thorax 2 Flashcards
what are the Component parts
Thoracic wall
skeletal elements and muscles
posteriorly
t is made up of twelve thoracic vertebrae and their intervening intervertebral discs;
anteriorly
the wall is made up of the sternum , which consists of the manubrium of sternum, body of sternum, and xiphoid process.
laterally
the wall is formed by ribs (twelve on each side) and three layers of flat muscles, which span the intercostal spaces between adjacent ribs, move the ribs, and provide support for the intercostal spaces;
anterior (distal) end of each rib is composed of costal cartilage
function of costal cartilage
which contributes to the mobility and elasticity of the wall.
how many costal cartliages articulate with the sternum
I to VII articulate with the sternum.
where is teh thoracic wall
the superior thoracic aperture, bordered by vertebra TI, rib I, and the manubrium of the sternum; and
▪ the inferior thoracic aperture, bordered by vertebra TXII, rib XII, the end of rib XI, the costal margin, and the xiphoid process of the sternum.
what are intercostal spaces
Intercostal spaces lie between adjacent ribs and are filled by intercostal muscles
what lie within the costal groove
Intercostal nerves and associated major arteries and veins lie in the costal groove along the inferior margin of the superior rib and pass in the plane between the inner two layers of muscles.
what is most superior
vein
what are the structures under it
the vein is the most superior structure and is therefore highest in the costal groove. The artery is inferior to the vein, and the nerve is inferior to the artery and often not protected by the groove. Therefore, the nerve is the structure most at risk when objects perforate the upper aspect of an intercostal space.
what is the endothoracic fascia
is the layer of loose tissue deep to the intercostal spaces and ribs, which separates them from the underlying pleura
where is the diaphragm and what does is seperate
The diaphragm is a thin musculotendinous structure that fills the inferior thoracic aperture and separates the thoracic cavity from the abdominal cavity
what is it under
xiphoid process of the sternum, ▪ costal margin of the thoracic wall, ▪ ends of ribs XI and XII, ▪ ligaments that span across structures of the posterior abdominal wall, and ▪ vertebrae of the lumbar region.
how many tendons attatch to the diaphragm
one central tendon
how many plueral cavities are there
Two pleural cavities , one on either side of the mediastinum, surround the lungs
where are they
Superiorly, they extend above rib I into the root of the neck.
▪ Inferiorly, they extend to a level just above the costal margin.
▪ The medial wall of each pleural cavity is the mediastinum.c
paritieal and visceral
where is the base of the lung
sits on base of the diaphragm
where does the apex sit
above rib 1 and into the roof of the neck
what are the 2 surfaces and where are they
costal surface lies immediately adjacent to the ribs and intercostal spaces of the thoracic wall. The mediastinal surface lies against the mediastinum anteriorly and the vertebral column posteriorly and contains the comma-shaped hilum of the lung, through which structures enter and leave.
what are the 3 borders and where are they
the inferior border of the lung is sharp and separates the base from the costal surface. The anterior and posterior borders separate the costal surface from the medial surface. Unlike the anterior and inferior borders, which are sharp, the posterior border is smooth and rounded.
what is the root
The root of each lung is a short tubular collection of structures that together attach the lung to structures in the mediastinum (
hilium
he region outlined by this pleural reflection on the medial surface of the lung is the hilum , where structures enter and leave.
what is the thoracic skeleton made up of
12 thoracic vertebrae
12 pairs of ribs and costal cartilages
Sternum
how many thoracic vertebrea/what are thoracuc vertebrea
12 in number (T1-T12)
Heart shaped body
how do they articulae this the body
Facets on body for articulations with heads of ribs
Facets on transverse processes for articulations with tubercles of ribs
how many ribs are there
12 pairs
how many are true/ which ones are true
1-7 reach sternum (true)
articulate with their own costal cartilage
which are false
Ribs 8-10 reach costal cartilage above (false)
which lack anterior attachments/floughting ribs
11 and 12 lack anterior attachment (floating)
what do they articulate with
joints)
with vertebral column via head and tubercle
with costal cartilages
how many aprts of the sternum
Sternum has 3 parts: manubrium, body & xiphoid
what is a thoracic ring formed of
1st thoracic vertebra (T1)
1st ribs
Manubrium
Contents of thoracic inlet:
Great vessels heading for neck and upper limb, oesophagus, trachea, nerves and lymphatics
what are the parts of a thoracic vertebrea
body pedicle transverse process lamina spinous process
what does the vertebral foramen carry
spinal cord and menigieal layers
what do ribs articulate with posteriorly
thoracic vertebra
where does the costal groove run
internal surface
Diaphragm
Has a flat central tendon with muscle radiating to costal margin and vertebrae.
why does the diaphragm flatten
Firstly the dome flattens to increase vertical diameter of chest. Secondly it pulls costal margin up to increase transverse and antero-posterior diameters.
function of intercostals
have a secondary role to stiffen chest wall to improve efficiency of breathing movements.
how many intercostal nerves are there
11 pairs T1-T11 (+ 1 subcostal – T12)
why type of nerves
mixed- both motor and sensory
what do they suuply
Supply the intercostal spaces
what does the lateral cutaneous branch divide into
anterior and posterior
anterior cuntaneous branch divides into
medial and lateral
where should you insert for a chest drain
safe area/triangle
The anterior border of latissimus dorsi, the lateral border of the pectoralis major, a line superior to the horizontal level of the nipple and an apex below the axilla. Thedrainshould be inserted just above the rib.
how many layers to the intercostal muscles
3
which bronchi is wider
Right wider and more vertical than left
what supplies the lobes of the lungs
Lobar (secondary) bronchi
Formed within the lungs
Supply the lobes of the lungs
what supplies the bronchopulmonary segments
Segmental (tertiary) bronchi
how many bronchopulmonary segments
10 in each lung
where is the apex of the lung
rises 3-4 cm above level of first costal cartilage
3 borders of the base of lung
3 borders - (edges) - anterior, posterior, inferior
3 surfaces of base
3 surfaces - costal, medial (mediastinal), inferior (diaphragmatic)
what does the diaphragm separate
right lung from right lobe of liver
left lung from left lobe of the liver, stomach & spleen
what are the 3 lobes of the left lung
Superior
Inferior
what is it seprated by
oblique fissure
what does the superior lobe have
Apex
Most of anterior part of lung
how many lobes in right lung
superior
middle
inferior
what is it seperated by
2 fissures
oblique fissure
horizontal fissure
what does horizontal fissure seperaet
separates superior from middle lobe
what does the oblique seperate
separates inferior lobe from the other 2 lobes
what does the root/hilum do
Connects mediastinal surface to heart and trachea
what is the the pluera
A thin layer of flattened cells supported by connective tissue that lines each pleural cavity and covers the exterior of the lungs
what are the 2 layers
visceral pleura
parietal pleura
visceral pleura function
- covers surface lungs and lines fissures between the lobes
parietal pluera
- lines inner surface of chest walls
what is the hilum
Visceral and parietal pleura are continuous with each other around the root of the lung – this is the hilum
how is plueral cavity expanded
Pleural cavity is expanded by muscles in walls
Elastic lungs expand with the pleural cavity, sucking air down trachea and bronchi into lungs
is quiet breathing active or passive
passive not requiring muscles
what is the main inspiratoy muscle
diaphragm
where is the pericardial sac in relation to the pericardial sac
in the centre
which side of the lung does the diaphragm go into deerper
right side
So high abdominal organs such as liver are covered by diaphragm, pleura and lung
what is the lowest cartilanginous ring
carina
