Session 2- Blood Supply ( workbook section in quizlet )

Question 1

Describe the bifurcations of the main aorta and what vessels arise from those bifurcations

Answer 1

Aorta splits into the brachiocephalic trunk, left subclavian, left common carotid

On right, common carotid and right subclavian both branch off of the brachiocephalic trunk

Vertebral arteries and thyrocervical trunk branch off subclavian

Question 2

What are the 3 branches of the thyrocervical trunk and what do they supply

Answer 2

Ascending and transverse- neck
Suprascapular- shoulder
Inferior thyroid- lower thyroid

Question 3

At what level does the common carotid bifurcate

Answer 3

C4- also level of superior part of thyroid cartilage

Question 4

What are the anatomical relations around the common carotid

Answer 4

Under SCM muscle and is medial to the IJV (IJV is lateral to common carotid)

Question 5

Borders of carotid triangle and relevance

Answer 5

Part of the anterior triangle
Upper belly of omohyoid
Posterior belly of digastric
Anterior border of SCM

Where bifurcation of common carotid occur

Question 6

Why is the carotid artery a common place for atheroma to form and what can occur due to it

Answer 6

Lots of turbulence at bifurcation causing sheer stress and eventual build up of plaque

Can cause TIA due to limited blood supply to brain (can travel to circle of Willis and block brain blood supply)

Question 7

What is the carotid sinus, what important features does it have and what is it’s relation to SVT

Answer 7

Carotid sinus is the bulge before the bifurcation which houses baroreceptors for detecting changes in BP

Question 8

Where is the carotid body and what is its importance

Answer 8

Houses chemoreceptors which detect arterial oxygen

Located next to carotid sinus

Question 9

What is the carotid sinus innervated by

Answer 9

Branch of the glosopharngeal

Question 10

What is the clinical significance of the carotid triangle

Answer 10

Gives surgical approach to carotid , IJV and vagus via carotid triangle

Can feel pulse below bifurcation and can perform carotid sinus massage

Question 11

Path of internal carotid artery

Answer 11

Goes through Peterous part of temporal bone and turns to enter the cranial cavity, bends (s shape) and goes through cavernous sinus

Question 12

What is the cavernous sinus’s, its clinical relevance and contents

What gland sits superiorly

Answer 12

Plexus of thin walled veins on upper surface of sphenoid

ICA, branches of trigeminal and many other important nerves so swelling here dangerous

Pit gland sits on top

Question 13

What are the important bifurcations of the ophthalmic artery and where is the opthalmic originally from

Answer 13

From the ICA
Supraorbital and supratrochlear supply eye
Ethmoidal supply nose

Question 14

What are the 6 branches of the ECA and its 2 terminal branches

What do they mostly supply

Answer 14

Mostly supply skin and scalp

Superior thyroid 
Lingual 
Facial occipital 
Ascending pharyngeal 
Posterior auricular 
Maxillary (terminal) 
Superficial temporal (terminal)

Question 15

What arteries form both internal and external carotids supply the scalp

Answer 15

External

• superficial temporal
• occipital
• posterior auricular

Internal

• supra orbital (opthalmic branch)
• supra trochlear (ophthalmic branch)

Question 16

What are the layers of the scalp and what layer d the vessels lay in and what is the clinical relevance

Answer 16

Skin 
Dense connective tissue 
Aponeurosis 
Loose connective tissue 
Periosteum 

Lie in subcutaneous connective tissue layer

Means walls of arteries attached to CM limiting constriction, if lacerated can get profuse bleeding

Question 17

Why do deep lacerations of the epicranial aponeurosis cause profuse bleeding

Answer 17

Cuz of opposing pull of occipofrontalis

Question 18

What artery supplies most of the scalps blood

Answer 18

Middle meningeal from maxillary

Question 19

Why does loss of scalp not result in bone necrosis

Answer 19

Because scalp get separate blood from face

Question 20

What are the superficial arteries of the face

Answer 20

Ones branching off of external carotid and 2 from internal

Question 21

What are some important branches of the maxillary artery

What do the maxillary branches supply

Answer 21

Middle meningeal - meninges
Sphenopalatine - nose (by joining other arteries)

Deep structures in face

Question 22

What is the blood supply to the nasal septum

Answer 22

Anastomoses of arteries in kiesselbach area 9castle back)

Sphenopalatine (septal branch)
Anterior ethmoidal arteries (form opthalmic)

Question 23

What is the most common area for nose bleeds

Answer 23

Kiesselbach cuz of anastomoses

Question 24

What supples the dura and why is this artery particularly vulnerable to damage

Answer 24

The middle meningeal

Because it foes through pterion to meet dura which is the thinnes part of the skull so common site of rupture is here

Question 25

What artery forms the grooves seen on the internal view of the skull cap (calvaria)

Answer 25

The anterior branch of the middle meningeal artery

Question 26

What does the middle meningeal artery supply

Answer 26

Skull and dura

Question 27

What occurs as a consequence of a pterion fracture and what does it form (/ show on CT)

Answer 27

Extramural haemorrhage which can incr cranial pressure Forms a convex haematoma outside of the dura

Question 28

In a craniotomy why is the bone and skull flap reflected inferiorly

Answer 28

To preserve blood supply

Question 29

What is special about the venous drainage of the supraorbital and supratrochlear veins

Answer 29

Unlike the rest, they unite at the medial angle of the eye and form the angular vein which drains into the facial vein instead of going back to the cranial cavity

Question 30

Describe the connection between venous drainage of scalp and rural venous sinuses Why is this important

Answer 30

Veins of scalp connect to diploic veins through emissary veins, which drain into dural venous sinuses Infection from scalp can spread to cranial cavity and affect meninges

Question 31

Describe the connection of the facial veins with the cavernous sinus and the pterygoid venous plexus Give an example

Answer 31

The facial vein meets superior opthalmic at angle of eye and drains into the cavernous sinus DEEP facial veins drain into pterygoid venous plexus meaning infection from facial vein can spread to dural venous sinuses Thrombophlebitis of facial vein where infected clot travel to intracranial venous system

Question 32

VEINS IN THE FACE ARE VALVELESS

Answer 32

K

Question 33

What is the danger triangle of the face

Answer 33

Infections in the middle part of the face (nose, top lip to t zone) can spread through venous system to dural venous sinuses

Question 34

List 3 examples of dural venous sinuses

Answer 34

Superior Sagittarius sinus Cavernous Sigmoid (leaves skull through jugular foramina as a continuation of the IJV)

Question 35

What is the IJV an indication of and how do you measure JVP

Answer 35

Right atrial pressure Measure by using RIGHT IJV as its a direct connection to atrium - head slightly left, patient at 45 degree angle - see pulsation through muscle - measure height from sternal angle and add 5 cm