H&N 1 (general organisation of head and neck)

Question 1

What is contained within the superficial cervical facial layer?

Answer 1

External jugular vein, platysma muscle, fatty tissue, superficial lymph nodes and cutaneous nerves

Question 2

What is the platysma muscle innervated by?

Answer 2

Facial nerve (cervical branch)

Question 3

What are the layers of deep cervical fascia?

Answer 3

• investing layer
• pre tracheal layer
• pre vertebral layer

Question 4

What does the investing fascial layer enclose?

Answer 4

• sternocleidomastoid and trapezius muscles
• parotid and submandibular glands
• it surrounds the neck like a collar

Question 5

Where does the pre tracheal layer of fascia attach?

Answer 5

It is only anterior, it superiorly attaches to the hyoid bone and extends down into the thorax to blend with the fibrous pericardium

Question 6

What does the pre tracheal layer of fascia enclose?

Answer 6

The infra hyoid muscles, trachea, oesophagus and thyroid gland

Question 7

What is the carotid sheath?

Answer 7

• formed by all 3 layers of deep cervical fascia
• runs from base of cranium to arch of aorta
• contains IJV, common carotid artery, vagus nerve and deep cervical lymph nodes

Question 8

Where does the pre vertebral layer run from and to?

Answer 8

Extends from the base of the cranium to T3

Also extends laterally as the Axillary sheath (to surround the brachial plexus and Axillary vessels)

Question 9

What is the buccopharyngeal fascia?

Answer 9

-a posterior component of the pre tracheal layer that covers the pharynx

Question 10

What is the retropharyngeal space and why is infection here significant?

Answer 10

Lies between the buccopharyngeal fascia and the pretracheal fascial layer
Infection here can spread and extend into the thorax and cause mediastinitis

Question 11

What are the muscles of mastication supplied by?

Answer 11

Mandibular branch of the trigeminal nerve (cranial nerve V)

Question 12

What nerve supplies the muscles of facial expression?

Answer 12

Facial nerve (cranial nerve VII)

Question 13

What are the sensory branches of the trigeminal nerve?

Answer 13

Ophthalmic, maxillary and mandibular

Question 14

What are the 5 extra cranial branches of the facial nerve?

Answer 14

• temporal
• zygomatic
• buccal
• marginal mandibular
• cervical

Question 15

Which pharyngeal arch are the muscles of facial expression derived from?

Answer 15

2nd

Question 16

Which pharyngeal arch are the muscles of mastication derived from?

Answer 16

1st

Question 17

Where does the facial nerve divide into its 5 extra cranial branches?

Answer 17

At the parotid gland

Question 18

What is the innervation of the SCM and trapezius?

Answer 18

Accessory nerve (CN XI)

Question 19

What is Bell’s palsy?

Answer 19

Paralysis of facial muscles on affected side of the face due to facial nerve malfunction. Thought to possibly be due to inflammation of nerve, possibly after a virus. Often gets better on its own in a few weeks.

Question 20

What are the borders of the anterior triangle of the neck?

Answer 20

Superior: inferior border of mandible
Medial: imaginary sagittal line down midline of the body
Lateral: medial border of SCM

Question 21

What can be found within the anterior triangle of the neck?

Answer 21

• bifurcation of common carotid artery
• internal jugular vein
• CN VII, IX, X, XI, XII
• carotid triangle

Question 22

What are the borders of the carotid triangle?

Answer 22

Lateral: medial SCM
Medial: superior belly of omohyoid
Superior: posterior belly of digastric

Question 23

What are the borders of the posterior triangle?

Answer 23

Anterior: posterior SCM
Posterior: anterior border of trapezius
Inferior: middle third of clavicle

Question 24

What are the muscles of mastication?

Answer 24

Temporalis, masseter, medial and lateral pterygoid

• LAteral pterygoid opens mouth (“say laaa”)
• MEDdial pterygoid closes mouth (ie elevates mandible) (“say meee”)

Question 25

What are the layers of the scalp?

Answer 25

``` S = skin C = dense connective tissue A = epicranial aponeurosis L = loose connective tissue P = periosteum ```

Question 26

Within which layer of the scalp can infection pass into the cranial cavity?

Answer 26

In the loose connective tissue layer This layer contains lots of blood vessels including the emissary veins, so infection could spread from scalp to the meninges and could cause meningitis

Question 27

What is the arterial supply to the scalp?

Answer 27

Branches from the external carotid artery and the ophthalmic artery (a branch of the ICA) From ECA: superficial temporal, posterior auricular, occipital From ophthalmic: supraorbital and supratrochlear

Question 28

Why do deep lacerations of the scalp bleed profusely?

Answer 28

- pull of occipitofrontalis prevents closure of the bleeding vessel - scalp blood supply has many anastomoses - blood vessels to the scalp are tightly adhered to the dense connect her tissue layer which prevents their vasoconstriction

Question 29

Why does loss of blood supply to the scalp not lead to bone necrosis?

Answer 29

Because most of the blood supply to the skull comes from the middle meningeal artery

Question 30

What is the innervation of the scalp?

Answer 30

From the trigeminal nerve: supratrochlear, supraorbital, zygomaticotemporal, auriculotemporal From the cervical nerves (anterior rami of C2 and C3): lesser occipital and greater occipital