chest and lungs

Question 1

what are 5 features of a rib?

Answer 1

head = end of a rib, where it connects to thoracic vertebrae, has two articular facets to connect with vertebrae above and of same number

neck = between head and body, has the tubercle

tubercle = a nub for the articulation to transverse process of vertebrae

body = shaft/main bit

costal groove = houses neurovascular bundle, between inner and innermost int. cost. muscles

Question 2

what are the true ribs?

Answer 2

ribs 1 to 7 as their costal cartilage attaches directly to the sternum in the anterior

they also articulate posteriorly with the vertebrae

Question 3

what are false tibs?

Answer 3

ribs 8-10

attach indirectly to the sternum, they attach to costal cartilage of rib above them

Question 4

What are floating ribs?

Answer 4

don’t articulate to the sternum, only articulate posteriorly to the vertebrae, the ends are found free in the abdominal wall connected to their costal cartilage

Question 5

what are the typical ribs?

Answer 5

ribs 3-9

typical head with two costal facets, include a neck, and have all the other stuff

Question 6

which ribs are irregular and how so?

Answer 6

1st rib = shorter and fatter and only has one articular facet as there is no above thoracic vertebrae

2nd rib = long and thin and has a notch on its superior surface to connect to the serratus anterior

10th rib = only one facet to connect to corresponding vertebrae

11th and 12th rib = no neck and only one facet for articulation with their corresponding vertebrae

Question 7

articulations of the rib?

Answer 7

Posterior - each rib articulates with the two vertebrae, the one above it in number, just once, and the vertebrae of the same number twice

Costotransverse joint - between tubercle of the rib and the transverse costal facet of the same number vertebrae
Costovertebral joint - between head of rib, superior costal facet of same number vertebrae and the inferior costal facet of the vertebrae above

The vertebral articular facets are where two vertebrae articulate. There will be one pair of facets on the superior side of the vertebrae and one pair on the inferior side of the vertebrae

Question 8

define the thorax

Answer 8

bit of body between the neck and abdomen, housing and protecting the thoracic viscera responsible for respiration and circulation

consists of thoracic cage and thoracic cavity

Question 9

what is the thoracic cavity bound by?

Answer 9

thoracic cage
superior thoracic aperture and inferior thoracic aperture

has cardiovascular and respiratory structures, nerves oesophagus and lymph nodes

Question 10

what is the neurovascular bundle?

Answer 10

found in the costal groove, from top to bottom its VAN (vein, artery and nerve, making the nerve slightly exposed)

Question 11

define mediastinum

what marks the superior mediastinum?

Answer 11

mediastinum = space between the lungs containing all the thoracic viscera apart from the lungs,like the heart

the superior mediastinum is bordered inferiorly by two lines, one at T4 for the posterior and one at the manubriosternal joint/sternal angle for the anterior

Question 12

what does the superior mediastinum contain?

Answer 12

aortic arch and its branches:
1. brachiocephalic trunk (splitting into right subclavian artery and right common carotid artery)
2. left common carotid artery
3. left subclavian artery

the SVC (and its two tributaries, the L and R brachiocephalic veins)

the trachea and upper oesophagus

Question 13

the inferior mediastinum is split into three

what are these three sections and what does each one contain?

Answer 13

Anterior = space between the posterior sternum and the anterior aspect of the pericardial sac (between front of the heart and the back of the sternum). has thymus remnants

Middle = the space where the heart is, including the ascending aorta, SVC, pulm. Trunk and pulm. Veins

Posterior = the space behind the heart (but in front of vertebrae) containing the oesophagus and descending aorta

Question 14

external intercostal muscles -

which way do the fibres run, what are their origin and insertions and how does this mean they work?

Answer 14

oblique, running down and forwards like putting hands in lab coat pockets

origin is lower border of a rib, going down to insert to upper border of the rib below, so when the muscles contract in inspiration they pull the ribcage up and out (as the diaphragm flattens)

Question 15

internal intercostal muscles -

what direction do the fibres run, origin and insertion and what this means for when they contract?

Answer 15

oblique but opposite to external, running up and forwards - grab your tits (together they form like an ‘X’)

origin = upper border of a rib, inserting on the lower border of the rib above, so when they contract in forced expiration, they pull the ribcage down and in

Question 16

at what level does the horizontal fissure arise?

Answer 16

fourth rib

Question 17

what is the cardiac notch?

Answer 17

a concavity in the anterior border of the left lung, made by an impression of the heart

Question 18

innermost intercostal muscle -

direction of fibres?
function?
where do they lie?

Answer 18

same direction as internal intercostal (oblique, up and back)

same function as internal intercostal (pull ribcage down and in)

sit behind the internal intercostal muscles, with the costal groove in between

Question 19

what are the three upper limb muscles?

Answer 19

pectoralis major

pectoralis minor

serratus anterior

Question 20

pectoralis major and minor - what do they each connect to?

Answer 20

major = most superficial muscle to anterior chest wall, attaching to the sternum, upper humerus, clavicle and the upper 6 ribs

minor = deep to the major, attaches to the scapula (insertion) and ribs 3-5 (origin)

Question 21

serratus anterior - what is this muscle and what does it connect to?

Answer 21

superficial muscle around the lateral side of the thoracic cage, attaching to the scapula- medial border? (insertion) and upper 8 ribs (origin)

Question 22

what do the scalene muscles do?

Answer 22

arising form processes of the cervical vertebrae and inserting on 1st and second ribs, they assist in raising the 1st and 2nd ribs in inspiration

Question 23

how are abdominal muscles involved in expiration?

Answer 23

pushing diaphragm up when they contract and inc. intraabdominal pressure

pulling lower ribs downwards

Question 24

1. What factors cause the lungs to expand and collapse as the thoracic cavity increases and decreases during respiration?

what contributes to increasng and decreasing throacic volume?

Answer 24

● Movements of the thoracic wall, intercostal muscles and diaphragm during inspiration increases the intrathoracic volume and diameters of the thorax. The consequent pressure changes result in air being drawn into the lungs (inspiration) through the nose, mouth, larynx, and trachea.
● During passive expiration, the diaphragm, intercostal muscles, and other muscles relax, decreasing intrathoracic volume and increasing intrathoracic pressure, expelling air from the lungs (expiration) through the same passages. Concurrently, intra-abdominal pressure decreases, and the abdominal viscera are decompressed

Question 25

2. A collection of gas or air within the pleural cavity is known as?

Answer 25

● Entry of air into the pleural cavity (pneumothorax) results from a penetrating wound of the parietal pleura. This results in partial collapse of the lung

Question 26

3. Why is a stab wound to the chest likely to cause the lungs to collapse?

Answer 26

● If a penetrating/stab wound opens through the thoracic wall or the surface of the lungs, air will be sucked into the pleural cavity because of the negative pressure. The surface tension adhering visceral to parietal pleura (lung to thoracic wall) will be broken, and the lung will collapse, expelling most of its air because of its inherent elasticity (elastic recoil). When a lung collapses, the pleural cavity (normally a potential space) becomes a real space

Question 27

● What may be some of the consequences of a collapsed lung?

Answer 27

● There are varying consequences, some symptoms may be; fatigue, a sudden, sharp, stabbing pain in the chest, rapid breathing or shortness of breath (dyspnoea)

Question 28

● How can the lungs be reinflated in the case of a pneumothorax?

Answer 28

● Inserting a chest tube into the pleura to remove air from the pleural cavity. The end that is outside of the body is connected to an underwater drainage

Question 29

4. What is the diaphragm made of and which nerve innervates it?

Answer 29

● The diaphragm is a curved muscular fibrous sheet that separates the thoracic from the abdominal cavity. The fibrous part occupies the centre of the diaphragm, and the muscular part lies in the periphery.
● It is innervated by the right and left phrenic nerves (C3-5)

Question 30

5. What would be the consequence of paralysis of the diaphragm?

Answer 30

● Paralysis of the diaphragm because of injury to the phrenic nerve results in the inability of the diaphragm to contract to allow proper inspiration

● Normally, during inspiration, the diaphragm contracts and flattens, however the paralysed dome ascends as it is pushed superiorly by the abdominal viscera that are being compressed by the active contralateral dome. Instead of ascending during expiration, the paralysed dome descends in response to the positive pressure in the lungs

Question 31

It is important to detect lung cancer in the early stages because the treatment depends on its stage. A tumour found in the lungs can have consequences on structures within the mediastinum.
● What structures within the mediastinum can the tumour invade and what are the consequences of the invasions of structures within the mediastinum?

Answer 31

● The primary tumour of the lung can metastasise and spread, not all lung cancers will spread. But if they spread they are likely to go to nearby lymph nodes and invade the mediastinum.
● The consequences of spread into the mediastinum include: spinal cord compression, spread to nearby structures such as the heart, lining around the heart (pericardium), and great vessels (aorta and vena cava), compression of the trachea results in respiratory insufficiency and compression of the oesophagus resulting in difficulty in swallowing

Question 32

during inspiration, what dimensions increase?

Answer 32

lateral/transverse, antero-posterior and vertical

Question 33

anterior of the ribs is ___ to the posterior

Answer 33

inferior

Question 34

describe what is meant by the bucket handle movement

Answer 34

refers to the movement of the ribs during inspiration -
the lateral shafts of the ribs elevate, like a bucket handle being lifted

Question 35

describe what is meant by the pump handle movement

Answer 35

refers to the movement of the sternum during inspiration - it moves up and out (superior and anterior) then when muscles relax in expiration moves back down, like a water pump handle

Question 36

describe all aspects of the pleura

Answer 36

two membranes surrounding the lungs - Resting lungs would actually collapse inwards due to their elastic nature.
The chest wall would tend to expand.
So these forces act in opposite directions on the pleural membranes, they find a balance.
This creates a subatmospheric pressure between the two membranes

inner one = visceral
outer one = parietal

space between = pleural space/cavity, filled with serous fluid for lubrication

Question 37

describe the features common to both lungs

Answer 37

apex - lies above first rib
costal, mediastinal and diaphragmatic surfaces (one facing ribs, one facing the middle/back, one facing diaphragm)

Hilum - an indent of the root of the lungs for structures such as veins arteries and bronchi to pass through

Question 38

what is different between the two lungs?

Answer 38

right = bigger with two fissures, horizontal and oblique, to give you three lobes, superior, middle, and inferior

left only has oblique fissure so only superior and inferior lobes
its smaller as it has space for the heart

left has the lingula, little flap on end of the superior lobe

Question 39

the hilum of the lung - where is it located and what is the typical layout of the structures in it?

Answer 39

located on the mediastinal surface of each lung from T5-T7

each will have a pulmonary artery, two pulmonary veins and the bronchi

typically the bronchus is posterior to the pulmonary artery

the pulmonary artery is superior to the pulmonary veins

you can also see vena cava, oesophagus and there should be some bronchial arteries/veins

Question 40

how is the
1. pulmonary artery
2. bronchi

distinguishable in the hilum?

Answer 40

1. large lumen
2. thick walls/ rings of cartilage

Question 41

bronchi - where does the trachea bifurcate?

Answer 41

sternal angle/ manubriosternal joint /T4 / second rib

Question 42

how do the right main bronchus and left main bronchus split?
what do lobar bronchi split into?

Answer 42

right = enters hilum as it splits into superior lobar bronchus and the bronchus intermedius which splits into middle and lower lobar bronchi (so three, one for each lobe)

lobar bronchi split into segmental bronchi

left = superior and inferior lobar bronchi

Question 43

which bronchi is more likely to be blocked when choking?

Answer 43

right, as it is wider, shorter and falls more vertically

Question 44

the thoracic diaphragm is where?

Answer 44

base of the lungs, at the inferior thoracic aperture, separating thoracic cavity from abdominal cavity

Question 45

what does the diaphragm do?

Answer 45

it is the primary muscle of respiration and also acts as a passageway for the descending aorta, oesophagus and the inferior vena cava from thorax to abdomen

Question 46

the diaphragm is innervated by the phrenic nerve, which consists of spinal nerves ___?

the phrenic nerve has peripheral attachments to what?

Answer 46

spinal nerves C3-C5

has peripheral attachments to the xiphoid process of the sternum

the costal margins of ribs 7-10 (direct attachments to ribs 11 and 12)

the lumbar vertebrae and arcuate ligaments (these connect the diaphragm to the spine)

Question 47

how can you spot the phrenic nerve?

Answer 47

the phrenic nerve runs anterior to the root of the lung

Question 48

what does the vagus nerve do to the thoracic viscera?

Answer 48

the vagus nerve, or CN X, enters the thoracic superior aperture to provide parasympathetic innervation

Question 49

how can you spot the vagus nerve in the thorax?

Answer 49

the vagus nerve runs posteriorly to the root of the lung