Thorax Flashcards
The thorax has two major openings
Superior thoracic aperture
Inferior thoracic aperture
Boundaries of the superior thoracic aperture
Manubrium of sternum
First pair of ribs
Body of the vertebra T1
Can we palpate the superior thoracic aperture
No.due to the clavicle being in the way
Then inferior thoracic aperture is almost completely covered by what muscle
Diaphragm 
Borders of the thoracic cage
Posteriorly: thoracic vertebral column
Anteriorly: sternum and costal cartilages
Laterally: ribs and intercostal spaces
Superiorly: suprapleural membrane
Inferiorly: diaphragm 
Where does the apex of the lung start 
1-2 cm above the clavicle
The thoracic skeleton consist of
-12 pairs of ribs and associated costal cartilages
-12 thoracic vertebrae and their intervertebral discs
-The sternum 
What is the sternum and what is its parts
Flat bone in the midline of anterior chest wall
- Manubrium
- Body of sternum
- Xiphoid process
The large, visible dip on the manubrium is called
Jugular notch or suprasternal notch
What forms the costal margin
Bottom edge of the rib cage
The manubrium articulates with the sternum forming what joint
Manubriosternal joint
Also called sternal angle or angle of Louis
 Besides the sternum, what else does the manubrium articulate with
-Clavicles
-First costal cartilage
-Upper part of second costal cartilage
The manubrium lies opposite to which vertebral levels
T3 and T4
The sternal angle is around which vertebral level
At the level of the intervertebral disc between T4 to T5
What is the significance of the sternal angle
At this level we have:
- Bifurcation of trachea
- beginning and end of aortic arch
- Adjacent to the second rib

Typical thoracic vertebrae are
T2 to T8
Atypical thoracic vertebrae are
T1
T9
T10
T11
T12
The transverse facet of the vertebrae articulates with what part of the rib
Tubercle of the rib
The Demi facets of the vertebrae articulate with which part of the rib
Head of the rib
Long curved, flat bones that form most of the thoracic cage
Ribs
Characteristic of ribs
Head: two facets
Neck
Tubercle
 party: costal groove 
Describe typical rib articulations
The head of the typical ribs articulate with TWO vertebrae.
- Body of numerically corresponding vertebrae
- Body of the vertebrae superior to it
Example: rib 5 articulates with which vertebrae
Body of T5 and T4
True or false
The tubercle of a typical rib articulates with numerically corresponding transverse process
True
Function of costal cartilages
-Prolong the ribs anteriorly
-Contribute to the elasticity of the thoracic wall
First 7 costal cartilages articulate ____________ with the sternum
DIRECTLY
What is meant by true rib 
Ribs attached directly to the sternum through their own costal cartilages
Another word for true rib
Vertebrocostal
Which ribs are true ribs
1 to 7
Ribs 8, 9 and 10 _____________ articulate with the sternum.
INDIRECTLY
What is meant by false ribs
Their cartilages are connected to the cartilage of the rib above them; thus, their connection with the sternum is indirect
Another word for false ribs
Vertebrochondral
Which ribs are false ribs
8
9
10 (usually)
What is meant by floating ribs
Ribs that do not attach to the sternum directly or indirectly
Another word for floating ribs
Vertebral , free
Which ribs are floating ribs
11
12
(Sometimes 10)
The thoracic skeleton consist of 3 major types of joints
- Costocondral
- Sternocostal
- Costovertebral
What type of joint is costochondral
Fibrous joints
What type of joint is sternocostal
Synovial joint
What type of joint is costovertebral
Synovial joint
How many intercostal spaces are there
11
How many intercostal nerves are there
11
Intercostal spaces are occupied by what
Intercostal muscles and membranes
Intercostal blood vessels and nerves
True or false
The space below the 12th rib is an intercostal space
False
Subcostal space
What is space is below the 12th rib and what does it contain
Subcostal space
Subcostal nerve
What are the three intercostal muscles
External intercostal
Internal intercostals
Innermost intercostal
Where is the neurovascular arrangement in an intercostal space
Between the internal intercostal and innermost intercostal
(VAN)
The thoracic wall is covered on the outside by what
Skin and muscles
The thoracic wall is lined on the inside by what
Parietal pleura
What structures are seen in the thoracic inlet
(Contents of thoracic inlet)
Subclavian artery and vein
Apex of lung
First rib
T1 vertebra
Common carotid artery
Esophagus
Trachea
Internal jugular vein
Manubrium
Which cavity is located centrally and bordered by two pleural cavities laterally
Mediastinum
The mediastinum consists of what cavities
Superior and inferior mediastinal cavities
The inferior mediastinal cavity is further divided into
Anterior, middle, and posterior compartments
Compartments of the thoracic cavity
- Two lateral compartments
- lungs and pleura - Central compartment (mediastinum)
- heart
- great vessels
- trachea
- esophagus
- thymus
The mediastinum extends from the ___________________ to the __________________.
Superior thoracic aperture
Diaphragm 
The division between the superior and inferior mediastinum is called
Transthoracic plane
Location of transthoracic plane
At level of sternal angle and T4/T5 vertebral column
What are the intrinsic muscles of the thorax
External intercostals
Internal intercostals
Innermost intercostals
(Likely includes the transversus thoracic)
One particular innermost intercostal that is located on the inside of the thoracic wall
Transversus thoracis
The order of neuromuscular structures within the costal groove
VAN
Intercostal vein
Intercostal artery
Intercostal nerve
How long is the esophagus
25 cm
Where does the esophagus originate at
Inferior border of the cricoid cartilage
The Esophagus is continuous superiorly with what structure
Laryngeal part of the pharynx (laryngeopharynx)
Order the position of the vertebra esophagus and trachea from anterior to posterior
Trachea
Esophagus
Vertebra
The esophagus enters the abdomen through the diaphragm via what opening
Esophageal hiatus at T10
How does the esophagus terminate
By joining the cardiac orifice of the stomach
What keeps the airways open
C-shaped cartilage rings
What is bronchial tree
Extensively branching respiratory passageways
What is the largest bronchi
Primary (main) bronchi 
Compare the right main bronchi to the left main bronchi
The right main bronchi is wider and shorter than the left
Tough flexible wind pipe that is anterior to the esophagus
Trachea
Where does the trachea start and end
Starts: cricoid cartilage C6
Ends: when branching at T5
The end of the trachea is known as
Carina
What is the hilum of the lung
Where primary bronchus, pulmonary artery and veins enter and exit the lung
How many lobes does the right lung have and what are they
3
- superior
-middle - inferior
How many lobes does the left lung have and what are they
2
-superior
-inferior
What fissures are found on the right lung
Horizontal fissure
Oblique fissure
What fissure is found on the left lung
Oblique fissure 
What separates the superior lobe from the middle lobe in the right lung
Horizontal fissure
What separates the middle lobe from the inferior lobe of the right lung
Oblique fissure
What separates the superior lobe and inferior lobe of the left lung
Oblique fissure
How many secondary/lobar bronchi are on the right side
3
How many secondary/lobar bronchi are on the left side
2
Tertiary bronchi are also called
Segmental bronchi because they branch into each lung segment
What are bronchioles
Little bronchi, less than 1 mm in diameter
Terminal bronchioles
Less than 0.5 mm in diameter
What is pleura
Double layered sac surrounding each lung
What are the two layers of the pleura
Parietal pleura
Visceral pleura

What is the pleural cavity
Potential space between the visceral and parietal pleurae
Pleura helps divide the thoracic cavity into
Central mediastinum
Two lateral compartments
What is atrium
The space at the entrance from the alveolar duct to an alveolar sac
Two phases of pulmonary ventilation
Inspiration – inhalation
Expiration – exhalation
What happens during inhalation
- Diaphragm contracts and pulls downward (flattens)
- volume increases
- pressure decreases
- intercostal muscles contract and raise ribs
What happens during expiration
- diaphragm relaxes and moves upward
- volume decreases
- pressure increases
Is inspiration active or passive and why
Active due to contraction of the diaphragm
Deep inspiration requires
- Scalenes
- Sternocleidomastoid
- Pectoralis minor
- Erector spinae
What does erector spinae do
Extends the back
Is expiration passive or active and why
Passive due to relaxation of the muscle
Is forced expiration an active or passive process
Active 
What muscles are responsible for forced breathing
Oblique and transversus abdominis muscles
Where can I locate the apex of the heart
Fifth intercostal space
Measurements of the heart
L: 12 cm
W: 8 cm
Thickness: 6 cm
Which circuit takes blood to and from the lungs
Pulmonary circuit
Which circuit transports blood to and from body tissues
Systemic circuit
Which chambers receive blood from the pulmonary and systemic circuit
Atria
What are the pumping chambers of the heart
Ventricles
Pericardium layers
- Fibrous pericardium
- serous pericardium
Which pericardium layer is a strong layer of dense connective tissue
Fibrous Pericardium
Which pericardium layer is formed by two layers; parietal and visceral
Serous pericardium
Layers of the heart after the pericardium
Epicardium - visceral layer of serous pericardium
Myocardium - cardiac muscle
Endocardium - internal walls of heart
Location of the heart
Superior right:
- costal cartilage of 3rd rib
- sternum
Inferior right:
- costal cartilage of 6th rib
- lateral to sternum
Superior left:
- costal cartilage of 2nd rib
- lateral to sternum
Inferior left :
- 5th intercostal space
Which ventricle is thicker and why
Left ventricle
Because it exerts more pumping force and flattens right ventricle into crescent shape
Average heart rate
70-80 beats per min
What is meant by systole and diastole
Stage of the heartbeat when ventricles contract and relax
Systole - contraction
Ventricles - relaxation 
Describe tricuspid valve and its purpose
Located between right atrium and right ventricle
Has 3 leaflets / cusps
Purpose: prevent back flow from right ventricle to right atrium
Describe pulmonary valve and purpose
Between right ventricle and pulmonary trunk
Has 3 leaflets
Purpose: prevents back flow from pulmonary artery to trunk
Describe mitral valve and purpose
AKA bicuspid valve
Has 2 leaflets
Located between left atrium and left ventricle
Purpose: prevent back flow from left ventricle to left atrium
Describe Aortic valve and purpose
Between left ventricle and aorta
Has 3 leaflets
Purpose: prevent back flow from aorta to left ventricle
What generates the heart’s impulses ?
Sinoatrial node
“Pacemaker”
True or false
Sinoatrial node sets the inherent rate of contraction
True
Conducting system of the heart in order
SA node
AV node
Bundle of His
Purjinkie fibers
SA node is made up of
Specialized cardiac cells
How many intercostal nerves are there
12
Intercostal arteries arise from two main arteries
- Thoracic aorta
- Internal thoracic arteries (branches of subclavian arteries)
Posterior intercostal arteries arise from
Aorta
Anterior intercostal arteries arise from
Internal thoracic artery
The intercostal veins drain venous blood from the thoracic wall into
- Azygos system of veins
- Internal thoracic veins 
