Intro to Main Structures of the Thorax

Question 1

What is the pericardium?

Answer 1

membrane enclosing the heart

divides into the fibrous and serous pericardium

Question 2

Describe the fibrous pericardium

Answer 2

outer
very tough and not distensible
attached inferiorly to diaphragm by pericardiophrenic ligaments
blends into adventitia of great vessels - superiorly

Question 3

Describe the serous pericardium

Answer 3

made up of: visceral (epicardium) and parietal layer (lines fibrous pericardium)
both composed of flattened layer of epithelial cells (mesothelium)
potential space (pericardial cavity) lies between

Question 4

What forms the anterior part of the heart?

Answer 4

mostly right ventricle

bit of left

Question 5

What forms the inferior/diaphragmatic part of the heart?

Answer 5

mostly left ventricle

bit of right

Question 6

What forms the posterior/base part of the heart?

Answer 6

mostly left atrium and pulmonary vein

bit of right

Question 7

What forms the pulmonary part of the heart?

Answer 7

mostly left ventricle in cardiac notch of left lung

Question 8

What forms the apex of the heart?

Answer 8

left ventricle, usually posterior to left ics 5 in adults

Question 9

Superior border of the heart

Answer 9

left costal cartilage 2 to right costal cartilage 3

Question 10

Right border of the heart

Answer 10

convex to right
right cc3 to right cc6
mainly SVC and IVC

Question 11

Inferior border of the heart

Answer 11

lies on diaphragm central tendon
right cc6 to left ics 5
mainly right ventricle and some left

Question 12

Left border of the heart

Answer 12

convex to left
left ics 5 back to left cc 2
mainly left ventricle and may be some left atrium

Question 13

Valves of the heart

Answer 13

pulmonary 
aortic
bicuspid/mitral
tricuspid
all are retrosternal and close to midline PAMT

Question 14

Pulmonary valve location

Answer 14

medial to left cc3

Question 15

Aortic valve location

Answer 15

medial to L ics3

Question 16

Bicuspid valve location

Answer 16

medial to L cc4

Question 17

Tricuspid valve location

Answer 17

medial to R ics4

Question 18

Where is the best place to hear valves for ascultation?

Answer 18

downstream of valve positions

Question 19

Where to hear sound of pulmonary valve and what sound?

Answer 19

left ics 2 near sternal edge

dup

Question 20

Where to hear sound of aortic valve and what sound?

Answer 20

right ics 2 near sternal edge

dup

Question 21

Where to hear sound of bicuspid valve and what sound?

Answer 21

left ics 5 at midclavicular line

lub

Question 22

Where to hear sound of tricuspid valve and what sound?

Answer 22

left ics 5/6 near lower sternal edge

lub

Question 23

What is the pleura?

Answer 23

a serous membrane divided into parietal and visceral layers which surround the lungs and contain the pleural cavities

Question 24

Parietal pleura

Answer 24

lines thoracic cavity lateral to mediastinum

sensory: intercostal and phrenic nerves, therfore sensitive to pain

Question 25

Visceral pleura

Answer 25

covers lung and follows lung fissures | supplied by autonomic nerve - not sensitive to pain

Question 26

What is pleuritis?

Answer 26

inflammation of the pleura lung surfaces are rough and 'pleural rub' can be heard with a stethescope leads to sharp chest pain when breathing or coughing

Question 27

Different surfaces of the lungs

Answer 27

mediastinal diaphragmatic costal cervical

Question 28

Mediastinal surface

Answer 28

flat faces mediastinum and has impressions of mediastinal structures contains hilum and pulmonary ligament

Question 29

Diaphragmatic surface

Answer 29

concave and faces domes of diaphragm

Question 30

Costal surface

Answer 30

convex and faces ribs

Question 31

Cervical surface

Answer 31

extends into neck 2-3cm above medial third of clavicle as apex/dome/cupola

Question 32

What are pleural reflections?

Answer 32

Line where the pleura change direction from one wall of the pleural cavity to another

Question 33

When do pleural reflections occur?

Answer 33

When the costal pleura becomes continuous with the mediastinal pleura anteriorly and posteriorly and with the diaphragmatic pleura inferiorly

Question 34

Describe the outline of the visceral pleura

Answer 34

Rib 2: reflections closest at plane of eternal angle Rib 4: parallel down to rib 4 Cc 6: left indented (cardiac notch), right continues to cc6 Rib 8: crosses here at midaxillary line Rib 10: crosses here at lateral border of erector spinae muscle

Question 35

Describe the outline of the parietal pleura

Answer 35

Close behind rib parallel down to rib 4 Left indented (cardiac notch) but right continues down to cc 6 Rib 8 at midclavicular line Rib 10 at midaxillary line Rib 12 at lateral border of erector spinae muscle

Question 36

Describe the lobes of the right lung

Answer 36

3 lobes - superior, middle, inferior Superior and middle: mainly anterior Inferior: mainly posterior

Question 37

Describe the fissures of the right lung

Answer 37

Oblique fissure: from T2 posteriorly to rib 6 anteriorly | Horizontal fissure: from rib 4 to oblique fissure

Question 38

Describe the lobes of the left lung

Answer 38

2 lobes: superior and inferior Superior - mainly anterior and has lingual Inferior - mainly posterior

Question 39

Describe the fissures of the left lung

Answer 39

Oblique fissure - from T2 posteriorly to rib 6 anteriorly

Question 40

Difference between right and left bronchi

Answer 40

Right is more vertical and wider than L

Question 41

How do the main bronchi divide?

Answer 41

into secondary bronchi - supply lobes | then into tertiary bronchi - supply segments

Question 42

How many bronchopulmonary segments does the right lung have?

Answer 42

10

Question 43

How many bronchopulmonary segments does the left lung have?

Answer 43

9/10

Question 44

Clinical relevance of bronchopulmonary segments

Answer 44

resecting a segment is preferable to resecting a lobe when there is disease in supine ps, fluid tends to accumulate in apical and posterior segments of the inferior lobe

Question 45

Describe the proximal aorta

Answer 45

from left ventricle | aortic arch with: 1. brachiocephalic trunk 2. left carotid artery 3. left subclavian artery

Question 46

Describe the descending aorta

Answer 46

thoracic artery wth intercostal arteries leading off | past diaphragm: abdominal aorta

Question 47

Where is the azygous system located?

Answer 47

posterior to the mediastinum

Question 48

What is the function of the azygous system?

Answer 48

drainage of the posterior thoracic wall

Question 49

Main veins of the azygous system

Answer 49

IVC, ic vein, azygous vein, SVC, left brachiocephalic vein, hemiazygous

Question 50

How to view a CT scan

Answer 50

from the feet on their back