Anatomy Flashcards
How are the superior and inferior mediastinum separated?
at the sternal angle (T4/5)
The inferior mediastinum is further divided into _______________________.
Anterior, Middle (heart), posterior
What are the borders of the superior mediastinum?
Superior: 1st rib
Inferior: T4
What are 5 contents of the superior mediastinum?
1) Thymus
2) Trachea
3) Esophagus
4) Thoracic duct
5) Aortic arch
6) Veins (SVC, brachiocephalic)
7) Nerves (vagus, phrenic, L recurrent pharyngeal)
The thymus is found in both the _________ and ___________ mediastinum and is supplied by the ________________.
Thymus:
- both superior and anterior mediastinum
- Internal mammary artery
What are 5 contents of the middle mediastinum?
1) Heart
2) SVC
3) Ascending Aorta
4) Pulmonary trunk
5) R/L Pulmonary veins
6) R/L Phrenic veins
7) Cardiac plexus
8) Lymph nodes
Does the pericardium cover the aortic arch and descending aorta?
No
What are 2 layers of the pericardium?
1) Fibrous
- outer, tough, inelastic
- bound to central tendon of diaphragm by pericardiophrenic ligament
2) Serous
- Parietal
- Visceral
True or false:
The heart is located within a double-walled fibroserous sac known as the pericardium containing pericardial fluid to enable frictionless movement.
False.
The heart is not within but surrounded by the pericardial sac
Which layer(s) of the pericardium are supplied by the phrenic nerves and thus sensitive to pain?
Fibrous and parietal of serous
Pericarditis pain is:
exacerbated by ____________
alleviated by ______________
Pericarditis pain is:
exacerbated by deep breaths
alleviated by sitting up and leaning forward (↓P on parietal pericardium esp on inspiration)
What kind of pain fibres innervate the visceral layer of the pericardium?
Sympathetic and vagus (insensitive to pain)
What are the 2 sinuses of the pericardial cavity?
1) Transverse sinus
- behind ascending aorta and pulmonary trunk
- infront of SVC
2) Oblique sinus
- behind L/R pulmonary veins, SVC and IVC
- infront of anterior esophagus
Which pericardial sinus would mostly likely be penetrated by a ingested fish bone?
Oblique
- posteriorly bounded by anterior esophagus
What is pericarditis?
Inflammation of the pericardium
What is a pericardial effusion?
The passage of fluid from the pericardial capillaries into the pericardial cavity.
What is a hemopericardium?
Stab wounds that pierce the heart may cause blood enter into the pericardial cavity
What is a cardiac tamponade?
Extensive pericardial effusion, the excess fluid does not allow heart to expand fully, thereby limiting the inflow of blood to the ventricles.
- potentially lethal condition, because the fibrous pericardium is tough & inelastic.
What is a perocardiocentesis?
drainage of fluid from the pericardial cavity
What are 4 contents of the posterior mediastinum?
1) esophagus
2) Thoracic (descending) aorta
3) Azygos vein
4) Thoracic duct
5) Sympathetic chain and splanchnic nerves
At which vetebral level does the esophagus begin?
From pharynx at C6
After entering the thoracic inlet, the esophagus lies anterior to ____________ and posterior to _____________.
Trachea < Esophagus < vertebra
At the level of the sternal angle, the esophagus is cross by:
i) the _______________ on the left
ii) the _____________ on the right
iii) the ______________ infront
@ Sternal angle, esophagus crossed by:
i) aortic arch on L
ii) arch of azygos vein on R
iii) L bronchus in front
Which chamber of the heart lies closest to the esophagus?
Left atrium
The esophagus pierces the diaphragm at which level?
T10
What are 3 physiological constrictions of the esophagus?
1) Junction of esophagus and pharynx
2) Crossing of arch of aorta (sternal angle) + compressed by L main bronchus
3) Enter diaphragm (T10)
What are 4 branches of the descending aorta?
1) Posterior intercostal
2) Esophageal
3) Bronchial
4) Pericardial
5) Subcostal
6) Mediastinal
Describe the lateral movement of the thoracic aorta inferiorly.
Begins @ L of T4 → moves medially to be anterior to lower thoracic vertebrae as it descends in posterior mediastinum
What are 4 tributaries of the azygos vein?
1) Posterior intercostal
2) Esophageal
3) Bronchial
4) Mediastinal
True or false:
The azygos vein drains blood from both the posterior wall of the thorax and the abdomen. It also forms a collateral pathway between the SVC and IVC.
True
The azygos vein ascends into the posterior mediastinum through the __________ of the diaphragm, on the (R/L) side of the vertebra and arches _________________ to join the SVC.
Ascends through aortic opening (T12) of diaphragm.
R of vetebrae
Arches on superior aspect of root of R lung to join SVC
Describe the drainage of the 22 posterior intercostal veins.
1st posterior on both side → brachiocephalic
remaining 10 on R → azygos
remaining 10 on L → hemiazygos → azygos
The thoracic duct originates from ________________, ascends through the diaphragm at ____________, emptying into the venous system at _____________.
Originates from cisternal chyli in abdomen
Ascend through diaphragm @ T12 (aortic opening)
Empty into venous system @ venous angle (union of L internal jugular and subclavian)
In the posterior mediastinum, the thoracic duct lies between _____________________ and crosses (L/R) at (which level) to ascending into the superior mediastinum (posterior/anterior) to esophagus.
Posterior mediastinum:
- btwn thoracic aorta (L) and Azygos vein (R)
Cross L into superior mediastinum at sternal angle (T4/5)
- posterior to esophagus
Which parts of the body does the thoracic duct drain and where does the rest go?
R Head, neck, upper limb and thorax → R lymphatic duct
Everything else → Thoracic duct
The sympathetic trunk/ganglion lie on which side of the veterbrae?
Both sides
What are splanchnic nerves?
Nerves containing both preganglionic sympathetic fibres and visceral afferent fibres
What are 3 types of splanchic nerves arising from the sympathetic trunk?
1) Greater splanchnic nerve (T5-9)
2) Lesser splanchnic nerve (T10-11)
3) Least splanchnic nerve (T12)
True or false:
The heart is shaped like a pyramid.
True lol
The heart has 3 surfaces:
i) __________________________
ii) _________________________
iii) _________________________
and 4 walls:
____________________________
Surfaces
i) Pulmonary (left/LV)
ii) Sternocostal (anterior/RV)
iii) Diaphragmatic (inferior/LV/RV)
Walls:
Septal, Anterior, Lateral, Inferior
Which heart chamber forms the apex of the heart?
Left ventricle
Which heart chamber forms the base of the heart?
Left atrium
What are the internal features of the right atrium (5)?
1) IVC
2) SVC
3) Tricuspid valve
4) Rough pectinate muscle
5) Interatrial septum (Fossa ovalis/where foramen ovale used to be)
6) Coronary sinus (between tricuspid valve and fossa ovalis)
7) SA node (near upper ends of crista terminalis: boundary of smooth and rough parts of RA)
8) AV node (between coronary sinus and tricuspid valve)
Atrial septal defect involved the incomplete closure of what structure?
Foramen ovale
What are the internal features of the right ventricle (5)?
1) Papillary muscles
2) Chordae tendinae
3) Tricuspid valve
4) Moderator band
5) Trabecular carnae
6) interventricular septum
7) Pulmonary valve
True or false:
The left intraventricular pressure is 6x higher than the right and its wall is 3x thicker.
True
What are the internal features of the left atrium (2)?
1) Pectinate muscle
2) Smooth and rough part of chamber
3) Pulmonary vein openings
4) Bicuspid (mitral) valve
What are the internal features of the left ventricle (4)?
1) Papillary muscle
2) Chordae tendinae
3) Mitral valve
4) Interventricular septum
5) Aortic valve
6) Trabeculae carnae
What structures does the left coronary artery supply (4)?
Left Anterior Descending (LAD):
1) RV
2) LV
3) AV bundle
4) 2/3 Interventricular septum
Left circumflex (LCx):
5) LA
2) LV
What structures does the right coronary artery supply?
Marginal:
1) RV
Posterior descending:
2) 1/3 Interventricular septum
3) LV
4) RV
What is coronary dominance?
The artery that suppled the posterior descending artery
- precisely which supply AV node
(TLDR: left dominant = bad coz then all supply to LV and AV node is from LCA)
Majority of the population is (right/left) coronary dominant.
Right (85%)
(TLDR: left dominant = bad coz then all supply to LV and AV node is from LCA)
What is an end artery and give 2 examples?
an artery that is the only supply of oxygenated blood to a portion of tissue.
Eg. splenic, renal
Where is cardiac pain referred to?
T1-4 dermatomes: neck, and left shoulder
Describe the venous drainage of coronary circulation.
Anterior cardiac vein → RA
Great, middle, small and posterolateral cardiac veins → Coronary sinus → RA
What are the branches of the aorta from right to left?
1) Brachiocephalic trunk
2) L common carotid
3) L subclavian
What are the branches of the brachiocephalic trunk?
1) R common carotid
2) R subclavian
What are the tributaries of the SVC (4)?
1) R Subclavian
2) R Internal jugular
3) R lymphatic duct
→ R brachiocephalic
4) R subclavian
5) R Internal jugular vein
6) Thoracic duct
→ L brachiocephalic
Injury to the phrenic nerve will cause (bi/ipsi/contralateral) paralysis of the diaphragm.
Ipsilateral paralysis of hemidiaphragm
Which spinal segments does the phrenic nerve arise from?
C3-5
The right phrenic nerve runs (anterior/posterior) to the root of the lungs and (lateral/in between) the R brachiocephalic vein and SVC.
Right Phrenic
Anterior to root of lung
Lateral to SVC and R Brachiocephalic vein
The left phrenic nerve runs (anterior/posterior) to the root of the lungs and (lateral/in between) the L subclavian artery and L common carotid artery.
Left Phrenic:
Anterior to root of lung
In between L common carotid and subclavian artery
Vagus nerves contains (para)sympathetic nerve fibres
Vagus: Parasympathetic
The right vagus nerve runs (superficial/deep) to the R subclavian artery, hooking under it to form the _______________.
Superficial to R subclavian artery, hooks under to form R recurrent laryngeal nerve
The left vagus nerve lies (anterior/posterior) to the L phrenic nerve, in between the L common carotid and subclavian artery. It wraps around the aortic arch below the ligamentum arteriosum to form the ______________________.
Posterior to phrenic
Forms the L recurrent laryngeal nerve
Which recurrent laryngeal nerve is found in the superior mediastinum?
Left only (right hooks under R subclavian above)
What is the ligamentum arteriosum?
Fibrous band passing from L pulmonary artery to aortic arch
- remnant of ductus arteriosus
Describe the nervous supply of the heart?
Intrinsic: pacemaker cells in SA node
Modified rate:
1) Cardiac nerve (SNS)
2) Vagus nerve (PNS)
The cardiac center, containing the cardioacceleratory and cardioinhibitory centers of the brain is located in the _____________.
Medulla oblongata
What are the 4 areas of ausculation of the heart?
Aortic: R upper sternal border (2nd ICS)
Pulmonary: L upper sternal border (2nd ICS)
Tricuspid: 4th L ICS (next to sternum)
Mitral: 5th LICS (below nipple)
Where is the apex beat normally felt?
5th ICS mid clavicular line
What is a Coronary Artery Bypass Graft?
A segment of a long saphenous (from lower limb) vein is connected to the ascending aorta and then distal to the coronary artery stenosis.
What are 3 functions of the lymphatic system?
1) Balance volume of interstitial fluid
2) Immune
3) Absorption of lipids and fat soluble-vitamines
True or false: The flow of lymph is multidirectional depending on the presence of valves and presence of edema.
False. Unidirectional because of one way valves
(even when no valves, pressure gradient maintain by vascular smooth muscle, skeletal muscle, respiratory movements
What are 2 difference between lymphatic capillaries and lymphatic vessels?
Lymphatic capillaries:
- highly permeable
- no continues basal lamina and smooth muscle
- thin
Lymphatic vessels:
- continuous tight junctions prevent leak
- continuous basal lamina and smooth muscle cells
- thick due to connective tissue and smooth muscle
Lymphatic capillaries have (greater/lesser) permeability than blood capillaries and there (are/aren’t) pericytes.
Lymphatic > permeability
- no pericytes, no basement membrane
True or false:
Lymphatic capillaries lack valves.
True
