord levels
c3-5
arise in the neck and decend though the mediastinum along their respective lateral sides of the heart [b/w the fibrous pericardium and the mediastinal pleura
what do the phrenic nerves supply?
each supplies its specific half of the diaphragm
each piece through the diaphragm
they branch to distributed to the diaphragm on its inferior aspect
hemidiaphragms
2 sides of the diaphragm
diaphragm sensory innervation
most of the diaphragm including the central tendon is supplied though the phrenic nerves
peripheral parts of the diaphragm recieve innervation from the lower intercostal and subcostal nerves
side ache
from over-stretching of the diaphragm during exercise
because of the phrenic nerves
can cause referred pain elsewhere chest, neck and shoulders
mediastinum subdivisions
created at a transverse plane between T4 and T5
a. superior mediastinum
b. inferior mediastinum
inferior mediastinum divisions
divided by the pericardium into
a. anterior mediastinum [in front of the pericardium]
b. middle mediastinum [pericardium and its contents]
c. posterior mediastinum [behind the pericardium]
3 branches of the aorta
brachiocephalic trunk
left common carotid artery
left subclavian artery
what does the an anterior mediastinum contain?
lower part of the thymus
what does the middle mediastinum contain?
H: heart and pericardium A: asending aorta P: pulmonary trunk S: superior vena cava - termination I: inferior vena cava- termination P: pulmonary veins -termination P: phrenic nerve
great vessels
these are the blood vessels attaching to the heart: aorta pulmonary trunk pulmonary veins venae cavae [ superior and inferior]
posterior mediastinum contains?
thoracic aorta[ direct branches] azygos venous sytem esophagus vagus nerve thoracic duct
TATE V
what does the superior mediastinum contain?
B: brachiocephalic veins A: aorta and 3 branch's T: trachea T: thymus [upper part] L: left recurrent laryngeal nerve E: esophagus - upper
P: phrenic nerve
V: vagus nerve
S: superior vena cava
T: thoracic duct
thymus
is not really a gland
it is a lymphatic organ located in there superior mediastinum - just behind the sternum
thymus function
main source of mature t lymphocytes
thymus and age
changes with age;
birth-adolescence : large and functional
adulthood: not really active and replaced by fat
visceral pleurae
portion lining the organ
there are 2- 1 for each lung [left and right visceral pleurae
fits into every nook and cranny
very thin the they can’t be dissected from heart surface
parietal pleurae
portion lining the inside wall of the cavity
2- 1 for each lung [left and right parietal pleurae]
thicker than visceral pleura
small amount of fascia between it and the surfaces it covers, as a result it cannot be dissected away from the surfaces it associates with
pleural cavity
potential space between the 2 pleurae
contains serous pleural fluid
serous pleural fluid
keeps the surfaces of the pleurae moist and lubricates them so they can move upon each other easily
the surface tension created by this provides the cohesion needed to keep the lung surface in contact with the thoracic wall [ie. the parietal pleura]
- so when the chest expands the lungs expand and fill with air
hilum
where the structures of the root of each lung enter and exit
Where do the visceral and parietal pleura join?
at the hilum
this where where they are continuous with each other
cupula
the cervical part of each parietal pleura that extends superiorly thought the superior thoracic aperture into the root of the neck forms a cup shaped dome over the apex of the lung called this.
outer surface of the parietal pleura lining the mediastinum
is on contact with the fibrous pericardium
there is a small amount of fascia connecting these layers
in this fascia the phrenic nerve run though the chest
costadiaphragmatic recess
note during expiration, the lungs do not completely occupy all of the pleural cavities. there are places where the parietal and visceral pleura are not on contact with each other. they are called this.
form the lowest portions of the pleural cavities . excess fluid gathers here first.
visceral pleura innervation
not highly innervated, so not very sensitive
supplied by the visceral afferent fibers [nociceptive fibers] - mostly carried along sympathetic nerves originating from the thoracic spinal cord levels
parietal pleura innervation
richly innervated by somatic afferent fibers
[nociceptive] via. the intercostal and phrenic nerves
painful stimuli of the parietal pleura
can causes local chest pain
and referred pain to the root of the neck and shoulder regions
pleurisy
=pleuritis
= inflammation of the pleura
3 sulcus found on the surface of the heart
coronary sulcus
anterior inter ventricular sulcus
posterior inter ventricular sulcus
coronary sulcus
groove located where the atria meet the ventricles
= atrioventricular sulcus
anterior interventricular sulcus
groove is located at the anterior aspect of the inter ventricular septum
posterior interventricular sulcus
groove is located at the posterior aspect of the inter ventricular septum
infundibulum
= cornus arteriosus
aortic vestibule
leads to aorta
left atrioventricular valve
mitral valve = bicuspid valve
semilunar valves
left semilunar - aortic valve
right semilunar vales - pulmonary valve
coronary arteries
2 of them right and left
supply the heart wall - myocardium
branch off the ascending aorta
heart
end artery organ because there is little anastomosis between the coronary arteries
right coronary artery supplies what?
right atrium
sinoatrial node
atrioventricular node
most of the right ventricle
posterior aspect of the left ventricle
left coronary artery supplies what?
left atrium
most of the left ventricle
anterior aspect of the right ventricle
cardiac veins
veins that drain the heart
primarily return the blood into the right atrium.
NO VALVES IN ANY VENOUS STRUCTURE
coronary artery disease
decreased blood flow to myocardium
occlusion of coronary artery
thrombus
if a clot forms and plugs the vessel where it forms
embolus
if a clot forms and travels to a different place and lodges a vessel
infraction
plugged artery -> ischemia->necrosis
necrosis as a result of lack of blood
heart attack other name
myocardial infarction
capula clinical tie in
there are many neuromuscular structure in the root of the beck that can be compromised buy this
and pathologies in the root of the neck can affect adjacent pleura and lung
acute pleurisy
starts with a dry stage with the pleura are red and covered in a thin exudate
dry cough, fever, stitch in side and a rub [ rubbing sound upon listening with a stethoscope
liquid effusion stage of pleurisy
pleural cavity is filled with copious exudation of serum
inflamed pleura can have adhesions that become permanent
less pain but develops
dyspnea - trouble breathing
right lung
larger than left , but shorter b/c of liver [ hemidiaphragm is higher]
3 lobes: superior , middle, inferior
left lung
smaller since it has to make more room for the heart
2 lobes: superior and inferior
apex of lung
each lung has an apex, portion that extended into the root of the neck and projects outside the chest
3 surfaces of the lung
costal
diaphragmatic - base
mediastinal
mediastinal surface of the left lung
has a concavity called cardiac impression [to make took of the heart]
lingula
thin tongue like part of the upper lobe that forms the anterior part of the cardiac impression
how is the mediastinum connected to the lung
connected at the mediastinal surface of the lung via the root of the lung
what is the root of each lung made of?
- primary bronchus - and blood supply
- . pulmonary artery
- superior and inferior pulmonary veins
- pulmonary plexus of nerves[sympathetic [visceral afferent] and parasympathetic[ visceral afferents]
- lymphatics
Sinus venarum
Where vena cava attach to rt atrium
Where sa node is
SA node
Sends impulse top down, so blood can travel down to up
Note cardiac skeleton insulates they ventricles from the stria so that the impulses cannot pass directly from the atria to the ventricles
