Thorax,Heart and Lungs Flashcards
Explain inspiratory action and the muscles that control it
Diaphragm contracts and descends. Inspiratory muscles: Sternocleidomastoid muscles and ext intercostals and scalenes expand ribs outward. low pressure generated High volume generated and air comes in.
Explain Exporatoty action
Elastic recoil of lungs and thoracic wall causes passive exhalation.
Exhalation is passive, for active exhalation what muscles may be involved
Abdominal muscles assist in active exhalation
What is FRC
the volume of air in the lungs at end passive exhalation; opposing elastic recoil forces of the lungs and chest wall in equilibrium
What’s the function of the thoracic wall
Protect the Thoracic and abdominal organs
Provides attachment for and Supports the weight of Upper limbs, Neck, ABd, Back and the muscles of respiration.
Resist the negative internal pressure generated by the elastic recoil of the lungs.
Maintain FRC
Thoracic apertures are divided into 2 namely
- Superior thoracic Aperture
2. In ferior Thoracic Aperture.
Name the function of the Superior Thoracic Aperture and what makes up this Aperture.
Allows communication between the upper limb, the thoracic cavity, and the neck
Its made up by :
Anteriorly by The superior border of the Manubrium
Laterally by the First part of Rib and their coastal cartilage
Posteriorly by T1
What makes up the Inferior Thoracic aperture and whats the function of this Segment
Allows communication between the thoracic cavity and the abdomen
Posteriorly by the T12 vertebra
Posterolaterally by the 11-12th pair of ribs
Anterolaterally by the joined costal cartilages of 7-10 ribs
Anteriorly by the xiphisternal joint
Diaphragm closes this space almost completely separating the two cavities
Name and number the 3 types of ribs we have
True ribs(Vertebrosternal)-1-7
False ribs 8-10(Vertebochondral)
Floating(Free) ribs 11-12
How do we name intercostal spaces
Intercostal spaces are named in relation to the rib on the superior border
Where is the Subcostal space located?
Immediately below the 12th rib
What’s the Location of the Manubrium and what are the important landmarks
Manubrium
Lies T3-T4
Clinical landmarks
Jugular (suprasternal) notch
Articulating point for clavicle and first rib
Sternal angle (of Louis)(bifurcation of the trachea)
Opposite 2nd pair of costal cartilages
Level of T4-T5
Name the position of the body of the sternum
T5-T9 level(Ribs 3-6)
Xiphoid process
T10 level
Function and Innervation of Thoracic wall muscle:
Ext intercostal
Forced inspiration, Elevate Ribs
run from the vertebral column, stops short of the sternum
Intercostal nerve
Function and Innervation of Thoracic wall muscle:
Int intercostal
Forced respiration;
interchondral part elevates ribs
interosseous part depresses ribs;
run from the sternum, stops short of the vertebral column
Intercostal Nerves
Function and Innervation of Thoracic wall muscle:
Innermost intercostal
Forced Inspiration :
InterChondral part Elevates ribs
Interosseous part Depresses ribs
found at the most lateral parts of the intercostal spaces
Intercostal nerves
Where does the neurovascular bundle lie within the intercostal muscles
Between internal and innermost layers of the intercostal muscles
Function and Innervation of Thoracic wall muscle:
Transversus thoracis
Intercostal Nerve
and Weakly depresses the rib
Anterior thoracic wall
Subcostal intercostal muscle function and Innervation
Posterior thoracic wall
Act in the same manner as internal intercostal
Forced respiration; interosseous part depresses ribs; intercontinental part elevates ribs
Intercontinental nerve
What’s the chief muscle of inspiration
Diaphragm
Dome-shaped with left and right domes
The right dome is slightly higher than left due to the presence of liver
Name the Diaphragmatic apertures and their function
Caval opening
Located in central tendon
Allows IVC and terminal branches of phrenic nerve to pass into abdominal cavity
During inspiration, diaphragm contracts causing this opening to widen which allows for dilation of the IVC and increased blood return to the heart
Esophageal hiatus
The diaphragm acts as a muscular sphincter for the esophagus that constricts when diaphragm contracts
Transmits the vagus nerve to the abdominal cavity
Aortic hiatus
Opening posterior to the diaphragm, therefore, blood flow is not affected by respiration
Transmits the descending aorta, azygos vein and thoracic duct to the abdominal cavity
The thoracic segment of the spinal cord supplies what nerves
12 pairs of thoracic nerves
Anterior and posterior Rami
What does the Anterior Rami form
T1-T11 form the Intercostal nerves
T12 forms the subcostal nerves
What does the Posterior Rami supply
Deep Muscles of the back
How does the Intercostal nerve do their supply
Intercostal nerves 1 and 2 passes on the internal surfaces of 1st and 2nd ribs.
all others along the inferior margin of the costal grooves (VAN-NAV)
Lateral and anterior cutaneous branches(skin over sternum)
What do intercostal nerves 7-11 supply
Intercostal nerves 7th-11th continue to supply abdominal skin and muscles
Lateral and anterior cutaneous branches(skin over sternum)
From the Thoracic wall nerves, what does the innervation of the Gray Rami supply via sympathetic trunk
Rami communications with sympathetic trunk to reach blood vessels, sweat glands, and smooth muscles
Name the important dermatome landmark
T4,6,8,10
T4 ..nipple line
T6 xiphoid process
T8 last rib
T10 umbilicus
NAme the Thoracic Wall Arterial supply and their divisions
Thoracic aorta
Intercostal and subcostal branches
Subclavian artery
Supreme intercostal arteries
Internal thoracic arteries
name the components of the Thoracic wall Venous system
Anterior intercostal veins:
empty into the internal thoracic veins to brachiocephalic veins
Posterior intercostal veins
empty into the azygos, Hemi-azygos, and accessory Hemi-azygos veins which convey blood to the vena cava
Hemi-azygos and accessory Hemi-azygos empty into the azygos vein
where does the lymph of the body transmit to
Thoracic duct
Explain the thoracic duct tract
Originates from the cisterna chyli
Beaded appearance due to valves
Empties into the venous system near left internal jugular and left brachiocephalic vein or left subclavian vein region
Difference between visceral pleura and Parietal pleura
Visceral pleura adherent to all surfaces of the lungs
Parietal pleura lines the
wall of the thoracic cavity,
the mediastinum,
and the diaphragm
Pleural sac function
the pleural fluid lubricates the pleural surfaces to allow the layers to slide smoothly with respiration
Lungs do not completely occupy the pleural cavities
they contain recesses namely?
Costodiaphragmatic and costomediastinal recesses
Name the Surfaces of the Lungs
Costal
Mediastinal
Diaphragmatic
Name the three borders of the lungs
Anterior
Posterior
Inferior
What are the 3 lobes of the right lung
Superior, Middle inferior
In the right lung, what is the function of the Hilum
Joins the lungs to heart and trachea
Name the components of the roots of the right lungs
Pulmonary artery (deoxygenated blood)- anterior superior
2 Pulmonary veins (oxygenated blood)- inferior
Bronchus/Bronchi-superior posterior
Note vena cava, azygos vein and esophagus
Name the fissures of the right lung
Horizontal and oblique fissure
NAme the fissure of the left lung
Oblique fissure
NAme the lobes of the left lung
Superior and inferior lobe
what are the components of the left lung
Cardiac notch and cardiac impression Lingula The root of the lung Hilum- joins lung to heart and trachea Pulmonary artery (deoxygenated blood)- most superior 2 Pulmonary veins (oxygenated blood)- anterior inferior Bronchus/Bronchi- posterior Note aorta and esophagus
whats the location of the Carina
Level of the sternal angle T4
MAinstem Bonchi division and characteristics
Right mainstem bronchi is 2.5 cm long with angle of 25º and wider than left
Left mainstem bronchi is 5 cm long with an angle 45º
COmponents of Lobar bronchi
Lobar bronchi (secondary bronchi) Right has 3; left has 2
component of segmental bronchi
20-25 generations of branches that end in terminal bronchioles
Respiratory bronchioles (beginning of gas exchange)
Alveolar ducts
Alveolar sacs (basic structural unit of gas exchange)
Explain the flow of blood in the pulmonary arteries(1 to each lung)
Deoxygenated blood
Enters hilum
Lobar and segmental arteries
Explain the flow of blood in the pulmonary veins (2 each Lung)
Oxygenated blood
Empty into the left atrium
Bronchial arteries supply blood to?
Roots of the lungs, Lung tissues, and Visceral pleura resp bronchiole Run posterior to main bronchiole
Bronchial veins drain blood into?
Drain only part of the blood supplied by bronchial arteries
R) into the azygos vein and
left into accessory Hemi-azygos vein
Pulmonary veins drain blood into?
blood is drained by pulmonary veins (oxygenated blood) into left atrium
Physiologic shunt
Bronchial arteries are branches of ?
Aorta and run posterior to the main bronchi
What are the vasculature of the lungs made up of
Bronchial arteries and Bronchial veins
Bronchial arteries supply blood to?
structures that makeup roots of the lungs,
supporting tissues of the lungs and
visceral pleura
Main bronchi and respiratory bronchiole
whats the innervation of the tracheobronchial tree
1.Pulmonary plexus
Anterior and posterior to roots of the lung
2.Parasympathetic fibers
Vagus (CN X)
3.Sympathetic fibers
Sympathetic trunks
what does the Vagus(PNS) do in the bronchial tree
Motor to smooth muscle- bronchoconstrictor
Inhibitory to pulmonary vessels- vasodilator
Secretory to glands bronchial tree- secretomotor
what does the Sympathetic fiber do in the bronchial tree
Sympathetic- paravertebral sympathetic ganglia
Inhibitory to bronchial smooth muscle- bronchodilator
Motor to pulmonary vessels- vasoconstrictor
Inhibitory to alveolar glands of the bronchial tree
Name the component of the mediastinum
Occupied by the viscera between the pulmonary cavities
Contains all of the thoracic viscera, except the lungs
1.Superior mediastinum
2.Inferior mediastinum
i) Anterior mediastinum
Lymph nodes, fat and connective tissue
ii) Middle mediastinum
iii)Posterior mediastinum
Components of the superior Mediastinum
Thymus* Brachiocephalic vein* SVC* Pulmonary Trunk Bifurcation Pulmonary artery Artery roots Arch of Aorta(Brachiocephalic, Left common carotid, Aorta)* Ligamentum arteriosum* Vagus* Phrenic* Cardia plexus* Trachea* Esophagus* Thoracic duct* BLASTTTVEPPPC
Components of the posterior mediastinum
Thoracic Aorta Thoracic Duct Lymph nodes Azygos, hemi-azygos, and accessory hemi-azygos veins sympathetic trunks(Thoracic) Splanchnic nerves(Thoracic) Esophagus Esophageal plexus Vagus nerve
LASSTTVEE
Middle mediastinum components
Pericardium Heart Ascending aorta Pulmonary trunk Superior vena cava Arch of the azygos vein Main bronchi
What are the layers of trhe Pericardium
- Double-walled membrane
- Encloses the heart and roots of the great vessels
Outermost layer is the parietal layer
Reflected onto the heart and great vessels
Innermost layer is the visceral layer
Comprises the epicardium (external layer of the heart wall)
Pericardial cavity
Contains serous fluid
Frictionless movement of the heart
Vasculature of the pericardium is made up of ?
Pericardiacophrenic artery (branch of the internal thoracic artery) and pericardiacophrenic veins
Nerve supply of the pericardium is made up of?
Phrenic nerve for sensory
Referred pain to C3-C5 dermatomes
Sympathetic trunks
vasomotor
NAme the heart layers
Thin external layer formed by the visceral layer of the pericardium
Myocardium
Thick, middle layer composed of cardiac muscle
Endocardium
Thin internal layer that lines the heart and covers the valves
apex location of the heart
Anteriorly and to the left
Inferolateral part of the left ventricle
5th intercostal space, 9 cm from median plane
Base location of the heart
Posterior aspect
Left atrium
T6-T9
The anterior surface of the heart is the?
Right ventricle
The inferior(Diaphragmatic) surface of the heart is the ?
Left ventricle and right ventricle
Left pulmonary surface of the heart is the ?
Left ventricle,
cardiac impression of left lung
The right pulmonary surface of the heart is?
By the right atrium
Components of the right atrium are?
Coronary Sinus receives blood from the Coronary veins(between right AV orifice and IVC orifice)
Sinus Venarum(smooth area) :SVC level 3rd intercostal and IVC level 5th intercostal
Cristae Terminale Fossa ovale Pectinate muscles Interatrial septum(separates the atria) Right auricle
Location of the Right AV Orificeis?
4th to 5th intercostal space
The function of the papillary muscles is
Prevent valve from prolapsing during ventricular contraction (systole)
Tricuspid valve)Right AV Valve Function and component
Guards right AV orifice (4th-5th intercostal spaces)
Three cusps
Anterior, septal and posterior
Chordae tendineae attach to anterior, septal and posterior papillary muscles:
Prevent valve from prolapsing during ventricular contraction (systole)
Papillary muscles contract slightly before ventricle to draw cusps together
Normal valve opening: 4-6 cm2
Right ventricle component and function are?
Sends blood to the pulmonary system
Conus arteriosus
Leads to pulmonary trunk
Trabeculae carneae
Irregular muscular elevations
Papillary muscles
Connect to chordae tendineae
Intraventricular septum
Separates left and right ventricles
Bulges into the right ventricle due to increased pressure in left
septomarginal trabecula (moderator band)
Carries part of the right bundle branches of the AV bundle to the anterior papillary muscle
Facilitates conduction time and allows for coordinated contraction of the anterior papillary muscle
Components and function of the pulmonary valve
Semilunar valve
Apex of the conus arteriosus (3rd costal cartilage)
Three cusps
Anterior, right and left
Pulmonary sinus just superior to valve, start of the pulmonary trunk
Blood prevents cusps from reopening during diastole
Normal valve opening: 2 cm2
Components of the Left Atrium and function
Receives well-oxygenated blood from pulmonary system Left auricle Overlaps pulmonary trunk Contains pectinate muscles Four valve less pulmonary veins Right and left superior and inferior Posterior wall Slightly thicker wall than right atrium Left AV orifice
Mitral valve component and function
Left atrioventricular (AV) valve; Bicuspid valve
Guards left AV orifice (4th costal cartilage)
Two cusps
Anterior and posterior
Chordae tendineae attach to anterior and posterior papillary muscles
Prevent valve from prolapsing during ventricular contraction (systole)
Papillary muscles contract slightly before ventricle to draw cusps together
Normal valve opening: 4-6 cm2
Left ventricle components and function
Walls are 2-3 times thicker than the right ventricle
Trabeculae carneae
Finer but more numerous than right ventricle
Anterior and posterior papillary muscles
Larger than those in right ventricle
Aortic vestibule
Smooth walled area leading to aortic orifice
Aortic orifice
Outflow to ascending aorta
Contains aortic valve
Where do the right and left coronary arteries arise from
Right aortic sinus contains the opening of the right coronary artery
Left aortic sinus contains the opening of the left coronary artery
AOrtic valve components and function
Semilunar valve
Apex of the aortic vestibule
Three cusps
Left, right and posterior
Aortic sinus just superior to the cusps, start of the ascending aorta
Right aortic sinus contains the opening of the right coronary artery
Left aortic sinus contains the opening of the left coronary artery
Posterior aortic sinus does not contain a coronary artery
Normal valve opening: 2.5- 4.5 cm2
what are the valve auscultation point and when do the close for s1 and s2 heart sounds
First heart sound, S1
Closure of the AV valves
Systole
Tricuspid valve
Near left sternal border in 5th intercostal space
Mitral valve
apex of heart in 5th intercostal space, midclavicular line
Second heart sound, S2
Closure of semilunar valves
Early diastole
Aortic valve
2nd intercostal space, right of sternal border
Pulmonary valve
2nd intercostal space, left of sternal border
What vessels supply the Epicardium and the myocardium
coronary arteries
RCA branches are(R Dom)
Arises from right aortic sinus
Runs along the coronary sulcus
Sinu-atrial (SA) nodal branch
SA node
Right marginal branch
Right border of the heart
AV nodal branch
Crux of the heart (junction of septa and walls of the four chambers)
AV node
Posterior interventricular branch
Left and right ventricles
Interventricular septum
RCA supplies(R Dom)
Right atrium Most right ventricle Part of left ventricle Part of IV septum (posterior third) SA node (60% of people) AV node (80% of people)
Left coronary artery branches(R Dom)
Runs along the coronary sinus
Anterior interventricular branch (left anterior descending)
Left and right ventricles
Interventricular septum
Anastomoses with the posterior IV branch of RCA
Circumflex branch
Left posterior ventricle
Left marginal artery
Left ventricle
LCA supplies? (R Dom)
Left atrium Most of the left ventricle Part of the right ventricle Most of the IV septum (anterior two-thirds) AV bundle of conducting tissue SA node in 40% of people
Veinous drainage of the heart is made up of ?
Great cardiac vein
Close proximity to LAD and circumflex
Empty into coronary sinus
Middle cardiac vein
Close proximity to posterior interventricular branch
Empty into coronary sinus
Small cardiac vein
Close proximity to RCA
Empty into coronary sinus
Coronary sinus
Empties into right atrium
Anterior cardiac veins empty directly into right atrium
Explain the conduction system of the heart and the location ?
Sinu-atrial (SA) node
Nodal tissue that initiates and regulates heartbeat; 60-100 bpm
Deep to epicardium, junction of SVC and right atrium
Internodal tracts to depolarize atria
Atrioventricular (AV) node
Smaller collection of nodal tissue
Directs SA nodal signal to septum and initiates and regulates heartbeat (if SA node fails); 40-60 bpm
Interatrial septum near the opening of the coronary sinus
Atrioventricular bundle of HIS
Distributes signal to ventricles
Right and left bundle branches
Purkinje fibers (subendocardial branches) Nodal tissue; if SA/AV nodes fail to fire will initiate heartbeat; 20-40 bpm
Where are the presynaptic fibers cell body of Superficial and deep cardiac plexuses
Sympathetic located
intermediolateral cell columns of the superior 5-6 thoracic segments of spinal cord.
Where are the postsynaptic fibers cell body of Superficial and deep cardiac plexuses
Sympathetic located and what are the function of this fibre
cervical and superior thoracic paravertebral ganglia of the sympathetic trunks
Postsynaptic fibers end in the SA and AV nodes and close to coronary arteries
Increases heart rate and force of contraction
Dilation of coronary arteries by inhibiting their constriction
Where are the presynaptic fibers cell body of Superficial and deep cardiac plexuses
paraSympathetic located
Vagus nerve
Where are the postsynaptic fibers cell body of Superficial and deep cardiac plexuses
paraSympathetic located and the function
Postsynaptic cell bodies located near SA and AV nodes and along coronary arteries
Slows heart rate and reduces the force of contraction
Constricts coronary arteries
