Week 2

Question 1

What is the carotid sheath? Which structures lie inside it?

Answer 1

The carotid sheath is an extension of the fascia of the neck muscles. The common and internal carotid arteries, the internal jugular vein and the vagus nerve are contained within it.

Question 2

Which arteries supply the spinal cord?

Answer 2

Neck: spinal arteries supplying the spinal cord are branches of the vertebral arteries

Thorax: posterior intercostal arteries

Lower back & pelvis: lumbar and lateral sacral arteries

Question 3

What are the consequences of a blockage of a cerebral artery by an embolus?

Answer 3

The tissue would become ischaemic as the blood supply would become insufficient to meet its metabolic needs.

Nervous tissue is highly susceptible to oxygen lack. Lack of glucose, K+ accumulation and other consequences of ischaemia lead to nervous tissues rapidly dying, and becoming infarcted.

Question 4

What is a stroke? Ischaemic stroke vs haemorrhagic stroke?

Answer 4

Ischaemic stroke arises when a large artery is suddenly occluded by an embolism or by a thrombosis.

Haemorrhagic stroke follows the rupture of an artery or an aneurysm.

Stroke or cerebrovascular accident (CVA) is a sudden damage to brain tissue. Tissues of the brain in the affected area die. This affects sensation and/or motor control of the area of the body that it controls.

Question 5

What type of blood (arterial, venous, mixed) are in

a) Epidural (Extradural) haemorrhage
b) Subdural haemorrhage
c) Subarachnoid haemorrhage

Answer 5

a) Arterial blood
Blood from torn meningeal arteries can fill up the epidural space: a potential space between the cranial bones and the dura mater.
An extradural haemorrhage may follow a sharp blow to the head which gives a depressed fracture of the skull.

b) Venous blood
Blood from a torn cerebral vein may force the dura and the arachnoid mater apart to give a subdural haematoma.
This form of haematoma is generally caused by a blow to the head that causes the brain to move within the skull.

c) Arterial blood
Rupture of an aneurysm of one of the cerebral arteries may fill the subarachnoid space with blood. The subarachnoid space lies between the arachnoid and pia mater and is normally filled with CSF.

Question 6

The carotid sinus is in WHAT artery, and contains WHAT types of receptors?

Answer 6

Internal carotid artery – Baroreceptors

Question 7

Answer 7

C → Common Carotid Artery, B → Internal Carotid Artery, A → External Carotid Artery

Question 8

A surgeon removes a lymph node from the right posterior triangle of a patient’s neck. A month later the patient reattends complaining that he can’t shrug his right shoulder and it feels stiff. Which cranial nerve has been damaged in the operation?

Answer 8

Accessory nerve (CN XI)

Question 9

You have a patient present to you with what seems to be an infection of their meningeal coverings of their brain. The only thing that you notice is that they have an infected looking pimple right next to their left nostril. What area is this pimple in, and where has the infection spread into in order to get from the face into the brain?

Answer 9

Danger triangle area, cavernous sinus

Question 10

A patient comes to you with a single very swollen left supraclavicular lymph node, you are confident it is Virchow’s node. If cancer, what type of cancer may this have originated as?

Answer 10

Gastric carcinoma

Question 11

You have a patient that has presented with SVT and you need to conduct a carotid sinus massage. Identify the two cranial nerves involved with the afferent and efferent innervation of this sinus, and what does this cause in the patient?

Answer 11

CN IX (afferent branch) – CN X (efferent branch) – Will tell the body there is increased pressure, and the vagus nerve then sends a signal out to the heart to SLOW it down.

Question 12

A man comes into A&E after a fall off the top of a construction site. You image his skull and see the following. What artery is causing this bleed, and what type of bleed is it?

Answer 12

Middle Meningeal artery – Extradural haemorrhage

Question 13

The internal jugular vein joins WHAT vein to form the brachiocephalic vein? This junction can be found posterior to WHAT joint?

Answer 13

Subclavian vein – Sternoclavicular joint

Question 14

What vein runs deep to the sternocleidomastoid and can be used to asses venous pressures? What side of the heart does this vein give particularly good insight into (in terms of how it is working)?

Answer 14

Internal jugular vein – Right side of the heart

Question 15

At what level in the neck does the bifurcation of the common carotid artery take place?

Answer 15

Superior border of the thyroid cartilage

Question 16

What are the THREE major branches the Subclavian artery gives off in the neck?

Answer 16

Vertebral, Thyrocervical and Internal Thoracic arteries

Question 17

Describe where pulsations of the internal jugular vein can be seen in the neck?

Answer 17

Carotid pulse

JVP

Deep to SCM and superior to the medial end of the clavicle

Question 18

In what condition is JVP usually raised?

Answer 18

right heart failure

Question 19

Describe how to examine the Jugular Venous Pressure (JVP)

Answer 19

As the right internal jugular vein is straighter than the left, evaluation of a patient’s JVP is undertaken on the right internal jugular vein. It is important to note that although the external jugular vein is easier to visualise, its pulsations are less accurate and are not used in clinical examination

The centre of the right atrium is 5cm vertically below the sternal angle when the patient is at 45 degrees. Normally the height of the jugular venous pulsation is 3 cm above. A normal JVP is therefore 8 cm of blood
With the head resting back on the pillow ask the patient to turn the head to the left
Look for pulsation along the right internal jugular vein.
The height of the pulsation is measured vertically in cm from the sternal angle. Add 5 cm to get the JVP.

Question 20

List 5 ways in which the JVP can be differentiated from carotid pulsation

Answer 20

Question 21

A contraction wave can pass up through the brachiocephalic vein to the internal jugular vein. Describe if venous pulses would increase or decrease in mitral valve disease, and why this would be?

Answer 21

Increase, as MV disease increases pressure in pulmonary circulation and the right side of the heart.

Question 22

What is the corresponding anatomical surface landmark at the A-B level

Answer 22

The sternal angle, also known as the angle of Louis. This is an important surface landmark as it marks a number of antomical features including the bifuracation of the trachea.

Question 23

What anatomical landmarks of the thorax (anteriorly) and vertebral column (posteriorly) does the A-B line run through?

Answer 23

It joins the manubriosternal joint (second pair of costal cartilages) anteriorly to T4/5 intervertebral disc posteriorly

Question 25

The A-B line also divides the thoracic cage into a compartment above, and a compartment below. By what name is the compartment i) Above called? ii) Below called?

Answer 25

i) The compartment above line A-B is the superior mediastinum
ii) The compartment below line A-B is the inferior mediastinum

Question 26

The A-B line is a marker for many significant anatomical landmarks of the body. State SIX of these?

Answer 26

The sternal angle
It marks the approximate level of the 2nd pair of costal cartilages

Boundary between the superior and inferior portion of the mediastinum

Passage of the thoracic duct from right to left behind oesophagus
Aortic Arch
Tracheal Bifurcation
End of the azygos system into SVC
Ligamentum arteriosum
Loop of left recurrent laryngeal nerve around aortic arch

Question 27

What are the origins of the right and left common carotid arteries?

Answer 27

Right common carotid artery originates from the brachiocephalic artery.

The left common carotid artery is the second branch of the aortic arch.

Question 28

Apart from thoracic pain, what other complaint might a patient with an undiagnosed aneurysm of the arch of the aorta present with?

Answer 28

The patient could present with hoarseness of voice as a result of the aneurysm.
Aortic arch aneurysms have a potential to damage the left recurrent laryngeal nerve as it loops around the arch of the aorta.

Unilateral palsy of the left recurrent laryngeal nerve will result in ipsilateral paralysis of the vocal cord and thus, hoarseness of the voice

Question 29

What physiological response might arise if you were to put pressure on the carotid pulse in the area of the carotid sinus? Explain the physiological mechanism underlying this.

Answer 29

The carotid sinus is found at the origin of the internal carotid artery. It contains baroreceptors that act as feedback monitors to help maintain circulation to cerebral structures. Afferent impulses from the carotid sinus are carried by a branch of Glossopharyngeal nerve (CN-9). Afferent impulses from baroreceptors present on the arch of aorta are carried by a branch of the Vagus nerve (CN-10). These carry impulses to the spinal cord and pons. From here efferent parasympathetic impulses are carried to the heart via the Vagus nerve to slow the heart rate

Question 30

What is the name given to the procedure of rubbing the neck in the region of the carotid sinus?What condition does it treat?

Answer 30

This is known as a carotid sinus massage. It is utilised to treat supraventricular tachycardia. Carotid massage is also used to diagnose carotid sinus syncope

Question 31

Why must one listen to the neck with a stethoscope before performing carotid sinus massage?

Answer 31

You MUST listen for a carotid bruit prior to CSM. A bruit would suggest an atherosclerotic plaque leading to narrowing of the artery, with generation of turbulent sounds (carotid bruit) that can be detected by auscultation. If this is present DO NOT perform CSM. Doing so may lead to plaque rupture and stroke

Carotid artery bruits or murmurs may be implicated in some ischaemic damage of cerebral tissues