CR Anatomy Flashcards
Compare the position of the pulmonary valve to it’s auscultation point
Position - behind sternum opposite the 3rd intercostal space
Ausculation - Left side of sternum at 2nd intercostal junction
Compare the position of the aortic valve to it’s auscultation point
Position - left side of sternum opposite left 3rd intercostal junction
Auscultation - 2nd intercostal space to right of sternal body
Compare the position of the bicuspid/mitral valve to it’s auscultation point
Position - left of 4th intercostal junction
Auscultation - 5th intercostal space in mid-clavicular line
Compare the position of the tricuspid valve to it’s auscultation point
Position - behind sternum opposite 4-5th intercostal junction
Auscultation - lower left quadrant of the body of the sternum
What structure divides the mediastinum into superior and inferior?
Transverse thoracic plane (found at sternal angle T4-T5)
Describe the contents of the superior mediastinum
Manubrium, sternal angle, great vessels from aorta
Describe the contents of the inferior mediastinum
Sternum, heart, diaphragm, descending aorta, xiphoid process
Where is the thymus located?
Anterior mediastinum
What are the recurrent laryngeal nerves motor to?
Vocal cords
Describe the passage of the right vagus nerve in the mediastinum
Enters mediastinum lateral to RCCA –> descends in carotid sheath –> anterior to SCA and posterior to SVC –> gives off R recurrent laryngeal branch as it crosses the SCA –> travels in posterior mediastinum
Describe the passage of the left vagus nerve in the mediastinum
Enters mediastinum lateral to LCCA –> descends in carotid sheath –> anterior to SCA and posterior to left brachiocephalic vein –> at lateral side of aortic arch gives off L recurrent laryngeal nerve which hooks under aorta next to ligamentum arteriosum
What nerve plexi does the left vagus nerve supply?
Cardiac and pulmonary plexi
What nerve plexi does the right vagus nerve supply?
Combines with the left vagus supply to form the oesophageal plexus
Where do phrenic nerves enter the mediastinum?
Between the subclavian artery and the origin of the subclavian vein
Describe the passage of the right phrenic nerve
Descends lateral to right brachiocephalic vein and SVC –> over pericardium of right atria –> diaphragm
Describe the passage of the left phrenic nerve
Descends between left SCA and left CCA –> crosses lateral surface of aortic arch anterior to vagus nerve –> superficial to left atrium and ventricles –> diaphragm
When does the trachea bifurcate?
Level of sternal angle (transthoracic plane) at T4-T5
At which spinal level does the trachea begin?
C6
What is the first ganglion of the sympathetic trunk usually fused with?
Inferior cervical (stellate) ganglion
What does the gray rami of the thoracic sympathetic trunk innervate?
Goes to all of the thoracic spinal nerves and post-ganglionic fibres with spinal nerve –> blood vessels, sweat glands, erector pili muscles (skin)
What do the first 5 ganglia of the thoracic sympathetic trunk do?
Give post-ganglionic fibres to heart, aorta, lungs and oesophagus
What do the lower 8 ganglia of the thoracic sympathetic trunk do?
Give pre-ganglionic fibres which are grouped to form splanchnic nerves
What is the role of the greater splanchnic nerve?
Formed from sympathetic ganglia 5-9 and supplies the foregut
What is the role of the lesser splanchnic nerve?
Ganglia 10-11 go to midgut
Ganglia 12 goes to hindgut
How many ganglia are there in the thoracic portion of the sympathetic trunk?
12
What is the outer layer of pericardium bound to?
Central tendon of diaphragm
What is the nerve supply to the fibrous and parietal pericardium?
Phrenic nerves (C3,4,5)
Describe the contents of the posterior mediastinum
Oesophagus, oesophageal plexus, thoracic aorta, azygos and hemi-azygos veins, sympathetic trunks and splanchnic nerves
What is the role of the azygos veins?
Drain blood from the posterior intercostal spaces, posterior abdominal wall, pericardium diaphragm and bronchii
Where does the azygos vein drain to?
Drains up through R side of thorax –> posterior portion of SVC –> RA
When are the coronary arteries perfused?
During diastole when the valves of the aortic sinus are shut
Describe the passage of the left coronary artery
Passes between auricle of left atrium and pulmonary trunk –> atrioventricular sulcus –> divides into left anterior descending and circumflex branches
Describe the passage of the right coronary artery
Leaves right side of the ascending aorta –> right of AV sulcus –> posterior surface of heart –> down posterior interventricular sulcus and gives off the posterior descending branch
Describe the passage of the left anterior descending artery
Runs within anterior interventricular sulcus towards heart apex (supplies anterior wall of left ventricle and anterior 2/3 of interventricular septum)
Describe the passage of the circumflex branch of the left coronary artery
Continues in the atrioventricular sulcus to the posterior surface of the heart giving off the marginal branch on the way
Describe the passage of the left marginal branch
Branch of circumflex artery (from left coronary artery) which follows the left margin of the heart and supplies most of the left ventricle
What structures does the right coronary artery supply?
Right atrium, SAN, AVN and posterior IV septum
What structures does the marginal branch of the right coronary artery supply?
Much of the right ventricle
How does angiogram appearance differ between left and right coronary arteries?
Right coronary arteries appear as C, left coronary arteries appear as M
What is the main vein of the heart and where is it?
Coronary sinus, within the posterior AV sulcus
Describe the passage of the 3 cardiac veins
Great cardiac vein - in anterior interventricular sulcus
Middle cardiac vein - runs in posterior interventricular sulcus
Small cardiac vein - parallel to right marginal artery
Which 3 veins drain into the right atrium?
Superior and inferior vena cava and coronary sinus
What is pectinate muscle?
Rough wall of the atria
What is cristae terminalis?
Smooth-surfaced, thick portion of heart muscle in a crescent shape at the opening into the right atria
What is trabeculae carnae?
Rounded/irregular muscular columns which project from the inner surface of the right and left ventricles
What is the moderator band?
Muscular band of heart tissue found in the right ventricle of the heart
What is the function of the fibrous framework of the heart?
Separates atria and ventricles, provides attachment for muscle, prevents valve overstretching and forms basis of electrical discontinuity between atria and ventricles
What level is the diaphragm in relation to the ribs anteriorly?
7th rib
What is a costophrenic recess?
The recess between the ribs and the lateral-most portion of the diaphragm
What is a cardiophrenic recess?
Angle between the heart and the diaphragm at either the right or left side of the cardiac projection
Where can the apex beat be located?
5th intercostal space in the mid-clavicular line
What are true ribs?
First 7 ribs: connected directly to the sternum
What are false ribs?
Bottom 5 ribs: don’t directly connect to the sternum, but do so via the ribs above them
What are floating ribs?
Bottom 2 ribs which are not attached to the sternum at all
Where do the intercostal veins drain to?
ANTERIORLY: internal thoracic vein
POSTERIORLY: azygos (right), hemizygos (left)
Where is the internal thoracic artery located?
Passes just behind the costal cartilages either side of the sternum
Describe the three layers of muscle between the ribs
External intercostals - hands into front pockets direction
Internal intercostals - hands into back pockets direction
Innermost intercostal muscles - hands into back pockets direction
Describe the attachments of the diaphragm to the bony skeleton
Attached to posterior aspect of xiphoid process, internal surfaces of the lower 6 ribs and costal cartilages and to the L1-L3 posteriorly
Name the 3 structures that pass through the diaphragm and at what spinal level
Vena cava - T8
Oesophagus - T10
Aorta - T12
What is the sensory innervation of the mediastinal pleura, pericardium and some parietal pleura covering diaphragm?
Phrenic nerve
Which nerves provide sensory innervation to the peripheral diaphragmatic parietal pleura?
Intercostal nerves
What type of pleura covers the thoracic wall?
Costal pleura
What type of pleura covers the lateral surface of the mediastinum?
Mediastinal pleura
What type of pleura covers the superior surface of the diaphragm on each side of the heart?
Diaphragmatic pleura
What is the lower area of the pleural cavity, into which the lung expands, known as?
Costophrenic/costophragmatic recess
Where does the nasolacrimal/tear duct drain?
Inferior meatus
Where is the maxillary air sinus?
Air sinus just beneath the eyes either side of the nose
Where are the nasal conchae?
Scroll-like bones in the sides of the nasal cavity –> superior, middle and inferior conchae
Where are the meatuses?
Meatuses are present beneath the conchae in the nose (they are air spaces) –> superior, middle and inferior meatuses
What 3 bones make up the nasal septum?
Ethmoid, cartilage and vomer
Where does the maxillary air sinus drain?
Into nose through the ostia (hole)
What forms the ‘Adam’s apple’ (Laryngeal prominence)?
Thyroid cartilage joined anteriorly
Where is the ‘vocal fold’?
Fold between the arytenoid and thyroid cartilages
Where is the false vocal cord/vestibular fold?
Lies above the vocal fold
Describe the attachments of the epiglottis
Leaf-shaped cartilage attached in the midline to the inner surface of the thyroid cartilage and extends upwards and backwards behind the tongue
Name the cartilage in the larynx from superior to inferior anatomically
Thyroid, (arytenoid behind thyroid), cricoid cartilage
Which cranial nerve supplies the larynx?
CN X (Vagus)
What is the function of the recurrent laryngeal nerve?
Motor to all intrinsic muscles of the larynx except for cricothyroid –> involved in phonation
What are the two divisions of the superior laryngeal nerve?
Internal laryngeal nerve (sensory) and external laryngeal nerve (motor)
What is the function of the internal laryngeal nerve?
Sensory to structures of larynx and laryngopharynx above the vocal folds
What is the function of the external laryngeal nerve?
Motor to cricothyroid –> intonation
What is the blood supply to the larynx?
Laryngeal branches of superior and inferior thyroid arteries
Where is the thyroid gland located?
Anterior to trachea at C5-T1
What are the progressive divisions in the bronchial tree?
Trachea –> two main bronchi –> lobar bronchi (3R, 2L) –> segmental bronchi –> bronchopulmonary segment –> bronchioles –> alveoli
Which side of lung is a foreign body most likely to get lodged and why?
Right side as the right lower lobar bronchus is more vertical than any of it’s left-side counterparts
What is the blood supply to the lungs?
Bronchial arteries (from descending aorta)
Where do bronchial veins drain to?
Azygos and hemiazygos veins
Where does lymph from the lungs drains?
Leaves hilum –> tracheobronchial nodes –> bronchomediastinal lymph trunks
What is the nerve supply to the lungs and visceral pleura?
Vagus (parasympathetic) and sympathetic fibres (not sensory to pain)
What is the nerve supply to the parietal pleura?
Intercostal nerves predominantly
What is the afferent branch of the choking reflex?
Internal laryngeal nerve (branch off of superior laryngeal nerve)
What is the venous drainage of the larynx?
Thyroid veins –> IJVs
