Cardiorespiratory Anatomy Flashcards
What is the Thoracic cavity continuous with?
The thoracic cavity is continuous with the neck via the superior thoracic aperture
What is the thoracic cavity separate from
The thoracic cavity is separate from the abdominal cavity done via the diaphragm
What is the diaphragm
The diaphragm is a sheet of skeletal muscle which is vital for breathing
What do opening in the diaphragm allow
They allow structures to pass from the thoracic cavity to the abdomen
What are the major organs found in the thoracic cavity
Heart
Lungs
What does the thorax contain
Heart
Lungs
Trachea
Oesophagus
Arteries and veins
Nerves
Lymphatic vessels
What is the rib cage also known as
Thoracic cage
What is the thoracic cage
The thoracic cage is the bony skeleton of the thorax which is semi-rigid
What does the thoracic cage do
-Protects the thoracic and some abdominal viscera
-Provides an attachment for the muscles used for breathing and upper limp movement
What is the thoracic cage composed of
The sternum
12 pairs of ribs
Thoracic vertebrae
Where is the sternum found
The sternum lies anteriorly in the midline of the thoracic cage
How many part is the sternum made up of
3
What are the 3 parts of the sternum
Manubrium- the superior part
Body- inferior to the manubrium
Xiphoid process- also known as the xiphsternum which is inferior to the body
What is the notch on the manubrium called and where is it found
The notch is the suprasternal (jugular) notch
Found on the superior border of the manubrium
What does the manubrium articulate with laterally
The clavicle
At what joint does the clavicle and the manubrium articulate
At the sternoclavicular joint
Where do the manubrium and the body articulate
They articulate at the manubriosternal joint
What is the manubriosternal joint also known as
It can be known as the sternal angle or the angle of Louis
What are the anterior parts of the ribs composed of
Costal cartilage
What do the ribs articulate with
The ribs articulate with the costal cartilage
At what joints do the ribs articulate with the costal cartilage
Costochondral joints
What does the costal cartilage of the upper ribs articulate with
The sternum
At what joint does the upper ribs and the sternum articulate
The sternocotal joint
What do the ribs posteriorly articulate with
The thoracic vertebrae
At what joint do the ribs posteriorly articulate with the thoracic vertebrae
At the costovertebral joint
What do intercostal muscles do and where are they found
Intercostal muscles lie in the intercostal spaces and move the thorax for breathing
How many thoracic vertebrae do we have
12
Where can the thoracic vertebrae be found
They lie posteriorly in the midline of the thoracic cage
At what joints do thoracic vertebrae articulate with each other
They articulate at the intervertebral joints
What do the thoracic vertebrae articulate with
Intervertebral joints, and the posterior part of the ribs and costovertebral joints
Name the bones of the sternum from superior to inferior
Jugular notch
Clavicular notch
Manubrium
Sternal angle
Body
Xiphoid process
Name the bones in the skeleton of the thorax
Jugular notch
Clavicular notch
Clavicle
Scapula
Sternum-manubrium
Sternal angle
Sternum-body
Sternum-Xiphoid process
Costal cartilage
What is the heart
A sophisticated muscular pump
What is the heart composed of
Specialised smooth muscle
What do the specialised nerve cells and fibres do in the heart
They spontaneously generate and conduct electrical activity that stimulates the contraction of the myocardium.
Are the nerve cells and fibres under somatic or autonomic control
Automatic control, they are involuntary
What happens to the heart rate under sympathetic stimulation
Heart rate will increase
What happens to the heart rate under parasympathetic stimulation
The heart rate will decrease
What are the 4 chambers of the heart
Right and left atria
Right and left ventricles
What is the function of the ventricles
The ventricles are pumping chambers, the high pressure contracts cause blood to propel out of them
What are the walls of the ventricles like
They are muscular and thick
What are the valves in the heart for
The valves ensure that all blood flows in the on correct direction stopping back flow
What valve is found between the right atria and ventricle
The tricuspid valve- a type of atrioventricular valve
What valve is found between the left aria and ventricle
The mitral valve- a type of atrioventricular valve
What valve is found between the right ventricle and the pulmonary trunk
The pulmonary valve- a type of semilunar valve
What valve is found between the left ventricle and the entrance to the aorta
The aortic valve- a type of semilunar valve
How is the myocardium supplied with blood
The myocardium is supplied by the coronary arteries
What is the cardiopulmonary circulation
The cardiopulmonary circulation is the circulation of blood between the heart and lungs
In the cardiopulmonary circulation what do arteries Carry
Deoxygenated blood
In the cardiopulmonary circulation what do veins carry
Oxygenated blood
Describe the flow of blood in the cardiopulmonary circulation system
1-right aria receives deoxygenated blood from the superior and inferior vena cava
2-deoxygenated blood pumps through the tricuspid valve into the right ventricle
3-deoxygenated blood pumps from the left ventricle through the pulmonary valve
4- the deoxygenated bloody travels via the pulmonary artery to the lungs
5-gas exchange occurs in the lungs
6-oxygenated blood leaves the lungs and travels back to the heart via the pulmonary vein
7-the oxygenated blood arrives to the left atria from the pulmonary vein and pumps through the mitral valve
8-the oxygenated blood pumps from the left ventricle through the aortic valve
9-the oxygenated blood travels through the aorta and to the rest of the body
In relation the the circulatory system what do veins carry
The veins carry blood towards the heart
In relation to the circulatory system what do arteries carry
Arteries carry blood away from the heart
How many lobes is the right lung split into
The right lung is split into 3 lobes- a superior(upper), middle, inferior(lower)
How many lobes is the left lung split into
The left lung is split into 2 lobes- upper and lower
What seperates the lobes?
Fissures
What is each lung served by
One pulmonary artery
Two pulmonary veins
One main bronchus
What is the bronchial tree
The bronchial tree is the branching system of tubes that conducts air in and out of the lungs
How is the bronchial tree formed
The bronchial tree is formed when the trachea bifurcates into the left and right main bronchi, these enter the left and right lungs
Where does gas exchange occur in the lungs
Alveoli
What are the walls of the trachea and bronchi made of
Smooth muscle and cartilage
What is the role of cartilage in the trachea and bronchi
To act as a scaffold and keep the structures open
What are the walls of the bronchioles made of
Smooth muscle
What control of the smooth muscle in the bronchioles under
Autonomic control, involuntary
What happens to the bronchioles under sympathetic stimulation
Narrows of the bronchioles = bronchoconstriction
What happens to the bronchioles during parasympathetic stimulation
Opening of the bronchioles = bronchodilaton
What is surface anatomy
Surface anatomy is the study of anatomical structures by looking, feeling and listening
Describe the looking in relation to surface anatomy
Looking is observing the anatomical structures such as bones or parts of bones which can be clearly seen under the skin eg-clavicle. These can be used as visible landmarks to guide examination.
Describe feeling in relation to surface anatomy
Feeling or palpating is used during examination of a patient. You can palpate certain anatomical structures such as bones, blood vessels, muscle and some organs. During palpating we many palpate something which is abnormal which may cause harm to the patient
Describe listening in relation to surface anatomy
Listening or auscultation is used during an examination of a patient where the doctor will use a stethoscope the auscultate the heart, lungs and intestines. These sounds we auscultate can be normal or abnormal
What is the name of the line drawn straight down the centre of the sternum
This line is the midsternal (anterior median) line
What is the line drawn inferiorly from the midpoint of the clavicle
This line is the mid Clavicular line
What is the line drawn inferiorly from the anterior axilla(armpit)
This line is the anterior axillary line
What is the line drawn inferiorly from the middle of the axilla(armpit)
This line is the midaxillary line
What is the line drawn inferiorly from the posterior axilla(armpit)
This line is the posterior axillary line
What is the line drawn inferiorly through the scapula
This is the Scapula line
What is the line drawn straight down along the spinous process of the vertebrae
This line is the mid vertebral(posterior median) line
What does the manubrium articulate with laterally and inferiorly
The manubrium laterally articulates with the clavicle at the sternoclavicular joint and the first rib
The manubrium inferiorly articulates with the body of the sternum at the manubriosternal joint which can be known as the sternal angle/ angle of Louis’
What does the body articulate with at the sternum and inferiorly
The body articulates with the second rib at the sternal angle (inferior to the manubrium and superior to the body)
The body inferiorly articulates with the Xiphoid process
What shape is the xiphoid process
The xiphoid process is small and can vary in size
What does the xiphoid process articulate with
The xiphoid process articulates with the seventh rib on the superior part
What are the anterior of the ribs made of
Costal cartilage
What happens at the costochondral joints
The ribs articulate with the costal cartilage
What do the costal cartilage of ribs 1-7 articulate with
The costal cartilage of ribs 1-7 articulates with the sternum directly at the sternocostal joints
What are ribs 1-7 known as
True ribs
What are ribs 8-10 known as
False ribs
Why are ribs 8-10 known as false ribs
They are known as false ribs as the costal cartilage unites and merge to join the seventh costal cartilage
What are the 11th and 12th ribs known as
Floating ribs
Why are the 11th and 12th ribs known as floating ribs
They are floating ribs as they are short and so do not articulate with the sternum
What happens at the costovertebral joints
At the costovertebral joints the ribs articulate posteriorly with the thoracic vertebrae
What are adjacent ribs connected by
Intercostal muscles
Which ribs are known as typical and what makes them classified as typical ribs
Ribs 3-9 are typical ribs
Typical ribs look similar and share common anatomical features
Which ribs are know as atypical ribs and why are they classified as this
Ribs 1,2,10,11 and 12 are all atypical ribs
Atypical ribs look different to typical ribs and could lack some features of typical ribs. These are much shorter than typical ribs
Where are the thoracic vertebrae found
T1-T12 lie posteriorly to the midline of the thoracic cage
What does the head of the ribs articulate with
The head of the ribs typically articulates with the vertebral body
What does the tubercle of the rib articulate with
The tubercle of the rib articulates with the transverse process of the vertebrae
What is the superior thoracic aperture
It is where the manubrium, the first ribs and the thoracic vertebrae form a boundary, it is the passageway through which structures pass through between the head and neck
Where do Spinal nerves (T1-T12) innervate
The skin of the thoracic wall
What sensations from the skin reach our conscious perception
Touch
Pain
Temperature
How do sensations reach our conscious perception
Somatic sensory fibres
What nerves innervate the skeletal muscle of the thoracic wall
Somatic motor fibres
What spinal nerves innervate the sweat glands, the smooth blood vessels and the hair follicles
Sympathetic fibres
What is a dermatome
A dermatome is an area of skin innervated by a single spinal nerve
What does each spinal nerve innervate
Each spinal nerve innervate a specific strip around the chest wall
Describe the location of the breast/mammary glands
The mammary glands are superficial to the muscle of the chest wall.
In males are breasts well develop or rudimentary
Rudimentary
In females are breast well developed or rudimentary
Well developed
Where can breast tissue be found
Breast tissue is found on the chest wall
Breast tissue extends towards the anterior axilla this is the axillary tail
What does the breast contain
Fat- various amounts
Glandular and secretory tissues arranged in lobules
Ducts which converge on the nipple
Connective tissues
Ligaments
Blood vessels
Lymphatics
What is the breast primarily supplied by
The breast is primarily supplied by branches of the internal thoracic artery arising from the subclavian artery and the axillary artery
Describe the location of the internal thoracic artery
The internal thoracic artery goes deep to the lateral edge of the sternum, giving rise to the anterior intercostal arteries which supply the breast and intercostal space
How does venous bloody return from the breasts
The venous bloody returns by the axillary and internal thoracic veins
What nerves is the breast supplied with
The breast is supplied with somatic nerves and sympathetic fibres by the intercostal nerves
How does lymph drain from the breast
Lymph from the breast drains to the lymph nodes in the axilla
How many groups of lymph nodes are there in the axilla
5 groups
What are the 5 groups of lymph nodes in the axilla
Central
Pectoral
Humeral
Subscapular
Apical
What areas do the axilla lymph groups drain
Breast
Upper limb
Chest wall
Scapula region
Abdominal wall
Where are the apical nodes found
In the apex of the axilla
Why are the apical nodes so important
The apical nodes received lymph from all other lymph nodes in the axilla
What is the clinical relevance of the apical nodes
They drain the most lymph from the breasts so are often the ones involved in the spread of breast cancer
How many layers of muscle are there in the intercostal space
3 layers
What are the 3 layers of muscle found in the intercostal space
External intercostal
Internal intercostal
Inner most intercostal
What are the intercostal muscles for
Collectively they move the ribs and alter the dimensions of the thoracic cavity with inspiration and expiration
Where is the pectoralis major found
This is the most superficial muscle of the anterior chest wall
What does the pectoralis major attach to
The pectoralis major attaches to the upper humerus, the clavicle and the upper 6 ribs
Where is the pectoralis minor found
This muscle lies deep to the pectoralis major
What does the pectoralis minor attach to
The pectoralis minor attaches to the scapula and ribs 3,4 and 5
Where is the serratus anterior found
The serratus anterior is a superficial muscle that sweeps around the lateral aspect of the thoracic cage
What does the serratus anterior attach to
The serratus anterior attaches to the scapula and the upper 8 ribs
What is the major function of the pectoralis major, pectoralis minor and the serratus anterior
There main function is to move the upper limb
What is the function of the pectoralis major
Addicts the humerus
What is the function of the pectoralis minor and the serratus anterior
The pectoralis minor and the serratus anterior protract the scapula
What can the pectoralis major, pectoralis minor and the serratus anterior also aid with
They can be accessory muscles for breathing because they attach to the ribs, hence they can move the ribs if needed
What is the clinical relevance of using the pectoralis major, pectoralis minor and serratus anterior for breathing
If you are using these muscles to aid breathing, when the humerus and scapula are fixed the patient could be in respiratory distress
What are rib fractures a result of
Blunt trauma to the chest wall
Eg- falls, RTC or assault.
When do rib fractures cause the most pain
Inspiration
How are isolated rib fractures treated
Isolated rib fractures are treated conservatively and so are left to heal on there own with adequate pain management
How are multiple rib fractures treated
Multiple rib fractures are more serious and complex to manage as irregular healing of the ribs may lead to dysfunctional movements of the chest wall and inadequate ventilation
What is shingles
Shingles is a common skin condition which presents with a red, painful and itchy rash normally over the chest and abdomen on only one side of the body
What part of the body does shingles affect
Shingles affects the dermatomes
What cause shingles
Shingles is caused but the reactivation of the herpes zoster virus in people who have previously had chicken pox. The virus will lay dominant in the dorsal root ganglion until reactivated
Why does shingles only cause a rah in one area
Shingles rash will only be present in the dermatome which is innervate by the single spinal nerve affected
Where does breast cancer spread to first
Breast cancer will typically spread to the axillary lymph nodes first because most lymph from the breast is drained to these nodes
How could you know if the breast cancer has spread to the axillary node
You would know as they could be a palpable lump which would be the inflamed node, this could be visible before the mass in the breast is noticed
What could occur if the axillary lymph nodes are removed due to the spread of the malignancy
If the axillary lymph nodes are removed it could lead to fluid accumulation and swelling due to the lymph from the upper limbs not been drained properly, this is known as lymphoedema
What are the spaces between the ribs known as
Intercostal spaces
What do the intercostal spaces contain
Three layers of intercostal muscles and their associated membranes
Intercostal neurovascular bundle made up of an intercostal nerve, artery and vein
Where do the muscles found in the intercostal spaces make attachments
The intercostal muscles make attachments to the rib which lies superiorly and inferiorly
What are the 3 layers of intercostal muscles
External intercostal
Internal intercostal
Inner most intercostal
Where is the external intercostal muscle found
The external intercostal is the most superficial of the intercostal layers
How are the fibres in the external intercostal layer arranged
The fibres are oriented antero-inferiorly
What is the function of the external intercostal layer
This muscle layer contracts pulls the ribs superiorly meaning it in most active during inspiration
What happens at the anterior of the intercostal space
At the anterior of the intercostal space the muscle becomes membranous and forms the external intercostal muscle
Where is the internal Intercostal found
The internal intercostal lies deep to the external intercostal
How do the fibres run in the internal intercostal
The fibres in the internal intercostal run perpendicular to the external intercostal and so run posterior-inferior direction
What is the function of the internal intercostal
The internal intercostal contracts and pulls the ribs inferiorly and so is most active during expiration
When does the internal intercostal become membranous
The internal intercostal becomes membranous in the posterior part of the intercostal space and forms the internal intercostal membrane
Where is the innermost intercostal found
The innermost intercostal is found in the posterior part of the intercostal space deep to the internal intercostal
How are the fibres in the innermost intercostal orientated
The fibres are orientated the same direction as the internal intercostal which is posterio-inferior
What lies deep to the innermost intercostal
The endothoracic fascia lies deep to the innermost intercostal
What does the endothoracic fascia lie superior to
The endothoracic fascia lies superior to the parietal pleura
Where is the parietal pleura found
The parietal pleura is found surrounding the lungs
Where is the neurovascular bundle found
The neurovascular bundle is found in each intercostal space which lies in the plane between the internal and innermost intercostal muscle
What does the neurovascular bundle supply
The neurovascular bundle supplies the intercostal muscle, overlying skin and the underlying parietal pleura
Where can the neurovascular bundle be found in the intercostal space
The neurovascular bundle lies in the inferior border of the rib which is superior to the intercostal space. It lies in the costal groove on the deep surface of the rib
Why is the location of the neurovascular bundle clinical important
It is clinically important because during the medical procedure such as placing a chest drain this involves piercing the intercostal space, the incision need to be made at the middle to lower part of the space to avoid the intercostal vessels and nerves
Where can the collateral branches be found
Collateral branches run in the same tissue plane but are located in the lower part of the intercostal space
What do the anterior and posterior intercostal arteries supply
The anterior and posterior intercostal arteries supply the anterior and posterior parts of the intercostal space
Where does the anterior intercostal arteries come from
The anterior intercostal branches from the internal thoracic artery, which is a branch of the subclavian artery
Where does the posterior intercostal arteries come from
The posterior intercostal arteries branch from the descending aorta in the posterior thorax
Where do the anterior intercostal veins drain to
The anterior intercostal vein drain to the internal thoracic vein
Where does the posterior intercostal vein drain to
The posterior intercostal vein drains to the anyhow system of veins
What type of nerves are the intercostal nerves
The intercostal nerves are somatic nerves
What do intercostal nerves composed of
Intercostal nerves contain motor and sensory fibres
What do the intercostal nerves innervate
The intercostal nerves innervate the intercostal muscles, skin of the chest wall and the parietal pleura
Do intercostal nerves contain sympathetic fibres….. yes or no
Yes
What is the pleurae
The pleurae is the two layers of membrane that cover the lungs and the structures passing into and out of the lungs including the pulmonary blood vessels and main bronchi
Where is the parietal pleura found
The parietal pleura is found lining the inside of the thorax
Where is the visceral pleura found
The visceral pleura is found on the surface of the lungs and extends in the fissures
What is found between the parietal and visceral pleura
The pleural cavity
Are the two layers of the pleura continuous?
Yes
What can be found in the pleural cavity
Within the pleural cavity houses cells which produce small amounts of pleural fluid
Why are the pleura and the pleural fluid important
They are integral mechanics of breathing
What are the parts of the parietal pleura
Cervical pleura
Costal pleura
Mediastinal pleura
Diaphragmatic pleura
What does the cervical pleura cover
The cervical pleura covers the apex of the lung
Where is the costal pleura found
Adjacent to the ribs
Where is the mediastinal pleura found
The mediastinal pleura is found lying adjacent to the heart
Where can you find the diaphragmatic pleura found
The diaphragmatic pleura is found lying adjacent to the diaphragm
What is the costodiaphragmatic recess
The costodiaphragmatic recess is a gutter around the periphery of the diaphragm where the costal pleura becomes continuous with the diaphragmatic pleura
What is found at the junction of the costal and mediastinal pleura
A smaller costomediastinal recess
What are the costodiaphragmatic and costomediastinal recesses there for
The recesses are potential spaces that the lungs expand into during deep inspiration
What is the parietal pleura innervated by
The parietal pleura is innervated by the intercostal nerves which innervate the overlying skin of the chest wall
What do nerve fibres in the parietal pleura carry
The somatic sensory fibres carry sensations to our consciousness, so injury to the parietal pleura can be painful which can occur by fractured ribs
What is the visceral pleura innervated by
The visceral pleura is innervated by autonomic sensory nerves known as visceral afferents
What are the lungs essential for
Lungs are the organs of gas exchange
What is the most superior of the lungs known as
The apex
Where does the apex rise to
The apex projects into the root of the neck above the clavicle
Where does the base of the lungs sit
The base of the lungs sit on the diaphragm
What are the oblique fissures
The oblique fissures are found in both the left and right lung, in the left lung it separates the superior and inferior lobes and in the right lung it separates the superior and middle lobes from the inferior lobe
What is the extra fissure that the right lung has
The right lung has a horizontal fissure which separates the superior lobe and the middle lobe
Where is the costal surface found
The costal surface is adjacent to the ribs
Where is the mediastinal surface found
The mediastinal surface is found adjacent to the heart
Where is the diaphragmatic surface found
The diaphragmatic surface is found on the inferior surface of the lung
What is the anterior border of the lung like
The anterior border of the lung is sharp and tapered
What is the posterior of the lung like
The posterior of the lung is thick and rounded
What is the inferior border of the lung like
The inferior border of the lung is sharp and tapered
Where can the rib markings be found
The rib markings can be found on the costal surface of both lungs
Where can indentations of the left ventricle be found
Indentations of the left ventricle can be found on the mediastinal surface of the left lung
Where can the indentations of the superior vena cava and azygos vein seen
The indentations of the superior vena cava and the azygos vein are seen on the mediastinal surface of the right lung
What does the root of each lung containing
The root of each lung contains the pulmonary artery, the pulmonary veins and the main bronchus
What is the hilum of the lung
The hilum of the lung is the region on the mediastinal surface where the pulmonary artery, pulmonary veins and the main bronchus enter and exit the lung
Are the positions of the pulmonary artery and the main bronchus the same in the left and right lung
No they are slightly different
What is the composition of the hilum in the right lung
The hilum of the right lung contains the main bronchus which lies anterior to the pulmonary artery the two pulmonary veins lie to the most anterior and inferior vessels
What is the composition of the hilum of the left lung
The hilum of the left lung contains the main bronchus lies inferior to the pulmonary artery and the two pulmonary veins are the most anterior and inferior vessels
How is the bronchial tree formed
The bronchial tree is formed by the bifurcation of the trachea at the level of the sternal angle
Describe the path of the right main bronchus
The right main bronchus is shorter wider and descends more vertically to that of the left main bronchus
What is the bronchial tree
The bronchial tree is the branching system of tubes that conducts air into and out of the lungs
What does each main bronchus divide into
Each main bronchus divides into lobar bronchi
How many lobar bronchi does the right lung have
The right lung divides into 3 lobar bronchi
How many lobar bronchi does the left lung have
The left lung is divided into two lobar bronchi
What does the lobar bronchus divide into
The lobar bronchus divides into segmental bronchi
How many segmental bronchi in each lung are there
There are 10 segmental bronchi in each lung
What is the function of each segmental bronchi
Each segmental bronchi supplies a functionally independent region of the lung called the bronchopulmonary segment
What do the bronchopulmonary segment divide into
The bronchopulmonary segment divides into the bronchioles
What is the function of the bronchioles
The bronchioles are small tubes that with each division become smaller, they conduct air to and from the alveoli
What is the function of the alveoli
Alveoli is the site of gas exchange within the lung
What is the wall of the trachea and bronchioles made from
The walls of the trachea contain smooth muscle and cartilage whereas the walls of the bronchioles contain just smooth muscle
What do the pulmonary arteries carry
The pulmonary arteries carry deoxygenated blood to the lungs
What supplies the lungs
The lungs are supplied by the bronchial arteries from the descending aorta
What do the pulmonary veins carry
The pulmonary vein carry’s oxygenated blood
How is venous blood returned from the lungs
The venous blood return bloody from the bronchial veins to the azygos system
What type of nerves innervate the lungs
Autonomic nerves innervate the lungs
What do parasympathetic fibres stimulate in the lungs
The parasympathetic fibres stimulates the constriction of the bronchial smooth muscle which is known as bronchioconstriction and they also stimulate the secretion from the glands in the bronchial tree
What do sympathetic fibres in the lungs stimulate
The sympathetic fibres in the lungs stimulate the relaxation of the bronchial smooth muscle known as bronchodilation and also inhibits the secretion from the glands in the bronchial tree
What fibres accompany the sympathetic and parasympathetic nerves of the lungs
The visceral afferents accompany the sympathetic and parasympathetic nerves
What is the function of the visceral afferents in the lung
The visceral afferents relay sensory information from the lungs and visceral pleura to the CNS but they do not reach our conscious perception
Where does lymph from the lungs drain into
The lymph drains into the venous system via the thoracic duct or right lymphatic duct
Where does the apex of each lung sit
The apex of each lung sits in the lowe neck superior to the medial end of the clavicle
Where is the inferior border of the lungs lies at
The 6th rib anteriorly
The 8th rib laterally
The 10th rib posteriorly
Where does the parietal pleura extent to
The parietal pleura extends to the
8th rib anteriorly
10th rib laterally
12th rib posteriorly
Where are the oblique fissures of both lungs found
The oblique fissures extend from the 4th rib posteriorly to the 6th costal cartilage anteriorly and the fissure runs deep to the 5th rib
Where can the horizontal fissure be found
The horizontal fissure extends anteriorly from the 4th costal cartilage and then intersects the oblique fissure
Where do you place a stethoscope to listen to the superior lobe of the lung
The stethoscope should be placed on the posterior of the chest wall to the markings of the oblique fissure
Where should we place the stethoscope to listen to the middle lobe
The stethoscope should be placed anteriorly or laterally
What are apertures
Apertures are openings in the diaphragm allowing the passage of structures between the thorax and abdomen
What are the structures that pass through the apatures
The structures include the aorta, the inferior vena cava, and the oesophagus
What attachments does the diaphragm make
The diaphragm is attached to the xiphoid process, costal margin, the top of the 11th and 12th rib and the lumbar vertebrae
What is the central part of the diaphragm known as
The central tendon
What happens to the diaphragm during inspiration
During inspiration the diaphragm contracts so the muscle fibres of the right and left domes are pulled towards the peripheral attachments causing the domes to flatten, this increases the intrathoracic volume from the lungs to expand
What happens to the diaphragm during expiration
During expiration the diaphragm relaxes and domes superiorly, this decreases the intrathoracic volume as such driving expiration of air from the lungs
What do the right and left phrenic nerves innervate
The right and left phrenic nerve innervate the right and left side of the diaphragm
What type of the nerves are the phrenic nerves
The phrenic nerves are the somatic nerves formed in the neck by fibres coming from the C3, C4 and C5 spinal nerves containing both motor and sensory fibres
What are the basic principles of ventilation
The muscles move the thoracic cage and change the dimensions
Changes in the intrathoracic cavity determine the intrathoracic volume
Changes in the intrathoracic volume alter intrathoracic volume
Pressure changes inside the thorax drive the processes of inspiration and expiration
Different muscles are used when the breathing is normal, vigorous or forced
Which dimensions change in the thoracic cavity during ventilation
Vertically- due to contraction and relaxation of the diaphragm
Laterally- due to contraction of the intercostal muscles which move the ribs
Anterior-posteriorly- due to the movement of the sternum secondary to the movement of the ribs
Why is the pleural fluid important in ventilation
The pleural fluid creates surface tension between the parietal pleura lining the thoracic cavity and the visceral pleura on the surface of the lungs
Why is surface tension important in the lungs
Surface tension keeps the lungs and thoracic wall together so when the thoracic cavity changes volume the lungs volume changes with it. Surface tension between the two pleural membranes keeps them in contact with each other and prevents the lung from collapsing away from the thoracic wall.
What happens if the surface tension is broken
If surface tension is broken, which can happen by a penetrating injury of the chest that punctures the parietal pleura and introduces air into the pleural cavity, known as a pneumothorax, ventilation may become dysfunctional.
Describe inspiration
The diaphragm and external intercostal muscles contract increasing the intrathoracic volume( the external intercostals pull the ribs superiorly and laterally and the ribs pull the sternum superiorly and anteriorly increasing the dimensions of the thoracic cavity.
The lungs expand increasing the volume with the thoracic wall due to the surface tension
The pressure in the lungs decreases below atmospheric pressure and air becomes drawn into the lungs
Describe expiration
The diaphragm and external intercostal muscles relax and the internal intercostala contract which decreases the intrathoracic volume (the internal intercostals pull the ribs inferiorly and the ribs pull the sternum inferiorly and posteriorly, decreasing the dimensions of the thoracic cavity.
The lungs recoil and decrease in volume
The pressure inside the lungs increase above atmospheric pressure forcing air out of the lungs to be expelled
What muscles are involved during normal breathing
Normal breathing or quiet breathing- inspiration is active and driven by the diaphragm and expiration is passive
What muscles are used during vigorous breathing
Vigorous breathing or breathing during exercise- the intercostal muscles become important. Active expiration uses the internal intercostal muscles
What muscles are used during very vigorous breathing
Very vigorous breathing or forced breathing can be caused by an exacerbation of asthma or COPD- the accessory muscles of breathing will contribute to the movement of the ribs and aid ventilation
The accessory muscles are sternocleidomastoid, pectoralis major and minor and serratus anterior
What is pleuritic Chest pain
Pleuritic chest pain is when the pleura can become inflamed or injured which could occur by been torn by a fractured rib. The chest pain caused by this injury is typically vey sharp and localised, as will be worse on inspiration.
What is a pneumothorax or haemothorax
A pneumothorax is the presence of air in the pleura cavity, usually caused by trauma eg-torn by a fractured rib but can also occur spontaneously when a tear occurs in the visceral pleura. If air keeps entering the pleural cavity but cannot escape- this is known as a tension pneumothorax. The volume of air rapidly increases compressing the lung, heart and great vessels. Patients will present with severe respiratory distress.
A Haemothorax is a collection of blood in the pleural cavity occurring to secondary trauma when the blood vessels are torn or cut.
What is pleural effusion
Pleural effusion is the presence of excess fluid in the pleural cavity however this is not a diagnosis, the fluid could be pus from infection, blood or fluid related to malignancy.
A chest drain is used to remove air and or fluid from the pleural space. An incision is made in the lower part of the chosen intercostal space to avoid the neurovascular bundle which lies in the costal groove
What is mesothelioma
Mesothelioma is a malignancy of the pleura
Describe the primary and secondary lung cancer
Lung cancer can be primary which is cancer of the lung tissue or bronchi or it can be secondary which means that cancer from elsewhere in the body has metastasized to the lungs
What is a pulmonary embolism
Pulmonary embolism is a blood clot in the pulmonary circulation. The clot will form in deep veins in one of the lower limbs and is carried via venous circulation to the right side of the heart and so into the pulmonary trunk. The clot will either get lodged in either the pulmonary trunk or one of the pulmonary arteries which will cause severe respiratory distress and can become rapidly fatal. Small clots that form could occluded smaller pulmonary vessels which can cause infarction of the part of the lung they supply
What is dyspnoea
Dyspnoea is breathlessness or shortness of breath. When patients present with this respiratory distress by using the accessory muscles.
