Anatomy

Question 1

What three parts are the sternum made up of?

Answer 1

Manubrium, sternal body and xiphoid process

Question 2

Describe the three diffeent types of ribs.

Answer 2

True rib: costsl cartilage attaches directly to sternum (ribs 1-7)
False rib: coastal cartilage attaches to cartilage above (ribs 8,9 and 10)
Floating ribs: do not attach to sternum (ribs 11 and 12)

Question 3

What are the two main functions of the thoracic cage?

Answer 3

Ridigity and flexibility

Question 4

What is the superior thoracic aperture?

Answer 4

The doorway of the thoracic cavity, neck and upper limb

At level of first rib and top of manubrium

Question 5

What is the inferior thoracic aperture?

Answer 5

The attachment of the diaphragm to the thoracic cage, separates thoracic and abdominal cavities

Question 6

What are the attachements and innervation of the diaphragm?

Answer 6

Lumbar vertebrae 1-3, inferior 6 costal cartilages and xiphoid process
Innervated by the phrenic nerve (C3 C4 C5 keep the diaphragm alive)

Question 7

Explain the external intercostal muscles.

Answer 7

Occupy spaces from posterior to costochondral junction then are replaced by membrane
Muscle fibres run anterio-inferiorly (like hand in pockets)
Most active during inspiration

Question 8

Explain the internal intercostal muscles.

Answer 8

Occupy spaces from anterior to angle
Muscle fibres run postero-inferiorly
Most active during expiration

Question 9

Explain the innermost intercostal muscles.

Answer 9

Deep part of the internal intercostal muscles

Intercostal neurovascular bundle lies between innermost and internal intercostal muscle layers

Question 10

Describe accessory muscles of respiration.

Answer 10

Pectoral girdle: when arm is fixed (i.e. leaning in something), you recruit muscles that move the arm to lift the ribs instead = forced breathing
Abdominal muscles can also assist forced inspiration

Question 11

Describe the intercostal neurovascular bundle

Answer 11

Contains the intercostal vein, artery and nerve (in that order descending)
Runs along the groove in the bottom of each rib
The vein gets the most protection from the rib and the nerve is the most exposed

Question 12

Where does the posterior intercostal artery originate from?

Answer 12

The aorta

Question 13

Where does the anterior intercostal artery originate from?

Answer 13

The internal thoracic artery

Question 14

Where does the internal thoracic artery originate and how does it branch?

Answer 14

The subclavian artery
Bifurcates into the musculophrenic artery and superior epigastric artery
Allows diversion of blood when the aorta narrows but only if the effect is gradual

Question 15

Why is the left lung smaller than the right?

Answer 15

Due to the placement of the heart, inferior section leans to the left

Question 16

Describe the serous membranes of the lung

Answer 16

Visceral layer covers the organs, cannot be detached
Parietal layer is continuous with the visceral layer but furthest away (think if punched a balloon, visceral layer touches the hand and the parietal layer is continous with the visceral layer
Layer of fluid between visceral and parietal layer provides lubrication

Question 17

Why can fluid gather in the costal diaphragmatic pleura?

Answer 17

It is a sharp angle at the lateral bottom of lungs, can be removed by a chest tube

Question 18

What structures would a chest tube to drain fluid in the inferior pleura pass through?

Answer 18

Skin, fascia, external and internal intercostal muscles, endothoracic fascia, parietal pleura

Question 19

How many lobes does the right lung have?

Answer 19

3 lobes
Superior and middle are separated by a horizontal fissure
Middle and inferior are separated by an oblique fissure

Question 20

How many lobes does the left lung have?

Answer 20

2 lobes separated by an oblique fissure
Has the linguila which is the remenant of a third lobe
Has the cardiac notch for the lung to sit in

Question 21

What structures attach to the mediastinum at the root of the lung and how are these organised ?

Answer 21

Bronchi
Pulmonary artery and vein
Nerves
Lymphatics

Superior: pulmonary artery (deoxygenated)
Inferior: pulmoary vein (oxygenated)
Posterior: bronchi

Question 22

Explain the branching of the bronchi

Answer 22

Trachea bifurcates into L and R primary bronchi at the level of the sternal angle (corena)
The right primary bronchi is wider, shorter and more vertical then the left
Primary bronchi branch into secondary (lobar) bronchi, 3 right and 2 left
Secondary (lobar) bronchi branch inti tertiary (segmental bronchi), 10 right and 8 left
Tertiary bronchi supply each brachiopulmonary segment (each have own artery, vein and bronchus)

Question 23

Which atrium forms the base of the heart?

Answer 23

Left atrium

Question 24

Describe the branching of the right coronary artery?

Answer 24

Originates from the right aortic sinus and follows the coronary sulcus between the atria and ventricles
Provides supply to the right atrium, SA and AV nodes and posterior part of IVS
Gives off right marginal branch supplies the right ventricle and apex of heart
Gives off posterior interventricular branch

Question 25

Describe the branching of the left coronary artery

Answer 25

Originates from left aortic sinus and runs in atrioventricular groove, supplies most of left atrium and ventricle and AV bundles
Gives off circumflex artery which runs to the posterior surface of the heart
Gives off left anterior descending (LAD)

Question 26

Which vessels are commonly used in a coronary aortic bypass graft?

Answer 26

Saphenous vein, radial artery, internal thoracic artery

Question 27

Explain coronary venius drainage

Answer 27

Cardicac veins drain into cornonary sinus, a large vessel that runs from left to right on the posterior of the heart
Receives the great cardiac vein at the left and the middle and small cardiac veins at the right
Drains into right atrium
Some small veins drain directly into right atrium