Anatomy - Thorax

Question 1

For the thoracic wall

Openings:
Skeleton parts:
Joints: 
Intercostal spaces:
Muscles:

Answer 1

Openings: superior and inferior thoracic apertures
Skeleton: sternum, twelve pairs of ribs, twelve thoracic vertebrae
Joints: intervertebral discs, costovertebral, sternocostal, sternoclavicular, costochondral, interchondral joints
Intercostal spaces: intercostal vein, artery, nerve
Muscles: intercostal muscles, (external, internal, innermost), transversus thoracis, subcostals, levatores costarum, serratus posterior superior, serratus posterior inferior muscles

Question 2

The attachments of diaphragm can be divided into?

Answer 2

The attachments of diaphragm can be divided into peripheral and central attachments.
It has three peripheral attachments:

Lumbar vertebrae and arcuate ligaments.
Costal cartilages of ribs 7-10 (attach directly to ribs 11-12).
Xiphoid process of the sternum.

Question 3

The parts of the diaphragm that arise from the vertebrae are ? in structure, and are called?

Answer 3

The parts of the diaphragm that arise from the vertebrae are tendinous in structure, and are called the right and left crura.

Question 4

Right crus – Arises from? Some fibres from the right crus surround what opening
Left crus – Arises from?

Answer 4

Right crus – Arises from L1-L3 and their intervertebral discs. Some fibres from the right crus surround the oesophageal opening, acting as a physiological sphincter to prevent reflux of gastric contents into the oesophagus.
Left crus – Arises from L1-L2 and their intervertebral discs.

Question 5

The pathways through the diaphragm and their vertebral levels:

What are the contents?

Answer 5

3 Hiatuses:

1) Cava hiatus (T8): Vena Cava, terminal branches right phrenic nerve
2) Oesophageal Hiatus (T10): R+L Vagus nerve, Oesophageal branches of Left gastric artery and vein
3) Aortic hiatus: Thoracic duct, azygous vein, Aorta.

Question 6

Trick for remember ing the level of diaphragm hiatuses?

Answer 6

A tip for remembering the vertebral levels: vena cava has eight letters (T8), oesophagus has ten letters (T10) and aortic hiatus has twelve letters (T12).

Question 7

Functions of the trachea and bronchi

Answer 7

Large airway conduits for gas exchange.

Pathway of expectoration

Question 8

The trachea begins

Answer 8

At the inferior edge of the hypopharynx, which is the inferior edge of the cricoid cartilage. At the level of C6.

Question 9

The trachea ends at:

Answer 9

In the thorax at the level of the sternal angle (T4) at the carina which is the bifurcation of the trachea.

Question 10

How much does the carina move with deep inspiration?

Answer 10

Movers from T4 to T6

Question 11

How big is the carina?

Answer 11

12cm long, 2.5cm wide

Question 12

Describe the trachea

Answer 12

Large airway conduits for gas exchange.
Pathway for expectoration
12cm long, 2.5cm wide fibrocartilagenous tube, whose structure is maintained by “u shape” bars of hyaline cartilage.
begins at the inferior edge of the hypopharynx, which is the inferior edge of the cricoid cartilage. At the level of C6. In the thorax at the level of the sternal angle (T4) at the carina which is the bifurcation of the trachea.
Carina moves between T4 and 6 on deep inspiration.

Question 13

Relations of the cervical trachea

Answer 13

Superior: Hypopharynx, inf edge cricoid, isthmus of thyroid (anterior superior)
Anterior: sternothyroid and sternohyoid
muscles, anterior jugular veins and JUGULAR VENOUS ARCH
Posterior: oesophagus, recurrent laryngeal nerve, Cervical vertebrae.
Lateral: Carotid sheath, lobes of thyroid

Question 14

Relations thoracic vertebrae:

Answer 14

Anterior: sternum, origins of right brachiocephalic and left common carotid arteries, left brachiocephalic veins
Posterior: oesophagus left recurrent laryngeal nerve
Left: aortic arch, left common carotid, left subclavian artery, left vagus, left phrenic and recurrent laryngeal n, pleura
Right: azygos vein, right vagus and pleura

Question 15

The lining of the trachea:

Answer 15

Respiratory epithelium:

Ciliated PSEUDOstratified columnar epithelia, w/mucous glands (goblet cells)

Question 16

Mnemonic for segments of the lung. State which bits are basal and which lingular.

ALSO applies to?

Answer 16

Right Lung:
A PALM Seed Makes Another Little Palm
- Capitals are upper and middle: APA = upper Apex, post, ant. LM = middle, lat and med
- lower case is lower lobe: everything but superior has basal in thename - i.e Lateral basal segment

Left Lung:
ASIA ALPS
ASIA = UL + Lingular (Sup and Inf LINGULAR segments)
ALPS = LL = Superior segment, then all the rest have BASAL in their name, i.e Lateral basal Segment

The above also applies to bronchi

Question 17

Relations of the right and left main pulmonary veins (also their tibutaries are?)

Answer 17

The right main pulmonary veins: passes the right atrium and superior vena cava inferiorly; the left in front of the descending thoracic aorta.

Question 18

What does the aortic arch loop over?

Answer 18

1) Left main bronchus or bifurcation
2) Bronchial arteries (which emerg from the anterior surface of the aorta just before the arch)
3) bifurcation of pulmonary trunk

Question 19

Main branches of aortic arch

Answer 19

Right: branchiocephalic trunk (i.e needs to be simple because Right and left brachiocephalic kinda in the way)

Left (proximal to distal): Left common carotid, left subclavian artery

Question 20

what nerve closely associates with the aortic arch?

Answer 20

The left vagus.

On the right the vagus travels over the subclavian proximal to the bifurcation, giving of a branch of the recurrent laryngeal which loops under and goes back up

Question 21

1st branch of left brachiocephalic vein?

Answer 21

right thyroid vein (this can come off the bifurcation though)

Question 22

The highest lymph nodes of the thorax are stations?
Where are they?

The next

The next

The next

Answer 22

The trachial nodes are Left Right, except 3 which are Ant Post. Highest - upper - retro - lower.

1 R and 1L “Highest mediastinal nodes”
Superior trachea, just superior to origin of right subclavian

2R and 2L Left upper paratracheal - above arch

3A and 3P are anterior and posterior trachial (3A is prevascular behind bifurcation of SVC.

4R and 4L are lower paraterachial

Question 23

The next groups of thorax nodes after the trachea (but not the bronchi)

Answer 23

Rule: All nodes not paired (i.e. no r/L, A/P) number from 1-8 going down trachea, 8 paraeosphageal.
5 = subaortic
6 = Paraaortic
7 = Subcarinal
8 = paraeosphageal

Question 24

After the paraeosphageal nodes, what comes next?

Answer 24

All are paired R+L
9 = pulmonary lig nodes R+L
then 10 is hilar nodes at the main bronchus (this are adjacent to 7 = subcarinal)
11 Bifurcation = interlobular nodes
12 = lobular
13 = segmental
14 = subsegmental nodes

Question 25

Branches of the left main bronchus

Answer 25

Left main becomes Left superior lobular and left inferior lobular - The ASIA ALPS Right main: the superior, middle and inferior lobular branches, then A PALM Seed Makes Another Little Palm

Question 26

Sensory innervation of the trachea:

Answer 26

Recurrent laryngeal nerve

Question 27

Describe the right main bronchi:

Answer 27

4cm long wider and more vertical than left bronchi Extends from carina to hilum of lung Gives of superior lobular branch before entering the lung, where divides into middle and inferior. Relations: - Superio-inferior to right pulmonary artery - Azygous crosses over it

Question 28

Describe the LEFT main bronchi:

Answer 28

6cm long, thinner than left and runs more horizontally Extends from carina to hilum where it dives into inferior and superior lobular branches. Relations: Passes under the arch of the aorta, anterior to the descending part. Anterior to eosophagus

Question 29

Innervation of the bronchi?

Answer 29

Left and right vagus

Question 30

Venous supply to bronchi:

Answer 30

Right: Bronchial veins to azygous | Left drain to accessory hemi-azygous

Question 31

How do the right and left main bronchus differ in terms of branching?

Answer 31

The main bronchus is short, quickly giving off a a superior lobular branch after which it becomes the intermediate segment. The left main bronchus is relatively longer, and does not have and intermediate branch.

Question 32

Describe the heart:

Answer 32

``` Pyramidal shaped hollow muscular fist size organ with apex directed anteriolaterally to the left. Apex, base and three surfaces: Sternocostal Diaphragmatic Pulmonary Positioned in middle mediastinum Covered in fiberous pericardial sac Function is as a pump to return deoxygenated blood from the venous system and recirculate oxygenated blood returning from the pulmonary veins ```

Question 33

Surfaces of the heart

Answer 33

Apex, base Diaphragmatic surface Sternocostal Pulmonary

Question 34

The base of the heart is mainly formed by? | Why

Answer 34

Mainly formed by left atrium | This surface dominated by the pulmonary veins

Question 35

Sternocostal surface of the heart is formed by:

Answer 35

Right atrium and ventricle

Question 36

Diaphragmatic surface of the heart is formed by:

Answer 36

Mainly left ventricle, partly right ventricle

Question 37

The apex of the heart is formed by? and is inferior to?

Answer 37

Formed by left ventricle | Lies behind 5th intercostal space in the midclavicular line

Question 38

Boarders of the heart

Answer 38

Right border –Right atrium Inferior border - Left ventricle and right ventricle Left boarder - right atrium Superior - Right and left atrium and great vessels

Question 39

``` What sulcus (aka?) runs transversely around the heart? • represents the wall dividing the? • contains important vasculature, such as? ``` What are the other 2 important sulci?

Answer 39

Coronary sulcus (or atrioventricular groove) runs transversely around the heart? • represents the wall dividing the atria from the ventricles • contains important vasculature, such as the right coronary art Other sulci: Anterior and posterior interventricular sulci

Question 40

The pericardial sinuses are formed by? what are they called?

Answer 40

The pericardial sinuses are formed by folds of pericardium around the great vessels. Transverse pericardial sinus: Run transversely above the pericardial fold for the pulmonary veins, and so superior to the left atrium. Runs posterior to the ascending aorta and pulmonary trunk Anterior to SVC Oblique pericardial sinus: Blind ended sac on base/posterior surface, space within fold for pulmonary arteries.

Question 41

Origin of aorta: | 1st segment. Branches in daughter branches:

Answer 41

Arises from the AORTIC ORRIFICE of the left ventricle 1st segment is the ascending aorta which lies within the pericardial sac. Left and right coronary arteries at aortic sinuses, just distal to the valve: LCA: Left anterior descending (1st branch), and left marginal. After which LCA becomes the CIRCUMFLEX RCA: Right marginal (1st branch), posterior INTERVENTRICULAR artery

Question 42

The thoracic aorta has how many segments? Describe the final 2:

Answer 42

3 1) Arch: begin as ascending aorta leaves pericardium Ligamentum venosum internal arch to bifurcation of pulmonary artery. Brachiocephalic trunk Left common carotid Left subclavian 2) Descending aorta: Posterior intercostal arteries. From sup to inf: Bronchial, mediastinal, pericardial and sup phrenic.

Question 43

The caval hiatus is at what level and passes though what structure in the diaphragm?

Answer 43

Vena Cava (8 letters) passes the central tendon (caval hiatus) at T8

Question 44

Course of the superior vena cava:

Answer 44

Formed by the confluence of the left and right brachiocephalic trunks in the superior anterior mediastinum at about the level of T3. Then vertically downwards behind first intercostal space and receives AZYGOUS vein just before it pierces pericardium opposite right second costal cartilage and its lower part is intrapericardial. Ends in the upper and posterior part of the sinus venarum of the right atrium, at the upper right front portion of the heart.

Question 45

Tributaries of the brachiocephalic veins | At what anatomical point is the confluence?

Answer 45

Behind the sternoclavicular joint the INTERNAL JUGULAR and SUBCLAVIAN Vein join. The Left then travel obliquely across the midline. The only difference in tributaries is that the left receives the superior intercostal vein. Other tributaries: L/R inferior thyroid vein posterior intercostal veins of the 1st intercostal space, thymic veins, Internal thoracic veins

Question 46

What minor vein groups does the SVC receive?

Answer 46

Mediastinal veins Oesophageal veins Pericardial veins

Question 47

Describe the course of the thoracic duct:

Answer 47

Origin is the cistern chyli immediately enters the thorax/posterior mediastinum via the aortic hiatus at T12. Thin walled, and dull white, the duct ascension the posterior mediastinum along the anterior aspect of the lower 7 thoracic vertebral bodies. Crossing to the left side between T4 and T6, posterior to the oesophagus. Receives branches from the middle and superior intercostal spaces of both sides through several collecting trunks. Also receives branches from posterior mediastinal structures. Typically empties into the venous system near the union of the left sublvian and jugular vein (can terminate in either).

Question 48

The thoracic duct drains everything but?

Answer 48

The right forequarter, which is drained by the right thoracic duct.

Question 49

Subsections of the mediastinum:

Answer 49

Superior | Anterior, middle, posterior

Question 50

The boarder between the superior mediastinum and the rest:

Answer 50

The lower boarder of T4/Manubrium sternum

Question 51

Contents of the superior mediastinum:

Answer 51

Thymus Oesophagus Trachea (bifurcation is below inf border) Vessels: Arch of aorta and its left and right branches. SVC and its tributaries (and the tributaries of the left and right brachiocephalic) Thoracic duct Nerves: L/R Vagus nerves, recurrent laryngeal nerve, L/R phrenic Muscles: Sternohyoid and sternothyroid muscles ( arise from posterior surface of manubrium). Longus colli

Question 52

Border of the anterior mediastinum:

Answer 52

Roof: Superior mediastinum Ant: Sternum, transversus thoracis Post:Anterior pericardium Floor: Diaphragm

Question 53

Contents of anterior mediastinum:

Answer 53

In children the thymus extends this far Fat, lymphatics Loose connective tissue, the sternopericardial ligaments

Question 54

Describe the thymus:

Answer 54

Most ant structure in mediastinum Primary lymphoid organ located in the lower neck and After puberty it undergoes gradual involution and is replaced by fa

Question 55

Contents of the middle mediastinum:

Answer 55

Pericardial sac: Heart, root/ascentending aorta, truck and origins of cardiac vessels. Lung roots NERVES!! Phrenic nerves and deep part of the cardiac plexus

Question 56

Describe the fibrous pericardium:

Answer 56

outer layer, fused with adventitia of great vessels and blended with the central tendon of diaphragm. Phrenic nerves lie on fibrous pericarduim Mediastinal pleura adherent to it Connected to posterior sternum by weak ligaments Supplied by internal thoracic arteries and veins

Question 57

Describe the serous pericardium

Answer 57

Inside fibrous pericardium Covers entire heart and forms epicardium Visceral and parietal layers Transverse and oblique sinus overdose of heart denied by reflections around the pulmonary veins.

Question 58

Nerve supply to to pericardium: Arterial and venous supply:

Answer 58

phrenic nerve except visceral layer of serous pericardium which is insensitive Blood supply: Internal thoracic, bronchial art and thoracic aorta Pericardial Veins to azygous system

Question 59

Lymphatic drainage of the middle mediastinum is via?

Answer 59

Via tracheobronchial nodes: | 2L+R, 3A+P, 4L+R

Question 60

Relations of the posterior mediastinum:

Answer 60

``` Roof: Sup mediastinum (inf border T4) Floor: diaphragm Ant: Posterior fibrous pericardium Post: Vert bodies T5- T12 Lateral: Left and right mediastinal pleura ```

Question 61

What happens to the position of the oesophagus in the posterior mediastinum?

Answer 61

Moves from right to the left as it descends, also moves anteriorly

Question 62

Contents of the posterior mediastinum

Answer 62

Oesophagus Vessels: - Descending aorta: branches = bronchial (usually 1 or 2 paired), oesophageal (~2 unpaired), sup.phrenic (paired branch at hiatus). - Azygous system Thoracic duct: posterior to aorta (remember it moves to left in sup mediastinum) Sympathetic trunks; give rise to the lower thoracic splanchnic nerves

Question 63

The azygous vein is formed by? | Where

Answer 63

Formed by right subcostal and right lumbar vine immediately before entering the thorax via aortic hiatus

Question 64

The hemiazygous vein is formed by? Where? Where does it join the azygous vein?

Answer 64

The left subcostal and lumbar veins. Then enters thorax via the left crus. Joins the azygous vein by turning right at T8

Question 65

The accessory hemiazygous vein is formed by? Where does it join the azygous SYSTEM?

Answer 65

Formed by intercostal veins 4-8. Joins directly to azygous vein at T7

Question 66

Describe the oesophagus:

Answer 66

A 25cm pink, fibromuscular tube. Cervical, thoracic and abdominal portions: Extending from the larynx pharynx, passing from the neck to superior, then posterior mediastinum to exit the diaphragm via the oesophageal hiatus at T9 to join the stomach. Can be compressed by diaphragm, aortic arch and left main bronchus. Function: conduit for injected food in the aeordigestive tract, along with secretions to reach the stomach.

Question 67

Divisions of the oesophagus, and describe the 1st part: Approx how long is each part?

Answer 67

1) Cervical: starts at inf boarder of hypopharynx (C6) anterior vertebral bodies and posterior to trachea, lateral to carotid sheaths and the recurrent laryngeal nerves that run in the trachea-oesophageal grooves bilateral. 2) Upper thoracic 3) Middle thoracic 4) Lower thoracic 5) Cardia All are 5 cm long, except Lower thoracic = 10, cardia = 3.

Question 68

Exact location of the exit of the oesophagus from the thorax:

Answer 68

At the level of T9, exists via the right crus of oesophageal hiatus.

Question 69

The oesophagus is surrounded by what plexus? Which nerves contribute to it?

Answer 69

Surrounded by oesophageal plexus: parasympathetic fibres from vagal nerves, sympathetic from thoracic sympathetic trunks.

Question 70

Describe the upper oesophageal sphincter:

Answer 70

Anatomical sphincter (unlike lower which is physiological), striated muscle sphincter At the junction between the pharynx and oesophagus Produced by the cricopharynxgeus muscle. Normally constricted to prevent the entrance of air into the oesophagus

Question 71

Relations of the thoracic oesophagus (for each position list sup to inf):

Answer 71

Superior: cervical oesophagus Ant: Trachea, LEFT Bronchus, posterior fibrous pericardium, crus of diaphragm Post: Vertebral bodies, thoracic duct, azygous vein, mor inferiorly the descending aorta Left Lateral: L.Vagus nerve, In the sup mediastinum the aortic arch then descending aorta Right: Pleura

Question 72

Describe the abdominal oesophagus:

Answer 72

In the abdomen, the oesophagus descends for 1 – 2 cm and then enters the cardiac orifice of the stomach to the left of the T11 vertebra. ***lies on the posterior surface of the left lobe of the liver, and is related posteriorly to the left crus of the diaphragm.

Question 73

What connects the oesophagus to the border of the oesophageal hiatus

Answer 73

Phrenoesophageal ligament connects the abdominal oesophagus to the border of the oesophageal hiatus

Question 74

Arterial supply to oesophagus:

Answer 74

1) Upper 1/3rd: inferior thyroid artery (Br of thyrocervical trunk) 2) Middle 3rd: Oesophageal arteries from descending aorta. 3) Lower 3rd: Oesophageal branches of left gastric

Question 75

Venous supply to oesophagus:

Answer 75

1) Upper 1/3rd: Inferior thyroid veins 2) Middle 3rd: oesophageal branches of Azygous * ***** 3) Lower 3rd: i) Portal: branches to via left gastric vein portal vein ii) Systemic: Azygous vein (i. e oesophageal varices)

Question 76

Lymphatic drainage of the oesophagus:

Answer 76

1) Upper 1/3rd: Deep cervical and supraclavicular 2) Middle 3rd: Superior and posterior mediastinal nodes (paratrachial nodes 2-4) 3) Lower 3rd: left gastric and coeliac nodes.

Question 77

Describe the layers of the oesophagus:

Answer 77

1) Adventitia 2) Muscular layer: - External longitudinal. Upper 1/3rd treated (voluntary control), bottom 3rd smooth muscle, middle 3rd is a mix - Internal circular layer 3) Submucosa 4) Mucosa: Non-keratinised stratified squamous epithelium

Question 78

Describe the lower oesophageal sphincter:

Answer 78

To the left of T12 vert body, marked by a change from eosophageal mucosa to gastric. Physiological sphincter formed by 4 phenomena: 1) Acute angle of entry to stomach 2) Intra-abdominal section compressed when stomach full 3) Lumen partial occlude by gastric folds 4) Right crus has "pinch-cock" effect

Question 79

Describe the pleura:

Answer 79

``` General: – Serous membranes lining lungs and thoracic cavity. – Permit respiration Composed of parietal and visceral layers Thicker than visceral plaura – Suddivided according to contact with – • Mediastinal • Cervical • Costal • Diaphragmatic • Visceralpleura – Covers outer surface of lungs – Extends into interlobar fissures ```

Question 80

Pleura histology:

Answer 80

The visceral pleura is composed of a thin, loose connective tissue. The Parietal surface is lined by specialized squamous-like cells, mesothelium. The connective tissue of the visceral pleura is contiguous with the connective tissue of the pulmonary lobular septae that course through the pulmonary parenchyma.

Question 81

Describe the nerve supply to the pleura:

Answer 81

Trick question: Visceral and parietal have different innervation. Parietal: Highly localised sensation (pain, pressure, temp) via intercostal and phrenic nerves Visceral: Only sensitive to stretch, via pulmonary plexus (from symp trunk and vagus)

Question 82

Arterial supply to the pleura

Answer 82

Bronchial arteries from descending aorta

Question 83

Describe the breasts

Answer 83

Paired skin covered structures located on the pectoral chest. More prominent in females after puberty, the rounded shape of the breast can be broken in body and tail parts. In females the enlarged body contains the lobulated mammary glands for lactation. Centered over the body, each breast has circular pigmented areolar containing numerous sebaceous glands, and in the centre the nipple largely composed of smooth muscle, in females this is larger, with a sinus connection to the ducts of the mammary glands. It extends horizontally from the lateral border of the sternum to the mid-axillary line. Vertically, it spans between the 2nd and 6th intercostal cartilages. It lies superficially to the pectoralis major and serratus anterior muscles.

Question 84

Borders of the boob:

Answer 84

Medial: Later border of the sternum Lateral: mid-axillary line. Superior and inf: 2nd and 6th intercostal cartilages. Posterior: Pectoralis major and serratus anterior muscles.

Question 85

Key anatomical boob structures:

Answer 85

The ducts (from lobule to nipple): Lactiferous duct->lactiferous sinus -> Lactiferous sinus (in nipple) Lobules of mammary gland The outside: Skin, areolar, nipple Support: Suspensory ligaments (attached to pectoral fascia), fatty tissue Behind: Reteromammary space, pectoral fascia, pec maj

Question 86

Lymphatic drainage of the boob:

Answer 86

There are three groups of lymph nodes that receive lymph from breast tissue – the axillary nodes (75%), parasternal nodes (20%) and SCF (5%). The skin drains to Skin – drains to the axillary, inferior deep cervical and infraclavicular nodes. Nipple and areola – drains to the subareolar lymphatic plexus. The axillary nodes are 5 groups

Question 87

Describe the axillary lymph nodes

Answer 87

There are 5 groups, lateral, anterior, posterior (subscapular), central and apical nodes. The apical nodes are the final common pathway for all of the axillary lymph nodes. Lateral (humoural) are posteromedial to axillary vein (1st nodes in chain from upper limb) *** Pectoral (anterior): inferior border of pectoralis minor, near lateral thoracic vessels. Drains to central and directly to apical. These drain the boob and skin and muscles of the supraumbilical anterolateral body wall, breast Posterior (sub scapular): along subscapular vessels on inferior margin of the posterior axillary wall Central: In the fatty central tissue of axilla. Drain to apical nodes. **** Apical: posterior and superior to pectoralis minor, towards the axillary vein. Drains into subclavian trunk (may drain into jugulosubclavian venous trunk, subclavian vein, jugular lymphatic trunk, right lymphatic duct (left into thoracic duct), inferior deep cervical nodes)