Anatomy

Question 1

What is contained in the hilum (root) of the lung

Answer 1

pulmonary artery
main bronchus
pulmonary veins
pulmonary lymphatic vessels & bronchopulmonary lymph nodes
pulmonary visceral afferents & autonomic motor nerves

Question 2

Where in the thorax Is the heart found

Answer 2

Within the fibrous sac of the pericardium

In the middle mediastinum

Question 3

Where would you find the phrenic nerve

Answer 3

It descends across the lateral borders of the pericardium
Lies on top of the pericardial sac
It’s anterior to the hilum

Question 4

Describe the structure of the pericardium

Answer 4

Made up of 3 layers:
Outermost layer = fibrous pericardium
Serous pericardium = divided into part in contact with the fibrous layer (parietal serous pericardium) and the part in contact with the heart (visceral serous pericardium)
Visceral serous is also known as the epicardium

Question 5

What happens if the pericardial cavity fills with blood

Answer 5

Known as haemopericardium
Pressure builds up around the heart and can prevent cardiac contraction
This is called cardiac tamponade

Question 6

What is pericardiocentesis

Answer 6

drainage of fluid from the pericardial cavity

Carried out by inserting a needle below the costal angle and pushing it superoposteriorly until it reaches the fluid

Question 7

What is the transverse pericardial sinus

Answer 7

a “space” within the pericardial cavity found behind the ascending aorta and pulmonary trunk

Question 8

What is the clinical relevance of finding the transverse pericardial sinus

Answer 8

Cardiac surgeons use this sinus to identify and isolate the great vessels
This is useful in cardiopulmonary bypass as you can block off the vessels
The surgeon will put their finger into the space and it should emerge in front of the SVC

Question 9

Name the 3 surfaces of the heart

Answer 9

anterior (sternocostal) surface
base (posterior) surface
inferior (diaphragmatic) surface

Question 10

Name the 4 borders of the heart

Answer 10

Right border
Left (lateral) border
Inferior border
Superior border

Question 11

Where do you palpate the apex beat (normally)

Answer 11

5th left intercostal space in the midclavicular line (mitral area)

Question 12

Why might the apex beat be out of place

Answer 12

Cardiac enlargement (cardiomegaly) often shifts the apex beat to the left

Question 13

Which branches come together to form the superior vena cava

Answer 13

Right internal jugular vein and right subclavian vein form the right brachiocephalic vein
There is the same anatomy on the left
The two brachiocephalic veins form the SVC
Also have the azygous vein

Question 14

How does the pulmonary trunk divide

Answer 14

Left pulmonary artery

Right pulmonary artery (superior and inferior)

Question 15

Describe the branches of the aorta

Answer 15

Ascending aorta has braches for L&R coronary arteries
The arch of the aorta has branches for the brachiocephalic trunk, which bifurcates into right subclavian artery and the right common carotid, the left common carotid and the left subclavian artery

Question 16

What are the auricles

Answer 16

extensions of the atria – they are capacity builders by allowing the atria to fill with more blood

Question 17

Describe the coronary sinus

Answer 17

Main venous drainage of the heart - it is a short venous conduit
Found in the atrioventricular groove posteriorly
Receives deoxygenated blood from most of the cardiac veins and drains into the right atrium

Question 18

Which vessels drain into the left atrium

Answer 18

Left and right pulmonary veins

Question 19

Describe the location and braches of the coronary arteries

Answer 19

Arises from the ascending aorta
Travels down right atrioventricular groove
Has many branches but main ones are:
right marginal artery which crosses the bottom of the anterior surface and the posterior interventricular artery
The left is found in in left atrioventricular groove between pulmonary trunk & left auricle
Has branches: left anterior descending, left marginal and lateral (diagonal across anterior surface)

Question 20

What are the two parts to the septum

Answer 20

The part between the 2 atria is called the interatrial septum
Part between the 2 ventricles is called the interventricular septum

Question 21

What is a septal defect

Answer 21

A hole in part of the septum
Can be either between atria or ventricles
Main issue with these is that you get a mixture of oxygenated and deoxygenated blood
This means deoxygenated blood is pumped around the body – causes hypoxemia

Question 22

What are the 3 entrances into the right atrium

Answer 22

Superior VC, Inferior VC and coronary sinus

Question 23

Describe the interior surface of the right atrium

Answer 23

2 surface textures
One very muscular and one smooth that forms the posterior wall
There is a line differentiating the 2 that’s called the crista terminalis

Question 24

What is the oval fossa

Answer 24

Depression in the smooth area inside the right atrium

It is a remnant of the foramen between the left and right which is present during development (closes at birth)

Question 25

What are the 2 'types' of valves

Answer 25

Leaflet design - Bi and Tricuspid | Semi-lunar - Pulmonary and aortic

Question 26

how many cusps does each valve have

Answer 26

``` Tricuspid = called so due to having 3 cusps (anterior, posterior and septal) Pulmonary = also has 3 cusps (anterior, right and left) Bicuspid = anterior and posterior cusps Aortic = 3 cusps (right, left and posterior) ```

Question 27

How are the valves attached

Answer 27

Tendinous cords attach them to the papillary muscles on the ventricle wall

Question 28

Describe the fibrous skeleton of the heart

Answer 28

Gives the valves structural integrity – they anchor onto it It also assists electrical conduction through the heart There is a part called the moderator band in right ventricle which gives shortcut for electrical activity This allows the anterior cusp of the tricuspid to contract at the same time as the other 2 as its further away

Question 29

How do sympathetic nerve impulses get from the CNS to the organs?

Answer 29

A presynaptic fibre connects the CNS and ganglion The ganglion is a synapse between axon of presynaptic neurone and cell body of postsynaptic neurone Acetylcholine allows impulses to cross the ganglion Then passes to the postsynaptic fibre which connects the ganglion and the organ noradrenaline passes impulse into the organ

Question 30

Describe the path presynaptic sympathetic fibres from the brain take

Answer 30

They travel inferiorly within spinal cord tracts Then exit the spinal cord in one of T1-L2/3 spinal nerves and then either: Go into ganglion at that level and synapse Travel superiorly in the sympathetic chain & synapse Travel inferiorly in the sympathetic chain & synapse Pass straight through the sympathetic chain ganglion without synapsing, as abdominopelvic splanchnic nerves Pass straight to the adrenal medulla without synapsing as an abdominopelvic splanchnic nerve

Question 31

What are the abdominopelvic splanchnic nerves

Answer 31

These are the sympathetic supply to the abdominal organs

Question 32

What are the cardiopulmonary splanchnic nerves

Answer 32

Sympathetic supply to the heart/lungs These nerves are bilateral Synapse with the T1-T5 ganglia and cervical ganglia They then feed into the cardiac plexus

Question 33

How do parasympathetic signals from the CNS reach the organs

Answer 33

presynaptic fibre connects CNS & ganglion Ganglia in the parasympathetic system are isolated/individual Acetylcholine acts as neurotransmitter at the ganglion (synapse between pre & post synaptic) A postsynaptic fibre connects ganglion & organ with acetylcholine as neurotransmitter

Question 34

Describe the path of parasympathetic nerves to the organs

Answer 34

There are 4 parasympathetic ganglia in head: one for CN III (oculomotor), 2 for CN VII (facial ) and 1 for CN IX (glossopharyngeal) CNX (vagus) supplies the heart and the other thoracic organs The post synaptic neurons are short as the ganglia are in the walls of the organs Also travel via sacral spinal nerves to supply organs of the lower abdomen

Question 35

What are some potential sources of somatic chest pain

Answer 35

Muscular, Joint, Bony, Intervertebral disc, Fibrous) pericardial, nerve

Question 36

What are some potential sources of visceral chest pain

Answer 36

Heart & Great vessels, Trachea, Oesophagus | Abdominal viscerae

Question 37

What is the nature of somatic chest pain

Answer 37

is typically sharp, stabbing, well localised

Question 38

What is the nature of visceral chest pain

Answer 38

more typically dull, aching, nauseating, poorly localised

Question 39

What is radiating pain

Answer 39

Pain felt in centre of chest and felt spreading from there to either the upper limbs, back, neck If originating in a somatic structures the pain radiates along the associated dermatome Caused by lack of precision in route taken by visceral afferents to the spinal cord so brain is unsure where pain is coming from

Question 40

What is referred pain

Answer 40

Pain ONLY felt at site remote from area of tissue damage in the chest such as in the upper limbs, back or neck Caused by lack of precision in route taken by visceral afferents to the spinal cord so brain is unsure where pain is coming from

Question 41

Explain how pain can be localised

Answer 41

Stimulation of specific mechanoreceptors in specific dermatomes will travel along precisely (somatotopically) organised pathways from periphery and projections to cortex The signal passes through the anterior ramus, spinal nerve, posterior root, rootlets and then reaches spinal cord

Question 42

What is the central sulcus

Answer 42

Line/ groove on brain which divides cerebrum into equal anterior/ posterior sections

Question 43

Describe the location and function of the postcentral gyrus

Answer 43

Found in parietal lobe, posterior to central sulcus somatosensory region Action potentials arriving here bring body wall (somatic) sensations into consciousness (e.g. pain)

Question 44

Describe the location and function of the precentral gyrus

Answer 44

Found in frontal lobe, anterior to central sulcus Somatomotor region Action potentials originating here bring about contractions of body wall (somatic) skeletal muscle

Question 45

What are some potential causes of sharp (somatic) central chest pain

Answer 45

``` Herpes Zoster = shingles Pectoralis major or intercostal muscle strain Dislocated costochondral joint Costovertebral joint inflammation “Slipped” thoracic intervertebral disc Pleurisy Pericarditis ```

Question 46

How does herpes zoster cause central chest pain

Answer 46

Reactivation of dormant virus in posterior root ganglion Pain can be felt anywhere in that dermatome Patient with shingles developing in T4/T5 dermatome may present with central chest pain

Question 47

What are some visceral sources of central chest pain

Answer 47

``` trachea - tracheitis aorta - ruptured aneurysm of aortic arch abdominal organs - gastritis; pancreatitis; hepatitis heart - angina or MI oesophagus - oesophagitis ```

Question 48

What are the divisions of the medistinum

Answer 48

superior - anything above line of sternal angle and T4 middle - contains heart anterior posterior - contains sympathetic chains, azygous vein, thoracic duct, vagus nerves, aorta, trachea, main bronchi and oesophagus

Question 49

Describe the location of the vagus nerve

Answer 49

Found on the surface of the trachea Passes posteriorly to the lung root and then follows the oesophagus down into the abdomen Left vagus nerve crosses aorta

Question 50

How do pain signals form organs reach the brain

Answer 50

Via visceral afferent nerves that travel alongside the sympathetic nerves Enter the spinal cord via the posterior roots They then pass bilaterally to thalamus & hypothalamus then diffuse to areas of the cortex

Question 51

What are the common sites of coronary atherosclerosis

Answer 51

Anterior interventricular branch (LAD) of LCA The RCA The LCA The circumflex branch of LCA

Question 52

Describe Coronary Artery Bypass Grafting (CABG)

Answer 52

Take a vessel from elsewhere in the body: commonly radial artery/internal thoracic (mammary) artery or great saphenous vein (leg) Graft new vessel to the aorta, pass the blockage and reattach further down so that heart still gets blood supply

Question 53

What arteries supply the SA and AV nodes

Answer 53

SA = from RCA near its origin in ~60% patients AV = AV nodal branch from RCA near origin of PIV artery in ~ 80% patients

Question 54

What arteries supply the interventricular septum

Answer 54

The LAD and the posterior interventricular